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Atlas

of

Neurosurgical Anatomy



John L

Fox

Atlas

of

Neurosurgical

Anatomy

The

Pterional Perspective

With a Contribution

by

Bengt Ljunggren

Illustrated

by

David M. Klemm

With 171 Illus

tr

a

ti

ons in 329 Parts, 133 in

Full

Color

Springer-Verlag New York Berlin Heidelberg

London Paris Tokyo



JN tN L. Fox,

M.D.

Clinical Professor of Surgery. Division of Neurosurgery, Uni"ersity of Nebraska Medical

Center, Omaha, NE68105,

USA

H

ENG

T LJUNGGREN, M.D.

Professor. Department of Neurosurgery, Uni,'ersity Hospital, Uni,'crsity of Lund, 22185

Lund,Sweden

Illttilmtor

D

AV

ID M.

K LEMM

Medical lIIustralOr.

Ed

ucational l\led ia Production and Services. GeorgelOwn University

Medical Center, Washington, DC 20007, USA

Portions of the work on this atl

as

were carried OUI by

Dr.

J.L.

Fox

at the following institu

tions: University

of

Zurich, Zurich, Swiuerland (1973-1974

);

West Virginia University Med·

ical

Center. Morgantown. West Virginia (1975-1982); King

Faisal

Specialist

Hosp

ital and

Re

search Centre, Ri

ya

dh, Saudi Arabia (1983-1985); Georgetown Unil'ersity Medical Center,

Wa shington. D

.C.

(1985-1987); and University

of

Nebraska

1-.ledic

al Center. Omaha,

Ne

braska (1987 -1988). The senior author is grateful for their suppor t in this academic en·

deavor.

On IM/TQnl coveT: Fig. 7. 13/p. 138.

Library of Congress Cataloging-in-Publication Data

F

ox,

John L.

,

1934-

Atlas of neurosurgical anatomy: the plerional perspective f John

L. Fox with a contribution by Hengl Ljunggren ; illustrated by David

M. Klemm.

p. cm.

Includes bibliographies and

in

dex.

\. Brain-Anatomy-Atlases. 2. Brain-Surger

y -

Atlases.

[. Ljunggren, SengI.

II.

Title.

[D

NLM:

. Nervous Syslem-anatomy

&

histology -atlases.

2. Nen'ous Sys tem-surgery-atlases. WL 17 F792aJ

QM

455.

F6

5

1989

61

18-dcl9

DNLMIDLC 88·39319

Printed

on add·free

paper

o3:l 1989 by Springer-Verlag New \or

lo:

I

nc.

Softcovcr repri

nt oTlllc

hardcover

1st edition 1989

All rights reserved. This work may not

be

translated or

co

pied

in

wbole or

in

pan without

the writlen permission

or

the publisher (Springer-Verlag, 1

75

Fifth A"enue,

New York

,

NY

100

[0. USA),

except for brief excerp

ts

in connection

with

reviews

or

scholarly analysis.

Use

in

connection

with

any form of information storage and retrieval, electronic adaptation,

computer software,

or

by similar

or

dissimilar methodology

now

known

or

hereafter de·

"e1o

ped is forbidden.

The use of general descriptive names, trade names, trademarks, etc.

in

this publication,

even if the former are not

e s p e i

identified, is not to

be

taken

as

a sign that such names,

as

understood

by

the Trade Marks and Merchandise Marks Act , m

ay

accordingly

be

used

freely

by

anyone.

While the advice and information

in

this book are believed to be trueand accuratealthe date

of

go

ing to pre

ss,

neilher the authors nor the editors nor the publisher can acce pt any legal

responsibility for any errors or omissions that

ma

y

be

made.

Th

e publisher makes no ,,'ar·

ranty, express

or

implied. with respect to the material contained herein.

Typeset, printed, and bound

by

Universitatsdruckerei H. Sturtz AG. Wunburg, Federal

Republic of Germany.

9 8

7 6 5

4 3 2 1

lSBN- 13: 978 -1-4613-8825-8

00[:

10 .1007/978-1-4613-8823·4

e

-[

SBN -1 3: 978-1-4613-8823-4



Dedicated

to James Winston

Watts,

M.D.,

Professor

Emeritus,

Department

of

Neurological

Surgery, George

Washington University

Medical

Cente'r,

Washington,

D.C.



Foreword

During the past 15 years, several publications

on

neurosurgical tech

niques, often with special emphasis

on

surgical

ana

tomy. have

appeared

in the literature. Howevel; this book by J

ohn L.

Fox goes far beyond

an

ordinary

effort.

Thi

s extraordinary work,

Allas ofNeurosurgical Anat011o/:

The

Pte1'ional

Perspective, has its or igins in the author's many years of devo

tion, exhaustive labors, and experience

as

a teacher in the operating

theater (to

wh

ich

hi

s many residents

will

attest). This surgeon, born in

Bill ings, Montana, in the ycar of 1934, a

uthore

d

one

of his first publica

tions as a seni or resident in 1964. The tide, "Differentiation of Aneurysm

from Infundibulum of the Posterior Communicating Artery," presaged

his future recognition as an intracran i

al

aneu rysm surgeon. Now Profes

sor Fox is known throug h

out

the world not only for his many publica

tions

on

su

bj

ects in neuroscience

and

clinical neurosurgery,

but

also for

his teaching methods, which utilize both television demonstrations and

color slides

of

live neurosurgical anatomy in realistic

depth and

clarity.

Such talents as a teacher have led J ohn Fox to be ca

lled

forth as an in

structor

and

lecturer in many neurosurgical seminars

and

courses both

here and abroad, East and West. His presentations with color photo

graphs showing true visual images now are capt

ure

d with perfection in

this atlas. Such

photograp

h

s,

wit h accompanying instructions

and

de

scriptions on

approaches

to aneurysms and tumors, have left a promi

nent

and

lasting impression on everyone who has had the opportunity

to

attend his lectures.

This

book gives us images in living color, images curremly unsur

passed by any other work and well illustrated as the su rgeon actually sees

them.

The

excellent accompanying and instructive drawings help

car

ry

the reader and

observer step

by

step through the

intricacies

of

cis

ternal

anatomy

and

pathways of intracranial s

urger

y.

Thi

s publication is di

vided into eight chapters, starting with the history of the pterional ap

proach in neurosurgery. The inclusion of this interesting and instructive

chapter

gives us an added evolutionary insight. It is co-

authored

by Pro

fessor B

engt

Ljunggren, whose interest

and expert

ise in neurosurgical

history

and

aneurysm

surgery are

well known. Professor Ljunggren,

from the University Hospital of Lund in Sweden, fascinates the

reader

with his accounts of the early evolut ion of techniques for

turning

the cra

nial

fl

ap. The next

three

c

hapler

s by Dr. Fox carry us

through

inst

rum

en

tation

and

positioning, photographic technique,

an

d cran ial anatomy.

His final

four

c

hapter

s take us from the sylvian fissure into

and th r

ough



VIII

Foreword

the carotid, chiasmatic, and inter pedu ncu lar cisterns and their en virons.

Such anato my could never be so we ll illustrated before the days of the

o

per

ating microscope.

I have fo llowed the career of john

Fo

x for nearly

30

years, including

the time since his days as a student

and resident at the George

Wash

ington

Un

i

ve

rs

it

y

Me

dical Cent

er

throu gh his appointment

as

Pro

fessor

of

Neurological Surgery at the same institution in Washington,

D.C., on Ju ly I, 1974. Subseque nt yea rs have shown that Professor Fox

not

only is singularly and eminently qualified and gifted

as

an author of

such an a

tl

as,

but

also continues to h

ave

the

ene

r

gy

and

dr

ive to give fu

ture students, anatomists, neurologists, and neurosurgeons such a

la

st

ing work on intracranial s

urgery via the pt

er

ional perspec ti ve.

L UDWIG G. K EMPE, M.D.

Professo r of Ne urol

og

ical Surgery and

Research Professor of Anatomy

UniversityofSouth

Caro

lina

Charleston, South Carolina



Preface

After completing a three-volume book entitled

inlmcranial Aneurysms

published by Springer-Verlag in 1983, this authorcominued to compile a

set of

surg

ical photographic s

li

des

that

served

we ll

for teaching anatomy

at neurosurgical rounds, meetings, and workshops. But preservation

of

these images for future

sLUden

ls required their publication in a more

permanent form. The plerional approach to cenain imracranial prob

lems is being used with increasing frequency, and the photographs pre

sented here give us the plerionai,

or

frontolateral, perspective - a per

spective that is turned upside-down and obliqued

in

comparison with

most standard anatomical illustrations.

Yet

, th is is the vlew as seen by the

neurosurgeon. For ease

of

comparison, all photOgraphs are oriemed as

if a right-sided operation

is

being performed.

In one sense, this atlas becomes "volume 4"

of

Intracmnial

Aneury

sms.

However, em phasis

is

on live anatomy and its va riations rather than on

pathology. h is for this reason that this author omitted cases with basal

tumors, for such masses often distort and compress the vessels and cra

nial nerves beyond dear recognition.

The earthly finality

of

death

is

m

it

igated

by

the deeds one does during

hi s or her lif

e.

One then leaves behind the results

of

interaction with

others. As physicians

we

hope to have mostly benefined our patients.

Sometimes we

fail. This atlas

nOl

only is

in

memory

of

those failures. but

also is a photographic epitaph

of

some of those very patiems, however

few

in number. For the many patients who survive the neurosurgeon's

hand and return home to family, the sur geon can gain more than any

ephemera l fame,

fonune

,

or fe

eling

of

"well done."

The

neurosurgeon,

more importantly, can be both a catalyst inspiring younger surgeons to

greater heights and a teacher leav ing behind works upon which others

can build.

The

a

uthor

, the con tributor to the c

hapt

er

on

hi

story, and the

ar tist hope that this atlas will serve such lasting purposes.

J owe a debt

of

gratitude to my friend and colleague Professor Bengt

Ljunggren at the Departmem

of

Neurosurgery of the University Hospi

tal,

The

University

of

Lund, Swede

n.

Beginning with the 1889 work

of

the German surgeon

Wi

lh elm Wagner. Professor Ljunggren contributes

a vital perspective to the history in Chapter 1. Special credit is

due

to

David

M.

Klemm, medical ill

ustraLOr

at the Georgetown University Med

ical Cemer in Washington, D.C., where I carried out

part

of the work on

this book. He drew and labeled a ll the illustrations that accompany the

color photographs.

JOHN L. Fox



Contents

Foreword

by

LUDWIG C. KEMPE.

Preface . . . . . . . . .

History of

the

Pterional

Approac

h

BENGT

LJUNCGREN and JOHN L. Fox

2 Instrumentation and Positioning

3 Photographic Technique . . .

4 Cranial Anatomy and the Cranial Flap

5 The S),lvian Fissure

6 The Carotid Cistern and Environs.

7

The

Chiasm

at

ic Cist

ern and

Environs

8

The

Ambient and I nterpeduncular Cisterns

In d ex

VII

IX

11

33

37

55

93

123

165

20

1



1

History of the Pterional Approach

BENGT LJUNGGREN and

JOHN

L.

Fox

Introduction

Many surgical a

pproach

es have

been

proposed

in order to facilitate

exposure

of lesions in

the

skull-base reg ion wi th a minimum of brain re

traction [I, 3, 12, 15, 18, 19,24,29,32-34,37,

39, 40, 49]. The pterional approach [ the cir

cle ofW

illi

s

and

its environs is routinely used by

many surgeons. A

pt

erional ap proach implies

that a small skull flap is raised with the pterion

(Creek

pterion,

wing [ II

])

- the craniom

et

ric

point located undern eath the tcmporalis mus

cle a

nd

formed by the junction of

the

frontal,

parietal, and te

mpor

al bones with the grea t

s

ph

enoid

wi ng

bone

-

in

the ce

nt

er

of

the base

of the flap (Fig.

1.1

). Additional drilling

do

wn

of

the

sphenoid ridge allo

ws

a

lo

w basal expo

s

ure

along the skull base. Equipped with

Fig. 1.1. Close-u p view of left

side of

dr

y sku ll with sutu

res

betwee

n the frontal (F),

parietal

(P),

temporal (1),

sphenoidal (S), and zygomatic

( l) bones outli ned by black

ink .

today's microsur gical instruments, the

neurosurgeon finds that the pterional ap

pr

oach to skull-base lesions is a more natural

and easier procedure

than

earlier-day

opera

tions. Yet, there is a fascinating hiSlOrica l back

ground over the last 100 years, that forms the

basis of the present-day

pteriona

l approach.

There are

several pi

onee

rs w

ho

made mo

nu

mental contributions to the development of

this access to deep-seated cran ial-base lesions.

Wilhelm Wagner and His

Osteoplastic Method

following studies on human cadavers for sev

er al years, Wilhelm Wagner (1848-1 900)

be

came the first su rgeon in the world to raise a



2

I. Hi

slOry of the Pterional Approach

bo

ne flap (temporal in site)

out

of the cra

ni

al

vault in a l

iv

in g

per

son , kee p

it

attached to the

o

ve

rly

in

g s

of

t

tiss

ue (per

io

steum, te

mpor

al

mus

cl

e,

and

scalp

),

and then re

pl

ace the

fl

ap

(a

fter evacuation of a la rge ep idural

hematom

a)

[4, 44

].

Wagner used hamm

er

and

chisel to raise the bone flap.

Th

e patient , a 27-

year-old man with skull-base frac

tu r

es and the

clinical pic

tu r

e of increas

in

g intracranial pres

sure, under

we

nt surgery on the second d

ay

fol

lo

wing a severe head

in

jury. He

was in

a p

oo

r

condition prior

to th

e operation. Following

evacua

ti

on of the hematoma,

it was

apparent

thal the int racranial

pr

essure had become nor

ma

lize

d ,

bUl

the patient did not recover and

d

ie

d

24

hou

rs

af

ter

surger

y.

At autop

sy

Wa

gner found no signs of

di st ur

bed

nut

r

iti

on

in the temporal, om

eg

a

-s

haped

fl

ap that he

had rai

se

d to allow e

va

cu

at

ion of the now-ab

se nt hematoma. He conclude d that h is osteo

pl

as

ti

c method

was

an exce

ll

ent proce

du

re that

res

ul

ted in a good exposure

of

lacerat ions

of

the middle me

ni

nge

al

a

rt

ery in the middle cr

a

ni

al fo ssa. He

al

so suggested that

hi

s osteo

plas

ti

c method could be used to ex pl ore and re

sect other intracranial lesions such as brain

abscesses, epileptic scar

s,

and brain tumors

[44

].

T

wo

years later (1891 ) Wagner rightly

cl

aimed prio rity for the intro

du

ction of the u

se

of

the above-described, intrao

per

at

ive osteo

plastic bone flap to ex

pl

ore intracranial le

sion

s.

He emphasized that such

fl

aps

ap

peared

to heal quic

kl

y and without complications

when attachment

to

the

so

ft tissue

was

retained

durin

g surgery [45]: The osteopl

as

tic method

of

tr

epanat ion is no morc difficult or da nger.

ous than an explo rat ive l

ap

aroto

my.

"

In 1895 Wagner publi shed t

wo

cases

of

suc

cessful evacuation of e

pidur

al hematom

as

t

hrou

gh h

is

then innovati

ve

osteoplastic proce

dure

. In this paper

[4

6) he again emphasi

;r.e

d

the ad

va

ntages associated with te

mp

ora

ry re

section of a large bone fl

ap for cx

pl

orat

io

n of

the middle meningeal branches.

In 1909 Harvey Cushing

[5]

described

Wagne r

's

original

pr

oce

dur

e to explore and

deco

mp

ress cere

br

al lllmors, w

hi

ch otherwi

se

pro

ve

d to be inopera

bl

e, using the usual os

teo plas tic method of exploration

.

He sum

m

ar

ized [5]: osteo

pl

ast

ic

resec

ti

on, what

ev

er

tools m

ay

be employed , has doubtless

come to be made, in the hands of a ll , under

some form of

tourniquet, with the om

eg

a

shaped

fl

ap broken off across the thin squa

mous win g of the temporal bone .

Wagner

was

a self-edu cated surgeon who,

like his great contemporary co lleague from

Be rlin, Ernst von Bergmann

1907),

had been in volved in the Franco-Pru

ss

ion

Wa

r

in 1870. He devoted h is life to working in the

local hospita l

of

Kon igs

hou

e, a sma

ll tow

n in a

mining d is trict in Upper Silesia, w

hi

ch in 1880

cou nted 27,600 inhabitant

s. Si

l

es

ia at this time

was

incorporated into the newly founded Ge

r

man Reich. In thi s sma

ll

place Wagn

er

became

an absolute master s

ur

geon, and like

vo

n

Bergmann he exhibited a particul ar interes t in

cranial and sp inal surgery. While von

Be rg

mann st

rong

ly o

bj

ected to the use of

opening the skull with chisel and ma

ll

et. t

hi

s

was

the technique s

up

erbly prac

ti

ced by

Wagne

r. T he l

attcr

al

so

pu

bl

is

hed importa

nt

contributions concerning the opera

ti

ve man

agement of compli

ca

ted sku

ll

fra

ctlll"

es

[4

3]

and on fracture

di

slocations in the cervi

ca

l

sp in e [47]. Hi s re port on the cli nical diagnosis

and operati

ve

evacuation of e pidural

he matomas is a master piece [46] .

Th

e sa me ca n

be said

of

the remarkable

vo

lume, "

Di

e

Ve

rlet

zu

ngen der Wirbelsaule und des Rocken

marks" [47] which he pub lished in collabora

ti

on

with

hi

s co

lleag

ue Stolper from nea

rb

y

Br

es

lau (Wroclav). D

espi te

a heavy clini

ca

l

da

il),

practice, he not o

nl

y kep t abreast with the

surgical

li

terature of the lim e

but

also followed

the

li

tera

tu

re in

ge

neral med ici ne and other re

lated branches . Wa gner was belo

ve

d by hi s pa

tients, for he radiated security and goodness

and was wide ly recogni zed in the whole of

S

il

esia not o

nl

y for

hi

s supreme s

kill

but also

for

hi

s vast medical kn

ow

ledge and h

is

good reo

s

ui ts

in the treat

me

nt of nons

ur

g

ic

al d iseases.

C

rani

a] Saws

In 1891 Professor

("

professe

ur

a la

Fac

uitc

libr

e

) Jean Toison from

Lill

e in France re

poned on h is use of a chain

saw

to divide the

bone between b

urr

holes from within

ou t

w

ard

to fac

ili

tate raising of

os

teopl

as ti

c sku ll

fl

aps

[38]. Th is saw could repl ace hammer and

c

hise

ls

pr

eviously used

in

opening the cran

ia

l

va

ult. I n

hi

s pape r Toi

so

n paid much attention

to

Wagner (already

in

his t

itl

e) as the true



de Martel's Sku

ll

Trephine a

nd

Meta l Gu ide

3

pi

onee r behind the revolutionizing method of

raising cranial flap

s.

He de

sc

ribed Wagner's

"

hi

stori

ca

l contribution w

hi

ch he first per

formed on a liv

in

g human on October 1st

1889" and continu ed [38], .. Aussi la nou ve

ll

e

methode opCraloire inaug

ur

ee

par

W Wagne r

(de Konigshuue) qui

permetde

creer

une

vaste

ouverture a a boite ossellse

du

crane

et

de re

fermer, a la fin de I'operation, avec de I'os,

J'ouverture r

endue

tcmporaire de la trepana

tion, constilUe-t-cile un grand progres chirur

gical. Ce chirurgien a donne a celle methode

opera toire Ie nOIll de rcseClion temporaire du

crane ..

Toison's saw

was

fairly cl um

sy

and

was

there

fore not much used [48]. T hree years later

(1894) Leonardo Gigli from Florence, Italy, de

scribed

hi

s

si

mple yet clever

in

s

trumem

, a wire

saw to

di

vi

de bone between two open

ings, Thi

s

tool has come to bear his name, being called the

Gigli saw [16, 17). Origina ll

y,

Gigli imemed

hi

s

wire saw to facilit.·

ue

symph

ys

iotomy in obste tri

cal surgery. He finished hi s o

ri

gi nal repo

rt

{16],

emphasizin g that one dozen saws could be or

dered from the Hermann HarLel Company in

Bres lau at the price of 3 German marks plus

40

pf

ennig for shipp

in

g

com

to an

)'

foreign

co

unt ry.

He also added that c

hi

efs of clinics

could obta in free samples by ju st sending in a

request.

Professor Alfred Obalinski from the

Ja

gi

cl

Ionian University of Cracow in Galicia (the

have n

of

Polish culturc at the time, although

under the government

of

Vienna) had in

tended to describe the use of the Gigli saw for

cranial trepanations at the

Im

ernational Con

gress

in

Mo

scow

in August 1

897.

However, he

was

prevemed from going and instead

pub

lish

ed hi

s innovative application in the Cen

tro/blatt [ilr Chimrgie that same

),ea

r [30]. In his

paper Obalins

ki

stat

ed

that it had

occ urred

to

him that by using a slightly bcnded cannu la as

an

inse

rter

,

the

fl

ex

ibl

e Gig

li

s

aw

was

ideal f

or

introduction between burr holes. He em

phasized that the use of the Gigli saw permits

the safest method of dividing the skull bone

from the inside to the outside without the type

of

trauma usually seen from the use of ham

mer and chi se l [30]. In

Mo

scow, Emile Doyen

from Paris demonstrated

hi

s

ow

n m

et

hod for

perform ing a cra

ni

ectomy in front of many

prominent professors

of

surger ) including

vo n Bergmann from Berlin, Czerny from

Heidelberg, Cermany, Kocher from Bern,

Swi

tzerland,

Simp

son from Edinburgh, Scot

land, and Sk lifassowski from

SL

Petersburg,

Ru ss ia. In his pioneer paper Obalinski gives

credit

to

Ka rl Da

hl

gren

(1864

- 1924), a

Swedish pioneer who, in 1896, had designed a

new bone-cuttin g forceps fo r making lin ear

cuts in the skull

bone

and which cut from the

i

ns

ide out [6]. With the increasing interest in

cranial surgery in the first decade

of

this cen

tu ry. the Cigli saw later became recognized also

in the United States by Harvey Cushing, who

adopted the use of this simplc instr

ument

to di

vide the skull

bone

between two

burr

hol es

[36].

de Martel's Skull Trephine

and

Metal Guide

In 1908 Co

unt Thi

erry de Manel (1875- 1940)

pre

se nted lhe perfect

so

lution to the rest of the

problem of trephining wi thout risk of produc

in g intracranial damage. As a bo)' de Martel

was already very inquisitive and e

nj

oyed taking

mechanic

al

things apart to learn how the ), op

erated [31]. Frequently he dissected the fowl

being prepared in the kitchen, and he bought

a skeleton that he displayed as an amiable com

panion, de Martel, a dcscendant of the

Mirabeau

fa

mil

)'

who played an olltstanding

role in the French Re volu tion, was an

ar

istocrat

f

ull

y conscious of

hi

s ancestry. At fi rst he

was

enrolled in a school for the training of en

gi neers and later

was

trained by several French

master surgeons. He became especially in

terested in neurosurgical instrumentation. At

the age of 33 he published an article [28] de

scribing

two

new neurosurgical ins

tr

uments.

Today, 80 ),ears later, both are in dail y use by

many thousa nds of neurosurgeo ns a ll over the

world.

In hi

s milestone paper the two instru

ments he described were

(a)

a motor-dr

iv

en

trephine equipped with an automatic di se n

gaging ge

ar

that stopped the trephine

as

soon

as

it h

as

penetrated the skull and (b) the metal

gu id e for the introduClion of the Gigli saw

be

tween se parate burr holes.

Wh en in Pa ris, de Martel presented his n

ew

automatic trephine, but it was received with de

ri

sion. He then performed a demonstration

lI

si

ng a dried skull with a balloon 0 11 the inside

as an im itaLo n of the dura mater. With his au-



4

I.

History of

the Pt

erional

Ap

proach

Fig. 1.2. The " hypoph yseal 0 a pproach of Heu er and

Dand

y.

F

rom

Dandy WE (1936)

The

braill, in Lewis

D (cd): WF Prior,

Proc/ice of SUrgfly,

vo l 1

2.

LOmatic tr

ep

hin

e he drilled a hole

in

this sk ull

without

puncturing

the balloon and com

mented

[31 ], "Well , as

yo

u call see, this

treph ine can

be

operated

by

an imbecile" ("ct

bien comme va lis voycz, Messieurs, cc trepan

pellt manie meme par un imbeci le"). Amer

ican ne

ur

osurgeons were even

more

reluctant

to accept de

Mart.e1 's

e lectric dri ll. By the late

1930$ it was used rout inely in Scandinav ia,

France, Germany, and Central Europe. Yet in

Bo

ston in 1948 its lise

was

rejected even at the

Massachuseus General Hospita

l.

The burr

ho les

we

re d

one

manually (and laboriously )

with Hudson drills. It was said that electric

drills were not used because Cushing had once

st

at

ed th

at

such drills caused too much vibra

tion transmitted to the brain (Bakay L, per

so nal communication, 1974).

Hagerstown, Maryland,

pp

145,

583-585. Re

printed

wit

h permission of Practice of Surgery

Ltd

.

[71 .

de Martel also had designed a hemostatic

forceps, a self-reta ining cerebral retractor, and

a special surgi

ca

l ch

air

supporting the patient

for

operat

in g on posterior fossa

tumor

s

wi

th

the p

at

ie

nt

in the siuing position. He was the

pioneer

neurosurgeo

n in France who foug

ht

and overcame the difficulties

of

blood lo

ss

and

inadequate posterior

Fossa

visuali

za

tion com

mon to neurosurgery during the first qua rter

of this centu ry. He had los t his only son in

Worl

d War I. In 1938, at the Annual Congre

ss

of the Deut

sc

he Gese ll

sc

haft

fUr

Chirurgie. de

Martel gave

an

impassioned speech

about

the

necessity

of

continued friendship between

French and German surgeons, a speech

that

was followed by thunderous applause. Two

yea

rs

later, on

Ju

ne 14 , 1940,

as

Hitler's troops occu

pied Paris, de Martel commited suicide [3 1

].



From a "Hypophyseal" to a More Pterional Approach

5

Fig. 1.3. Another view of the "concealed incision"

(be hind the hairline) of Heuer and Dandy. From

Da

nd

y WE

(1936

) The brain, in Lew is D (ed): WF

From a .. H ypophyseaJ" to a More

Pterional Approach

In

1918

Waller Dandy took the liberty

to

report

for George Heuer, one of his yo unger col

leagues, on a "

hypoph

yseal" a

pproach to

pituitary tumors [23]. Heuer later described

this

approach

in

more deta

il

and

used it

for

sel

IaI' and suprasellar LUmors [21, 22]. In the

1940s Dandy made some modifi cations [7

-

10

]

and

this lype of cranial

opening

became

popu

larly known in

the

United States as

the

" D

andy

na p " (Figs.

1.2-1.4).

This hypophyseal ap

proach used a skin incision concealed behind

the hairline.

Prior, Practice

of

Surg

ery,

\'01 12. Hagerstown, Mary·

land, pp \45.583-585. Reprinted

with

permission

of Practice of Surgery Ltd . [7].

In

19

62 George "{ayes,

one of

Dandy'S stu

dents and former chief of neurosurgery at The

Walter Reed Army Medical Center 111

Washington, D.C., briefly illustr

ated

his fron

totemporal

approach

in

a publication with

Slocum [20]. One of their figures showed " ...

the

visualization of an ane

ur

ysm of

the

an

terior

communicating artery

as exposed

through

a small Dandy pituitary lype of flap. "

Hayes

and

his colleagues commonly used this

approach to the base of the brain (Hayes GJ ,

personal communication, 1974).

In 1963,

before

the period of micro

neurosurgery, Lougheed and co-workers [27]

stated that their operative procedure was car·

ri

ed out through

a

front

o temporal bone flap



6

L History

of

the Plerional Approach

A.

I

Openo nS .r.·chnldl

e t w ~ ~ ,

optic

n.

ad

GJrotid

L

Fig.

1.4. Dandy

's

ap

proach

to

an intracra

ni

al

aneurysm. From Dandy WE

(19

44, reprilHcd

1969

)

Intracranial Arterial Aneurysms. New

York, H

afner

.

Skin irn:: i$i

on

Fig. 1.5. The ptcrional craniotOmy flap as outlined

by Kempe. From Kempe LG [25] .

mal\cr

Copyright ]944

by

Comstock Pu b

li

shing Co

mp

an

y,

In

c. Re printed by permission of Corne

ll

U

ni

versity

Press [9].

with removal of the pterion and a bit of the

outer third of the lesser wing o

hh

e sph enoid. "

Ludwig Kempe. w

ho

succeeded Ha

yes

at

T he

Walter Reed Army Medical Center,

Ili

cely illus

trated various features

of

the plcrional ap

proach (Fig. 1.5) in his 1968 two-volume

alias,

OPerative Neurosurgery [25].

Of

interest is the de

scription g

iv

en to the critical

burr

hole placed

at

the junction of the temporal line, the

zygoma tic process of the frontal bone, and the

orbita l ridge. At The Walter Re ed Army Hosp i

tal this became known as the " psyc

hopat

hic

p

oi

m " [14, 26, 41],

pr

obably in reference to the

dispos ition of the s

urgeon

should the res

idem

fail

to

pla

ce

th

e

burr

hole correctly Sub

seque mly Fox

learned

the

pt

erion

altcc

hnique

of

cran ial ope ning [ 13 , 14] by observing

or

as

sisting George Hayes, Ludwig Kempe, and

Hu

go Ri

zzo

li

, Dand

y'S

las t

neurosurg

ica l res

i

demo Barnes Woodhall, another of Dand y'S

trainees, simila r y used the

pt

erional approach

at

Duke Uni

ve

rsity (Woodha

ll

B, per sonal com

munication, 1980).

With the

imroduct

ion of mic

roncuro

s

ur

gi

cal techniques, Gazi a ~ a r g i l illus

trat

ed his



Bi b

li

ograph y

7

Fig. 1.6.

D

iag

ram

of s

kull

w

ith

area

us

ua

ll

y includ

ed in

a pterio

nal fl

ap

a

lt

hough modified

by

var iou s surgeons.

F

ro

m F

ox

JL

[14] .

microtechnical pterional approach [51, 54

],

which was a refinement of hi s 1969 frontotem

poral description [50]. He emph

as

ized the

sma

ll

, low basa l expos

ur

e

by

drilling down the

sphenoid bone. At that time the basic differ

ence between hi s published description and

that of Kempe's [25] was the use

of

micro

technique, sphenoid bone drilling, a w

id er

opening of the

sy

lvian

fi

ssure, the

pl

acement

of

the posterior

burr

holes more ant

er

iorly

(making it a frolHos phenoidal craniotomy),

and the avoidance

of

r

et

raction

on

the tem

por

allobe [54].

and co-workers used

the pterional approach for lesions in the inter

peduncular cistern [52], in which situation the

poster ior clinoid process is a landm ark that, on

occasion, may hind

er

a clear ex pos ure [35].

The

skin incision likew ise has changed with

the needs and

pr

eference ofthe indi

vi

dual sur

geon. Dand

y's or

iginal incision is illustrated

in Fig

s.

1.

2 th r

oug

h

1.4.

Kempe's incisi

on

(Fig.

1.5)

permitted greater exposure

of

the

temporalis muscle as

well

as

a more basal exp

o

sure. Various s

urg

e

on

s

at

tim

es

extend the

fronta l limb a s

hon

distance into the skin of the

forehead above the junction

of

the medial

twO

thirds and lateral one third of the eyebrow.

Th is

mi

ght permit a sh

orter scal

p incision,

but

itdid

make part of the surgical sca r

visi

ble after

hair regrowth. incision was long

er

but rema in ed concealed beh in d the hairline

w

hil

e descending lo w enough to permit a

lo

wer, basa l a pproach [53, 54

].

The pterional

approaches at times can injure the fromalis

"

branches

of

the facial

nerve,

a point of recent

di

sc

uss ion [2, 55].

Throug

hout the ye

ar

s n

euro

logical s

ur

geons have altered and modified the a

ppr

oach

to the middle fo ssa and se llar region. In one

form

or

anOlher the p te rion has been incorpo

rated within the reflected bone fl

ap

in modifi

cations

of

the

pter

ional

fl

ap" (

Fig

.

1.6).

Its

evolution from the Heuer-Dandy flap to the

Hayes- Kempe flap posteriorly and basa

ll

y and

then to

th e

Yaprgil nap anteriorl y and basally

has been accompanied

by

par

a

ll

el ad

va

nces

in

imagi n

g,

anesthesia, magnification,

li

ghtin

g,

retraction, in str

um

entation, and intraopera

tive ene

rg

y transfer

(by

lase r, ultrasound, elec

trocautery, and the like

). The

pterional ap

pro

ach is n

ow

finding its place as an important

surgical route to t he

ci

rcle

ofWilli

s

and

itsenvi

rons. The pioneers who laid the fundamental

cornerstones to th

is

procedure include

Wilhe

lm

Wagner, Leona

rd

o Gig

li

, Alfred

Obalins

ki

,

Thierr

y

de

Martel, George Heuer,

and

Walter Dand

y.

T hese

are

the m

en of

years

long past to be remembered

by

a

ll

ne

uro

sur

geons who today regard the pterional ap

proach to the sku

ll

base as an elementary and

most obvious and fundamental principle.

Bibliography

1.

AI-Me f

ty

0

(1987)

Supraorbital-ptcrional ap

proach

to skull

base

I

csions. Ne

ur

os

ur

ge

ry

21: 474-477

2.

Ao

ki N

(1987)

I

ncision

offacial nerve b

ra

nch

al



8

I. History of the Plerionai Approach

aneur

ysm surgery.

(Leuer

to the Editor) J

Neurosurg 66: 482

3. Brock M, Dietz H (1978) The sma ll frontolateral

approach for the microsurgical treatment of

intracranial aneurysms. Neu r

ochirurg

ia

(Stultg)

21:

185-

191

4. Buchfeldcr

M,

Lj

unggren B (1988) Wilhelm

Wagner

(1848-

1900).

Surg

Neural, in press

5.

Cushing

H (1909) A met hod of combiningexplo

ra tion and decompression for cerebral tumors

which prove to be inoperable. Surg Gynecol

Obstet

9:

1-5

6.

Dahlgren K (1896) Ein neues Trepanations

in strument. Centralbl Chir 23: 217 -220

7. Dandy ,-\,IE (\936) The brain, in Lewis 0 (ed):

PracliceofSurgery,

Hagerstown, Md, WI<- Prior, vot

12, pp 145,583-585

8. Dan

dy

WE (1938) I

ntracranial

aneurysm of in

ternal carotid artery.

Cured by operat

ion. Ann

Surg

107:654-659

9. Dandy

WE

(1944, reprimed

1969)

Intracranial

ArterialAneurysms. New York, Hafner

10.

Dandy WE (1945) Intracranial arterial

aneurysms, in:

The Brain.

New

York,

H

arpe

r

&

Row (Reprinted 1969 from WF Prior, Lewis Prac

tice o/Surgery, Hagerstown, Md)

II. Dorland's

Illustrated Medical Dictionmy

(1974) cd

25. Philadelphia, WB Saunders Co, p 1284

12. Dotl NM (1933) Intracranial aneurysms: cere

bral arterio-radiography: surgical treatment.

Edinb Med J 40:

219-234

13. Fox

JL (1979) Microsurgical exposurc of intra

cran ial ancurysms. J Microsurg I: 2-31

14.

oX

JL

(1983)

Intracranial

Aneurysms.

Ncw Yor

k,

Springer-Verlag

15. Frazier CH (1913) An approach to the

hypophysis through the anterior cranial fossa.

AnnS

urg57: 145-150

16. Gigli L (1894) Ober ein neues Instrument wm

Durchtrenncn dcr Knochen, die Drahtsage.

Centra lbl Chir 21: 409-411

17. Gigl i L (1897) Z

UI"

praktischen Vcrwertung der

Drahtsage. Cemral

bl

Chir 24: 785-788

18. Hakuba

A,

Liu

S, Ni

sh

imu ra S (1986) The or

bitozygomatic infratcmporal approach: A new

surgical technique. Surg Neurol 26: 271

-276

19.

Harris

P,

Udvarhely i GB (1957) Aneurysms aris

ing at the internal carotid-postcrior com

municating artery junction. J Neurosurg

14: 180- 19 1

20. Hares GJ , Slocum HC (1962) The achievement

of

optimal brain relaxation

by

hypervemilation

technics

of

anesthesia.] Neurosurg 19: 65-69

21. Heuer GJ (1920) Surgical experiences with an

intracrallial approach to chiasmalles ions. Arch

Surg I: 368-381

22. Heuer G] (193 1) The surgical approach

and

treatment of tumors and other lesions about the

optic chiasm. Surg Gynecol Obstet53:

489-5

18

23. Heuer C] , Dandy WE (1918) A new hypo physis

operation.]ohns HopkillS Hosp Bu

ll

29:

154

24.

Jane

JA, Park

TS,

Pobereskin LH et al (1982)

T he supraorbital approach: Technical

no

te.

Ne urosurgery 11:537-542

25. Kempe

LG

(1968)

Operative Neurosurgery,

wl/

Cranial,

Cerebral,

and

Intracm71ial Vascular Disease.

Berlin, Springer-Verlag

26. Kcmpe LG, VanderArk GO (197 1) Anteriorco

m

municating artery aneurysms. Gyrus rectus ap

proach. Neurochirurgia (Stult

g) 14:

63-70

27. Lougheed WM. BOltereH EH,

r..

lo rley TP (1963)

Results

of

the direct attack in the surgical man

agement of internal carotid and mid dle cerebral

aneurysms. Clin Neurosurg9: 193-200

28.

de

Martel T (1908) Un point de technique

operaLOire dans la craniectomie. Presse Med

16:641-643

29. McArthur

LL

(1912) An aseptic surgical access to

the pituitary body and its neighborhood. J

AMA

58:2009-2011

30.0balinski A (1897) Zur Technik del' Schadel

trepanation. Centralbl Chir 24: 857-859

31. Pec ker ] (1980) T hierry de Martel, 1875-1940.

Surg Neurol

13:

40 1-403

32. PiteHi SO, Almeida GGM, Nakagawa EJ etal

(1986) Basilar aneurysm surgery. The subtem

poral approach with section of the zygomatic

arch. Neurosurgery 18:

125-

128

33. Pool] L (196 1) Aneurysms of the anterior com

municating artery. Bifrontal cranioLOmy

and

routine use of temporary dips. ] Neurosu rg

18:98-112

34.

Pool

] L (1962) T iming

and

techniques in the

intracranial surgery

of

ruptured aneurysms of

the anterior communicating artery.] Neurosurg

19:

378-388

35. Samson

OS,

Hodosh RM, Clark WK (1978)

Microsurgical evaluation

of

the ptcrional ap

proach to aneurysms

of

the distal basilar circula

tion. Neurosurgery 3: 135- 141

36. Seeger W (1973) Allgemeine neurochirurgische

Operations tech nik,

in

Sailer

FX,

Gierhake

FW

(cds): Chirurgie histQrisch gesehen. Deisenhofen bei

t.

H.inchen, Dustri Verlag: pp 237 -238

37. Sugita K (1985) MiC1"01liurosurgical Atlas. Berlin,

Springe r-Verlag

38.

Toison]

(189 1) De la trepanation

du crane

p

ar

resection temporaire d'un lambeau osteoplas

tique (procede

de

Wagner et procede person

nel). Co ng Fr Ch ir 5: 325-338

39.

To

nnis W (1936) Erfolgreiche Behandlungeines

Aneurysma der Art. commun. ant. cerebri. Zen

tralbl Neurochir I: 39-42

40. Tonn isW, Walter W (1960) Ein neuer operativer

Zugang zu den sackrormigen Aneu

rys

men de r

basalen Hirngef.isse. Wien med Wochellschr

11

0:

145-147

41.

VanderArk CD, Kempe LG, Smith DR (1974) An-



Bibliogr

ap

hy

9

terior communicating aneurysms: the gyrus

rectus approach. Cl in Neurosurg 21:

12

0- 133

42. Wagner W (1885) Uber Halswirbellu xationen.

Ard,iv fur klinische Chirurgie . Be

rl

in, Ver lag von

August Hirschwa ld ,

pp

192-2 16

43. Wagner W (1886) Die Behandlung der komp

li

cirten

Sc

hadelfrakturen. Centralbl Chir

26: 2405-2510

44. Wagner W (1889)

Die

temporare Resekti

on

des

Sc hadeldaches an Stelle der Trepanation. Ein

Vorschlag. Ce lllra

lbi

Chir 1

6: 833-838

45. Wagner W (

1891

) Zwei Fa

il

e von temporarer

Schadelresektion. Ccmra lbl Chir 18: 25- 29

46. Wag ner W (1895) Z

wei

Faile

vo

n HaematOm der

Du ra mater geheilt durch temporare Schadel

resektion. Berl klin \-I/ochenschr32 (7) : 1

3i

- 140

47. Wa gner W, Stolper P (1898) Die Verletzungen der

Wirbelsa ule und des Riicke

nmar

ks, in vo n

Bergmann E, von Bruns P (eds): DeutscM

Chirur

gie,

No

40,

Stutt

gar

t,

Ve

rl

ag

vo

n F

er

dinand Enke,

pp 1-564

48. Walkcr EA (1951) A Hs/ory ofNeu.rological Su.rgery.

Baltimore, Williams & Wilkins Co, p 50

49. Wolff J (1863) Die Osteoplas

ti

k in ihren Be

ziehungen zur Chirurgie und Ph ys iologic. Arch

klin Chir 4: 1

83-29

4

50.

~ a r g i l

MG (1969) Microsurgery Applied

10

Neurosurgery. Stuttgart, G

Thieme

, pp 119-

14

3

51. r g i MG (

19

84) Microneurosurgery. Stuttgart,

GT

hieme

52.

MG

, AnticJ , Laciga R et a1 (1976) Micro

s

ur

gical pterional approach to aneurysms of the

basilar bifuf(:ation. S

ur

g Neurol6:83-9 1

53.

Y a ~ a r g i l MG,

FoxJL(1975)The microsurgical ap

proach to intracran ial ane

ur

ysms. S

ur

g Ne

ur

ol

3:7-14

54.

a ~ a r g i MG,

FoxJL,

Ray MW

(1975)

Th

e

ope

ra

tive approach to aneurysms

of

the anterior com

municating artcry, in Krayenbiihl H

(cd):

Ad

vances

and Technical Standards in Neurosurgery.

Vienna-New York, Springer-Verlag, pp 113 - 170

55. Yaprgil

MG,

Reichman

MV,

Kub

ik

S (

19

87) Pre

servation

of

the frontotemporal

br

anch

ofth

e

fa

cial ner

ve

using the inter

fasc

ialtcmporalis nap

for pter ional craniotOmy. Technical ar ticle. J

Neurosurg 67: 46

3-466



2

Instrumentation and Positioning

Introduction

This chapter describes the surgical instru

menlS and equipm

ent

utilized by the author

during the plcrional approach to intracranial

lesions. Since part

of

the instrumentation is

used to maintain the proper position and align

ment of

the patient, positioning

is an

inti

mately related

sub

jec t.

The Japane se samumi was a dedicated and

courageous warrior skilled in

batt

le. He and his

sword or bow-and-arrow were a si ngle fighting

unit. They were such an integral p

an

of

each

other that activation

of

cerebral and muscle

memory effected rapid and nearly subcon

sc ious communication, resulting in precise,

"computeri

zed" de live

ry of the weapon

upon

its

targeted foe.

The

above simile is meant to emphasize the

conceptual and real changes occur ring in the

modern neurosurgical operating room.

The

neurosurgeon (samurai), the instrumentation

(bow-and-arro

w),

and the patient's lesion (foe)

are no longer separa te en tities. Through ex

tensive laboratory and clinical training, un

learning old habits, and learning new methods

of

hand-brain-eye coordination, the

modern

neurosurgeon now develops cerebr

al

and mus

cle memory akin to

that of

the

sa

murai.

The

operating microscope and microsu rgical in

struments become an

in

tegral part

of

the sur

geon who must deftly deliver his

therape

utic

a

rrow on

target. If this is

to be

done with mini

mal disturbance to the patient's brain, the

arrow's trajectory is limited to narrow path

ways

between cranial and intracranial structur

es.

It n

ow

can be appreciated that,

in

addition to

being a

bl

e to work

in

small, op tically magnified

spaces with de licate and long dissecting instru

ments, thc position

of

the neurosurgical pa

tient nowadays

is

critical to the "s tereotax ic"

alignment

of

the su

rgeon's eye, the micr

o

scope, the dissecting

in

struments, and the

ta rgeted lesion.

The

surgeon must supervise

the positioning of the p

at

ie

nt

so

that

when the

target

is

reached later

in

the

day,

the surgeon is

comfonably situated for delicate dissection

of

the tumor

or

vascul

ar

anomaly within

ve

ry nar

row spaces. As the patienland instrumentation

are being se t

up

, the surgeon reviews a mental

check list(much as an air

pl

ane pilot does) based

on past experience and endeavo rs

to

control in

terlocking events with

in

the

operat

ing room.

Inexact patient posi tioning or imperfect align

ment of

the patient's h

ead in

the historical pas t

could be compensated by more br

ai

n retrac

tion or by rotation

of

the patient's head rest

in

g

on a cranial "donut."

Nei

ther is acceptab le in

most modern-day microneurosurgical proce

dures where the patient

'S

cranium is im

mobilized

by

a skull-fixat ion apparatus and the

brain

is

supported

by

se lf-retaining retractors

usually attached to the operating table. Thus,

an incorrect positioning

of

the skull-fixation

apparatus, f

or

ex.a

mple,

may

cause

part of

this

a

ppar

atus to

intcrfer wi

th later pl acement

of

a

sma

il

,

se

lf-retaining retractor

0

11 the in ternal

carotid artery

and

thereby hinder the sur

geon

's

line-of-sight to the interpeduncul

ar

ci

s

tern.

It is in

this context th

at

"interlocking

events" must be well thought out and control

led.

Because the neurosurgeon is working within

very narrow confines, it is even more incum

bent

upon

the surgeon not only to have a

thorough knowledge

of

normal and aberrant



A

B

c

12

2.lnstrumemation and Positioning

Fig.

2.1

. A. Top of skull with

burr

hote at ri

ght

coronal su

ture and sma ll hole

(arrow)

ju s

t behind burr hole. B.

View with cam

era

lens

at

burr hole. Anterior clinoid

processes

(triangle

s

),

poste

rior clinoid processes,

and

left foramen ovale (wroed

arrow) are

, ,'ell seen

at

sku

ll

base. Small arrow lies on

right

posterior clinoid processand

poims toward metal pin pro

jecting up\\'

ard

from n

oorof

sella turcica.

C.

Similar but

morc restricted view with

camera l

ens

at smaller cra

nial hole (behind burr hole

in A). Arrow crosses left

pe

trous pyramid

and

intracra

nial opening of carotid canal

and p o i n ~ LO the

for amen

ovale. Figures 8 and Care

rotated 90

0

counter clock

wise compared with

A.



Head Holder

13

neuroanatomy but also to be able to concep

tualize the anatomy in its three dimensions

(stereoimage concept).

The

tomographic plan

es

of

computed tomography (CT) and magnet

ic

resonance imaging (MR I) detract from such

conceptua lization (whereas stereosco

pi

c im

ages and pneumoencephalography [45J en

courages it

). The

medical student learns hi s

anatomy from standard cadaver dissections

and textbooks.

The

surgeon,

at

least in the

pterional approach illu st rated in this atlas,

must view the p

at

ient's anatomy from an ob

lique and

up

side down oriemation (wi th re

spect to the patient).

Cranial openin gs have become smaller as

microsurgical techniques have advanced. In

theory, an intracranial lesion could be operated

on via a tiny (eg, I mill) cra ni al opening

(F

i

g.

2.1). In a sense, the operat ing microscope

brings the surgeon's eye closer to the cran

ial

opening. If the surgeon's eye were at the open

ing like peering through a keyhole, a full view

of

the intracranial spaces could be seen - if re

tractors cou ld fit

through

the opening - and

the lesion cou

ld be removed

or

corrected - if

dissectOrs, like a laser beam, could fit through

the opening. Thus, among the factors limiting

the u

se of

very sma

ll

cranial openings

in

most

cranial operations are intracranial instrumen

tation and maneuverability.

Instrumentation continues to change, de

pending on s

ur

gical needs. There are

va

ri

ations

among

specific types

of

instruments (eg,

retractor systems, cranial-fixation systems,

operating tables), and an individual surgeon

often uses the system that he was trained in or

that fits his particular approach. The instru

ments and equipmem herein described ha

ve

been the

au t

hor's personal preference for the

pterional approach to various intracranial le

sions. Much

of

the following

is

reproduced

from a previous publication

[16].

External Instrumentation

Operating Room Table

We

place the patient on the Amer ican Sterilizer

operating room (OR) table so that the patient'S

head is at the foot end

of

the table (Fig. 2.2).

This has several advantages: (a) the table ped

als are not

in

the way

of

the sitting s

urg

eon's

feet (the anesthesiOlogist

or

circulating nurse

manipulates these as needed); (b) there

is

more

room for the base

of

the mi croscope (w hich we

position to the left

of

the sur geon); (c) the nor

mal opening in the OR tab

le

lies under the lum

bar region

of

the patient's back, facilitating

lumbar cerebral spinal fluid (CSF) drainage

without turning the patient. The only disad

vantage

of

this alignm

ent

is that the main

weight of

the patient

is off

the center

of

gravity

for the OR table. An assistant often must assist

in elevation of the surgeon's end

of

the table

by

lifting lip the table

under

the patient's shou

l

ders when the patient

'S

head is raised (table

fl exed) to

its

final position (aboma 10- to 15-de

gree elevation of the patient'S head).

Thi

s ac

lion lightens the unbalanced

lo

ad on the table

wh ile the table is flexed. One must becareful to

avoid sliding the bUllocks into the opening,

which would risk sciatic nerve pressure

in

short

patients.

Head Holder

In this

era of

minosurgical technique and self

retaining retractors, it usua

ll

y is essential that

the head be immob ilized

by

three-poim skull fi

xation.

We

use

the

Mayfield-Kees skull clamp

(Kees Surgical Specialty Company). T his clamp

(F ig. 2.3) is inserted into the normal foot end

of

the American Sterilizer table.

The

horizon

tal part

of

the head holder should be nearly

parallel wi th the fl oor. We prefer to have the

two-point

si

de of the clamp

on

the side

of

the

surgery, as the opposite one-point side may

project Out tOO fal: All joints are tightened se

curely (from above downward), and the head is

immobilized throug

hout

the operation.

A study group stated (17):

Unde r the sur

gica

l microscope, the

slig

htest

movement

of the patient's head

is

magnified con

siderably. Microsurgery demands a precisely

maintained position of the

firmly fixed cra

nium

throughout the entire opel'ation, whe

th

er one op

crates with the patient in the sitting. supin

e,

or

prone position. This is

beS

t

achieved

by

a

pillion

head

holder in which the essclllial clemem is a

clamp made to accommodate three relatively

sharp p

ins.

The pins penetrate the

scal

p a

nd

are

then firmly fixed to the outer (able of the sku

ll.

\Vhen

placing the pins, the sur geoll shou ld take

care to

avoid

a spinal

fluid

shunt, surface

vessels,

thin bone

(such as

over the frontal and

mastoid

sinuses),

and the thick temporal muscle where the

pos ition of the pin tends to remain unstable, how

ever

tightly

the clamp

is

applied. A

pin on th

e

forehcad s

hould

, of course,

be we

ll away from

th

e

eyc; and whe n the clamp

is

positioned too

close

to



14

2.

Instrumentation

and Positioning

A

"

B

c



fi g. 2.3. A. Mayfield-Kees head

holder

with demon

stration sku

ll

(bone flap removed) in position

for

right fron(Oiatcrai craniotomy. 8 . Pa tie nt in position

A

B

wi

th head turned 40° to left, tilted 15° to left. and

d ro p

ped

bac k 15°, From F

ox

[16].

Fig. 2.2. A. Sketch

of

American Steri

li

ze

r OR table.

Th

e usual head end is

to

the observer

's

lefl.

The

head rest has been rCII1O\'cd from th

is

end

and

placed at the normal foot end on the observer's

right. T he

patient'S

head in it

ia

lly rests on the head

rest on the observer's right with that end c evated

10°_

1

5°

and

wit

h the

lu

mbar region o

fl h

e patient's

back resting

Me

r the

ope

ning

(arrow)

in the table.

B.

Same

after

specia

ll

y mad e maltress

is

in place with

ope

ning f

or

l

umbar

CSF

dra

inage. A model skull

(see Fig. 2.3) is held

by

the sku

ll damp

(replacing

the

h

ead

rest). An

ether

screen" (bar w

it

h k

no

b project

ing toward observer) p rojects away from the left sidc

of

the paticlll to later ho ld the d ra p

es

alld suction

tubes.

The

Leyla sel

f-

r

eta

i

ni

ng

retrac

t

or

b

ar

(see

Fi

g.

2. 11

)

atl<lc

hcs (aITow) to

the

O R table ju st

cephalad to the

ether

scr

ee

n attach me n

t. The

micro

scope stands JUSt cephalad to lhe et her screen, and

the anesthesiologist

is

position

ed

caud al LO lhe ether

screen. C. Preli mina ry dr aping of paticnt. In st

ru

me nts

are

placed on the overh ead instrument ta

bl

e

(Phelan

Ma

nu fact

urin

g Co r

porat

ion, Minnea polis).

Note

the

steralized "C-clam ps" at each end with rub

ber

tubi

ng

stretch

ed

between. T hese

are

covered

after

fi na l draping

and

prel'cnt instruments from

falling offinto the ancsthesiologist's nonsterilc field.

From Fox [ 16].

15



16

2. Instrumenta tion and Positioning

the incision, a pin·casing can

be

a hinderance.

Special sma

ll

er pins available for infants can also

be used f

or

patients who have thin skulls. Particu

l

ar

attention should

be

given to p

at

ients who have

had a lo ng history of hydrocephalus. Having se

cured the clamp .

the

surgeon holds the head

in

the de si

red position while the final attach ment

to

the operating table is made. Man ipulation of the

head holder accurately and with

safe

ty may bcdi f·

ficull at first,

but

with experience any obstacles en

counlcred can

us

ually be surmounted. This

method of skull fixation avo ids the

pr

essure in

juries

th

at may occur

to

t

he

scaJp or face w

hen

the

head has been resting on rubber pads for lo ng

pe riods.

Th

e time

of inse

rtion

of

the poinlS imo the

scalp and skull is a critical period . T he head

must be perfectly posiLioned according to the

approac

h u

se

d by the surgeon .

Any

deficiency

wi ll cause defective a

li

gnment

of

the target,

cranial

ope

nin

g,

mi croscope, and surgeon

's

eyes.

The

alignment must

be

such that there

will be a dear view

of

the aneu rysm at the focal

poim

of

the microscope with the surgeon in a

comforta

bl

e position. Upon inserti

on of

the

Fig. 2.4. Pneumatic lift chair (C.C.R. Medical Corpo

ration, Pittsburgh). The dark cushion is added for

extra height. From Fox [16] .

poinlS, the patient's blood pressure and intra

cranial pressure

wi ll

rise unless he is properly

anesthetized and his blood pre

ss

ure is under

control.

Th

e sur geon must notify the anes

thesiologist before he inserlS the poims. Colley

and Dunn

(6]

recommended local anesthesia

in the

sca

lp at the point-insertion sites.

Surgeon's Chai r

Surgeons' chairs are

ava il

able from

va

rious

companies, eg, Storz Instrument Company,

Aesculap Company, Stryk

er

Corporation, and

V. Mueller Company. e l al [57] re

ported on their spec

ial

chair; we have found

the recent modification so

ld by

the Aesculap

Company to be qu ite sa tisfactory. \Ve also have

used the pneumatic lift chair (style P390244)

ava

il

able from lheC.C.R.

Me

dical Co

rp

oration

of

Pit lS burgh (Fig. 2.4). A hard cushion may be

pl aced on the seal to gi

ve

the surgeon a bit

more height. The stool h eight

is

adju stable by

press ing on the foot bar.

Operating Microscope

After years of experience with neuros

ur

gery

sa ns microscope fo llowed by microneurosurgi

cal experience in hi s operating room, Cha

rl

es

Drake concluded [

12]:

Th

e

remarkable

new surgical world revealed

under the operating microscope and the beaut i

ful instruments ava ilable to work in it have un

doubtedly played a m.yor role in placing the

sa fety and scope

of

aneurysm surgery

\\

'here they

are

tod ay.

And Gazi ~ a r g had advised [55]:

However, it should never

be

forgotten that there is

much

mo

re to microtechniquc in ne urosurgery

than the possession of a highly pe

rf

ectcd optical

instrumen

t. Thi

s al

one

is of

litt

le

valu

e without

special methods of bipolar coagulation, carefully

adapted in struments,

and,

above all, atraumatic

operation techniques.

In 1865

Bi

schoff [4] published his work on

dissections

of

the cranial nerves. He began

wi

th

lou pes and later graduated to the dissecting

microscope with up to

50x

power.

The

evolu

tion of the u

se

of the operating mi croscope in

surgery is detailed in other publications [9, 17,

36,41, 43 ,55].

In

19

78 a stud y gr

ou

p concluded the foll ow

;ng

[In



Operating

Microscope 17

The

use

of

th

e operating mic

roscope

and

micro

technique is onl y

on

e part of the modern trend in

the surgi

ca

l treatment of certain cerebrovasc

ul

ar

probl

ems. Co in

c

identally,

a

team

of experts

has

evoh'cd, each of

whom

is s

pecially

trained

to

carry

Out his or her wsk

in

this type of surgery ...

Al

th

oug

h

we

pl

ace

major empha

sis

upon

the micro

surgi

ca

l tedmi<lues, advances h

ave

occurred as

we

ll in anesthesiology, nu rsi ng

care, radiol

ogical

di ag

nos

ti

c methods, pharma

cology,

a

nd avai

l

ab

le

monitori ng

syste

ms. Certainly t

he

judicious

use

of

vascu

lar h

ypote

n

sion and

of techniques

to co nt ro

l

intracranial pressure

has

hel

pe

d grea tly

o

redu

ce

pa tient morbidity. Some operations would

be

ex

tremely difficult if not

impossib

le

to

pe

rform

without

tod ay s so

phisticated personnel ...

Both

re

ports

in th

e recent literature and the in

creasi

ng

use of the microscope by neurosurgeons confirm

the o

pin io

n a

nd

experience of study group

mem

bers

that

th

e application of

the

operating

micro

scope and

m

ic

rotechnique

has

markedly reduced

the

mortality and

morbidi ty assoc

iated w

ith

intra

cranial aneur

ysm

sur

ge

r

y.

Para llel improveme

nts

in

equipm ent

have co

ntributed additiona

ll

y

to

these results. The cardinal factors,

ho weve

r, arc

the train in g, expe rience, and expertise of the

operating surgeon who

util

i

zes th

ese

new

tech

niqu es and

the capabilities of h

is

ope

ra tive

team.

Some

of

the techni

ca

l

as

pects

of

optics, su

p

ports, accessories, use, care,

and

sterili

za

tion

of

the

mi

croscope and i

ts

accesso

ri

es

are

given

elsewhere

[10,

14

,

15

,

17

,3

1,

35, 37, 40, 43, 55,

57

]. The

Zeiss operating microscope (Carl

Zeiss, Inc) is the unit most commonl y used at

this time (Figs.

2.5-2

.

7).

We have been usin g (he counterbalanced

Zeiss-Contraves unit (

Fig

s. 2.6 and 2.7) with

ele

ct

ron

ic sw

itches

that

release magnetic locks,

immobilizin g the

mi

croscope in any desired po

sition [57].

Our prefere

nce has been the OPM I

No.

I

Ze

i

ss

magnification system rather than

the zoom lens sys tem attached to the Contraves

stand. We also prefer the floor

mount

to the

ceiling mount. In o

ur

OR the television camera

is attached to the left

si

de

of

the beam splitter,

and the binocular observation lUbe or sti

ll

cam

era is attached to the right sid e.

The

newer in

clinable binocular tube (Fig. 2.8) has impro

ve

d

the

ve

rsatilityof this in strumenl.

With exper ience, the counterbalanced Zeiss

Contra

ves mi

c

ro

scope and the surgeon be

come a

si

ngle entity, wo rking comfortably

"hand-in-g love" in attacking the lesion. Nor

mally

we

ha

ve

one s

ur

gi

ca

l a

ss

ista

nt

on the

right s

id

e of a right-handed s

ur

geon.

Thus,

this surge

on'

s left hand is his first a

ss

ista

nt and

the other s

ur

geon, in

ef

fect, is

hi

s second assis

tant.

The

counterbalanced Zeiss-Contraves

microscope, first used by

[57] in

Zurich,

ca

n be auached to laser systems

or

u

se

d

in

conjunction with

an

ultrasonic aspirator.

With the

former

, the mobile microscope comes

over the left should

er of

the surgeon while the

at tached laser unit is

off

to the surg

eo

n's dire

Ct

left and s

iLS

between the

mi

croscope stand and

the anesthesiologis

t'

s equipment.

Other

exce

l

lent operating microscope

sys

tems arc avail

a

ble.

For example.

Keni

chiro Sugita in Mat

sumoto,

Jap

an, h as developed a hi ghl y sophi

s

ticated system [48].

Although agreement

is

not uni

ve

rsa l as to

when the microscope should be

brought

into

the operative field, experience sh

ows

that a

more

gent

le,

ac

c

urat

e, and rapid dissection can

be carried out if, once the dura is opened, the

entire ap proach to the aneur ysm and its dissec

tion

ar

e

carr

ied

out

und

er

the microscope.

With the pat ient supin e, the angled position

of

the incl in a

bl

e binoc

ul

ar

lUbe

is used most

often. Thi s now can be easily altered to a

straighter position when

dr

illing the sphenoid

wing and to a sh

ar

p

er

angle when dissection is

in

the

sy

lvian

fi

ss

ur

e

or antcri

or perforated

substance. With

ex

p

erie

nce, the su rgeon often

finds that he routinely uses the same higher

magnification (eg,

6x

or

8x

t

ru

e magnifica

tion) for the

ap

proach to the tumor

or

aneurysm

as

he does for i

ts

dissection.

Several

disadvantages

to the operating micro

scope have been mention ed [ 17]: Spec

ial

train

in g is requir

ed

for usin g the microscope.

microtools. and microsllture; it necessitates

operating in a dee p, narrow gap; it requires

longer adaptation time; it does not permit

good tissue palpation (i nstruments are used ,

not fingers) and requires visual manipula tion ;

work is indirect; work

is

tiring to the eyes; stiff

neck, shoulders, and back generally result; dis

tractions

are

poorly toleraLCd; eq uipme nt and

training are expensive; it la

ke

s

up

space in the

operating room; and the operating time for

most surgeons

is

longer.

The advantages

for the ne

ur

osu

rgeo

n far a

outweigh any drawbacks, however [17]: Fewer

parallax problems occur because the objective

lens brings the largetcloser to the surgeon's vi

sion; binocular vision is improved; i

ll

umination

is incrcased; the focus is s

harper

; and magnifi

cation permits a smaller craniotom

y,

less brain



18

2. Instrumell lation and Posi

tioning

retraction, a smaller cortical incision, and bet

ter

delineation of normal and abnormal

anatomy. Structures

that are

beller idcmified

by

the microscope

are

the arachnoid space,

compartments,

and

bands; the perforating

ar·

tcries; vascular variat ions in the circle

of

Willis;

aneurysmal

anatomy; microaneurysms; the im

pending rupture of an aneurysm; small bleed

ing points for bipolar coagulation; and the

nerves [17]. The advantages to the patienlarc a

smaller wound, beller repair or nerves a nd ves

sels, the fact that some inoperable lesions be

come operable, optimal hemostasis, fewer sur

gicallcsions, and fewer postoperative compli

cations [ 17 ]. Educational advantages include

Fig. 2.5. Standard Zeiss operating micro

scope wi

th

zoom lens system. f\lounted on

Zeiss Universal S3B noorstand.

Counesy

of Carl Zeiss, In

c.

use of the observer tube, television with tape

recording,

and

cinematogra phy

or

st

ill

photo

graphy. I

n

addition, the television system al

lows

the

scrub nurse and

anes

the

siologist to

know the state of the surgery from

moment

to

moment.

As the mi crosu rgical era began, Drake in

1965 stated [11]:

The ability to see the minute details of the struc

tures about an aneurysm has been, in my opini on,

the source

of

much

trouble in this as ill

other

fields of neurosurgery . . . There is a new

wo

rld

waiting

fo

r us.

The

dissecting microscope with its

superb

illumination is

ideal.



A

Operaling Microscope

fig. 2.6. A.

CoUi

ltcrixliallccd

7..ciss-Co

lltra\cs

ollCrat i

ng

micrOKope. B. Close·up of microscope.

From Fox [16]:cou

rlCsy

ofC:lrI Zeiss. Inc.

19

B



20

2. Inst rumenta tion

and

Positi

on

i

ng

A

B

Fig. 2.7.

A.

Zeiss-Contravcs op

era

ting microscope in

position at surgery. The bo ne flap has been turned.

Note the rubber wbing that holds the drapes firmly

down

and

cauda

lly.

Abo\'c

arc

two suction tubes in

readiness. In the background is a telc\·is ion monitor.

B. Close-up of microscope

and

alLach ments. Left:

Sony lclc\·ision camera and microph one. Cn Ur:

bi nocular system and beam-spiller. RighI: assistant's

observation tube.

Th

e l

auer

is rcmo\'cd when st

ill

camera photographs arc made. From Fox [16].



Operating i r o s o p e

21

B

Fi g. 2.8. Inclinable billoclliartube (Carl Zeiss. Inc) flanked by SonyT Vcamerit on left and Contax st

ill

camera

on right. A. I n straight positiull . B. 111 angled positiun.



22


Gillingham cautioned , however [22]:

This is

a moment

1O

reflect

on

the use

of

magnifi

cation. [\ may make us len times morc gentle but

it

leads to obsessive over dissection

in

an endeavor

to find

the

neck

ofa

sac which is nonexistent

orcx

cessi

vc

manipulation

in

the

region

oftbe

neck.

Television

As memioned above, television has imponant

ed ucational adv3mages (live visualization of

microanatomy and taping procedures for fu

lure teaching) as well as practical advantages

[

17

,32]. Operati

ng

room physicians and nurses

alter their anesthe

ti

c techniqu

es

and ongoi

ng

activities

as

well as morc efficiently prepare for

anticipated operative CVClllS based on informa

tion received from

the

television monitor.

Color television systems (see Fig.

2.7

B) for

the microscope arc in a state of rapid evolution

in

terms of image clarity and brighmess,

weight, durability,

and

freedom from need f

or

frequem

repairs. Hence, il is pointless to rec

ommend specific systems allhis time.

Many

of

the newer television cameras can

operate at a lower light level. Yct it is still advan

tageous to obtain good lighting to allow a smal

l

er

diaphragm opening and consequently a

greater depth

of

fie

ld

and sharpe r focus.

Table

2.1

summarizes some methods to im

prove lighting for the s

ur

geon

and

for

the

tele

vis ion or pho1.Ographic cameras.

Overhead Table

In our

experience, the overhead table (sec

Fi g. 2.2 C)

made

by the Ph elan Manufacturing

Corporation (Minneapo

li

s) has provided

maxi mum advantages for the surgeon, anes

thesiologist, scrub nurse, and patien t. The cra

nial end of the table should bejustcaudal to the

patient's shoulder (more caudal if the cervical

carotid arter y needs

1.0

be

exposed).

The

table

height is easily adjusted, and the nurse or tech

nician has clear

and

rapid access to instr

u

mems and the su rgeon 's hanet.

I ntraoperative Instrume ntation

Fishhooks

The use

of

improvised

ti

ssue-retraction hook

s,

or "fishhooks," connected to rubber bands h

as

Table 2

.1

. Methods

of

mprovi ng lighti ng for the sur

geon an d/o r camer<ts."

I. I ncrease voltage in transformer

(s

hortcns bu lb life).

2. Use an cfficiem lighting sys tem (currently

in

state ofim·

pnll'ement).

3.

Keep

hull>s

and

op

tic

al

system clean.

4. Discard bulbs ",it h blue or dark spots

in

light image.

5. Usc

add -on light sources.

6. Usc short focal length objecti\'e lens.

7. Avoid zoom ens system. which absorl>s more light.

8.

Turn

off

bright lights in opcr.lting room (bener con

u'ast; surgeon's pupils arc dil'lIcn. rcrruiring less lig ht ).

9. use of inlernal rencctions in surgical wound;

a,-oid rencclion s back

in

to the microscope.

1_

Remo" e black paint border aruund glass light dencctor

behind objecti

ve

lens (present

in

some microscopes).

II.

Usc

30-70

beam splitrer (70% to side arms. onl),

30%

(0 surgeon) inslead of 50-50 beam spliuer.

1

2.

Use greater magnification

in

e)'cpicces. thercby requ i

r

less rnagn

.i

fic3tion (hence less light loss) inside

mrr.ros<;ope

unll.

13. OllCn diaphragm to camera (with loss

of

sharpness and

depth of focus).

14

. l'rollCrI}, adjust

TV

camera power supply and TV

monitor.

15. SeleCl

efficient

TV

camera

or

film that can OllCrale

wit

h

less light.

Certain mClhods li sten ha\'e particular \'"Iue

in

some cir

cumstances, whereas

in

others they may pro\'e unneces

sary or impractical.

It

ems I through 10 also increasc

brightness for the surgeon. Item II d e c r e s e ~ image

brightness

to

the surgeon. From

Fox

et

al [ 17 1.

been used by many surgeons to retract scalp,

muscle,

an

d du ra. More recently a fi shhook re

tractor devi

ce

usi

ng

springs (Aesculap Instru

melll Co.) instead

of

rubber bands has been

suggested [57

].

We prefer the "disposable"

Week

Durahoo

ks (Edward

Week

and Com

pany), although one can remove their rubber

bands for repeated usc.

The hooks are used to retract the froillolem

poral scalp flap tlIrned over the patient's

forehead as follows (Fig.

2.9):

The sterile

dr

apes between the overhead ta

bl

e (neu

ro

sur

gical instrume ll t table; Phelan Manufactllring

Corporation, Minneapo

li

s) and the patient's

head are-held firmly downward and cauda lly

by

st

andard rubber

suction tubing of appro

priate length. The looped end s of thi s tubing

arc secured LO stirrup clamps on each side

of

the OR table. This lube

(a)

firmly h

ol

ds the

drapes in place and (b) allows a convenient site

of

allachmem fo r the

rub

ber bands th

at

retract

both the scalp hooks

and

the bone flap. I n this

way

the drapes of the pcrioperalive field are



Intraoperati\ e Ins trumentation

23

Fig. 2.9. Close-up view of ru bber tube holding

drapes firmly (sec Fig . 2.7

A).

H

ere

the samc tubing

is

used to attach the rubber

b..1nds ho

ld ing thc fish

hooks. T hese fis hhooks retract thc oxrccllulose-co-.

vcred scalp

nap

forward.

The

ri

ght fromolateral

smooth, firm , and dear

of

unnecessar ydamps

and other retractors.

SUClion an d SUClion- l

rrigat

i

on

Devices

SUClion tubes usually are sized (diameter) by

the "French" (Fr) designation: a 3- Fr size has

an oLlterdiame ter of 1 mm; a9-

Fr

size is 3 mm ;

ct

c.

Standard si

zes

for ane

ur

ys

m s

ur

gery are

3-

Fr

, 7-Fr, 9-Fr, and II -

Fr

, al though there are

many other va riatio n

s.

There are a multitude

of types of suc

ti

on lubes with variations in

length. ang

ul

ation, tip con figuration, and

vac

uum pre

ss

ure [3, 5, 17,28,29,44,56, 57J.

A S

UCl

ion system wi th a mechanism to con

trolthe negative pressure at ve ry l

ow

levels is

essential.Th e suction should be finel yadjusled

to eliminate the ha7

..1n

l of small anatomical

structu res be

in

g entrapped and damaged.

Many neurosurgical suction tubes are con-

bo nc nap is attachcd

to

the l

cm

p

ora

l

is

musclc (a t

cemcr of figure). Dural lack-up sutures and bonc

nap

sutures are in place in the cranium before the

dura is opened. From Fox

[ 16].

slruCled to allow reg ulation

of

suction strength

by adjust ing the degree to w

hi

ch the

thumb

occludes the air ho le. T h

ese

holcs can be en

larged [5, 29]. and/or ventin g needles can be

placed in rub

ber

suc

ti

on tubes. T he trap bot

tles can have press

ur

e- regulating gauges.

When di ssecting delicate Slnl

ClUres,

it may be

helpful to use special smooth-tipped su

ct

ion

tubes and negative pre

ss

ur

es of about 2 m

of

Wale I' (a pproximatel y 0.2 alln ) [57]. I n place of

wa ll sllction, s

ome

sllrgeons prefer an electric

suction pump, easily regula ted by adjus ting the

d ia ls on the pum p.

Irri

b'<lt

in g fluid in cunjunction with the suc

tion apparatus is essential during the surgical

proced

ure

. In addition to keeping tissues from

drying and t he an

eu

r

ys

m wa ll from becom in g

briule, it disco

ura

ges the formalion of small

blood clots and their.adherence to the dissect

ed surfaces; it also increases the effectiveness



24

2.

Instrumentation and Positioning

of bipola r coagulati

on and

re

du

ces tissue adhe

siveness. Co nsta

nt

bathing with CSF has the

same effect. Some s

ur

geons

pr

efer a comb ina

tion suction-irrigation unit.

We usually use an angu latcd Frazier suction

tube of va ryi ng leng ths. The II-Fr and

g-Ff

sizes are used for cra nial wo rk

and

the 7-Fr for

aneurysm dissection. We use the 7-Fr size

r

at

her than sma

ll

er sucti

on

tubes because of

its

usc as a dissector and retractor as we ll as a suc

tion device. Moreover, the la rger diameter pro

vi

de

s less air a

nd

liquid ve loci ty for the same

vacuum

pr

essure.

The

metal sucti

on

tube can

also

be

used for resting micro

sc

issors or

other

instruments to reduce tr

emo

r when making a

delicate dissection. The suction lube is held in

the su

rgeo

n's left hand , often with his ha nd or

fifth finger resting

on

the Leyla retractor bar

of

the sku

ll.

(T

his

rest

i

ng fi

nger" serves

more

to provide

pr

oprioceptive feedback

rather

than comfol"( to the surgeon. ) The

SUCl

ion is

often used against sma ll dental cotton balls

(Ri chmond Denta l Colton Co

mp

any, Char

lotte, North Carolina) or sma ll cottonoids for

su

ct

ion protection and retraction. Rubber tub

ing is

pr

ef

erred

to plastic tubing, the latter

being too stiff for com

fo

rta

bl

e usc.

We

routinely put 1,000

unit

s

of

heparin in each

liter of irrigating solution

1.0

limit

dotting

,

which could cause obstru

ct

ion within the tub

ing; this practice may r

etar

d undesirable d

Ol

ting in

the

basilar cisterns as well. The

on

ly

time we use a suction-irrigation apparatus

(House-Radpour unit) is

during

bone

(s phenoid wing or clinoid

pro

cess) drillin g.

Bone-Remova l

Instrum

ents

In

19

30 Rogers [46] gave

an

excelle

nt

historica l

account of cra niotomy m

ethods.

He noted th

at

the

Hor

sl

ey tre

phine h

ad

its

or

igins in

the

time

of Hippocra tes (ca 400 years Be). The

technique

of

bone flap removal made a si

gn

ifi

cam adva nce with Cigli's

ap p

lication of the

wi re saw (the Cigli saw) in 1894 [19, 20]. This

saw

is still routinely used by many s

ur

geons -

especially in elderly pat ients w

her

e the dura

may be stuck to the inner table of the skull. T he

prese

nt

-d

ay

use of

powe

r (pneumatic or elec

tr

i

c) dr

i

ll

s and

cran

iotomy for lifting skull flaps

is

we ll

known

and

requires no

further

discus

sion here.

Rongeurs for biting a

way

the base of the

bone flap

are

stand

ard

in any cranio

lOm

y set.

We commonl y use the Le ksell, Echlin, and

Le

mpert

r

ongc ur

s for fronto

tempo

ral

crani

olO

my, wh

ere bone is

ronge

ured

away

at

the

base.

The

flat-jawed Le

mpert rongeur

is

especially helpful for removing that portion of

the sp henoid wing sticki ng Out as a ridge to

wa

rd

the

sylv

ian fissue.

The

neurosurgeon

needs a sma ll , high

speed electric

or

pneumatic drill f

or

removing

the sp henoid ridge, the clinoid

pr

ocess,

and

other

protrusions of the cranial base; however,

only

after

he has become acquainted with and

skilled in its application in

the

laboratory

should he use a high

-s

p

eed

drill in a ne

uro

s

ur

gica l

operation

[17J . A drill that ca n reve rse its

dir

ection is pre fe rred by some to

one

th

at

cuts

in only

one

direction. A constantsuctioll-irriga

tion sys t

em

with physiological saline ca n be

used to cool the

dr

ill

; o

ther

wise, h

ea

t is trans

mitted to nearby ne

ur

al structure

s.

One ob

mins a m

ore

acc

urat

e and controlled use of the

drill when it

is operated at

high speeds; onl y

very slight pressure should be used to remove

the bone. Dan

ge

rous skiddi ng may OCClll"

at

slow speed sor with dull drill bi ts because of the

greater

pr

essure needed to cut bone. When

using

li

ghtweig

ht

dr

ill

s

or bur

rs, steel

burr

s are

used when the drilling is remote

fr

om the

dura. Diamond burrs are safer close to the

du ra or vital stru ctures, for they tend less to

tea r SOflli

ss

ue.

We

use oxycellulose

rather than

cotton s ponges to cover the n

ear

by galea, mu

s

cle, and bone flap, as no ha rm occurs if these

get caught in the drill. Co

uon

, on the mher

hand

, may cause serious damage if caught in

the drill.

When using bonewax

under

the micro

scope,

we

have fo

und

the fo llowing to

be

help

ful:

The

sc

rub nu

rse

app

lies a sma

ll

bit of

bonewax to

one

side of a sma

ll

, d

ry COllo

noid

and hands it by bayon

et

forceps

to

the

center

of

the surgeon

's

op erative field. The surgeon

then can use his bipolar forceps

(w

it

hout

cur

rent applied) or h is finger to pu sh the C01-

tonoid against the wax, which is pressed into

the bl

eeding bone. Usua

ll

y

we

use this

technique on the sph enoid wing after drilling

it

und

er magnification.

Electrocautery

Electrocautery for coagulation of vessels

and

vascular

ti

ssues has been

an

in1.egral pa

rt

of

neurosurger

y

ever

since the

advent

of the



Im

r3oper.uivc Instrumentati

on

Fig. 2.10.

Fox

bipolar elec

trocautery f

orceps in

three

len

gt

hs: 16, 18,

an

d 20

em.

Eac

h of

th

e straight force ps

cO l11

es

in

0.5-

and

1.0-111

111

diamete r t

ip

s; curved and

angled tips al

so

are

availa

bl

e.

From Fox [16]; counesy of V.

Mue

ller

Compau)'.

Chicago.

..

B

ov

ie electrosu

rg

i

cal

un i

t,

repo

ned

by

Cus

hi

ng and Bov ie in 1928 [7]. Light [38] gave

a good histor

ica

l overview of the subject in

1945. In 1967 Malis [39] reviewed the de,'elo

p

men

ts

and evolution of bipo

la

r cl

e<.:

trocoagula

tion since thc

ti

me of Grcenwood in 1940 [2 3].

" Monopola r" elcctrocoagulation has be en

and continues

to be

commonly used to coagu

late or c

ut tissues. (Of course, it is really bipo

lar: On e pole is the ground plate and the

other is the hand-hcld electrode.) Bi polar elec

trocoagulatio n

of

the type whcre both poles

arc

in the forceps

was

d

ev

eloped by Grcen

wood [23-26]

to

caute rize sma

ll

blood vessels

on the spinal co

rd

, whcre minimal heat and

electr ical spread ,.,re re essentia

l.

Accordingly.

the bipolar forceps basically consis

ts

of a mod

ification

of

ordinary

bayo

net forceps or jewe l

er

s' fo rce ps in wh

ic

h each blade of the forceps

is one of the electrodcs or po

le

s; the blades are

i

so

l

at.e

d from each Other by insula

ti

on, whi ch

se parates them at thei r base.

For microvascular and intracranial

aneurysm surgery and ford issection of tumors

from the brainstc

lll

, bipol

ar

electroc

aut

ery

units have become essential. Th ere h

ave be

en

many mod ifica tions in both the fo rceps and the

po crs

upp

ly [8, 13, 1

8,23-27,33,3

4

,3

9,47,

52.53, 5

6,57].

Ma

li

s [39] improved

th

e powe r

supply ( 0 prov id e a damped wave spark unit

that

was

electrica lly bener

iso

lated.

Thi

s unit

(Cod man and Shurtleff Company) has been

one of the more popular and reliable un its for

neurosurge ry (a nd is prefe rred by us).

Th

e

unit was designed spec

ifi

cally to prov ide the

be st coagul ation at the lowest

vo

ltage with the

least mu

sc

le stimula

ti

on. At the same

ti

me, it r

e

stricts the cur rent to the shon cst path bet

wee

n

the tips of the twO blades of the forceps, with

no currenL of consequence now ing from tip to

gro

und

or tip to pa

ti

ent. Th e greater sa fety of

bipolar coagulation compat'ed

wi

th monopolar

coagul ation around bra

in

stem structures was

demonstrated by Gestr ing

et

al [18].

So

me t ried to

pr

ovide a single unit f

or

both

mono polar and bipolar electrocoag

ul

ation [ 18,

27]. Sugita

et

al (52, 53] uscd a ther

mi

ster at

the tip of

their forceps to

aUlo

maticaliy cut o rf

the eleclri

ccur

ren t when a preset temperature

was rcached. Others developed a suctio n [47]

or irri

ga

tion [13, 34] sys tcm attached to one

blade of their forceps. Del ong and Fox

[8]

d

e

scri

be

d an automalic

cy

cling on-off bipolar

electrocautery powe r supp ly.

We

used to

pref

er the bipolar for

cc ps [56, 57] (Mat hys & So h

n,

Zur ich

),

but we

now use the stain less-steel Fox bi polar bayo net

forceps (V. Mu eller Co

mp

an

y,

Chicago)

(Fig. 2

.10

). T hesc forccps come in 16-, 18-, and

20-cm lengths and with 0.5- and

I.

O-mm tip

diametcrs.

Ot

her popular bipolar forceps

fo

r

sur

ge

ry include the Rh oton

round

-handled

forceps and the Malis forc

ep

s with the blades

slightly angled dow nw

ard

rathe r than parallel

lO the hand le. Ti tanium

or

st

ai

nless steel are

comm only us

ed

metals, the fo rmer being

liglllcr. We pref

er

the heavier

weig

ht of the

sta in less-steel forceps for bettcr balance, com

fo rt, and p ropriocepti

ve

feedback.

It

is impor

tant n

Ol

to sterilize titanium and stainless-steel

instruments in the same pac kage, for the dif

fere

nt. metals in close proximity m

ay

create an



26

2. Instrurnenta

ti

on

and

Positioning

electrical potcmial conductive

to

rusting and

co rr osive activit),.

De Long and Fox [8} recommended the fol

lowing

care

of these forceps to limit

thc slicking

oftisslICS to

their

tips:

I.

Do

not

short-circuit the elect

ri

c c

urr

ent

by

touching the forceps lips together.

2.

Clean the

lips

frequem ly only with a

damp

d

ot

h (not with the scalpe )

3. Po

li

sh the lips periodically (

or

obtain new

forcep

s)

when the tips become pitted and

rough.

4." Knead " the tissue between the forceps tips

by gelltly squeezing and releasing the for

ce ps blades.

5. Lift lhe forceps from tissue contact fre-

quentl y.

6. K

ee

p

the

ti

ssue moist with CSF

or

sa

line.

7. Avoid high current settings.

8.

Apply

the

currCIll

in shon

bur

sts

to

allow

heat dissipation.

Wc usc the bipolar forccps as the principal

d isscCling a nd tissuc-separating instrument

intracraniall

y.

For this reason the blades of the

forceps mu st have

pr

oper s

pr

eading tcnsion,

yc t n

ot be

so tense as to ma ke tip approxima

tion un comfortable. T h

ey

must not rotatc in

appropriately in the s

ur

gcon's hand. In terms

of tim c, its actual application for e lec

tr

ocautc

ri

zation is quite sh

ort

compared with

its use

as

a

tiss

ue dissector, pcrforator,

spreader, se

par

atet; and grasper. It is uscd to

place and remove cotlonoids , cotton balls, gela

tin sponge, gelatin paste, oxycellulose, and I'LIb

bel' or

plastic sheclS.

On

tcrms of frequenc ),

and duration of usc, for us the suction lube (in

the surgeon 's left hand) and the bipolar elec

trocautcry forceps (in the right hand) havc be

come thc main micros urgical inSlrulllcnlS dur

ing intracranial s

urg

cr)',

For most of o

ur ext

racranial cauterizati

on

we

u

sec

ither

the mon

o

polarorth

e bipolar unit

with the

Mali

s powcr supply dial set at 30 or 35.

On

cerebral cOrtcx wc use the Malis bipolar

power supply dial al the 25

to

30 seuings: on

the brainstem

we

use the 15 to 25 setting

s.

"ine r-tipped forceps increase thc cun'ent den

sity

at the tips. I f

hi

gher settin

gs

are

required,

lhe spark ga p in the unit probabl y needs reset

tin

g.

With faulty spark gap distances or other

electrical problems, one can use hi gher power

settin gs to obtain

mor

e current, but the quality

(waveforms)

of

the electrical OLitput w

ill be

pOOl

; resulting in p

oor

coagulat ion and a tcn

den

cy

for vcssels to explode or be incised. Pro

longed or illlensh'C use, even in one patient,

may res ult

in

a need for an elCClrical overhaul.

Thcrefore, twO or more such bipolar powcr

supplies should be available.

We

use a 15-foot

cord between the power supply and the for

ceps. Longer cord s may cause defective electri

ca

l output at the forcep

s. We

set the pow

er

sup

pl

y at the foot

of

the

OR L:'l

ble. I n this position

it does not add to

th

e instrument cluneI' near

the surgeon, and ilS electromagnetic noise

emission is a sufficient di stance from the televi

sion sys tem so as to not c"eatc any significalll

audiovisual in t

cr

ference. For the same reason,

the wa

ll

socket plug-i n sites for the television

and the bipolar I)()\\'er supply units should be

at a considerabl e di stance from each other. The

"

mono

polar" a

nd

bipolar electrocautery cords

should not be dose to each other.

Retractors

In past yea rs m

OSt

brain retrac

ti

on

wasdonc

by

assistant surgeon

s.

Such retraction

was

often

in

consistcnt , inaccurate, and dangerou

s,

as

brain retraction prcss urc exceeded cerebral

pcrfusion pressure. In 1958 Gi llingham

[21]

warned that bleeding from an aneurysm at

s

urger

y (causing reversal of blood now from

vital brain tissues and a

drop

in blood pressure)

may res ult in ischem ia of nearby brain tissuc.

He wa rned that this would be aggravated

by

ex

cess or prolonged brain retraction. Addition

all y, he ca ution

ed

th

at

inacc urate o r excessive

retraction may place traction on vital per

forators, produc

in

g vasospasm and in

adequate cerebral perfusion. Albin et al

[ I.

2,

17 ] havc sh

ow

n

that

brain retraction pressures

exceeding 20 I.orr cause underlying brain dam

age. I f induced hypotension is used, evcn Icss

brain retraction prcssUl'e

is

IO

lerated.

A num

ber

o f authors have described t he use

of self-rel.aining brain retractors [17,29,30,40,

42,57], Various t )'pes, eit her in the literature

or in co

mmer

cial catalogs, have included the

de Mane l , Dolt (Edinburgh

),

Hamby, Green

berg, (Le yla), Dohn-Carton.

Malis,

Cloward, Enker, Mi skimon, and Jannclta re

tr

actor

sys

tem

s.

Self-retaining retractors also ha

ve

become

indispensablc to aneur

ys

m surgery because

they allow th e surgeon to work in a relatively



Othe r Microsurgical Instruments

27

confined space unhinde red by the presence o

f'

an assistant's hands, whi ch are less dependable

for maintaining constant retraction

of

the

brain.

Sel

f-reta

in

ing brain retractors arc

of

two

basic types [17].

One

is composed of a series

of

straight shafts attached

by

small clamps to gi

ve

the co rrect arm length

and

con

fi

guration re

quired for holding the brain spatula in place.

The oth

erco

nsislS

of

a series

of

ba

ll

-and-socket

un its resembling a chain of peads wi th an inter

n

al

cable th

at

when tightened, remains

in

the

desi red position.

Of greatest impo n ance in intracranial

surgery

is

the minimal brain re trac

ti

on neces

sary (Table 2.2), ascribable not only to u

se of

the su rgical microscope and microtechnique

but also

to

improvemenls in exposure tech

n

iq

u

es

that a

ll

ow

a lowel; basal, and ta ngential

approach to the base

of

the sk ull and the circle

of

Wi llis, which is partly aided

by

removal

of

a

portion

of

the sphenoid wing and lhe use

of

special self-retaining brain retractors. How

ever, these aids wo u

ld

be tota lly useless without

a relaxed brain effected

by

proper timing

of

surgery and

by

supe

ri

or anesthetic and life

support methods.

The selection

of

a self-retaining retraClo r

system is up to the individual surgeon's prefer

ellce and habi

t.

Many prefer systems that at

tach only to the sku ll. T hey

are

concerned that

table- mounted retractors may move relative to

the brain even if the skull is immobilized

by

three-point fixatio n

[40].

We have found that

the

a ~ a r g i

(Lcyla) retractor system

(Fig.

2. 11) is ideal for most cases

of

intracranial

aneurysm surgery. We auach the bar to the left

Table 2.2. Minimal brain retraction.

I

crmincd by:

I. Usc of microS(ope. mi<;rotC(;hnique

2.

Low

oosal. tangemial approach

3. Self-retaining br.lin retractor

4. CSF drainage

:1. Neumanest hetic techniques

Avoids:

I. Removal

of

significant brain for exposurc

of

lesion

2. CUlling

of

Olfactory nCf\'c

3. Dil'iding

of SOIllC

bridging I'eins

4. Secondary brain contusion o r edema, vascular spasm

5. Vascular compression

by

retractoror stretched arachnoi

dal bands

6.

Tr.letion on aneurysm

7.

UnnC(;essary exposure

of

A·I and

M-I

arterial segmcl11s

From Fox et

al

r 7 1

side

of

the O R table

just

cranial to the "ether

screen" attachment (which holds drapes that

separate the microscope from the anes+

thesiologist; see Fig. 2.2 B) . Two or three

fl

exi

ble (unless tightened) retract

or

ar

ms

are at+

tached to the connectors on the bar.

All

joints

must be firmly tightened to

avo

id drif

t.

Fi rst, se t the retractor blade (in the flexible

arm)

neal"

the planned retraction site. T hen

tighten the flex ible bar by turning [he sc r

ew,

which pu lls the internal wire tau l. Last, "toe

in" the retractor blade to its desired position

and retraction pressure and then tighten its

win g nut. Drift

is

minimal or absent if done

prope

rl

y.

Al

ways

have the poilll

of

connect

io

n

between the retractor blade and flexible bar

away

from the

cra

n

ial

opening. This requires

auaching the flexible arm

ncar

the

end

of the

re tractor blade and bending the blade at its

proper point for descent in to the c ranial cavi ty.

T hi s maneuver gives better

in

tracranial expo

sure wi

thout the ends of the

fl

exible retractor

arms being in the

way.

Alth

oug

h these retractors are usua lly

ap plied against brain tissue

or

its coverings, on

occasion a narrow retractor ca n be used to

gently retract nerves, aneurysms, or

ane

ries

such as the internal carotid anery or the mid

dle cerebral artery during frontotemporal ap

proaches to the interpeduncular cistern [16,

48,50,51]. Such retraClion requires d

is

pl ace

ment and protection

of

these arteries \I'jthout

occluding the

m.

O ther Microsu rgical Instruments

T h

ere

are n

ow

a large number

of

microsurgi

ca l instruments in the fie ld of neu rosurgery.

We cannot review

all

of

them in th is rapidly

changi ng field .

Fig

ures

2.

12

and

2.

13 i

ll

ustrate some

of

the

instr uments we most commonly use for micro

dissection.

The

jewelers'

fo

rceps is used to pick

up the arachno id over the

sy

lvian

fiss

ure to

in

i

tiate opening of this fissure. T he Aescu lap

bayonet sc issors (curved and straigh

t)

come in

three lengths (16 cm for surface wo r

k,

18

cm

f

or wo

rk

about

the ante rior circle of

Wi

llis, and

20 cm for deeper work, eg, abou

lthe

posterior

circle

of Wi

llis). T here is also a 22-cm scissor.

The bipolar forceps have been described in the

ea

rl

ier section on electrocautery. T he Rhoton



28

A

B

c

2. Instrumemation and Positioning

....

-

Fig.

2.11. A- D. Leyla

gil) re

tractor system.

Cour

tesy of Aescul ap-

\'\

'

er

ke AG,

TUlliingen, \Vest Ge rmany.

B. Close-up view of auach

mCIlt

head between the bar

(left)

and retractor arm co

n

nector (right). C. Close-up

view

of

connector bell,'ceo

b

ar

and OR table.

D.

Retrac

tor h.1r and attachment head

in prcliminaryposition.Above

is the draped sca lp wit h an

outline

of

a righl

froruolat

eral craniotomy incision.

From Fox [ 16] .



Olh

er

Microsurgical Instruments

29

fig.

2.

11

instruments show n

in Fig.

2.13 are the four

types most commonly used

by

us.

Th

e "Iong

flat instrument"

(a ,.

micro-Penfield No.4

")

is

used

to

retract nerves, arte

ri

es, and the

aneurysm. The short

fl

at instrument" is ideal

for se parating adhesions between an aneurysm

and adjacent tissues because the edges

of its

angled, flat end are somew hat sharp.

The

40°

hook is

sa

fer to use than the rig

ht

-angled hook,

for it w

ill

not

catch and tear tissues

upon

iLS

re

moval from the field. A ba ll-tipped hook also is

helpful.

I nstruments

and

suture for reanastomosing

or

repairing blood vessels and nerves should

be available along wit h the expertise to do so.

These are detailed in many articles on micro

vascular anastomosis.

These microsurgical instruments require

some trai ning and experience in their use and

manipulation through a small opening and in

sid e a deep narrow cavi ty. The surgeon can rest

hi s hand on the skull

oron

the Ley la retractor

bar (named after the daughter

of

which holds the self-retain

in

g retractors.

Often the surgeon rests only his fifth finger as

a point of propr io

cept

i

ve

feedbac

k.

This allows

sensory orientation and reduces tremor.

One

in

strument can also be rested on the suction

tube

of

the surgeon's left hand to reduce tre

mor in critical moments.

On occasion a

mirro

r at the tip

of

a probe

can be useful for seeing behind and around

va rious structures. Wilson and Spelzler 154]

used a dental mirmr, Sugita et al [49] a 5-mm

mirror, and a ~ a r g i l and colleagues [57J a mir

ror that changes positions when the grip han

dle

is

squeezed.

There

now are many types, sizes, and config

urations

of

vascular and aneurysm dips and

clip-appliers. These are in a continual state

of

evol Ulio n, and lhe reader is referred to oth

er

articles on the subject

[14, 16

]. T he technology

D



30 2. Instrumentation

and

Positioning

fi g. 2.12.

uft:

Jc\\'clc l'

s'

forceps (Ed ward Week &

Co .).

C ~ l I l f r ; Bayonet sha ped m icroscissors (Aes

culap Instruments). Rig"': Ua),oncI shaped bipolar

electrocautery forceps (Math)'s & Soho

).

From Fox

116].

of

energy transfer (la

se

r, ultrasound)

in

the

operating room is a large and changin g field

that will not

be

a

ddr

essed her

e.

Bibliography

I. Al

bi

n MS, Bun

cg

in L, Be n nc lt MH et 31 (19i7)

Clinical and experimemal brain retraction pres

sure monitoring. Ac ta Ncurol Scand (supp 64)

56: 522 -523

fi g. 2.13. En larged view of microsurgical dissecting

instr

um en

ts

(Rhoton ty pe: V. Mueller

Co

mpany).

Ltft

nld:

No. 7,

or

"Iong

nat

ins

tru

ment."

ufl

1 l ~ r :

No.2, o r "short nat

instrument,"

RigJllullter: No.

II

,

or

"40

0

h

oo

k."

Righi tl,d:

No.

10,

o r right angle

hook." From Fox l I6].

2. Albin MS, Bun

eg

in

L.

Dlti

OV

IlY M et al ( 1975)

Brain retraction preSS urC

dur

ing

intra

cranial

pr

ocedu rcs. S

ur

g

,"b

rum 26: 499 - 50 0

3. ll.1d cr DCH (1975)

i c r o - s r g i c a l

trea tmen t of

intracranial an cur

ys

ms. J Neurosurg Nurs

7:25

- 27

4. Bischoff EPE ( 1865)

M i k r r u w J ~ h

Analys

t

der

ArwstomoStn der Kopfr trot

rl.

Mun ich , Vc rlag der

JJ Lentncr'schen Buch

handlun

g. See 'H

icroscopic

Arw{ysis

of

tht Allas/olllos;s

U

p/weer

/IU

emllia{

Nerves, translated by Sachs EJr, Va ltin £W (1977 )

Hanover, NH, Uni\'ersity Press o r New En gla

nd

5. Bo

nd u

ra nt CP (1977) Altera tion or su

ct

ion lip

prcssure. J Neurosurg 46: 559

6. Co lley PS, Du n n RC J r (1979) P

re \

'ent ion or

bl

ood

pr

essu re responsc

10

sku ll

-p

in head

ho

ld

er

by

local

anest

hesia. Anesth

Ana

lg (C le\'e)

58:241-243

7.

Cushing H, BO" ie WT ( 1928) Electro-su rgery as

,III aid to the rcmoval or im racra nial tu

mor

s.

Surg G}' llccol Obstel 4 7: 751- 784



Bibliography

31

8. De lo ng \VB, Fox J L (1977) Automatic q-cling

bipola

rcoag

ul ator. Surg Neurol8: 15 - 16

9. Donaghy R

fo.

·IP (1979) The history

of

micro

surgery in neurosurgery.

Cli

n Neurosurg

26:619-625

10. Donaghy Y a ~ a r g i l MG (1967) MicrQ-WSW

lar

Surge/yo

Stungart, G T hieme

II. Drake

CG

(1965) On the surgical treatment

of

ruptured intracranial aneurysms. Cl

in

Ne

urosurg 13: 122 -

155

12. Drake CG (l976) Ccrcbral aneurysm surgery

an u

JXI

atc, in Sc h

ei

nberg P (cd):

Cerebrqvascular

Disease. Tenth Prineeton Conference. New ' ork,

Ral'en Press, pp 289- 310

13. Dujovny M, Vas R, Osgood CP et al (1975) Au

tomatically irrigated bipolar forceps. Technical

note. J Neurosurg 43: 502-503

14

.

Fox

J L(1976) a ~ c u l a r c l i p s forthe microsu rgical

(reat melll of stroke. Stroke 7: 489-500

15.

Fox

J L (1979)

Mi

u osurgical cxposure

of

intra

cranial aneur ysms. J Microsurg I: 2- 31

16. Fox

J L (1983)

Intracranial Aneurysms.

New Y

or

k,

Sprin

ger-Ve

rl ag, pp 678 - 707

17. Fox .I L, Albin MS, Bader DCH et a1 1978) Micro

surg ical treatment of neurovascul ar disease.

Ne

urosurgery

3: 285-337

18. Gestring FG,

Koos

WT, Boeck FW (1972) Bipolar

coagul ation with modified cOtl\'emi onal elec

trocoagulators. Tec hnical note .I

Ne

llrosurg

37:50 1- 504

19. Gigli L (1894) Ober ein neues I nstr ument zum

Du rchtrcnnen der Knochen , die Drahtsage.

Centralbl ChiI' 21: 409 - 4 11

20. Gigli L (1898) Zur Technik

der

temporaren

Schadelresektion mit meiner Drahtsiige. Cell

tralbl Chir 25: 425- 428

2

1.

Gi

ll

ingham

fJ

(1958) Th e management

of

ru p

tured intracran

ia

l aneurysm. Ann R Co

li

Surg

23:89-1 17

22. Gi lli

ng

ham FJ (1976) Twent)'-five

exper

i

ence wit h mi ddlc ccrcbral aneu rys ms. Rev Ins[

Nac Ncurol (Mcx) 10; 16-21

23. Gree nwood J J r (1940) 1 \\'0 point coagulation. A

new p ri nciple and instrument for applyi

ng

coagul ation current in ncurosurgery. Am J Surg

50:267-270

24. Grecnwood

.I

JI"

(194

2)

1

\\'0

point coagulation. A

fo ll

ow-u p r

eport

on a new techni<l

lI

e and instru

ment for electrocoagulation

in

neurosurgcry.

Arch Ph

ys

T her 23: 552- 554

25. Greenwood J J r (1955) Two-point or interpolar

coagulation. Review after a twelve-}'car period

wit h lotcs on add ition of sucker tip. J Neul"Osurg

1

2:

196- 197

26. Greenwood J

.I

I'

(1974) ElcClrocaag ul ation in

n

eurOSUl-gcry.

Surg Ne urol 2: 4

27. Gurdjian

ES,

Thomas L

M,

Gurdjian

ES

(1968) A

sin glc unit for bipolar, rnollopol

ar

coagu

la

tion,

and cutting / Nc urosurg 29: 567 -568

28. Hamby

\V

B (1952) Intracranial Anellrysms.

Sprin gfield , IL. Charles C

Th

omas Pu blisher

29. Hamby \VB (1969) Intracra nial surgery for

aneurysms. P

rog

Neurol Surg 3: 1

-65

30. Hamby \VB (1970) Remark

scoll

cerni ng intracra

nial aneurysm

sU

I·gery. Clin

Ne

urosurg 17: 1- 17

3

1.

Hocrenz P

(1980-

1981) The

opera

ting micro

scope. J Microsurg I: 364-369, 419-427;

2:

22-26, 126-139: 3: 179- 182

32. Housepian EM, Ungcr \VH. Scharff

TB

et al

(1975) Expericnce with videotape monitOring of

mi

croscopic neurosurgical proce

du

res. J

Nc urosurg 42: 204 - 208

33. Jacques S, Bullara L

A,

rudcnz

RH

(1976) Micro

vascul

ar

bipolar coag

liJ

ator. Technical note. J

Ne urosurg 44: 523 - 524

34. King

TT,

Worpo e R ( 1972)

Sel

f-irrigating bi

lar diather

my

forceps . J Neurosurg 37; 246-

247

35.

K

riege

l'

A (1978)

The

Use

of

the Operating Micro

scope. New York, Carl Zeiss

36. Kurze

T

(1964) Microtechniques in neurological

surgery. Clin Neurosurg I I : 128-137

37. Kurze T, A puzzo M q , \ \'eiss M H e t aJ (1977) E

x

pericnces with sterilization of the operating

microscope. J Neurosurg 47: 861

-8

63

38. Lig ht RU (1945) Hemostasis

in

neu

l"Osurge

r

r·

.I

Neurosurg

2:

414-434

39. Malis

LI

(1967) Bipolar coagulation in micro

surgery. in Dtmaghy RMP, Ya§argil

MG

(cds):

Micro-vascular Surgery.

Sw ug;m , G Thieme,

pp 126- 130

40. Mal is Ll (1979) Ins trumentation and techniques

in microsurgery. Cl

in

Ne

uros

ur

g 26:

626-636

41.

Ny

len CO ( 1954) Th c microscope

in

aural

surgery. I S first use and l

ater

development.

Ac

ta

O[olaryngol [Supp l] (Stockh) 116: 226- 240

4

2.

Peerless

SJ

(1974)

The

surgical approach to mid

dle cerebral

and

posterior commu ni cating

,IllC\lI·ys ms. Clin Nc urosurg 21: 151- 16.?

43. Rand RW (1985) Micronellrosmgel)i cd 3 SI Lo u

is,

CV Mosby Co

4

4. Kh

oton AL, Merz W (1981) Suction lU

beS

f

or

con

\'eI1lional a

nd

microscopic neurosurgery. Surg

Neurol 15:

120

- 124

45. Robertson GE (1967)

Pllellmoenuphalogm//hy,

ed 2 Springfi

el

d, 1L, Charles C T hom

as

Pu

b

li

sher

46. Rogers L (1930) T he history

or

craniotomy: an

account of the methods which have been prac

ticed

and

the instruments used f

or

openi

ng

the

huma

ll

sk ull

du r

ing life. Ann

Med

Hist 2:49:)-

514

47. ScarffTB

(197

4) A nell' bipol

ar

suction-camery

forceps fo r microncurosurgical use. Surg

Neurol

2:

213

48. Sugita K (1985) Mic1"01Ie1lrOSlagicai

Atlas.

Be rli n,

Springer-Verlag

4

9.

Sugita

K,

Hirota T , Tsugane K (1975) Appl

ica-



32


lion of

nasopharyngeal mirror

for aneurysm op

eration . Technical note. J Neurosurg 43: 244-

246

50. Sugita K, Kobayashi

S,

Shintani A el

al

(1979)

fl. licroneurosurgery for aneurysms o f tile basilar

artery.] Ncurosurg 51: 61

5-6

20

51.

Sugita K, Kobayashi

S.

TakemaeT et al

(

19

80)

Di

rect retraction method in aneurysm surger

y.

J

Neurosurg 53:

41

7

-419

52. Sugita K. Tsugane R (1974) Bipolar coagul

ator

with

automatic

thcrmocomrol. Technical note.

J

Neurosurg 41:

777

- 779

53. Sugita K, Tsuganc R,

Kagcyam3

N (1975) Bipo

lar coagulator

wit

h automatic thcnnocontrol

and some impro\'cmciltsofmicrosurgicai insl

"

u-

melliS, in Handa

H (cd):

Microneurosurgery.

Balti

more, University Park Pre

ss,

p 17

54. Wilson CB, Spetzler RE (1979) Operative ap

proaches to aneurysms. Clin

Ne

urosurg

26:232 - 247

55.

a ~ a r g i l Me (

19

69) MicrosUlgery

Applied

to

NeuroSllrgery. StUttgart, G Thieme, pp 119 - 143

56. a ~ a r g i MG. FoxJL, Ray MW (1975)

Th

e opera

tive approach

to

aneurysms

oflhe

anteriorcolll

municat in g artery, in

Kr

ayenbiihl H (cd): Ad

Milas

and Technical

Stlllu/mtis

in

Neurosurgery,

vol

2.

New York, Springer-Verlag, pp 113- 170

57. Y 1 ~ a r g i l MG , Vise WM, Bader DCH (1977) Tech

nical adjuncts

in

neurosurgery_ Surg Neurol

8:33 1-336



3

Photographic Technique

I

ntrodu

ction

The col

or

illustrations of live microsurgical

anatomy as shown in th is atlas were repro

du

ce d from photograp hic color sl

id

es .

Th

e

photogra phs were taken du ring actual opera

tive proced

ur

es performed

by

the au th

or

since

1975.

Th

ey

re pr

escnL

vis

ual r

eco

rds of selected

su

rg

ical cases treated at the

West

Virginia Uni

ve rsity Medical Center in

I'v

lorgant

ow

n, West

Vi

rgini a; the

Ki

ng Faisal Specialist Hospi tal

and Research Centre in Ri

ya

dh , Saud i Ara

bi

a;

and the Georgetown Unive rsity Med

ica

l

Cen

ter

in

Was

hington, D

.C.

T he maj

or

ity

of

these cases we re pal

ie

nt5 with illlracra

ni

al

aneurysms,

bu

t th e e mphas is here

is

o n live

ana tomy such as may be seen in the p

te r

ional

approach to many oth

er lypeS of

ne urosurgical

pr

oblem

s.

Photograph ic slides

we

re selected

for demonstration on the basis of illustrating

clarity of fea

tu r

es, h

av

ing absence of si

gn

ifi

cant t

iss

ue distortion by tumor o r hemorr hage,

showing normal anato

mi

c va riations, an d/or

portraying special neuroana lOmi cal points.

From a recent

hi

storical stand poin t, the au

thor learned the ph

otogra

phic technique de

scribed herei n from trial-and-error expe ri

ence and from lec

tur

es give n by Leo

nar

d

Ma

l

is,

Chairman of the Depar tment of

Neur

osurgery,

Mo

unt

Si

nai

Sc

hool of

Medici ne, New York City. Earl y in hi s experi

ence the author VLF)

was

und

er

the miscon

ception that increased lightin

g,

a wi

de

opening

of the ca mera d ia ph ragm (s ma ll I-s top

num

ber

),

and sho rt time exposur es were neces

sary lO gain sufficient exposure of the

im

age

on the film in the presence of movement of

ne

ur

al and vascul

ar

intracranial tiss ues re

fl

ected

by

cardiac pulsa

ti

ons (direc

tl

y on the

bl

ood vessels)

and

r

es

pi

ra

tor

y pulsations (indi

rec

tl

y via the venous circulation). Ma ny surgi

cal

photog

ra phers still photogr

ap

h through

the operating mi croscope with these concepts

in mi nd. However, in many instances, ph

olO

graphs taken with such techniques have lacked

shar

pn

ess of image. appeared somewhat flat,

and fa iled to provide a good de pth of field.

The key lO improving the quality of the color

photograph

s is to na

rr

ow the lens apera

tu r

e

(we use an f -

St

Op o f 44). T his results in a signif

icant improvement in clarity and sharpness of

images

and

in dep th

of

focus (re

du

cing the

fl

at

ness of image eff

ect). To accomplish this one

must increase the br ightness of the

li

ghtsour

ce

and/or increase the du ration of film exposure.

The light intensity can be increased to so me ex

tent by ove rloading (increasing the voltage) the

transformer of the 30- or 50-W tungsten bulb.

Stronge r halogen o r xenon li

ght s

ou

tcescan

be

used. Bu t excess light energy, even wi th the use

of fi berop tic

dr

ies out intracran ial tis

sues rapidly and reasonab le limits are finite.

One can, however, extend the film exp

os

ure

time la, for exa

mp

le. 1 seco

nd

. Because a

rt

e

rial systolic pulsations are qu ite br ief com

pared wi th the entire dura

ti

on of one pulse.

th is m

ovi

ng (blu

rr

ed ) image is not detected by

thc hu man eye observing the resulting photo..

graph . In otherwords, th is systolic movemem

(o

r " noise") is ave raged out by the stable image

of

re lat ively much longe r dura

ti

on [4].

Th

e sur

gical photograp her mu Sl ta ke care to avoid any

respir

at

ory- i

ndu

ced movement by as king the

anesth

es

iologist

to

hold the pat

ic

m

's

respira

tions du ring the du rat ion

of

fi lming if possible.



34

3. Photographic Tcch

ni<Jue

In

the author

's

early years

of fi

lming with

narrow lens aperature and I-second exposure

limes, excellent col

or

slides were obtain

ed

with

any sim pl e camera bacK (film hol

de

r) and with

30-\V incandescent lighting (givi ng a 2,800° to

3,

100

° K color te

mp

erat

ur

e). Recen t and

mo

re

sophisticated cameras, optics, and microscope

lighting systems have not improved the quality

of the phoLOgraphs, and in many situations the

quality

deteriorated.

Th

e co nversion of

some

Ze iss

mi

croscopes to the usc

of

halogen,

tungsten-filament lam ps (giving a 3,200° to

3,400° K color temperalUre) has improved the

light intensity without noticeable deg radation

in the photographic image

on

tun gsten (ASA

or ISO No.

160)

Kodak Ektachrome film (ba

lanced for color temperatures of 3,200° K [4,

5]). We have been sa tisfi ed with th is light.

More recently

we

temporarily sw itched to

the use of the much brighter xenon light

so

ur

ce (shown on microscope in Fig. 2.5). How

ever, its color temperature is around 6,000° K.

ils e

miued

liglll energy is stronger in the blue

green spect

rum

(com

par

ed wi th light from

tungslen-filamentlamps), and hence one

mu

st

use day light color slide film (Kodak

's

Ekta

chrome fi lm, ISO No. 200, is ba lanced at a

color

tempera

ture of 5,500° K). U

nfortu

nately, the heat-absorbing (red-absorbin

g)

path ways of the microscope's optical system

further

reduced the red speClrum in the

li

ght,

and the r

es

ulting photograph (even with da

y

light film) port rayed defective col

or

reproduc

tion. White

or

gray tissues had a yellow-green

cast and red blood vessels had a brownish cast

(due to the red and green color mi xture). Al

though proper filters may improve the color,

the liglllioss may resultin no signi ficant netim

pro

vem

em

in brightness with the xenon light

source compared

wi

th the tungsten-halogen

light so

ur

ce. Accordingly, we have r

et

urned to

the tungsten-halogen la

mp

on the Zeiss-Con

lI

'aves op

erat

ing microscope.

Current Techniques

Except for the Zeiss cam

era

adap ter and 2x

mag nification attac

hm

ent, the optics is that

which is contained within the Zeiss operating

microscope system [3]. The still ca mera (cam

era

back to hold and move the film; Fig. 3 .1 )

can be any good-quality model and is attached

to the right or left side of the beam splitter (we

use the right; the

TV

camera is on the left; see

Fi

g.

2.7). We have tried using special adapters

a

ll

ow in g the TV camera and still camera to be

attach

ed

to the same side of the microscope's

beam spl ineI' (pe rmitting an observer's tube to

be attached

LO

t

he

o

ther

side),

but the

ca

m

era

lens a

per

ature had to be widened (sma ller [

stop number) with a res ulting degradation of

the photographic image.

As reported previously [I, 2], the following

we

re utilized by the author. For

photograp

h y,

we

used a

Ze

i

ss

OPM I- I oper ating microscope

equipped wi th a 275-mm objective lens, a 160 -

mm focal-length binocular tube , 12.5X

eyepieces, a 30-70 beam spli tter (70% of the

light is deflected and divided equa

ll

y between

the film on the righ t and the camera on the left;

30% goes to the s

ur

geon's eyes), a Zeiss camera

adapter

and 2x magnification auachment, a

Contax camera body, and ISO (f

orme

rl y called

ASA)

No.

160 (tungsten) Ektachrome 35-mm

fi l

m.

The tun gsten-halogen light so urce was

used without auxiliary lighting but with the

transformer

co

nstantly on "overload "

th roughout the operation. (If the heat is al

lowed to escape

direct

ly into the room, the light

bulb usua

ll

y la sts

throughout

several opera

tions.) Before 1980 no drapes we re used, but

the microscope, camera, film, and T V system

were cold-gas-sterili

ze

d for 12 to 18 hours wit h

pure

ethyl

ene

oxide gas. (New federal regul

a

tions have now restricted this m

et

hod of sterili

zation.) Any black-paint border aro

und

the

glass prism deflecting the light

thr

ough the ob

jective lens was removed. Overhead lights in

the

operating

room were turned o

ffLO

provide

beller contrast and LO facilitate dilation of the

surgeon's pupils.

Photographs \·

..

ere made

wit

h respirations

temporarily stopped or during the expiratory

phase of the automatic respirator and wi th the

[ s top on the Zeiss photoadapter set at44 . With

nonautom

at

ic cameras,

the

expo

sure

time

was

set

at

I second. Wi th automatic cameras the ex

posure time ap proxi mates t

hi

s duration. We

use the del

aye

d sh utter-release mode so that a

ll

camera

an

d microscope movements have

ceased by exposure

ti

me occurring about

12 seco

nd

s after pressing the exposure button.

Self-retaining retractors and while cottonoids

we re positioned to provide light reflcClions

within the wo

und

while avoiding re fl ections to

wa

rd

the microscope. Unl ess otherwise indi

cated, the photographs presented we re made



Currenl Techniques

35

Fig. 3. 1. Contax camera at

tached 10 microscope beam

splitter via ad

apter

(not

seen) alld 2x magnification

attachment

(arrow).

with the

Ze

iss magn ification dial se t at its third

magnification

se

lling (the old

No.

16 01' the

new No. 1). providing a true 6x magni fication

for the surgeon. Although lhe photographs

lhemsel

ves

do not provide stereoscopic vision

and sufficient depth

of fi

eld, which may be

6 em from the sku

ll

surface, the reader's know

ledge

of

analom),

wi

ll

compensate for this.

Bib

li

ography

L Fox J L

(1979)

r.,I ic rosurgical exposure

of

i

mr

a

crani

al

aTleurysms .

1

Microsurg

I: 2-

31

2. Fox J L (1983)

llitracranial

Al1

e

Ul

ysms.

New York,

Springer-Verlag,

vol 2

3.

Hoerenz

P

(1980- 1981) The operating micro

scope, J Microsurg I:

364- 369,

419-427;

2: 22 - 26 ,

126

- 139;3:

179

- 182

4.

Ma lis LI

(1981)

Neurosurgical photography

through the mic roscope. Clin Neurosurg

28: 233- 245

5. MartIn-Rodriguez JG (1985) Colol' still and mo

tion pholOgraphy and color tcle\·

is

ioll recording

through the

operating

microscope, in Rand

RW

(00):

Mi

crQrlclI.rosllrgery. SI

Louis,

CV

Mosby Co.

ed 3, pp

83-9)



4

Cranial Anatomy and

the Cranial

Flap

Anatomy

The

pterion

ha

s

been

defined

in

Chapter

I.

Figure 4. 1 illustrates

that

the pterion

is not

a

speci

fic

point

but rather

a

genera

l region

of

the

skull lying under the tcmporalis muscle and in

do

se prox im ity to the frontal, parietal, tem

poral,

and

sphenoid bones.

The

frontoparietal

(coronal) suture and the sphenoidotemporal

suture do not meet at a common point but in

stead come

to

a T' intersection

(Fig.

4.1) with

the parietotemporal, parietosphenoidal. and

frontosphcnoida l sutures (the latt

er

two form

ing a relatively straight posterior-ta-anteri

or

extension

of

the parietotemporal sut

ur

e).

This

anatomical arrangement allows a sh

ort

com

mon boundary between the parietal and

sphenoid bones and causes a separation

be

tween the frontal and temporal bones.

Fig.

4.1_

View of left side of skull model .

TI le sutu re lines between JX)rtions

of

the

sk ull arc outlined in ink. F, frontal;

P

parietal;

T, tempora

l; S, sphenoidal; and

Z,

zygo mat ic bones.

Figure 4.2 shows the anatomical arra nge

ment

of

these bones at the inner base

of

the

skull

[I].

Although

not

prominent on

the out

side, the sphenoid bone represents the "key

slOne" of cranial-base analOmy.

The

word

sphenoid

is

derived from the Greek word

sphenoeides,

meaning wedge-like

[6].

From its

body this interesting struclllre

(F

i

g. 4.3)

sends

out

lalerallesser

and

greater wings, appearing

rather

like a butterfly in flight [2]. For the sur

geon operating at the base of the skull and

brain, this hidden keystone contains land

marks

of

orientation

as well

as structures that

may have to be removed by rongeurs and high

speed drills.

The

latt

er

structures include the

sphenoid wings, anterior clinoid process, pos

terior clinoid process,

roof of op t

ic canal,

tuberculum sellae, floor and septum

of

the

sphenoid sin us, and floor of the se lla turcica.



38

Iw

gw

"

"

o

d.

Fig.

4.

2. Base of skull, upper surface. Note that

Ihe anlerior clinoid process is a posterior pro

jection of

the

origin of

the

lesser wing of

the

sphenoid oone.

Components

of the sphenoid

wi

ng include

lu,

lesser wing;

gu'.

greater

wi

ng;

ls, tuberculum sellae;

ae,

alilcrior cli noid pro

cess;

s

, sella lUrcica; pc. posterior clinoid pro

ccss;fo, foramen ovate; ds, dors u m sellae. Re

drawn from Clemente CD (ed)

(198S)Al alomyoj

tht H/lInol Body by Hem)' Gmy, 30th American

ed. Philadelph ia, Lea &

l< eb

igcr, p

17

1 [ IJ.

"

Fi

g. 4. 3.

Vicw

of disaniculatcd sp henoid bone of

sku ll as seen from behind. The

dorsum

se llae hides

the sella turcica (pituitary fOS5<1) seen best from

aoc·vcin Fig. 4.2. Note the relationship of the

greater

and lesser wings

separated by

thcsupcriororbi

l.al

fis·

surc. A

n o

pt ic

strut separates the

supe

ri

or o,'hital fis·

su

re

from the op tic canal. From E

tter

L E (1955) Atlas

of

Roentgen AI/atomy

of

the Skull.

Sp

ri

ngfield, 1L ,

Charles CThomas Publisher. p 17 [2).

V



The Cranial

Fl

ap

39

By whatever approach to basal struct

ur

es, the

surgeon must ha

ve

intimate know ledge

of

the

sphenoid bone.

Th

e basal cran ial anatomy takes on a differ

ent perspec tive when viewed in the surgica l up

s

ide-

d

ow

n, oblique position (see

Figs.

2.3 and

4.8).

Fi

gures 4.4

an

d 4.5 illustrate a skull model

with a sma

ll

pterional cranial opening. T hesc

show the value

of

remov ing much of the

sphenoid wi ng (ie, lesser and grea ter win

gs)

[3,

4]. Before the sphenoid w

in

g is remo

ve

d , the

s

urg

eon

's

view

of

the supras

ell

ar region is

blocked by the latcral projcClio n

of

the win g

unless greater and haza rdous brain retraction

is appl

ie

d. Partial removal

of

thc sphcnoid

wing, practiced for years

by

Walter Dand y's dis

ciples, pcrmits a

low

cr, basal, tangential a p

proach

to

the circle of W

illi s.

Once the s

ur

geon

u

ses

this tcchniquc rOUl

in

ely and then omits it

from an operative case, he will appreciate its

significant value for permitting easier visuali

zation of basal cistern s. This technique,

coupled with the s

kill

ed u

sc of

sel f-ret.'lining

retractors and

of

the operat

in

g microscope on

a relaxed bra

in

, a

ll

ows thc sur geon to manipu

late microinstruments in small but sa tisfactor

il

y visuali

ze

d spaces.

I f

we

take the same

dry

sku

ll

model shown

in

Figs. 4.4 and 4.5, one can see the relat ionship

of the ba silar artery to the anterior and pos

terior

cl

inoid processes as visua

li

zed throug h a

pterional exposu re (

Fi

gs. 4.6 and 4.7).

One

ca n

understand from

Fi

g. 4.7 that removal

of

much

of

thc sphcnoid win g on one side and a

widely opened sy lv

ia

n

fi

ssure on the othcr side

arc necessary to approac h the midbrain, pons,

and inlerpeduncul

ar

cislern wilh

mi

ni mal

brain retraction. T he posterior clinoid process

of

the sphenoid bone then becomes a critica l

landmark, lying medial to the oculomotor

nerve passing for

wa

rd from the midbrain.

The Cranial Flap

All surgical photogra phs in th

is

atlas arc show n

as a right-sided pterional craniotomy. Those

th

at

originally

we

re left-sided h

ave

been re

ve

rsed to per mit consistency in anatomical il

lu

strat ion. Muc h

of

the following in this chap

ter

is

modified from a previous publication

of

the auth

or [4

].

For a right frontolatcral cra niotomy, the

head is held

in

a skull-

fi

xa tion ap

paratus (see Fig.2.3) and lUrned approxi

mately 30

0

t045° to the left, tilted 15

0

to the left ,

and dropped back about 15

0

(Fig. 4.8). This

brings the "p

syc

hopat

hic point" (see Chap

te r I) into the center and to thc highest point

of

the opcrat ive field .

(W

hen a rig

ht

-handed

surgeon operates on the left side

of

the head , a

40

0

to 45

0

rotation to the riglH is used.) For

aneurysms

of

the middle cerebral artery or the

internal carotid artery bifurcation, the head

is dropped back further so that thc surgeon's

line of vision

is

as perpendicular as poss ible

to the M-I portion

of

the middle cerebral ar

tcry.

T he skin incisio n is kept behind the hairline

rather than curvi ng for wa rd into the exposed

forchead.

Thi

s requi res a long incision, but the

cosmetic resul t

is

better

after

the hair grows

back. T he incision (Fig. 4.8) be gins at the mid

line. curves laterally be

hi

nd the hairline, and

terminates

one

fingerbreadth

in

front

of

the

ear at the level of (or s

li

ghtl), below) the

zygomatic arch. T he skin flap and galea are

stripped from the temporal is fasc ia and

teum, covered with oxycellulose gau

ze

(co lton

may get ca ught in the hi gh- speed drills), and

pu

ll

ed fo rward with

fi

shhook retractors.

An incisio n

is

made in the anterior and pos

tcrior

lim

il of the expo

se

d lemporalis muscle.

T he ante rior portion of the temporalis muscle

is

stripped posterioriy from the zygomat ic pro

cess

of

the frontal

OOne

. Herc one may have to

clectrocoagulate

one or

two branches

of

the an

terior deep temporal artery (from the imcrnal

maxillary arter y). Also. tiny art.eries perforat

in

g the frontal bone just behind its zygomatic

process may have to be coagulated (w ilh cut

tin g current) and

/or

sealed with bonewax.

Th

e

periosteum is stripped along the line

of

inci

sion from the exposed frontal, parietal, and

lemporal bon

es.

Howe,'e

r,

a triangle

of

perios

leum (Fig. 4.9) is preserved anteriorly for later

suturing

to

the te mporalis fascia, thereby cov

er in g the anterior frontal burr ho le at the end

of

the opera tion. This piccc of periosteum,

with its base

anter

iorly,

is

laid on the galea

of

the skin flap, covered with oxycellulose, and

held

by

a fi shh

oo

k retractor.

The frontotemporal bone

fl

ap itself

is

simi

l

ar

to th

at

illustrated

by

Ludwig Kempe (sec

Fig.

\.5) with the

fo llow in

g modifications

(Fig. 4.10),



40

4. Cranial Anatomy and the Cran

ial

Flap

I.

The first burr hole is

ju

st behind the

"psychopathic

point"

and its anterior ed

ge

touches

on

that point.

2. The

second burr hole is also

in

the frontal

bone. This hole lies mo re medial than that

il

lustrated

by

K

empe

(see

Fi

g.

1.

5).

Th

ere

are

three advantages to this:

(a)

It a ll

ows

more

room for frontal lobe retraction without the

retractor striking the fron tal bone. (b) It per

mils plenty

of

room f

or

maintenance oftem

poralis mu

sc

le attachment to the

frontOlcm

perosphenoparietal bone flap, thereby re

ducin g the incidence

of

later temporalis

muscle atrophy. (c) T here is enough ex

posed bone flap for placement of flap-edge

holes for suturclrubber band retraction of

the bone flap.

3. The

third

burr

hole

is

placed

in

the parietal

bone just inferi

or

to the temporal line.

4. The fourth burr hole is dr i lled in the tem

poral

bone

ju

st

in

front

of

the ear a nd above

the zygomatic arch. If placed too far back,

temporal bone air cells may be encountered.

The bone dust

is

saved an d used to fill the

burr holes

after

clos

ur

e

of

the bone flap,

thereby helping to preve

n1.

any future inde n

tations of the scalp into the burr holes.

In patients yo unger than 55 yea rs, the

dur

a

is not usually tightly adherent to the skull bone.

In these cases we often uti

li

ze the ai r-driven

craniotome to cut the sk ull

fl

ap in a similar de

sign between two holes: only the most anterio r

and the most inferoposterior

bur

r holes.

Otherwise a Gigli

saw

is used to

cut

the skull

bone between the four burr holes. Prior

to

either of these techniques

of

craniotom

y,

rongeurs are used

(we

usually u

se

the Echlin

rongeur)

to

bite away as much of a channel

in

the fronto-spheno-temporal bone as possible

between the two basal burr holes under the

te

mp

oralis muscle. Doing this before saw ing

the bone between the

upp

er calvarial

burr

holes a

ll

ows this inferior bony channel

to

be

cut

without the bone flap inadvertently fracturing

too hi gh above the base.

After the bone

fl

ap

is

cut free, its inferior

edge is rongeured (Leksell rongeur) until

it

pr

esents a smooth, n

onpr

ojecting s

urf

ace.

Heavy si lk sutures are passed t

hr

ough two of

the small edge holes (already drilled f

or

future

reattachment

of

the bone flap to the cal

varium).

The

sutures are each connected to a

rubber band that has been wrapped around

the rubber tubing show n previously in

Figs. 2.7 A and 2.9. In this manner, the bone

fl

ap, still attached to the temporalis muscle,

is

re tracted over the zygomatic arch, thereby ex

posin g the dura

(Fig.

4.11). The bone flap is

waxed

at

i

ts

edges and then covered with wet

oxycellulose. T he calvarial edges are also

waxed .

The dura

is the n tacked up with sutures

that are passed through the calvarial edge

holes (also

to

be used for reattachment

of

the

bone

fl

ap. T he sph enoid wing is rongeured in

fe

ri

orly as far as possi ble and then waxed. In

cases where an even more basal expos ure is re

quired, we cut the zygomatic arch anteriorly

and posteriorl

y.

I t can be left attached to soft

tissues while the b

ul

k of the temporalis muscle

is displaced inferiorl

y. The

zygoma is reat

tached at the end

of

the surgery.

The superficial temporal a

rt

ery runs in

front

of

the

ear

and just su perficial to the

galea. Preservation

of

this artery

is

useful,

especia

ll

y if the su rgeon plans an

ext

racrania

l

to- intracranial anastomosis. This may

be

neces

sary if one plans on a trapping proce

dure

or an

arterial occlusion. In such a circumstance,

meticulous techniqu e is needed to prevent su

perficial temporal artery injury.

The frontalis branches

of

the facial nerve

pass forward between the galea and lemporalis

fascia and are usually seen passin g anteroin

fe

rior to the first burr hole. They can some

tim

es

be preserved

by

turning a s

up

erfical

layer

of

the

tempora

l s fascia forward over the

zygomatic

pr

ocess

of

the front

al

bone before

incising the tcmporalis musc le anteriorly. Elec

trocoagulation in the area must be kept at a

minimum. T he ne

rves are

ofte

n

injured, and

the patient m

ay

have an immobile forehead

on

the ipsilateral side foll owing surgery. In most

such cases, frontalis muscle function returns

wi thin 6 month s.

Sphenoid Wing Removal

The

operating microscope is n

ow brought

into

the s

ur

gica l field and used until dural closure.

The Ley la se lf-retaining retractors

are

at

tached to the

operating

table (see fig. 2.1

1).

The dura of

the frontal and temporal lobes are

retracted gently from the sphenoid bone and

the lateral roof

of

the orbit. If necessary, some

cerebrospinal fluid (CSF) ca n be drain ed

by



Sp

henoid

Wing

Removal

41

lumbar puncture to relieve pre

ss

ure on the

bra in. Release only a suffici

ent amount of CS

F

to permit a relaxed brain, as excess removal

risks premaLUre rupture

of

an ane

ur

ysm, tear

in

g

of vc in

s bridging th e

dura

and the brain,

or

downward hern iation

in

cases with ma

ss

le

sions.

The dur

a of the temporal lobe is often

quite

vasc ul

ar and w

ill

require bipolar ele

c

trocoagulation, oxycellulose application,

an

d

occasionally the u

se of

malleable dips.

With a suction-irrigat

io

n apparatus

in

the

left hand and a high-speed drill in the

ri

ght

hand (of a right-handed surgeon), the surgeon

removes

projections

of

the sphenoid w

in

g and

lateral

or

bital roof.

Ke

ep all couono

id

s o

ut of

the immediate field to avoi d

in

ju ry

by

their

being caught in the drill.

The

steel drill bit is

used in i

ti

ally because ofiLS more rapid removal

of

bone.

As

the base

of

the

anteriordinoid pro

ce

ss

is approached, the drill bit is changed to

the d

ia

mond type, which tends less to tear the

n

ear

by dura.

Th

e Lemp

ert

rongeur is ve

ry

helpful in removin g slive r-like projections

of

the sphenoid wing. A tiny

bi

t

of

bonewax on a

small , dry couonoid is applied aga

in

st the bone

with the bipolar forceps to stop bone bleeding.

One mllst be careful to avoid drilling into the

orbital cavit

y.

I f this occurs, the p

at

ient

will

have greater temporary swe lling and ec

chymosis of orbital ti

ss

ues during the pos

t

operative period. In some pati

ellLS

there

is

a

partial, congenital absence

of

the greater wing

of the sph

eno

id bone behind the o

rbi t.

The

sphenoid w

in

g is removed with a

rongeur and then burred down with the hi gh

speed drill

dose

to the base

of

the anterior

clinoid process, a medial depth

of

about 5 cm

(Figs.

4.12

an

d 4 .13).

As one ap

proaches this

point, the men in go-orbital artery (su praorbital

branch

of

middle men in geal arter y) is a land

mark seen in the dura;

it

passes from the mid

dl

e meningeal a

rt

ery through

it

s own "lacri

mal" foramen (Hyrtl

's

canal)

in

the sphen

oi

d

wing

or

through the lateral corner of the

superior orbital fissure to communicate with

the lacrimal artcry in the orbit. (This artery is

on

e

of

the remnanLS

of

the embryo nic stapedial

arterial system

[5]). The

meningo-orbital ar

tery usually is electrocoagulated and severed,

allowing further drilling ofthe sphenoid win g.

At

this point the fast

er

steel drill bit is swi tched

fo r a diamond bit.

Th

e base

of

the amerior

cl

in

oid process appears as a glistening while

bone o ften contain

in

g a single sma

ll vasc

ular

channel (Fig. 4.13).

Th

e dural opening

is

cons

id

erabl y smaller

than the craniotomy defect. The bony open ing

is

la

rger for the reasons stated earlier in this

chapter.

The

dura is permitted to cover the

brai n as much as po

ss

ible to

pr

otect the brai n

from the drying effecLS

of

air and light. The

du ra is opened in a modified, sha

ll

ow horse

shoe-shaped man ner (Fig.

4.

1

4). The dural

nap is retracted o

ve

r the smoothed-out

sphenoid bone

by

suturing it to the galea.

Often a secondary

dur

al incision over the syl

vian fissure is needed if the

fi

ssure is to be

opened widely. At this point, some CS F can be

remo

ve

d by

lumbar

dr

ai

nage

or

by

aspiration

from the chiasmatic and

ad

jacent cisterns

under a minima

ll

y elevated frontal lobe

(Figs.

4.14

and 4.15). Auention must be paid to

the one or more ve ins bridg ing the temporal

lobe and the sphenoparietal sin us. Although it

is good practice to preserve ve nous drainage

where possible, we have not seen any complica

tions from electrocoagulating and severin g

these

vei

n

s.

I n cases where minimal temporal

lobe retraction is necessary, these veins may be

preserved.

The

fo llowing chapter details the

anatomy of the

sy

lvian

fi

ssure

in

the approach

to

the basa l cisterns.

Bibliography

I. Clemente C D (ed) ( 1985) Anatomy

of

Ille Human

Body

by

Henry

Gmy,

30th

American e

d.

Philadel

phia, Lea & Febigcr, p

171

2. Etter Lf. ( 1955) A/las of Roentgen Anatomy of lhe

Skull.

Springfield, 1L, Charles C Thomas Pu

b

lisher,

pp 16-44

3.

FoxJL

(1979) Mi

crosurgical exposure of intracra

nia

l aneurysms.J

Microsurg

I : 2-31

4. Fox

JL (1983)

Intracranial Aneurysms,

vol 2. New

York, Springer-Ver lag, pp 877-887, 1030

5.

Lie

TA (1983) Variat

ions in cerebrovascular

anatomy, in Fox J1. (ed): Intracranial Aneurysms,

\'01 I. New

Yo

rk, Springer-Verlag, pp 432-489

6. Sin/man's Medical DicliOl l1ry, ed 24. (1982) Balti

more

,

William

s

& Wilkins Co,

p

1312



42

4. Cranial Anatomy and the Cranial Flap

Fig. 4.4. View of dry skull in

the

same surgical pos

i

tion as in figs. 2.3 and 4.8 prior to removal of the

sp heno id \ ~ i l \ g

Th

e right orbit is at the upper left

corner. spit, L1.leral aspect of greater sphenoid

wi

ng;

pel,

pClrous pyramid;

ac,

anterior clino

id pr

oces;

pc,

tip of ]X>sterior clinoid process; crossed an-ow, ex

posed lOp of red rubber eraser

("lUm or

or

",

j l lcurysm").



Analomy 43

""'It

Fig. 4.5. Same dry skull as in Fig. 4.4. Th e sphenoid

w

in

g

(sPh)

h

as

been drilled away.

Crossed arraw:

red

r

ubbe

r eraser

("

tumor" or "aneurysm")

si

tting on

lhe tuberculum se llae nanked by both ame ri

or

clino id processes. ac, Rig

ht

am

er

ior clinoid

pr

ocess;

pel, ri ght petrous pyra mid ;,,£;, righl post

er

ior clino id

process. From

Fo

x [3].



44


Fig. 4.6. Same dr y skull as in '-igs. 4.4 and 4.5. Skull

is in upright, oblique position with view over lateral

roof of orbi

l.

zy. Frontal processofzygoma;pet. right

petrous pyramid;

ac,

anterior clinoid processes

flank ing tubercu lum

se

llae

(ts);

PC. right posteriur

clinoid process;

00,

red pen representing basilar ar

ter

y.

(Be hind the latter would be the midbrain and

pons.)



AnalOmy

45

Fig.

4.7.

Same dry skull as in Figs.

4.4-4.6.

Sku ll

now is in

surgical upside-down, oblique position.

Thesurgeon's view is more caudal to view the region

of

the "basilar artery" (00, a red pen) as seen via the

pterional approach.

Th

e

orbit

is in th e

upper

left

corner of the figure. pc, Right posterior clinoid pro

cess;

pel,

petrous pyramid; *, right anteri

or

clinoid

process: sph, drilled down sphenoid wing. From Fox

[3).



46


Fi g. 4.8. Pa tient's head in a skull clamp. The incision (triallgle) iso udin cd to stay behind the hairline. ret allows

the bone

nap

to remain

auac

hed to

the

temporalis mu

sc

le. From

I-ox

[3).



Th

e Cranial Flap

47

Fig. 4.9. Scalp

nap

turned for right pte

ri

onal

craniotomy. Paticnt in position show n in Fig. 4.8.

G a ~ a

exposed. Crosstd

01'7'01/,\ junct

ion of tcmpo

dl

line wit h orbital ridge and zygomatic proce

ss of

f ron-

tal bo ne; fb. frontal bone;

If,

tClllporalis fasc ia; pt.

perios te

um

;

re,

raney clips on scal p edgc;

s,

suction

tube:

If,

thumb forceps

el

evat

in

g triangul

ar

patch

of

periosteum offfrontal bo ne Vb).



48


Fig. 4.10. The oxycellulosc

(ox)

covered galea and

scalp flap

arc

held

by

fishhook

retraCLOrs (fit).

A re

tractor

(ret)

is pulling the incised lcmporalis muscle

forward. One parietal (P). one temporal (I), and lWO

frontal if)

burr

holes have been drilled and covered

with bonewax. fe, Periosteum; el, elevator; if, tern

poral

is

fascia.



The

Cranial Flap

49

Fig

.

4.11.

The

bone flap

(bj),

covered byoxyce

ll

ulose

(ox), has becn turned latera lly o\·er the zygomatic

arch. It rcmains attached to the temporalis muscle

(t1ll). lph,

Sphenoid

....

,ing;td. temporal

dura;fd.

fron

tal dura : su, suture for later reattachment of the

bone flap.



;0

4. Cranial AnatOmy and the Cranial Flap

I

,

/CO

Id

.1

Fig. 4.12

. The sp

henoid

wi

ng

(sph)

prior to removal.

hII,

Amcrior frontal

burr holc;fd,

fron tal dur<t;sf,

dura

over sy lvian fissure; It , temporal

dura.



Sp henoid Wing Removal

51

Fig. 4.13.

The

right sphenoid wing (spl ) h

as

been

burred

away.

Crossed

arrow, vascul ar channel ill lesser

wing

of

sp henoid wing near base of ante rior clinoid

process; mo, mcningo-or

bi

tal artery.

On

righ t is a re-

tractor on the dura of the tempo ral lobc (/d). On le ft

is a suction tube

(5)

and retractor (ret) 0 11 the dura of

the right frOlllallobe ifd). Ze iss dial

SCl

at magnifica

tion

Hu

mber 0.6 (old no. 10). From Fox [3].



52


Fig.

4.14. Initial

exposure

of

carotid cistern.

Ma

gnifi

ca

ti

on reduced. Re

tractor

s (rtt) elc\'ating the right

Icmporallobe (about') and frontal lobe

(below)

I em

frO Il1 right spheno id wing

co\

'c red by the turned-

down dural flap

(dura), The sy

lvian fi

ss

ure

(sf)

is not

ye t opened. 2, Optic nerve; ica, imernal carotid af

tcry. Zeiss magnifica tion dial set at number 0.4 (old

no

.

6).

From Fox [3].



Sphenoid Wing Removal 53

Fig.

4.15. View

along spheno

id

wing to the right an

teriorclinoid process

(*). ti.

"I"emporal lobc;j1, fronlai

lobe. The internal carotid artery (ica) and optic

nerve

(2)

are covered by arachnoid. J, Right olfac

tory tract;

s.

suction lube.

Zeiss

dial set at

0.6

(old

no. 10 ). From Fox (3).



5

The Sylvian Fissure

Introduction

E

ve

n though the pterional approach to skull

ba

se

le

sions has become more

w

id

ely

used

by

neurosurgcons, significam separation of the

frontal and tcmporal lobes

by

opcning the

sy

l

vian fissure is often not

done

. However, as

we

have gained morc experience.

we

hav e opened

the

sy

lvian fissure more and morc. This has

several benefits [3, 5): (a) small vessels arc not

compressed

by

arachnoid al bands

durin

g re

traction of the brain; (b) there is le ss resistance

(and hence less bra in-ret ractor pressure) to re

traction

of

the fronta l lobe;

(c)

traction

011

onc

lobe does not pull and

injure Lh

e other lobe;

(d) fewer bridging

ve in

s need

be

sacrificed;

(e)

the olfactory nerve usually can be preserved;

and

(f)

there is minimal traction on perforatin g

arteries an d on an aneur

ys

m.

Fig.

5.1.

CT

scan

after

injec

ti

on

of

iopamidol into CS F.

Arrow runs from posterior

cerebral artery (at junction of

ambient cistern with inter

pedu ncular cistern) to optic

tract. Arrowhead. middle cere

bral artery in sylvian fissure.

Section is at level

of

midbrain

and optic chi asm. Note an·

tcrior cerebral arteries in

chiasmatic cistern (trianglt)

and interhemispheric fissure.

Fi

gure 5.

1 is a computed tomography (CT )

scan that

ni

cely

ill

ustrates the significant cere

bral

spinal fluid (CSF) space

(sy

lvian cistern)

between noncom pressed frontal

and temp

oral

lobes. Thi s space, containing the midd le cere

bral a

rt

ery and its branches. is quite prominent

in the old

er

01" the atrophied brain. h m

ay

be

minimal in the edematous

or

compressed

brain.

Th

e sy lvi

an

cistern is larger near its basal

zone, as seen

in Fi g.

5.1. and becomes smalle r

in

the more peripheral

zo

ne

s.

At the surface the

sy

lvian fi ssure may appear to be absent (i t is

no

t)

owing

to

the close approximation of the

fromal

pi

a and temporal pia mater. This zone

is covered by fi rmly adhering arachnoid

s

tr

elched over the pia,

and

at

first observation

the

untut

ored observor m

ay be

mislead into

be

l

iev

in g that an

opening

of the

sy

lvian

fissur

e

is

too difficult

to wa rr

ant performing. Indeed.



56

5. The Sylvian Fissure

the difficulties encountered with

opening

the

sylvian fissure co

mp

ressed

by sofland

ede

mat

ous

br

ain cont

ai

ning friable,

nonautoregu

lat

ing vessels may make the procedure LOa

haza rdou

s.

But in most circumstances the fis

s

ure

can be widely

opened,

t

hu

s permitting ex

ce llent exposure of basal anatomy between a

drilled-down sp henoid wing and a widely ex

posed sy lvian fissure.

Anatomy

Fig

ure

s 5.2 th rough 5.8 illustrate the initial

opening

of the

sy

lvian

fi

ss

ur

e

in

five cases

(a ll

photographs in this a lias are presented as vi

ew

ing the right side). With initia l elevation of the

frontal

an

d temporal lobes

(Fi

g. 5

.2),

the sur

geon

w

ill see fine arachno id bands passing in

the s

ubdur

al space between

the

arachnoid a

nd

dura

(both being meso

dermal

leptomeningeal

tiss ue of similar embryonic origin). I n some

cases the arachnoid over the sy lvian

fi

ssure is

distended by contained CS F (Fig. 5.3). Th is

often occurs when the brain has been mildly

shrunken as wa ter is transfe rred from the

brain into the

CS

F space owing to controlled

hyperventilation [7].

The sylvian fissure is usually opened on the

frontal lobe side of the sylvian veins (Figs.

5.4-5.8). Initially, we use ajeweler's forceps to

pick

up

the arac

hn

oid (Fig. 5.6), which

is

incis

ed

wi

th microscissors. The self-retaining re

tractor

bl

ades

are

employed

to separa

te the

frontal and tempora l lobes, thus gently s

tr

e tc

h·

ing the arachnoid in the

fi

ssure. This facilitates

ex posure of the next, deeper layer of arach

noid and i

ts

contained peripheral branches of

the middle cerebral a

rt

ery (Fig. 5.7). Close i

n

spection via the operating microscope revea ls

the ever-present, fine

arac

hnoid bands or

fi

bers s

upp

orting the arteries within their bath

of CS F.

This

anatomical

phenomenon,

to be

emphasized

throughout

this atlas, has been

stressed by Arutiunov and colleagues in th eir

drawings

[1]. They related mechanical disto r

tion of these s

up

porting

fi

bers to the evolution

of vasospasm after

ane

urysmal s

ubarac

hnoid

hemorrhage.

We no lon

ger

hesitate to coagu late and incise

veins

and

su perficial

arter

ies passing between

the two lobes. In this manner the surgeon, with

the suction tu be in his left hand and the bipolar

forceps or microscissors in his right hand ,

works his

way

down toward the base of the sy l

vian fissure (

Fi

gs

.

5.8-5.12).

Meticulous

ca

re is

taken

wi

th the small arachnoid a

dh

esions

and

band s adjacent to middle cerebral ar tery

branches d

eeper

in the fissure. When released ,

these band s will not compress and compromise

vessels as the lobes are separa ted, and the sur

geon w

ill

find

the

fissure

sud

denly

ope

ning

up

to

significant advantage. A sma

ll

cotton paddy

or dental cotton ba ll (counted) is helpful for

co

mpr

essing bleed ing vessels with the suction

tube prior to their electrocoag ul ation.

One

finally reaches the mu ch

tougher

arachnoid fibers

at

the base of

the sy

lvi

an

fis

sure

(F

igs. 5.9-5.1 1

).

When these arc cut, the

surgeon gains immedia te entrance into the

carotid cist

ern and

more CS F is re leased. Dur

ing this approach, the surgeon mu st decide

wh

et

her or not to electrocoagu late and cutone

or

more bridging veins between the sylvian

vei ns of the l

emporal

lobe and the dural

sphen

opa

rietal sinus (F igs. 5.1

0 -5 .1

3). Preser

vation of bridging veins generally is a good pol

icy, bUllheir presence may limit adequa te expo

sure in some cases. Also, these veins may lear,

resulting in ve no us bleeding

at

a difficult time

durin

g the operation.

We

rarely, if ever, had a

complication

due

to removal of these particu

l

ar

ve in

s.

Figure 5 .1 3 shows the preliminary

anatomy in

one

patient

after ope

ning the syl

vian fissure.

The following figures illustrate va riatio ns in

s

ur

gical

anato

my

of

the

rig

ht

sy

l

via

n fissure.

Figures 5 .14 and 5.15 are

twO

separate cases

where

on

ly the d istal zone of the

sy

lvian fissure

(simil

ar

to site of jeweler's forceps in

Fig.

5.6)

has been opened. In each case branches of the

middle cerebral artery project

out

and

arachnoid bands are noted. In Fi g. 5.15 the

morc superficial

part

of the sy lvi

an

fissure has

been oblit

era

ted la terally by adh esions (from

prev

ious hemorrhage) between the fronta l and

t

empora

l lobes. Figures 5.16 and 5.17 are illus

trations (at

different

magnifications) of middle

cerebral arterial

br

anches projecting outward

after the lateral portions of the frontal and

temporal lobes in Fig. 5.1 5 have been scpa

rated. Emphasis

is

placed

on

the arachnoid

bands of

Ar

ut

i

un

ov

( I], which

are

clearly re

vealed in these photographs. Of course, nor

ma

ll

y they

are bat

hed in CSF within the sylvian

cistern .

Figure 5 .18 indicates a later state of dissec

tion where the tough arachnoid between the

base of the frontal lobe and the base of the tem

poral lobe is being severed by microscissors

(compare

with Fi

g.

5.

11

).

Figure 5. 19 s

ho

ws

a



Anatomy

57

va

riation in the M-I and M-2 arterial anatomy

after cutting basal arachno

id

fibers.

Fi

g

ure

5.20 is an example

of

a long M-I artery project

ing laterally through an early superfi cial open

ing of the sy lvian fissure. Figure 5.21 illustrates

another long M-I artery taking the m

ore

usual

course deep in the sy lvian fissure. Figures 5.22

and 5.23 are exam ples

of

a long M-l artery and

a short M-l artery, respectively. In both in

stances, the

M-1

artery

is

best seen with the

su

r

geon's view a

im

ed perpendicular to the axis of

the artery, and this is best obtained

by

a greater

than-usual extension

of

the patient's head

when lesions along the M-l artery and internal

ca rotid

anery

bifurcation are treated surg

i

ca

ll y.

As

the

sy

lvia n fissure is opened more widely

at the base, the bifurcation of the internal

ca

rotid artery into

its

M-J

and

A-

I branches

comes into view. A structu re often seen but not

common ly recognized here

is

the optic tract

(Figs. 5.23-5.29) . In this region the optic tract

fo

rm

s the lateral border

of

the lamina ter

minalis and its cistern,

is

crossed

by

the A-I ar

tery, and

li

es d

eep

to perforators passing to the

anterior perforated substance from

A- J,

M-I,

and the carotid bifurcation vasc ulature.

Fig

ures 5.24 and 5.25 are good examples

of

im

portant anatomy seen

at

and just

be

yond the

widely opened sylv ian

fi

ssure. In addition to

that described above. this anatomy includes the

anterior choroidal artery, stria thalamic per

forators. reCUITen t artery

of

Heubncl; and the

anterior temporal artery. Figures 5.

26an

d 5.27

are additional examples wh

ere

the internal

carotid artery is short.

The

multitude

of

stria

thalamic perforators as seen

in Fi

gure 5.28 will

be obscured

by

an aneurysm at the bifurcation

of the internal carotid artery (

Fi

g. 5

.2

9).

In an occasional case, gentle retraction to

separate the fromal an d temporal lobes will

ex

pose middle ce rebral artery branches usually

deeply hidden in the

sylvi

an fissure (Fig. 5.30

).

With microlechnique to open the arachnoid

membrane and to sever the fine arachn

oi

d

bands supportin g the arteries, the a rte ries (dis

tended and pulsating with blood)

may

project

outward toward the surgeo n (Fig. 5.31). Usu

ally a second layer

of

arachnoid membrane is

found covering the lar

ger

M-2 branches and

must be removed to see these branches clearly

(

Fi

g. 5.32). These arteries then can be followed

down to the M-I artery and its perforators

(Fig.

5.33).

It

is thi s author's opinion that the

brain

is

covered by a double layer

of

arachnoid

as if the brain had settled down onto a balloon

made

of

arachnoid membrane.

As

the brain

settled, the opposing arachnoid wa lls ap

proximated, leav ing an inner layer (wrapped

around and supporting the arleries at the base

of

the brain) a

nd

an

outer

layer (covering the

brain and stretched between neu ral protru

sions so as to form CS F-co maining cisterns and

fi

ss

ures). Ju st as fine arachnoid band s and fib

ers run between the dura and the arachnoid

(see Fig. 5.2), similar

ba

nds and fibers (of

Arutiunov) run from the inner arachnoid

la

yer

(surrounding arteries) to other nearby inner or

outer arachnoid layers (see

Fig.

5.17). Often

the inner laye r of arachnoid el1\'elops not only

the conduit arteries but also the perforators

running in the CSF space between the artery

and the brain (the anterior thalamic per

forators from the posterior communica ting

ar'

tery shown in Chapter 8 being the best exam

pl

e). Thus, these perforators appear to be

lined on both sides by a layer

of

inner

arachnoid membrane [4]. This membrane be

comes stretched, perforated, and discontinu

ous with growth of the child.

Figures 5.34 and 5.35 are two illustrations of

a leash

of

stria thalamic perforators passing

from the M-I

ar

tery,

through

the base

of

the

sylvian cistern , over t he optic tract, and into the

amerior perforated substance. Figure 5.36 is

an angiographic example

of

such perforators.

The nex t chapter will ta

ke

the obse rver deeper

into the carotid a

nd

adjacent cisterns.

Bibliography

I. Arut

iun

ov A,

Baron

MA, Majorova NA (1974)The

role

or

mechanical

ractors in the pathogenesis or

short-term and prolonged spasm or the cerebral

ancri

es.

J Ne urosurg40:

459

-

472

2.

Fox

JL (1979) Microsurgical exposure orintracra

nial

aneurysms.] Microsurg I:

2-31

3.

Fox

JL

(1983) Intmcrallial Aneurysms.

vol 2. New

York,

Springer-Ver

la

g,

pp

877

-

10

69

4.

Fox

JL, J

erez

A (1

974) An

unusual

aCOus

tic

neurinoma loca lized betwee n brain

stem

and basi

lar arlery using emulsified Pantopaque cisternog

raphy.

Surg Neurol 2:

329

-

332

5. Fox JL, A

lbin

MS, Sader DCH et al (1978)

Micro

su

rgical treatment of neurovascular disease.

Neurosurgery

3:

285-337

6. )<

ox JL, Nugent GR

(1976)

R

ecent advances

in

intracranial aneurysm surgery. \V Va

Me

d J

72:

104-

106

7.

Hayes

GJ , Slocum HC (1

962)

The

ac

hieveme m of

opt imal brain relaxation by hypervcntilation

technics

or anesthesia.J Neurosurg

19:

65-69



58

5. The Sy lvian Fissure

Fig. 5.2. Initial intradural exposure down right

sphenoid wing.

dum,

Dura rencctcd over drillcd

dowlJ sphenoid wi ng: tlr, arachnoid

hand

s between

dura and arachnoid mcmbranc;jf, frolllal lobe; 1l1,

brain rClraClOrs; II. tcrnporall obc; \'cin.



Anatomy 59

r·

•

"

.

.

-.

<

,

fig. 5.3. Arachnoid mem

bra

ne

(ar) in

sylvian

fi ssur

e

distended

by

CS

F.

Prom in ent sylv ian vein (v) cov·

ered by this arachnoid

and

divides periphera lly into

twO bra

nches

(single-crossed

arrows) entering

•

,

....

•

. '

•

-

•

.

"..

••

f-

,

•

,

.....

.

.

) .

sphenoparie tal

si

nu

s. clp.

Malleable clips on d ural

edge;

If.

lem porallobc;jl. frontal lobe;

(lolJbie-crossed

r r u ~ a rachnoid on fronta l lobc side

of

sylvian veins.



60

5.

Th

e Sylvian

Fis

s

ure

Fig.

5.4. Initial incision into sy lvian fissure

(arrows).

This is

0

11 the fronta l lobe (jl) s

id

e of the syl\·

ja

n veins

(v). Arachnoid membrane

(ar, lOP) is

stretched over

the

sy

lvian fissure. A rachnoid bands (ar. bottom) cross

a peripheral branch

(a, bottom) of

the middle cerebra l

artery. Abo\'c is a surface branch

(a, toP) of

the mid

dle cerebral artery o n th e temporal lobe.

rei,

Retrac

LO

r ;cot, cOllonoid.



AnaLOmy

61

Fig. 5.5. Same case ("ig. 5.4). Distal ponion

of

right

sy lvian fissure widely

opened,

exposing a large fron·

tal M-2 ar lery

(m-2, bottom)

and a sma

li

lemporal

M-2

an

ery (rn -2, loP). ica , Imernal carolid ancry (oU(

of

focu s) ;

co

l,COltonoid under

rClracLOr;j1,

frontal lobe;

If, lc

mporal

lobe;ar, arachnoid band .



62


II

Jf

(

"-

dura

- '

Fig .

5.6. Another case illustrating jeweler"s forceps

(jj)

grabbing arachnoid over

Syh,j.Ul fiss

ure

(arrow). fl.

Fromallobe; II, temporal Jobc;d1lra, dural margi n;$, suction

lU

be;

t',

vein. From to x [3).



Anatomy

63

fI ret

Fig. 5.7. Fu

rthe

r

opening

or sy Jvian fissure coma

in

in

g entwining vessels.

ar (toP),

Arachnoid

on

at herosclerotic inte rnal carot

id

artery

(ica); Ie,

tento

rial edge;

li·ret, temporal

lobe rei ractor;jl-rel, rrontal

tl-ret

(

,

JolJe retral:tor;

v, sy

l vian ve ins. N

ote

arachnoid bands

(ar, bottom) octween sy lvian vessels and pia. From

Fox

[3].



64

5. The

Sy lvian

Fi

ssure

I \

II-ret

Fig.

5.8. Anoth

er

case to illustrate u

se of forcep

bla

de

s

ifcPl

to open and separate arach

no

id (ar) on

fr

ont

al lobe s

id

e of

sy

l\'ian veins.

/l-ret,

Temporal lobe

tl.f et

rct

rac to r;jl-rel,

fr

ontal lobe re tracLOr; col,

sma

ll cot

t

Oil

ba

ll

(from dental supply house).



Amllomy

65

Fi

g.

5.9. Arachnoid at base

of sylv

ian

fiss

ure is usu·

ally th

ic

kened

(ar)

and needs to be cut to expose basal

cisterns.

gr,

Gyrus rectuS;

2, opt

ic ne

..

. ej

ita,

illlernal

carotid artery;

dum, du

ra o,'cr sphen

oi

d wi ng; 3,

oc

ul

omotor nerve;

v, ve

ins;ti, temporallobe;fcp. for

ceps.



66

5. T he Sylvian fissure

Fig.

5.10. Anot her case after

partial opening

of

arachnoid

(ar,

lOP)

over sylvian fissure. Arachnoid

ba

nds (ar, hottom) connect branch (a)

of

m

id

dle cere·

br

al

artery

wit

h pia. cot, Cottonoids under retractors;

fl.

frontal lobe; 2, optic nerve; ica, internal carotid ar

tery; pc, poste rior clinoid process; v, sy lvia n ve ins; It,

temporal lobe. T he vei n

(v, lOP)

is entering the

sphenoparietal sinus.



Anatom),

67

Fig. 5.11 . Same case (Fig. 5.10) after further separa

tion

of

arachnoid

(ar,

below) b

)'

blades

of

forceps

ifcp}, or (toP), Arachno

id

band

O\

'er optic ne n'eJ

carotid arrer)' ju ncuon;pc, I>ostenor cli no id process;

V, vein;

I'll,

retracto r on tcml>oraiiobe.



68

5. The

Sylvian Fissure

\

--

Fig. 5.12. Same case (Fig. 5.10) after clearocoagula

lion

of

vei n (v) to sphenoparietal

sin

us. dura,

Du

ra

over drilled-down sphenoid wing; te, tentorial edge;

mem,

membrane

of Liliequisl ill background (pointer

crosses more supe rficial frontal lobe and internal

carotid artcry) ;sc, microscissors.



Anatomy

69

Fig. 5

.1

3. S

.

me case (Fig.

5.

10) arter rur ther separa

lion or rrontal lobe

(j1)

and te

rn

pordl lobe.

Th

e

arachnoid membrane or Li licqu iSl

(mem)

has beC I1

partially opened. re\'ealing the basi lar artcry (ba) in

the interpeduncular cistern. T he uncus (un) is sti

ll

ad hercnt to thc oculomotor nerve (3). s. Suction

tube; 2, optic nervc;pt:. posterior cli noid process; at ,

ante

ri

or

cli

noid process.



70

5. The

Sylvian Fissure

fig. 5.14. Another case after opening per ipheral

part

of

right

sylv

ian fissure. Note arachnoid bands

(ar) between arteries and between arterial branches

and pia.

The

temporal (I) and frontal

if)

branches

of

(

I

/1- t

r

•

,

fJ

I

,

the middle cerebra l artery are projecting out of the

depths

of

the sylvian fissure and toward the ob

server. rei, Retractor;

Il,

temporal lobe;

fl.

frontal

lobe.



Anatomy

71

Fig. 5

.15.

Another

cas

e after partial opening

of

right

sy lvian

fis

sure

(crossed arrow).

Branch

(a)

of middle

cerebral arter y lies on island of Reil

(*)

and co mes

from depths

of sy

lvian

fi

ssure.

ad,

Adhesions (elec-

trocoagulated) between frontal

lo

be

(jl)

and tem

porallobe (If). col, Coltonoids under brain retractors;

ar,

arachn

oi

d band.



72

5. The

Sylvian Fissure

Fig. 5.16. Same case (Fig. 5. 15) after

furt

h

er opening

of sy

l

vi3n

fissure.

dura,

Dura over drilled-down

sphenoid wing; or, arachnoid membrane stretched

between frontal and temporal lobes;

Ii-ret,

tempor

al

lobe re

tr

actOr;

floret,

frontal l

obe

retractor. Note

many arachnoid bands between branches (a) of lhe

middle cerebral artery and between arteries and pia

(shown

unde

r

greater

magnification in the next fig

ure).



AnalOmy

73

Fig. 5.17. Same case (Fig. 5.16) and vicw

undcr

grcat

er

magnification (o ld Zeiss dial No. 25 or new Zeiss

dial No. 1.6). Crossed arrows, examples

of

the many

arachnoid bands: col, coltonoid

under retraclor;fl.

frontal lobe.



74

5. The

Sy lvian Fissure

Fig

.

5.18. Another case where arachnoid at base

of

sy

l

via

n

fis

sure is being cut by microscissor

s.

A suc

lion

tube

(s) is in

the surgeon's

Jcrt hand and mi

cro

scissors are in his righl.

Th

e optic nerve (2)

and

the

i/Hernal ca rotid artery (ica) arc still covered by

arachnoid.

cot,

Sma

ll cOlton

ball;

rtt,

retractor on

frontal lobe; v, ve in from temporal lobe to

sphenoparietal

si

nu

s; II,

temporal lobe. From

Fox

[2].



Anatomy 75

Fig. 5.19. Example of 1\\'0 fron

t..a

l (I:Mmom) and one

temporal (top) M

-2

branches

(m-2)

arising from the

M-I artery (m-/). on,

Ba

se of aneu rysm with dome

buried in temporal lobe

(If); ala,

anteri

or

temporal

arte

ry;

v. \·eins;j1. fronta l lobe.



76

5.

The

SyJ

vi

an

Fi

ssure

Fig. 5.20. Exampleof middlecerebral arter y pmject

ing through partial opening of sy lvian fi ssure.

cot,

Coltonoids

under retractor;jl. frontallobc; an

,

twO

microanc

urys

ms of

1\'1-1

artery (m -I) bifurcation; pia,

posterior temporal ar tery: fl, temporal lobe;

I,

tem

pol-al M-2 branch;

G,

small artery;

v,

vcins;f, frontal

1\'

1

-2

brauch.



Anatomy

77

Fig. 5.21. Vi

ew

along a widely opened right sylvian

fissure uncler le

ss

magnification (old Zeiss dial

No. 10

or

leI,' Zeiss dial No. 0.6). fl·rel, Frontal lobe

retranor; 2, optic nerve; ica, imerna l carotid artery;

double-crossed

arrfJUl, origin

of

anterior choroidal ar

tery; single-crossel{ arrow. crosses dome of ica

aneurysm and poims to poste rior commu nicating a r-

-

tcry dcep to aneurysm; ala, antcrior tcmporal ar

tcry; Il-,.et, temporal lobe retractor; cot, couono id ; 1/1-

2, M-2

arter

ies

ar

isi ng wit h multilobulated

aneurysms at bifurcation of the M- I artery (m-/); ox,

ox),ce

ll

ulose (Surgicel);ar, arachnoid band

s;a-I,

A- I

artery. From "ox [3].



78

5.

T he Syl\'ian Fissure

Fi

g.

5.22. Example of lo ng M-l artery (m-/) buried

deep

in right

sylv

ian fissure. rei, Retractor on the

tempor

al

lobe;

cot,

cOltonoid; v, \'cins;

an,

small

aneurysm flanked by tempo l'a] M-2 artery

(loP)

and

,,'

(

r

onlal M-2

artery

(bottom).

NOle

perforators sUlek

to

dome

of

aneurysm.

ala ,

Anterior tempo ral artery.

From

Fox

[2].



AnaLOmy

79

Fig.

5.

23. Example

of

short M· I artery (m.I) at base

of

sylvian fissure.

slw,

Superior hypophyseal artery;

ica, bifurcation of internal carotid artery; ala, an·

terior temporal artery;

an,

small aneur

ysm

nanked

by temporal M·2 artery (t) and frontal aner), (j);

ar, arach noid fibers enveloping perforators;

p,

per

forating arteries arising from the

A-I

artery (a-I)

and entering the a nterior

per

forated substance; at,

optic tract. The M- I perforators are mostly hidden

be

hind the M-l ar te ry. From Fox [2].



80

5. The S)'lvian Fissure

Fig. 5.24. Example of atherosclerotic internal

carotid a rlery (*) bifufcation seen after a wide open

in

g of the sy lvian fiss ure .

mem,

Dceply located mem

br

ane

of Liliequist; a-I, A- I anery; mol, M-I arter),;

ach, am criorchoroidaJ artcry;ar, arachnoid band be-

I

\

. r?-

u

C?,

,

tween artery

and

tempora l lobe; I, temporal

M-2

af

ter

y;f,

frontal M-2 artery; p, perforators from A-I

and M-l an e rics;o/, optic tract;

v,

veins;

110.,

ret:

ur

reru

artery of Heu

bner;

ch, optic chiasm.



Anatomy

81

Fig. 5.25. Internal carotid artery (ica) bifurcation at

base

of

syl

via

n

fis

s

ure

(at higher magnification: old

Zeiss dial No. 25 or new Zeiss dial No. 1.6). hp,

hypothalamic perforators from internal carotid ar·

lery (ica); acll, anterior choroidal artery; mem, deeply

located arachnoid membrane

of

Liliequist;

m-l,

M-I

artery entering

sy

lvian fissure; p, perforators from

internal carotid and M-J ar teries; ho., artery

of

Heubner; a-J, A-I artery; ret, frontal lobe retractor;

ot,

optic tract; eh, opticchiasm;ar, arachnoid bands.



82


\

."

. -,

.,

'"

gel

f[-ret

Fi

g. 5.26. Transsylvian view of M-J (m-l)

and

A-I (a

J) origins from internal carotid artery (ica). CrOSJed

arrow, or

igin

of

anterior

choroida

l

anery;

pea, minis

cule posterior communicating artery whose anterior

thalamic perforaLOrs (p) are notable; 00, basilar ar

tery in background; sea, right superior cerebellar ar-

terYi 1'-1, large P_I

artery;

/l.ret,

tcmporallobe

retrac

torian, base ofaneu rysm (from bi furcation o f basilar

artery);

ot,

optic tract (see a<ljacent

perforato

rs from

A-I

l;jl-ret,

frontal lobe retractor; gel, gelatin sponge

(G

cl foam); ch, optic chiasm; 2, optic nerve;

Pit, piLUil

ary stalk. From Fox [3].



Anatomy 83

Fig. 5.27. Another exam p

ic of

transsylvian view

of

A-I (a-I)

and M-I

(m-l)

origins from short internal

carot

id

artery

(iea).

Note anterior thalamic per

forators and arachnoid bands coming

of

f posterior

communicat

in

g arlcry (pea) . Retraction

of

the uncus

(unc)

causes angulation

of

the oculomotor nc

l '-'

c (3)

lateral to the poste l-ior clinoid process (pe).fib, Fibrin

from previous hcmorrhage;

ala,

anterior temporal

arlery; m-2, M-2 a

rt

ery; 01, op

tic

tract; p, perforator

from

anery of

Heu

bner;jl-ret,

frontal

lobe

retractor;

cit,

optic ch

ia

sm;

2,

optic nerve; ac, anterior clinoid

process. From "ox (3].



84

5. T he Sy lvian Fissure

Fig.

5.28. An

other

case where the interna l carotid

ar

lCr

y bifurcation

(crQSMd

arrow)

is well

seen

af

ter the

sylvian

fiss

ure

is

widely opened. Note leash

of

arachnoid bands

and

perforators (p) passing from A-

I

(a-I) to

the

anterior

perforated substance.

ell, opt

ic

chiasm;

Qt,

optic tracl;

00,

basilar artery;slm, superior

hypophyseal arlcry;o7l, aneurysm

orica

at

rakeoffof

anteri

or

choroidal aftery;

m-I,

M-l artery.



Anatomy

85

Fig. 5.29. Base of aneurysm (an) at bifurcation of in

lernal carotid artery

(ica),

transsy lvian

view

. Artery

of Heubner (1m) is adherent to aneurysm. a-I,

A-

I ar

tcry; If, lamina terminal is; ot, optic tract; adm, an-

ter io r ch

or

oidal artery; pea, poste rior communic

.1.t

ing artery; If, temporal lobe; m_l. M- J aner)';cof, cOt

tonoid ;

1111,

rctractoTs;j1, frontal lobe . From

Fox [3]

.



86

5.

The Sylv

ian Fissure

Fig. 5.30. Another case illustrating the anatomy of

the right syJv ian fissure. Arachnoid sti ll CQ\ 'crs the

sy

lvia n fissure (between crossed

arrows) in

which the

ar teries arc exposed

by

separation

of

the frontal

(jl)

and temporal (tf) lobes. rei, Retractor; spit, dura rc

nected over s

phenoid

wing; v. ve in.



Anatomy

87

Fig. 5.31. Same case

(Fig.

5.30) after the arachnoid

(ar)

over the

sylv

ian fissure has been opened.

Periphera l branches

(a)

of the middle cerebra l arte ry

project themselves toward the surgeon. Deeper

M-2

branches rem

ai

n covered by a deeper layer of

arachnoid (crossed

arrow).

Note strands

of

arachnoid

fibers su

ppor

ting the arteries.

*,

Unseparated

deeper portions

of

the fromal and tempora l lobes.



88

5.

Th

e Sy h'ian Fissure

Fig. 5.32. Same case (Fig. 5.30) after removal of the

deeper arachnoid layer.

Th

e frontal M·2 branch

(single-cros.sed arrow) and the temporal

M-2

branch

(dQuble-trOSMd an-ow)

are seen. ala, Aillcri

or

temporal

ar tery.



Anatomy 89

".

Fig. 5.33. Same easc (Fig. 5.30) aflcrcxposurc of the

M-

I

arte

r}'

(m-l) deep

in the sylvian fiss ure. The M-I

division into the frontal (single-crossed arrow) and

tempor

al

(double.crossed arrow) is seen. Note leash of

stria thalamic perforators (perf) passing from M-l.

cr

ossi

ng the right op

tic

tract (ot), and enter ing thc an

tcrior perforated substance

under

the frontal lobc

retractor

(ret).

fl, Temporal lobe; an, giant intern al

carotid aneurysm; ala, anterior temporal

arte

r y.



90

5.

The

Sy lvian Fissure

}

Fig. 5.34. Samccase (Fig. 5.30) wit h more magnifi

ed

view

of

]\,1· I

1/1+

1) perforators. pel[.

One

of man)' M-l

perforaLOrs; m-2, M-2 arteries;

rei,

fromal lobe re-

tractor;

01,

optic t

ra

ct;

an,

aneu

rys

m;

(1.1;

linc

arachnoid fibers

from

art.eries.



Anatomy

91

Fig . 5.35. Another case showing arterial anatomy

of

base of right

sy

l

via

n fissure. Note unusually large

perf

or

ator (double-crossed arrow) arising from the M-

1

ar t

e ry

(m-/).

II, Temporal lobe;

ala,

an t

er

i

or

tem

poral artery;

lia,

ar tery of Heubner; 01, op tic tract

;j1,

.I

fmnla1 lobe;

aI;

arachnoid fibers;

a- I, A-

I artery; eh,

optic chiasm; iea, internal camtid arter

y; pea,

pos

t

er

i

or

communicating artery; single-crossed arrow. an

terior choroidal anery.



92

5.

The Syh"ian Fiss ure

Fig . 5.36.

Left

internal carotid

ancriogram

illustrating stria thalamic perforators

frolll lhe

M- I and

A-I

ar

teries. Patient had aneurysm

(arrow)

alorigin of A- I and al or igin ofantcl"ior choroidal artery. From

Fox

and

Nugent [61 with permission from the West Virginia State l\Iedical Association.



6

The Carotid Cistern and

Environs

Introduction

The

carotid cistern,

the

chiasmatic cistern,

and

the cistern of the lamina lcrminalis lie rostral to

the arachnoid membrane

of

Liliequist (mem

brane of Key

and

Retzius). Surgical observa

tions regard ing the cerebra l sp inal nuid (CSF)

cisterns and their

companmental

divisions arc

de

scribed elsewhere [3]. Fi g

ure 6.1

is a coronal

com pUled tomography (CT) image

(a

cistern

ogram) that nicely illustrates the rela tionship

of the illlcrn

al

carotid

ar t

ery to the carotid c

is-

tern bounded late rallyby the medial portion of

the temporal lobe.

Po

steriorly the carotid

cis

tern

is

se

par

ated

from

the

in ter peduncular

ci

s

t

ern

(see C

hapter

8) by the arachnoid mem

brane of Lilicquisl; mediall y the carot id cistern

joins the chiasmatic

and

lamina terminalis cis

terns and superi orly it joins the sy lvian ciste

rn

(

fi

ssure). In Fig. 6 .1 note the bifurcation of the

internal carotid

arte

ry into the middle cerebral

artery (r..'I-1 segment)

and

the

anterior

cerebral

artery (A- I segment). Th is occurs

altheconflu

ence of thc

upp

e r pan of the carotid cistcrn,

Fig. 6.1. Cisternogram with iopamidol in CS Fimaged by coron

al

CTscan

LO

show anatomyofimernal carotid

arte

ry

(

black (/),-ow) wilh cisterns

and

brain. Open arrow, A-I arter),; black

arrowhead,

optic chiasm;

while arrow

head,

uncus of temporallobc; wltill' (j/TOU \ contrasl medium in s)'Jvian fissure

(c

istern ). See text.



94

6. Th e Carotid Cistern

and

Environs

Fig.

6.2.

Tomographic image after ai r has replaced some CSF

by

pneu moencephalography (pati

eoti

n sitting

position). Closed G/'rQW, lies in interpeduncular cistern

and

poims to arac

hn

oid membrane of Liliequisl (Key

and

Retziu

s). Open arrow,

ai r in aqueduct ofSylvius. Sec text.

the lower-medial

pan

of the sylvian cistern

(co

ntaining the

M-

I origin

),

and the

upper

-lat

eral part

of

the chiasm

at

ic

ci

stern

(c

ontaining

the A- I orig

in ).

This confluence is bounded

superiorly

by

the an terior perforated sub

stance of the frontal lobe.

In earlier years when pneumoencephalog

raphy

was

a co

mmon

intracranial

im

aging

pr

o

ce

dur

e, th e injected gas (u

sua

ll y air), which re

pl aced or di

sp

laced some of the CSF often was

tempo

rarily trapped

in

the int

er peduncular

ci

stern (Fig. 6.2).

The

air

was pr

evented from

pa

ss

in g through membrane openings and into

the anterior cisterns by the membrane

of

Liliequist until a sufficient

pr

ess

ur

e

diff

ere

n

tial developed to overcome adhesive forces be

tween the air bubbles and the moist arachno id

membran

es

.

The

membrane

of

Liliequist. known origi

nally as the membraneof Key and Retziu s. isan

important arachnoid landmark [2]. The mem

brane run s from the

dor

sum

sella

e and po

s

terior clinoid processes up

wa

rd toward the

mammillary bodies

of

the hypothalamus. It

passes from

si

de to side between both

oculomotor nerves (see

Fig.

8.1).

No

rm ally

it

is

eith

er

a solid, translucent sheet with openings

on either side

or

a multi perforated membrane

allowing passage of CSF from the posterior

fossa into the anterior cistern s, from whence

CSF circulation continues over the surface of

the brain. After subarachnoid

hemorrha

ge

or

meningitis, adhesions along this membrane

m

ay

seal offCSF passageways and ca use a com

municating h

yd

roce

ph

alus.

Opening

either

this mem

br

ane

or

the lamina t

er

minalis at

s

urger

y releases much CSF and may be a per

manent cure for patients wi th hydrocephalu

s.

U

nl

ess

one

is

approaching

a lesion

in

the inter

peduncular

ci

ste rn

or

attempting lO release

CS

F from the posterior cisterns,

it

is better to

leave the

Lili

equ

is

t membrane intact.

It

acts

as

an effe

Clive

barrier to

surg

ical blood entering

the posterior basal cistern s. Further details are

given in another textbook [2].



Anatomy

95

Anatomy

Th

e surgical anatomy prc

sc

mcd

in

this alias is

oriented as the surgeon sees it through the

operating microscope at surgery.

I t

is

always

de

pi

cted on the right

si

de

of the patient for ob

server consisten

cy, and

the

reader

may

ne

ed to

refer to the figures

in

Chapter 4 (especially

Fig.4.8) for occasional orientation of the

supine p

at

ient's head. T he

ri

ght o

lf

actory tract

wi

ll

al

ways

head toward the uppe r- left corner

of

the figure (towa rd the paticm's nose), and

the

ri

g

hl

lcmporallobc (usually its uncu

s) wi ll

li

e und er a ribbon re

tr

ac tor 011 the right s

id

e of

the field (toward the

p

al

iem's

riglll ear).

Now

that the

sy

lvian fissure has been

opened

(C

hap

ter

5), the surgeon recognizes

normal

(o

r abno

rm

al)

va ri

at

ions

in

s

ur

gical

anatomy as seen between the ba sc

of

the sy lv

ia

n

fissu re and t he dura reflccted ovcr the drilled

d

ow

n and surg ica

ll

y

fl

attcncd sphenoid w

in

g

i g s 6.3 and 6.4). The

fi

rst visible branch

of

the internal carotid artcry is usuall} not lhe

ophth

al

mi c artery, f

or

the

or

igin of the

ophthalmic artery invariably

is

hidden by the

superiorly and medially overlapping optic

nerve.

The

ophth

al

mi c artery usually

ar

ises on

the medial side

of

the carotid artery ju st below.

above. or at the level

of

the exit

of

the carotid

artery from thc cavernous sinus. Most com

monly the surgeon first recogni zes the ori gin

of the posterior communicatin g artery on thc

latcral, poste

ri

or, or posterolateral side

of

the

ca rotid

ar t

ery; but on close inspection onc can

see more proximal (ie. toward the heart ) arte

rial

br

anches, which are the superior hypo

physea l artery (

Fi

g. 6.4) and hypophyseal per

forators. Throughollt this cha pter the reader

will note how close the

in

ternal carot

id

artery

comes to the posteri

or

clinoid process. and at

times its bifurcation is behind the level

of

the

dorsum

se ll

ae.

The

oc

ul

omotor nerve (third

cran

ia

l nerve) al

ways

l

ies

external to the pos

terior

cl in

o

id

process. as th is nerve passes fo

r

ward

under

thc anterior reflcc

ti

on of the ten

torium and into the to p of the cavernous sinus

(sec Fi gs. 8.2 and 8.3).

The intracranial portion

of

the internal

ca rotid artery may be fairly long, as noted in

Figs. 6.3 and 6.4,

or

sho rt , as demonstrated in

i g s

6.5 and 6.6. T he shorter this internal

carotid artery segment. the more readily the

surgeon can expose the

or

ig

in

s

of

the

A-I

and

M I branches.

A leash

of

vi tal perforating ar tcries arises

from the posteroinferior s

id

e

of

the internal

carotid artcry and the posterior communicat

in

g artery (

Fi

gs.

6.7 and 6.8). Often

one

has to

retract the carotid artcry medially

or

latera lly

to sce thcm. Thcse perforators include the

superio r hypophyseal artcry. hypophyseal per

forators, and anterior thalami c p

erforato

r

s. As

the s

urg

eon ret racts the fro ntal lobe. the olfac

tory tract and gy ru s rec tus come into v

ie

w.

Commonl

y,

thc r

ecurrc

nt artery

of

Hcubner

(pc

rf

orator from the antcrior cerebral artery)

is seen in the Cl"cvicc betwee n the retracted

frontal lobe

and

the optic nerve (Fig. 6.7).

Wh cn large, this may be mi staken for the A-I

artery, which

li

es

be

hind

(o

r in front) and

below the artery of Hcubner.

As

one retracts the temporal lobe, a major

i

nt

ernal carotid artery branch with

in

the

carotid cistern will be the antcriorchoroidal ar

tcry

or

arteries (

fr

equently there may be two

or

evcn three) as illustrated

in Fi

gs. 6.9 and 6.10.

This artcry arises latera

ll

y, postcrio

rl

y, or pos

t

erolatera

ll

y from the internal carotid artery

and passes posterio

rl

y under the uncus

of

the

temporal lobe.

II

.

ente

rs the choroid fi

ssur

e

and

pa

sses thence into the temporal horn .

As

this artery travels bac

k,

it m

ay

come

in

close

proximity to the bifurcation of the internal

ca rotid artcry and i

ts

perforator

s.

The

posterior communicating

ar

tery may be

seen decp to the space between the carotid

ar·

tery and the optic ncr

ve

(see

Fi

gs. 6.6 and 6.9).

or

it

may bowolltlatcraliy as show n in Figs . 6.11

and 6 .12 . Eve n when the posterior

CO Il l

municating ar tery is small (Figs. 6. 13 and 6 .14),

it will contain v

it

al anterior thalamic per

forators to the brai nstem. Often an infun

dibulum

of

the posterior communicating ar

tery is seen, and its appearance suggests a

prcanc

ur

ys

m

al

anomaly (

Fi

g. 6

.1

5)

dcveloping

at the distal angle

be

tween

in

tern al carotid a r

tery and the poster ior communicatin g artery,

the classical si tc

of

such aneurysms (

Fig.

6.16).

Although the pituitary stalk

li

cs

in

the

ba

ck

of

the chiasmatic cistcrn, it often is readily

identificd upon exposure

of

the carotid cis

tern. As show n in Figs. 6.7 and 6. 11 , for exam

ple, the ptcrional approach renders the pituit

ary stalk

visi

ble through the space betwecn thc



96

6.

The

Carotid Cistern and Environs

Table 6.1. Structures contai ned within the carotid 6sterns',

1.

Internal carotid artery

2. Origin of the ophthalmic artery (not always)

3. Origin of the superior hypophyseal anery

4. Origin

of

the posterior communicating

anery

5. Origin of the anterior choroidal artery

6. Origin orlhe middle cerebral artery (M- I)

7.

Origin orthe anterior cerebral artery (A·l)

8. Origins of the hypothalamic perforator s from the carotid

artery

9. Origins of the more rostral anterior thalamic perforators

10. Some stria thalamic perforatorll

II.

A portion orthe

artery of

Heubner

12.

A portion

of

Ihe ante rior perforalCd substance

of

the frontal lobe

13.

Medial surface orthe temporal lobe

14. Lateral border orlhe optic nerve

15. Sympathetk fibers on the internal carotid artery

16. Rostral edge of the poster ior clinoid process (dural covering)

17. Anterior cli noid process (du ral covering)

18. A portioll

of

the tentOrial edge between the anterior

and

postcriorclinoid

processes

Items 12-14 and 16-18 can be considered to form portions

of

the margins

of the carot id cistern. Sec Fig. 6.1.

oplic apparatus and the carotid arter

y.

The

sla

lk

li

es

be tween the arachno id membrane

of

Liliequisl posteriorly and the o ptic chiasm an

teriorl

y.

It appears as a reddish, vascularized

projection pa

ss

ing inferiorly through the

op

ening

in

the

diaphragm

se

ll

ae. T he superior

hypophyseal artery and hypothalamic per

forators pr

ov

ide a rich

ane

rial blood supply,

an d the ponal plexus

of ve

ins also are visible

under micro

scope

.

Regard

less of

the locati

on of

the lesion,

we

not

on

ly open the sy lvian fi

ss

ure substantiall y

but

we

also lyse a

dh

esi

on

s and arachnoid

(which separates the carotid and chiasmat

ic

cisterns) betwee n the ips

il

atera l optic nerve

and the base of the frontal lobe when usi ng the

pter ional ap proach (Figs. 6 .1 7 and 6. 18). This

allows: (a) gentle retraction

of

the frontal lobe

without adhesions pulling on the

op ti

c nerve,

(b) less brain retraction pre

ss

ure, (c) occa

sional inspeClion

of

the anterior communicat

ing complex

in

aneurysm cases, (d) exposure

of

the lamina tc rmina

li

s in cases with hydro

cephalu

s,

and (e) assessment

of loc

al anatomi

cal variations and enha

nc

e

ment of

the su

r

geon's knowledge of surgical anatom

y.

In our

experience the latter is done at no risk [Q the

patient and has

be

en extremely important

in

honing the surgeon's s

kill

s. in patients without

lesions in the

anterior

communica ting region,

actual exposure

of

the anterior communicat

ing a

ner

y is not

done in

pa tients who would re

quire significant frontal lobe retrac tion .

Figures 6.19 and 6.20 illustrate how,

in

some

cases, the internal ca rotid artery ca n extend

or

project above

and

behind the level

of

the pos

terior clinoid processes and the dorsum se llae.

H

ere we

are l

oo

king med

ia ll

y behind the

op

tic

apparatus (nerve, chi asm, and traCl); the lOp

and side of the do rsum se

ll

ae are brought into

vIew.

Although not proved hi stologically

in

this

case (Fig. 6.21), we believe that sy

mp

athetic fi

bers are seen traveling on the adventitia of the

internal carotid

aner

y in the carotid cis t

ern.

T hey ca n

be

mi staken for arachnoid bands and

vIce versa.

Upon elevation

of

the frontal lobes

in

the

nons

wo

ll

en brain , a

view of

the medial side of

the opposite carotid cistern can be visualized

(Fig. 6.22) . Note h

ow

the medial s

id

e of the

temporal lobe forms the lateral

boundar

y

of

the caro tid cistern. Figures 6.23 and 6.24 aga in

show how the carotid cistern is bounded be

hind

by

the arachnoid membrane of

Lil

iequist,

above by the anterior perforated substance,

laterally by the tem poral lobe, and medially by

the chiasmatic cistern. T he membrane

of

Lili

equist

appears

blue when CSF remains be

hind it

in

the interpeduncular cistern.

Th

e



Anatomy 97

color turns black when the CS F is drained (eg,

by aspiration or

lu

mbar puncture) so as to leave

only a shadowed space without the reflecting

and refracting water (CSF ). Note the unusual

ve in

s (bilateral) from the unseen cavernous

sinus to the unseen ba si lar vein

of

Ro senthal,

the unusual position of the pituitary gland in a

shallow pituitary fossa, the portal veins on the

pituitary sta

lk

, and the opposite posterior com

municating artery seen

through

the space be

tween the optic nerves.

Figures 6.25 and 6.26 represent another

exam

pl

e

of

the carotid cistern and environs.

No te the superior hypo

ph

yseal artery, pituit

ary sta

lk

, and anterior thal amic perforators

with hypophyseal perforators (dis

pl

aced me-

dially

by

giant aneu rysm). Table 6

.1

sum

maries the

va

rious structures fo

und in

the

carotid cistern.

The

next chapter will take us

i ~ t o the more medial chiasmatic and adjacent

cIstern s.

Bibliography

I. Fox JL

(19

79)

Microsurgical exposure ofintracra

nial ane urysms. J Microsurg

I: 2-3 1

2. Fox

JL

(1983) IntmcranUiI Aneurysms. New York,

Springer-Verlag, frontispiece,

pp 877

- \069

3. a ~ a r g i l MG, Kasdaglis K, Jain KK et al (1976)

Anatomical obser

va

tions

of

the subarachnoid cist

erns

of

the brain during surgery. J

Ne

urosurg

44:298-302



98

6. The Carot id Cistern

and

Environs

Fig. 6.3. View of right carotid cistern and environs.

aI', Arachnoid membrane between the optic nerves;

1, olfactory trdct; gr, gyrus rcctus; 2,

ri

ght optic

nerve;

Ttl,

retractor

on

frontal lobe;

crossed arrow,

ori

gin of the posterior communicating artery; ica, inter

nal carotid arter

y;

3, oculomotor nerve passing for

ward uncler the morc lateral tentorial edge (Ie), by

the more medial posterior clinoid process (PC)

and

thence imo the C3 \'e

rn

OUS si

nu

s; mem, a refleClion of

Liliequisl's mcmhl<tlle. Between the oculomotor

nerve and Liliequisl's

membrane

is a black,dear CSF

passageway into the interpeduncular cistern. Note

the attachment of Li liequist's arachno

id

al mem

brane to the posteri

or

clinoid and adjacent do rs um

sellae. Opening this membrane between the

oculomotor nerve and the internal carotid

arte

ry

is

the usual frolllolatcral route

to

the interpeduncular

cistern. From

x

[ I].



Anatomy 99

Fig.6.4. Carotid cistcrn in another patient.

or,

Arachnoid between optic nerves; 2, right optic

nerve;

slUJ,

superior hypophyseal arter y; ica, internal

carotid artery; Ie, anterior reflection

of

tentorial

edge, 3, oculomotor nerve passing late ral

to

duraon

posterior d inoid process (PC

); pea,

posterior com·

municating anery;

mem,

membrane

of

Liliequis

t;fl·

rei , froma

ll

obe retractor; 1, ol factory tract; v, ve in 011

gyrus rectus (gr). From Fox

[2

].



100

6. The Carotid Cistern

and

Environs

Fig. 6.5. Right carotid cistern with shon internal

carotid artery

(ica).

2, Optic nerve;

ac,

anterior

clinoid process; mem, membrane of Lil

ie

quisl (cover.

ing posterior clinoid process); pea, origin of pos

terior commu nicating artery; ), oculomotor nerve;

ad,

adhesions between aneurysm

(an)

and temporal

lobe (/l);cot, couonoid;ata, anterior temporal artery;

crossed

arrow, origin

of

anterior choroida l artery; bif,

bifurcation of carotid artery; fr i , origin of A-I ar

tery;ft. frontal lobe. From Fox [2].



Anatomy

101

Fig. 6.6. Anotherexample

of

a short internal carotid

artery (ica)

.

Note yellow atherosclerotic plaque. pea,

Or igin of post

er

ior communicating artery (lateral

pea)

passing behind carotid artery and reappearing

deep to space betwcen optic nerve

(2)

and carotid ar·

{cry;

gel,

Gelfoam on optic nerve;

a-I,

right

A-

I

ar

tcry; bif, bifurcation of carotid artery; ret, temporal

lobe re tractor; an, aneurysm; ad, adhesions between

aneurysm and tentorium

(te).

From F

ox

[ I

].



102

6. Th e Carot

id

Cistern and Environs

Fig.

6.7.

Example

of

long atherosclerotic internal

carotid artery (ica) and environs. Many

hypothalamic (including superior hypophyseal ar

tery) and anterior thalamic perforators (enclosed in

an envelope

of

arachnoid)

arc

seen passing back and

media lly from the carotid artery and the posterior


(pea). peif, One

of these per-

rorators comingoff he carotid

ancry

; , oculomotor

nerve, tl, uncus

of

temporal lobe;jl. frOlltal lobe; ret,

retractOr; J, olfaClory tract;

ar,

arachnoid between

opt

ic

nCfI'

CS;

2, right optic nerve;

JUl,

recu rrent ar

tery

of

H

eubner;pil

, vascular pit

ui

tarystalk;pc, d ura

on posteri

or

clinoid process. f rom Fox [2].



Anawmy

103

1( /

, ,

I ,

/

Fig. 6.8. Greatly magn

ifi

ed

view

between

ri

ght optic

t

ra

ct

(ot)

and internal carotid artery

(ica). Ze

iss d ial

set at

No.

2.5

(ol

d

No.

40). Anterior thalamic per

fOTawrs(jJeifj

from carotid

aneryand

posterior com-

municating artery

(pca)

are see

n. 2,

Optic n

en

-e;

mem ,

membrane

of Lili

equist; pro probe retracting

carotid artery laterally. From

Fox

[I

].



104

6. The Carotid Cistern

and

Environs

Fig.

6.9. Carotid cistern with origins

of

posterior


(pea)

and anterior choroidal

artery (acha) from internal carotid artery (jea). mem,

Membrane of Liliequist;

an,

aneurysm; 3, oculo-

',

mOLOr ncrvc;ad , adhesions between frontal lobe

and

optic tract (ot); pit, pituitary stalk; 2, optic nerve; 00,

origin

of

ophthalmic artery; ret, retractors. From

Fox [2].



Anatomy

105

ha

Fig

.

6.10.

View

of

carot

id

cistern showi ng relation

ship

of

anterior choro

id

al

anery (acha)

to the uncus

(tine)

of the temporal l

obe./I(1.,

Anery

of

Heubner;

J,

olfactory tract;

gr.

gyrus rectu

s; 2,

optic nerve;

iea.

i

n

lel'llal ca rot id

ar

ler

y; pea,

origin of posterior com·

muni

ca

tin g anery;

Ie,

tentorial edge;

all,

aneur

ys

m

(shrunken and elongated by bipol

ar

electrocoagula

tion);

ad,

adhesions and fibrin between aneurysm

and temporal lobe and tentorium. Deep to the an

terior choroidal anery

(adUJ)

li

es the arachnoid

membrdne

of

Li liequisL From Fox [I].



106

6, The Carotid Cistern and Environs

Fig.6. 1I . View of carotid cistern with laterally di·

rected posterior communicating artery

(pea). mol,

M-l origin;peif, perforators from A-I (a-I); ot, righ t

optic tract; Jryp, hypothalamic

per

foraLOrs from

carotid artery; pil, pituitary stalk; ch, optic chiasm; 2,

l

eft and

right optic nerves; (-ica, medial side

ofleft ill-

lernal carotid artery; dia, diaphragm

se

ll

ae;

pc,

left

posterior clinoid process; crossed arrow, superior

hypophyseal artery; r-ica, right internal carotid ar

tery; r-pc, right posterior clinoid process; ), oculo

motor

len"e. F

rom Fox

[2J.



An alO my

107

Fig. 6.12. A very athcrosclerOlic imcrnal carotid ar

tery

(ica)

with the posterior co mmunicating artery

(fxa) goi

ng latcrall

y. Crosud

r r ~ crosses dome

or

atherosclerotic aneurysm and points to

perf

orator.

adm,

Ante rior choroidal artery; 00, basitar

arter

),

lying

in

imerpedunc

ular

cistern and seen

ar

t

er

re-

mova l

of

membralle

or

Li licquist

(In. m)

sti

ll

attached

to oc

ul

o

mO lOr ncn 'e

(J) and posterior clino

id

pro

cess

(PC),

rtt, Retractor on

ri

ght tempora l lobe;

e

, ten

lorial edge; at:, anterior clinoid process; 2, optic

nerve,



1

08 6. The

CarOlid Cistern and Environs

cot

--=- ---

Fig.

6.13.

Example of small, sh

ort

posterior com

mun icating artery (crossed arrow) connecting internal

carotid artery (ica) with posteri

or

cerebral artery (p-

2). cot,

Cotlonoid;

unc,

uncus

of

temporal lobe;

an

,

small aneurysm at takeoff of anterior choroida l artery ;

m-

I, origin

of

M-I

ar

tery;

a-

I, origin

of A-J

artery;lUl,

artery

of

Heubner;

01,

optic tract;

2,

optic nerve;

ac,

anterior clinoid process;

pc,

posterior clinoid pro

cess;

te,

tentorial edge;

),

oculomotor nerve. From

Fox (2].



Anatomy

109

Fig.

6.14.

Same case as Fig. 6. 13 with probe

(pr)

dis

placing carotid artery medially.

Crossed arrow,

site

of

anterior thalam ic perforators from posteriOl· com-

""'

\

municating artery;

01,

optic tract;

pc,

posterior

clinoid process;

p-J,

P

-l

artery; 3, oculomotor nerve;

unc, uncus;p-2, P-2 artery.



110

6.

Th

e Carot id Cistern and Environs

Fig.

6.15 . Ex

ample of prcaneur

ys

mal

type

of infu n

dibulum

(cro

SM

d

af7"ow) of posterior communi

ca

ting

artery

(pea).

perf. Anterior thalamic pe rfor.uors;

adm,

aillcrior choroidal anc )';

V,

vein;

a-l,

A-I ar

tery;

Qt,

OPlic tract;

fl-rt/,

frama l lobe retractor;

pro

pr

obe retracting carotid artcl1'i Pit, pituitary stalk; 2,

optic nc n'c;llC, anlc rior di no id process; un, inte

rna

l

ca rotid artery;

Ie,

tentorial edge;

pc.

postcriordinoid

pr

ocess; J, ocul omotor Ilcn'c; II-rei, temporal lobe rc

tractor. From

,"ox

[2].



Anatomy

I

II

mom

Fig.

6.16.

Carotid cistern after bipolar eleclrocoagu·

lalion of aneurysm

(an)

with ad hesions

(ad)

to

oculomotor nerve

(3)

and uncus

(unc) of

tcmporal

lobe.

col,

Cottono

id

s;

mem,

membrane of Li liequist

oot

(or Kcy

an

d Retzius); ac, autc

rior cl

inoid proccss;

ica,

internal carotid artery;

pc,

posterior clinoid process;

pea, origin of postcl'ior communicating artcr

y.

From

Fox [2].



112

6.

Th e Carotid Cistern and Environs

Fig.

6.17.

Anatomy

of

carotid cistern

and

environs.

Arachnoid membrane of

Lili

eq

ui

sl(mem) is we ll seen

deep to

and

between the internal carotid artery

(ica)

and oculomotor nerve (3). Crossed arrow, anterior

choro idal

arte

ry;

IInc,

uncus; m·l, origin

of

M

-l

ar

tcr),; an, base of aneurysm at bifurcation of ca rotid

artery; a-1, righ t A-I al "ter}';

a-a,j

unction

of

ri ght A-I

and unseen right

A-2

and ante

ri

or communicating

(aea) arteries; gr, right gyrus rectu

s; perf,

perforators

from anterior communicating artery;

hr,

bridging ar

tcry from anterior comm

un ica

ting artery to

left A-2

artery (connection out of view);

a-2, Icrt

A-2 artery;

2, optic nerves;

ch.

optic chiasm; ft, lamina termi nalis;

ot

,

right opt ic tract;

a

c, ante

ri

or clinoid process;

ds,

diaphragm sel lae;

pc,

posterior clinoid process; pea,

post

erior

communicating artery.



Anatomy

11

3

Fig. 6.18 . Sa me case as Fig. 6.17. Upper in ternal

carotid artery (ica) and the

M-

I origin (m-

/)

are re

tracted by a probe (pr) to \'iew perforators (crossed ar

rows) and optic tract

(ot)

behind aneur

ys

m

(an)

and

bifurcation

of

carotid artery.

pea, Po

sterior

COIll-

municating artery; -UIIC. uncus; acha, anteri

or

choroi

dal artery;s, suction lube;

perf.

perforators;00, recur

r

em

artery

of Heubner;jl

, frontal lobe;

a-I,

A-I

ar

ter

y; Ma.

anterior communicating artery;

it,

lamina

termina

lis.



114

6. The Carotid Cislern and Envi

ro

ns

Fig.

6.19. Ano th er case with view of carOlid

ci

stern

and e nvi rons, looking morc medially. Appearing deep

between

ri

ght internal carotid artery

(

r-iea) and o ptic

apparatus a re seen perforators (peif). pituitary stalk

(Pit),

right posterior clinoid process

(PC),

lOp of lhe

dor

sum se

ll

ae (ds), left

superior

cerebellar artery (l

sell),

and

left oculomotor nerve (3). Lateral to the

right carotid artery 3rc noted the tentorial edge (te ),

side of the

dor

s

um

sellae

(ds),

a

dural

ve

nous

si

nus

(us)

be

hi

nd the dorsum sellae, the posterior com

municating artery

(pea)

and

its

adjacent aneurysm

(crosud arrow),

the P-2 artery

(p.2).

basilar artery

(00),

and right oculomotor l

en'c

(3). 2, Optic nerves; ch,

optic chiasm; 01,

right

optic tract;foo. right (bottom)

and l

ef

t (toP) fronto-orbital

arterie

s;gr, right (bottom)

and left

(lOP)

gyri recti; l-ita, med ia l side of left inter

nal carotid artery; a.-I,

A-

I arte ry_



Anatomy 11

5

Hg

. 6.20. Same case as

Fig

.

6.19

emphasizing r

eo

lationship

of

intcrnal carotid artc ry (ica) and pos

teri

or

cl inoid proccss

(PC). Ids.

Top of dorsum se

lla

c

covcrcd bydura ;fds, front ofdOT5um

seU

ae;sds. side

of dOT5u m

se

llae; vs, vcnous sinus in dura behind

dOT5u

m se

ll

ae;

J,

oculomotor ncrve;

col,

cottonoid

s;

P01l

S, rostral pons;

se

a, right superior cerebell

ar

ar

tery be hind 3rd ncrvc;p-2. P·2 artcry

in

front

of3rd

ner

ve; une,

uncu

s;a

1l

. second ane

urys

m at tak

eo

ff of

anterior choroidal arlery (hidden);

CTossed

arrow, first

aneur

ys

m at takeoff of posterior co mmunicating ar

tcry (hidden); rtf, right temporal lobe re t

ra

ctor;

m·J,

M- I arte

ry

o

rigi

n;

00,

bas il

ar

artery;

Iry,

hypophyseal

perf

or

ator from ica;

a-I,

A-I arter

y; 01,

optic trac

t.

Note Icft lateral m

edu

llary per

fo

rator from basil

ar

;lrtC

I

),

and

in

shadows behind d

or

sum s

ell

ae.



116

6. The Carotid Cistern and Environs

,.,

Fi

g. 6.21. Ano ther case illu.nra ting sympathetic fi·

bers (5)'"') on internal carotid artery (ica). ar (]

alen

]),

Arachnoid band ; Ie , tcnlorial edge; an, aneu rysm

at

takeoff

of

[.N)Sterior commun ica ting artery (hidden:

most

of

aneurysm is below lc

nlo

rium);cot, cottonoid:

Il t, frontal lobe rclrdctQr; ar (medial), arachnoid

membrane between optic nerves; 2, right optic

ncn'c;

mem,

membrane of Li liequist;

ac,

anterior

clino id process. Fro m Fox [ I].



Anatomy

117

Fig. 6.22. Another tase showing

view of

medial side

of

opposite

(kfl)

carotid cistern. reI, Retractor on

right frontal lobe

(fl); ch,

optic chi

as

m; 2, both optic

nerves;

cot,

cotton ball; clp, shank of aneurysm

cl

ip;

ac, right anterior clinoid process;

ar,

arachnoid fi-

bers;

1.5,

tuberculum sellae;

unc,

medial side

of

left

uneus;foa, left fronto-orbital artery on left frontal

lobe;

m-I,

origin

oflef

t

M-

I artery; v. vein;

ica,

left in

ternal carotid artery (medial side near bifurcation);

a- I, origin

ofle

ft A-I artery.



liS

6. The

Carotid Cistern and Environs

Fig.

6.23. Another case with

vi

ew

of

carotid and

chiasmatic cistern

s.

The pituitary g land (pit) projects

superior to

the

level of

the

diaphragm sellae.

Sing/to

crossed arrow,

portal veins of pituitary stalk ; 2, optic

nerves; ell, optic chiasm; r-ica,

right

internal carotid

arter

y;

hy, hypothalamic perforators from internal

carotid artery; pc. dura

of

posterior clinoid process;

mem

o

membrane

of Liliequist; v, unusual

vei

n a

ri

s

in

g

from cav

ernou

s sinus; double-crossed arrow, posterior

communicating a

rt

ery; aella,

one

of two alllerior

choroidal arteries;t l-ret, temporal lobe retractor ;

111-1,

M- l pordon

of

middle cerebral artery;

fmi,

per

forators from bifurcation

of jea to

alllcrior perfo

rated substance; ot, right optic tract; a-I, A-I portion

of

anterior cerebra 1artery;fl-rel, fro mal lobe retrac

tor; l-ica, left

imernal

carotid arter

y;

l-pea, left po

s

terior communicating artery. From Fox [2].



Anatomy

119

Fig. 6.24. Some case as Fig. 6.23. View is looking me

dia

ll

y

tow ar

d the le

ft

inte

rn

al

Gl.r

otid artery

(i-ica). 2,

Optic nerves;

Pit,

pituitary

st.a

lk; l-pea, left posterior

communicati

ng ar

tery;

ch,

optic ch iasm; a-1

, A-

I por

tion

of

left anterior

cere

bral artery;

cot,

COtton strip;

1/j.-1, M-l portion of left middle cerebral artery;jl-ret,

frontal lobe retractor; v,

unu

sual vein

on

left arising

from cavernous sinus; pr, probe retracting the vein;

cr

ossed

arrow, medial left tempora llobc. , 'rom Fox [2].



1

20

6.

The Caro

tid Cistern and Environs

Fig. 6.25. Another case illustrating internal carotid

artery (ita)

and

environs.

pc,

Posterior clinoid p ro

cess;

an,

giant aneurysm of right P·1 artery;

tl,

right

tem poral lobe; mol, M-I artery;

a-i,

A-I artery; ret, re

tractor on frollla lobe;a-2, right

A-2

ar tery;gr, gy

ru

s

rectus;

am,


2,

optic

nerves; ch, optic chiasm;

sha,

superior hypophyseal

artery;

crossed

arrow,

one

of several hypophyseal and

anterior thalamic per fo rators in an arachnoid

shea th;

Qt,

optic trac

t.



Anatomy

121

Fig. 6.26. Same case as

Fig.

6.25. Probe

(pr) is

retract

ing right optic

ne n

·c (2) mcdia lly to show pituitary

stalk

(pit). pc ,

Posterior

cl

inoid proces

s; all.

giant

ancurys

m;

te,

telltorial edge;

UIIC,

uncus;

),

oculomOlOr

llen

'c; I'll, temporal lobe retractor; bif,

bifurcation

of

right internal carotid artery.



7

The

Chiasmatic Cistern

and

Environs

Introduction

As

the s

ur

geon d issects media

ll

y from the ptcr

iona l exposure, he or she encounters a conflu

ence of cistern s

in

the ccnt

er of

which is the

chiasmatic cist

ern

. T he computed tomography

(CT) scans with cerebral spinal fl uid (CSF) con

trast enh ancement show the ch iasmatic cistern

and

adjacent cisterns (Figs. 7. 1

and

7.2).

The

ca rotid cisterns are lateral, the cistern of the

Fi

g. 7.

1.

Axial \·icw

of

CT scan after injection

of

iopamidol into the CSF

by

lumbar puncture: cister

nogram of chiasmatic cistern containing

op

tic

chiasm (black

arrowhead) and

medial poI-lions

of

optic

nerve.

Closed black

arrow crosses ant.el-im-clinoid pro

cess and poin ts to lateral portion of optic nerve in

carotid cistern; open arrow lies

in

confluence of

upper

lamina

ter

minalis is behind and above, and the

olfac tory cisterns pass anterior to the chi

as

mat

ic cistern. T he o lfactory ci

stern

lies

be

tween the gyrus rectus and medial

orb

ital

gyrus. In the mid line between the fronta l lobes

is the perica llosai cis t

ern and

interhemispher ic

fiss

ur

e (cistern).

carotid cistern with med ial chiasmatic cistern from

wh ich arter

ial

shad ows of A-I (mediall

y)

and M-I

(laterally) can be seen 10 originate; white arrow points

to optic tract lyi

ng

lateral to the laleral portion

of

the

cistern of the lamina terminalis and medial to the

confluence of the two cisterns (ca rotid and sylv ian);

while triangle lies

on

lamina termi nalis.



124

7. The Chiasmatic Cistern and Environs

Fig.

7.2. Coronal (fromal) view

of

CT scan after in

jection of iopamidol into the CSF by lumbar

punctu re: cistcrnogram of olfactory cistern. Black ar

ruws

lie

in

olfactory cistern and poim to olfaClory

tracts; while triangle,

gy

ru s

rec

tu s; while dosed arrow,

Anatomy

As

the surgeon elevates the frontal lobe, the ol

fa

ctory tract m

ay be

stretched

if

the brain is

vcry rel

axed

.

If

this ha

ppen

s,

vei

ns n

ea

r the

midline

and

trav

er

s

in

g bcnveen the frontal

lobe (gyrus rectus or adjace

nt

medial orbital

gy

ru

s)

and nearby dural

si

nuses

may lear

and

bleed . When such occurs,

it

w

ill be

necessary to

expose the olfactory cist

ern

(

Fig

s.

7.3

and

7.4)

.

This maneuver is not necessary unle

ss

bleed

in

g occurs, req

ui

ring bipolar elec trocoag

ul

a

tion

of

these

ve

in

s.

The

olfactory tract appears

as

a white band

lying in the olfactory cistern. P

os

teriorly, it

arises from the medial and lateral olfactory

stria , forming the

from border

of

the anterior

perforated substance.

Th

e tract is

adherent

to

the froma

llobc

between the gyrus rectus (me

dially) and the medial orbital gyrus (laterally).

further anteriorly the olfactory tract se parates

from the brain (figs.

7.2

and

7.5)

and passes to

ward the olfactory bu lb lateral to the crista ga

lli

(Fig. 7.6). From this olfactory bulb pass the hid

den fil aments of the olfactory nerves d

ow

n

th

roug

h the cribiform plate and into the mu

cosa

of

the nose.

As

the dissection proceeds medially from

branch of anterior cerebral artery in

int

erhemis

pheric

fiss

ure;

open arrow, co nt

rast medium in sub·

arachno id space (optic cistern) surrounding optic

nerve

in

orbit.

the carotid cistern

and

into the chiasmatic

cis

tern toward the

anterior

communicatin g com

pl ex, the surgeon m

ay

fo ll

ow

the A- I

ar

tery ifit

is eas ily seen.

Th

is usua

ll

y occurs if the internal

carotid artery

is

fairly short.

In

cases where the

internal carotid a rtery

is

long and the

A-

I ar

tery is hidden

po

steriorl

y,

the s

urg

eon shou

ld

avoid retraction

of

the frontal lobe to expose

the A- I artery. If an anterior communicating

artery

aneurys

m is the target. the ap proach is

then

di r

ec

tl

y through the gyrus rectus [2-4].

The landm

ar

ks for the I-cm incision in the

gy

ru

s rectus are illustrated in Figs.

7.7

and

7.8.

The

tr iangular or

quadran

gu l

ar

zone inferior

and lateral to the franta-orbita l artery lying on

the gyrus rectus is described in the legends f

or

the

se

figures.

I f the

sy

lvian fissure has been widely

opened, elevati

on of

the frontal lobe

will

bring

the optic c

hi

asm,

op t

ic tract,

and

lamina ter

minalis (be

twe

en the

opt

ic trac

ts)

into vi

ew in

cases with a prefixed optic c

hi

asm (ie, sh

ort

opt ic

ner

ves intracran ia

lly).

Figures 7.9and

7.10

are t

wo

examples

of

a prefixed chiasm.

The

lamina termina

li

s a

ppear

s as a thin, translu

cent membrane retain in g third ventricul

ar

CS

F inside. The CSF on its outer, visible side

li

es in the cistern of the lamina terminal is ,



Anatomy

125

which contains the medial portion

of

the A- I

arteries, their interconnecting anterior com

municating artery, and the recurrent artery

of

Heubner (Figs. 7.10-7.12). The cistern

of

the

lamina ter minalis merges with the chiasmatic

cistern be low and anteriorly and with the in

terhe mi spheric

fiss

ure (

ci

stern ) superiorl

y.

Laterall

y,

the cistern of the lamina termina lis

merges with the confluence

of

the sy lvian and

carotid cisterns lateral to the optic tract.

Figures 7.13 and 7.14 are intraoperative

photographs

of

the sa me patient. In I-ig

ure 7.13 we see through the right carotid

cis

tern and the lam in a te rminal is and ch iasmatic

cistern s into the left (o pposite) carotid cistern.

The

tented lamina tenninalis is prominent.

Th

e medi al s

id

e

of

the left internal carotid ar

tery is seen superior and inferior to the image

of the l

ef

t optic nerve.

The

left posterior com

municating artery is visualized deep to the

pituitary stalk. Pani cularly important are the

hypophyseal perforators from the carot

id

a

r

teries. If the

A-

I arteries are

fo ll

owed medially

and

superiorly, the anterior communicating ar

tery is seen lying in the cistern above and an

terior to the tented-

up

lamina terminalis

(Fig. 7. 14).

Figures 715 through 7. 18 are four exam

pl

es

of

variations in the anatomy

of

the chiasmatic

and lamina t

er

minalis cisterns. In each case the

inferoanterior zone o f the lamina terminalis

is

visua

lize

d . In

Figs.

7. 15

an

d 7. 16 the r ight lateral

margin

of

the pituitary stalk is see

n.

This pitu

itary stalk , along

wi

th the optic nerves and

chiasm,

li

es

in

the chi asmatic cistern (bounded

caudally

by


Lili

equist). Howeve r,

in

many cases the mem

brane

of

Liliequist, which lies caudal to the

pituitary stalk, sends an ante

ri

or reflection of

arachnoid membrane in front of the pituitary

stalk .

Th

is situation puts the pituitary stalk in

side

it

s ow n hypophyseal cistern (Fig. 7.16). In

l'ig.

7.16

note

that

the frontal lobe retraction

is

stre tching arachnoid bands at the lateral mar

g

in of

the cistem

of

the lamina terminalis.

Figu res 7.1 7 and 7.18 additionally illustrate

the many

va

riations in the pathway

of

the recur

rent

artery of Heubner. Generall

y,

this artery

a

ri

ses from the A-I artery

or

the A-2

ar

tery

near the a nterior communicating ar tery (refer

to Fig. 7.40). There may

be

two arteries of

Heubner

on one

s

id

e.

The

artery passes later+

a

ll

y and lies super ior to and behind

or

in front

of

the

A-I

and medial

or

igi n

of

the

M-

) arteries

and se nds branches into the anterior perfo

rated substance.

Fr

equently the

anery

o f

Heubner is seen before the

A-

I artery is

id

en+

tified, and it may bequite large (as in Fig . 7.11

).

Fi

gures

7.19

and

7.20

are photographs

of

the

same patient before and after p

er

foration

of

the lamina terminalis to treat hydrocephalu s.

One

of

the many variations in the anteriorcom

municating artery complex inside the lamina

terminalis cistern is shown here. Such vari

at ions, with dupl ica tions and cross-bridges, are

common (refer to Fig. 7.39).

Th

is is a tripli

cated anterior communicting artery complex

with a bridge between two

of

the arteries.

The

ar tery

of

Heubner is we

ll

see

n.

Figures 7.2 1 through 7.24 demonstrate two

patien

ts

in whom the artery of Heubner is the

sa

me diameter as the A- I artery (Figs. 7.21 and

7.22)

or

larger than the A- I artery (Figs. 7.23

and 7.24) . In Fig. 7.21, the A- I a rtery

is

almost

t

.. .::

si

ze of

an adjacent large M-I

perforator

,

and the

M-

I artery is equal

in

si

ze

to the inter

nal

cal"Otid

artery. In Fig. 7.22 the pituitary

stalk

is

surrounded

by

arachnoid (

Lili

equist's

membrane behind and an anterior reflection

of the same membrane

in

front). Hence the

pituitary struc

tu r

es are 111 their own cistern

(hypophyseal cistern).

The same is tru e

In

another patient

(Fig.

7.23)

where pa

rt

of

the anterior ar achnoid

enclosing this ciste

rn

has been opened by the

surgeon.

Th

e pituitary sta

lk

is redd ish due to

the marked arte rial and portal

ve

nous vascul ar+

ity (which partly accounts for i

ts

enhancement

on

CT

scans with contrast medium).

Fi

g

ure 7.24 in the sa me patient shows a

ve

ry

hypoplastic right A-I artery and a large right

artery of Heubner. Ad ditional anomalies are

the low takeoffof the frontopolar arteries.

The

large left A- I artery supplies this unusual an

terior commu nicating complex. Because the

anterior communicating a rtery is lifted

up

by

an ane

ur

ysm

in

the cistern

of

the lamina tel'

minali

s,

descending "hypothalami

c"

per

forators are well shown .

Figure 7.25 is an example

of

a pa tient wi th a

pr

efixed chiasm and

short

internal carot

id

ar

teries. Without the sur geon go in g through the

gy ru s rectus, the right A- I, anterior com

mun icating, and left A- I

arter

i

es

are seen upon

elevation of the frontal lobe. Im

ponan

t per

forators from the right A- I a rtery to the right

optic tract, chiasm, and nerve are seen.

I-i

gure

7.26 also is a photograph

of

a shon internal



126

7. The

Ch

ia

smatic Cistern

and

Environs

Thble

7.1. Structur

es

contained within the chiasmatic cistern '.

I. Optic chiasm

2.

Optic ner\'es. medial borde r

3.

Surface of the gyrus rectus of the frontal lobe

4.

Tuberculum sellae (dural covering)

5. Arachnoid membrane of Liliequist (Key and Retzills), rostral surface

6. Arachnoid between optic

neTl

'

es

i. Superior hypophyseal artery

8. Hypothalamic perforators

9.

A portion of the fronto-orbital artery

10. Pituitary stalk (often lies within its own cistern)

Items

2-5

can be considered to form portions

of

the margins of the chias

matic cistern.

Table 7.2. Struc

tur

es contained ... ithin the lamina terminalis cistern' .

I. Outer surface of the lamina terminalis

2. Surface of the optic tracts

3. Surface

oflhe gy

r

us

rectus of the frontal lobe

4. Anteriorcommunicatingartery

5. Anterior cerebral artery, A-I portion

6.

Anterior cerebral artery, origin

of A-2

portion

7. Origin of the fronto-orbital artery

8. Artery of Heubner, proximal portion

9. Hypothalamic perforators from A-I and anterior communi catinganeri

es

1

0. St.r

ia thalamic perforators from the A-I arte ry

II . Origin of an occasional accessory anterio r ce re

br

al

artery

• Items 1-3 can be considered to form portions of the margins of the lamina

terminalis cistern.

carotid artery and a prefixed chi asm . An un

usual arterial anomaly is also illustrated: the ar

tery of Heubner and the frolltopolar artery

arise from a common trunk.

Thi

s arterial

trunk origi nates at the right A- IIA-2 arterial

junction. Branches from the ascend in g fron

topolar artery suppl y the territory

of

the ab

sent franta-orbital arte ry.

Fig

ur

es

7.27

th rough 7. 30 reveal a common

variation in the amerior communica ting artery

complex. In Figs.

7.27

through 7.29 the an

terior communica ting artery forms a "Y" with

one

limb on the right and two limbs

on

the left.

the superior

one

anastomosing higher

up on

the left A-2 arter

y.

In

Fig.

7.30 the anterior

communicating artery is duplica ted ; the

superior one is hidden by a layer

of ar

achnoid.

Fi

gures 7.31 and 7.32 illustrate another

example of a V-shaped ante rior communicat

ing

ar

tery with the common trunk on the right

and the two limbs on the lefl. Additiona

ll

y a

large per foralor and an accessory amerior

cerebral artery (a third, midline A-2 artery)

arise at the division

of

this Vs haped anterior

communicating arte ry.

The common ly dup

li

ca ted anterior com

municating ar tery again is seen in Fig. 7. 33. Fi

g

ure

7.34

sho

ws th

e

und

erside

of

an

anter

i

or

communica ti ng artery and nearby perfo rator

s.

Th

e optic tract is rarely well seen unle

ss

the

sy lvian fiss ure has been opened. Figures 7.35

through 7.38

are

examples i

ll

ustrating this

tract in two patients. I n fi gure 7.35 the origin

of

an accessory anterior cerebral artery is seen

(sometimes mistaken for the base of an

aneurys m) . Figure 7.36 (sa me patient) isa more

magnified

view of

the lamina terminalis seen

between a large arte ry o f Heubner and the A- I

ane

ry. A l

arg

e

ve

in

turns posteriorly and pa

ss

es along with the optic tract to join the unseen

basilar

ve

in

of

Ro senthal.

Fi

gures

7.37 an

d 7.38 are

tw

O views

of

the

right optic t ract and chiasm.

Th

e

A-

I arteries

join the anterior communicating artery

we ll

above the lamina terminalis, and the left A- I ar

tery has an unusual bridging

arter

y returning

back to the le ft A-I. Note the arachnoid band

(compare with th

at in Fig.

7. 16) over the rig

ht

A-I ar tery at the lateral border

of

the cistern

of

the lamina terminalis. Tables 7.1 and 7.2 sum-



AnalOmy

127

marize the various stru ctures found in the

chi asmatic and lamina terminalis cisterns.

The

duplications and bridges

of

ten seen as

the anterior communicating artery complex

were illustrated by Bremer [1] in 1943

(Fig. 7.39).

But it

was

only with routine use

of

the

ope

rating m

ic

roscope th

at

surgeons saw

how commonl y such

va ri

ations occurred.

Fig

ure 7.40 is Westberg's representation of the

usual course of the recurrent artery

of

Heubner [5]. This large perforator

se

nds

branches illlo the anterior perforated sub

stance along with the stria thalamic perforators

from the A- I and M- l arteries.

Bibliogr

ap

hy

I.

Bremer J L (1943) Congen ital aneurysms

of

the

cerebral arteries. An embryologic study. Arch

Pathol35: 8 9 ~ 8

2. Fox J L (1979) Microsurgical expos

ur

e

of

intracra

n

ia

l ane

ur

ysms. J Microsurg

I: 2-

31

3. Fox J L ( 1983) Intracranial Aneurysms,

vol

2. New

York , Springcr-Vc

rl

ag, pp 877 -

1069

4. Kempe LG (1968) Operative

Neurosurgery, vol

I : Cra

nial,

Cerebral,

ami Intracranial Vascular Disease. New

York, Springer-Verlag, pp 1- 75

5. Westberg G

(196

3) The recurrent artery of

Heubner and the arteries of the central ga ng lia.

Acta Radiol (Diagn) 1:

949-954



128

7. The

Chiasmatic Cistern

and

Environs

'0'

Fi

g. 7.3. Lowe r portion of olfactory tract (1). gr,

Gyrus rcclus;2, right optic nerve;dura, dural margin

of optic canal;

ar,

arachnoid covering internal

carotid artery (carotid cistern);

ac,

anterior clinoid

process;

v,

vein on

temporallobe;

s,

Sliction

lube;

ret,

retractor on frontal lobe.



Anatomy

1

29

Fig.

7.4.

Same case as

Fig. 7.3

. Midd

le

portion

of

right olfactory tract

(1)

in olfactory cistern. V, Vein in

sulcus bet

wee

n frontal lobe

(jT)

and olfactory tract;

dura,

dura

coveri

ng

orbital roof (floor

of

anterior

fossa) projections;

nt,

retractor on frontal lobe.



130

7. The

Chiasmatic Cistern and Environs

Fig. 7.5. Same case showing olfactory tract

(1)

pass

in

g through subarachn

oi

d space from frontal lobe

(jl)

toward cribiform plate and nose. v, Vein;

a,

ar

tery;cg, dura

of

crista galli.



Anatomy 131

Fig. 7.6.

Another case demonstrating olfactory bulb

(ob)

and upper olfactory tract (I). cg, Crista ga

lli

;

ret,

retractor;jZ, base

of

frontal lobe ;dura,

dura

covering

orbital roof projections.



132


Fig. 7.7. Initial exposure of gyrus rectus (gr) during

an approach to an amerior communicating artery

aneur

ysm

where the A-I artery

is

not followed me

dially. Note the quadrangular zone bounded

by

the

edge of the frontal lobe retractor blade (jl

-

ret), the

fTOlllo-orbital a

rt

ery

fjo),

the frontallobe/optic nerve

junction (dQuble-crossed arrow), and the olfactory tract

(/). T he incision in the gyrus

rcelusis

made here and

the fronto-orbital artery is followed to the aneurysm.

v, Vein;

ar,

arachnoid between optic nerves; 2, ri gln

optic nerve;

ica,

interna l carotid artery;

Ie,

ant

er

i

or

reflection of tentorial edge; Ii , temporallobc; II/em,

membrane of Lili equ isl; cot, cotton st rip lying on syl

vian fissure. From Fox [3].



AnaLOmy

1

33

Ag.7.8. Another case illustrating the initial expo

sure of gyrus rectus on the right

(r-gr)

where the

right

A-I anery

(a-I, hottom) is

fo

llowed medi

ally.

Crossed arrow, interhemi spheric fissure. Note quad

rangular zone oounded

by

the frontal lobe

and

right

A-I

j unction, the olfaclOry tract (/) , the front.allobc

retractor blade (jI-ret), an d the f "OO lo-orbital artery

I/o). The initial incision

is

made within this zone. r-gr,

Right gyrus rectus; lIa, left artel-Y of Heubncr; i-gr,

medial surface

of

left gyrus rct:lus; i-10, left fronlo

orbital artery; aT, arach noid between optic nerves; 2,

le ft

and

right optic nerves; Ii, temporallobc;

ch,

optic

chiasm;it, lamina terminalis;o/, right optic tract;mca,

branch

of

middle cerebral aner}, in sy lvian fissure;

a-l, left (toP) and right

(hoI/om)

A-I arteries converg

ing lOward the hidden anlerior communicating ar·

ter y. From

Fox

[3J.



1

34


Fig. 7.9. Another case

ill

ustrating prefixed optic

chiasm (ch). Lamina terminalis (it) and i

ts

cistern be·

tween the

op

t

ic

tracts

(ot) arc

seen. With

in

the cistern

oft

be lami na terminalis is pari of the

A-

I ane

ry(a-J)

and a duplicated amerior communica ting artery

(aca). ar, Arachnoid between optic nerves (2); ica, in

terna

l carotid

arte

r

y; ac, anterio r dinoid

process;

pc,

poste rior clinoid process; »Mm, arachnoid mem

brane of Liliequist; te, tentorial edge; ata, anterior

temporal ar tery; It, temporal lobe; hij, bifurcation of

iea; tUmble-crossed arrow, origin of hidd

en anter

ior

choroidal artery;

single-crossed arrow,

origin of hid

den

posterior communicating artery;

/w.,

artery of

Heubner.



Anatomy 135

Fig. 7.

10.

Another case

with

prefixed chiasm

(ch)

and

short intracran

ia

l optic nerves (2). T he carotid,

chiasmatic, and lamina terminalis cisterns appear

here without identifiable boundaries after dissec·

' .

tion.

ica,

Imernal carotid artery;

Ii.

temporal lobe;

a·l,

A·I

ar

tery;

Ia,

artery

of

Heubner;j1, frontal

lobe;

1$,

tuberculum

se ll

ae;

it,

lamina terminal

is; ot,

optic tract. From Fox [2).



136

7. The Chiasmatic Cistern

and

Environs


Fig.

7.10. A short imernal

carotid artery has permitted exposure of the an

terior communicating arte ry (aca) by following the

right A- I artery

(a-I,

bottom).

The

upper chiasmatic

cistern and

the

cistern of

the

lamina tcrminalis are

exposed.

ch,

optic chiasm; It, lamina terminalis;

ot,

optic tract; ha, right (bottom) and left (toP) arteries of

Hcubner; gr,

right

gyrus rectus; a-J

(lOP),

left A-I ar

terYi/o, left [ront()-orbital artery

on

left gyrus reclus.

From

Fox

[2].



Anatomy 137

Fig. 7.12.

Same case after removing about I·em

length

of gy

rus rectus to expose an anterior com

mun icating artery aneurysm

(an)

surrounded

by

left

(lap) and riglll

(bottom)

A

-2

arteries

(a-2).

Above are

the left and below are the right

A-

I arteries

(a-I),

ar-

teries

of

Heubner

(ha),

and fr

orlLO-orbita

l arteries

1/0).//,

Lamina lerminatis;gr, teft gyrus rectus. These

st ructures l

ie

within the lamina terminalis and in

terhem ispheric cisterns. From Fox

[2].



13

8

7. Th

e Chiasmatic Cistern and Environs

Fig. 7.13. Another

case with expos

ur

e of a ll the an

terior cisterns bounded by the left

and

ri ght tem

poral lobes

(l-Il, r-el).

s, Suction tube above bifurca

tion

oflef

t internal

ca

rot id

ar

tery

(l-ica); (1- 1,

both A-I

arteries; ii, lamina terminal is; ot, ri ght optic tract;fl.

right frontal

lo

be; 2, both oplic nerve s; ky. left and

right hy

poph

yseal perf

or

ators; Pit, pituitary stalk

(a nd its hypoph

yse al

cistern) surrounded by

arachnoid (ar), which splits and surround s it; pc,

posterior clinoid process; mem, membrane of

Li liequist;

l-ica and

r-ica, both internal carotid ar

terie

s;l-pca

and r-pea,

both posterior communicating

an erie

s. The

left one

(i-pea)

lies in fro

Ol of

Liliequist

membrane and is seen through the s

pa

ce between

the pituitary stalk (pit) and [he rig ht carotid artery

(r-ica).

From Fox [3].



Anatomy 139

fl ret

Fig.

7.14.

Same case after exposure ofrwo aneurysms

(an) on the anterior communicating artery.

The

small one projecting upward is obvious.

Th

e large

one projects downward and is hidden

by

the anterior


(aca). Above

and below arc

the left and right A-I arteries (a-I) and A-2 arteries

Olf

-l

(

(a-2) . 111.

left frontal lobe,

Lt,

lamina terminalis,

01,

right optic tract; bif, bifurcation

of

right internal

carotid artery;

col.

couonoid;

JUl,

ri

ght ar

tery

of

Heubner; fl-ret, right frontal lobe retractor. From

Fox

[3].



140


Fig. 7.

15. Another case

showing chiasmatic cistern

both rostral

and

abo\'c (to observer's left)

and

caudal

and behind (to observer 's right) the optic ap paratus.

$, Suction

tube

; l-fl, left frontal lobe; ar, arachnoid be·

tween left oplie nerve and frontal lobe and separat

ing

left

carotid cistern from c

hi

as

matic cistern;

2.

bolh optic nerves;

fo,

left fronto-orbital anc l

} '; ha,

l

ef

t arteries of H

cub

ncr;

ell,

optic chiasm;

01,

right

op

tic tract;

ac,

right anterior clinoid process; Pit,

pituitary gland projecting above (with

rc

spca

to

pa

liem) sella lUl'eica; ita, inte

rn

al carmid artery;

frs,

pituitar y stalk; ft, lamina term in alis;

rei, rctractoron

right fromal lobe; an, aneurysm ar ising from an

terior commun ica ting artery;

a-I

and a-2, left (toP)

and right (bol/om)

A-

I and A-2 artcrics:fp, low .akrofr

of le n f

ro lH

opo l

ar

artcr)';col, sma ll coHon hall.

Fr

om

Fox

[3}.



Anatomy

14 1

Fig. 7.16. Anoth

er

case sh

ow

ing surgica lly induced

commun ica tion between chi asmatic cistern rostra

ll

y

and interpeduncular ciste

rn

caudall y. T he latler con

tains the basilar ar tery

(ha)

seen after opening the

membrane of Liliequisl (mem). Note Li liequist's

membrane

se

nds an ant

er

ior reflection around

pi tuitary sta lk (pit), th

us

enclosing the hypophysea l

ciste

rn

. Double-crossed arrow, reflections of light from

CS

F in int

erpe

duncul

ar

cistern;

ji"gle-crossed

an-ow.

lies on sho

rt

internal carotid ar tery

and

points 10 ori

gin of posterior communicating artery; /l-ret, tem

poral lobe retractor ; m·}, M- I arter

y;

perf, largest of

several perforatOrs from A-I ar tery (a-1); ot, right

op

tic tract;

ar,

arachnoid ba nds at lateral margin of

cistern

of

the lamina tennina l

is;

fl, lamina termina l

is

(covered by A- I artery);j1-rel, frontal lobe retractor;

ell,

optic chiasm; 2, both optic nerves; ac, anterior

cl

inoid process.

FrOIll Fox [2]

.



142

7. The Chiasmat

ic

Cistern and Environs

Fig. 7.17

. An

other

examp

le of structures in chiasmat·

ic , carotid, and lamina lerminalis cisterns. 2, both

optic nerves; ch,

op

tic chiasm; ii, lamina terminalis;

Q/,

right

optic tract; ac,

ailler

ior clinoid process;

d()U

ble-cro5Sed

arrow, origin

of


artery from internal carotid artery;

)/1--/,

M-l artery;

perf, perforator from A-I artery (a-I); ha, artery of

Heubner;fo, franto-orbital artery;

rei,

retractor on

frontallobe;sillgle-crossedarrow, interhem ispheric fis

sure; gr, left gyrus rectus.



Anatomy

143

Fig. 7.18. Another example

of

the lamina terminal is

(It). A bi lobed anterior communicating artery

ane urysm (an) is surrounded by the lert

A-2

artery

(a-2,

loP),

the anterior communicating artery

(aca),

and the

ri

ght

A-2

artery (a-2, boltom). Th

e

termina

tion

of

the lert A-I artery (a-I,

toP) is

see

n.

2, both

op

tic nerves; ell, optic chiasm;

ot,

right optic tract;a-I

(bottom), right A- I artery;ha, artery

of

Heubner; r-[o,

right fronto-o rbi tal artery;Jl, right frontal lobe;

ret,

retractors; V,

vei

n on lert gyrus rectus (gr); l-fo, left

fronto-orbital artery.



144

7.

The


Fig. 7,19 . Another case illustrating lamina tcrminalis

(ll),

its

cistern, and a variati

on

of the anterior com

municating complex with 3 arteries

(uca)

and a

bridge (brl between 2

of

them. a-I,

Left

(lOP) and

right (bollom) A- I arteries; eh, optic chiasm; ot, right

optic tract; single-crossed arrow, origin

of

posterior

commu nicating artery:

douhle-crrused arrow,

origin of

anterior

choroidal artery; mol, M-I artery;

v,

vein; r-

JUl,

ri

ght artery of

Hcubncr;

ju,junction of anterior

communicating artery and hiddell right A-2 artery;

r-fo,

right

franto-orbital artery; an, microaneur

ysm

on


a-2,

left A-2 ar

tery;

ar,

arachnoid in interhemispheric fissure ; l-fo,

left frollto-orbita.l artery;

t-fla,

Icrt artery of

I-Ieubnc r. From Fox [3].



Anatomy

145

Fig. 7.20. Same case as Fig. 7. 19 after putt ing muslin

(mu)

on microaneurysm and open

in

g

(singk-U05Std

arrow)

the lamina terminalis

(It); ica,

internal carot

id

artery;

doublt-cro.s.std arrow.

anterior choroidal

anery;

nt,

frontal lobe retractor;

ot,

opt

ic tract ;3v, third

ven

tr

icle;

tot, small

cotton

ball .



146

7.

The

Chiasmatic Cist

ern

and Environs

Fig. 7.21.

Chiasmatic cistern

in

case with

hypoplas

ti

c

right A-I artery

(a-l). The

recurrent artery

of

Hcubncr

(ha)

is as large as the A-I artery.

p.

Per

forators;

mol, M-I

artery;

m-2,

frontal

(bottom)

and

temporal (top) M-2 arteries; aT, arachnoid over syl

viall fissure; II, temporallobe;jl, frontal lobe; cot, cot-

tonoid;

rei,

frontal lobe retractor;

ft,

lamina lcr

minalis;

ot,

right optic trac ljch, opticchiasm;gr, right

gyrus rectus; 2, both optic

nen

'es; l-ica, left internal

carotid artcrYipit, pituitary stalk; mem,

membrane

of

LiliequisljT-ica,

right

internal ca rotid artery.



Anatomy

147

Fig. 7.22. Magnified

view of Fig. 7.2 1.

Arachnoid

membrane of Liliequist (num) sends anterior sheet in

front of pituitary stalk (pit). ac, Anterior clinoid pro

cess; r-ica, atherosclerotic right internal carotid ar

tery; cot, cottonoid; aM, anterior temporal anery

from internal carotid artery;

ret,

temporal lobe re-

tractor; m-I, M-l artery; a-I, hypoplastic

A-I

artery;

p, perforator;

IUl,

artery of Heubner;foa, fromo-or

bital anery;

r-

gr, right gyrus

reClUS; ihf,

interhemis

pheric fissure; l-gr, left gyrus rectus; l-ica, left inter

nal carotid anery; 2, both optic nerves;

ch,

optic

chiasm; ft, lamina tenninalis; ot, right optic tract.



148

7.

The


Fig. 7.23.

View

of opposite imcrnai carotid cistern

and

chiasmatic cistern. 2, both optic nerves;

{-gr,

left

gy

rus reclUs;

i.oa, left ophthalmic

artery going

unde r left optic nerve;

l-iea,

atherosclerotic left inter

nal carotid artery (medial sidc);is, tuberculum se llae;

r-oo, origin

of right

ophthalmic artery; r-ica. right in-

lernal carotid artery; mem, part of membrane of

Liliequisl (opened) passing in front

of

pituitary stalk

(pit); p, hypothalamic perforator;

ot,

right optic tract;

it, lam ina terminalisj ch. optic chiasm;

ar,

arachnoid

between optic nerves. From Fox [3].



Anatomy 149

Fig.

7.24.

Same case as

Fig.

7.23

after

removal of

,I

small amount

of

right gyrus rectus (r-w) to

view

cist

ern

of

the lamina terminalis.

Another

example

of

a

hypoplastic ri ght A-I artery

(a-I. mllom)

and a large

right artery

of

He

ub

ner

(r-ha).

The left A-2 artery is

hidden by the right A-2 artery (a-2). an. Ane urysm

projecting back against the lamina termi llalis (It);

p.

hypothalamic perforators stuck to allleri

or

COIl1-

1T1unicat

i

ng

,1I·tcry aneurysm; *, anterior com

municating artery; r-/pa, right frontopolar artery

(unusually low takeoff from the

A-2

artery);

I-[pa,

left frontopol

ar

artery; l-gr, left gyrus rectus;[oa, left

fronto-orbital artery; I-ha, left artery of Heubner;

a

I (loP), left A-I artery; 2, both o ptic nerves; ch, optic

ch

ia

sm;

Pit,

pituitat·y stalk;

ot,

right optic tract. From

Fox

[3].



150


Fig.

7.25.

Example of chiasmatic cistern with pre

fixed oplic chiasm

(s

hort intracrania l optic nerves).

gel, Gelfoam

on

left optic nerve; 2, both optic nerves;

ch, optic chiasm; iCG, internal carotid anery; elp,

shanks of two aneurysm

dips

; 01, oplic tract; a-I,

right (bottom)

and

left

(toP) A-I

arteries;

aca,

anterior

communicating artery; it, lamina terminalis; ha,

right artery

of

Heubner;

T-fl,

right frontal lobe;

ihj,

interhemispheric fissure (cove

red

by arachnoid);

l-fl,

left f rontal lobe; l-foa, left fronta-orbital artery.



Anatomy

151

Fig.

7.26.

Another case revealing an unusual com

mon trunk (*) from which arise the right frontopolar

artery

(r-fpa)

and the artery

of

Heubner

(ha). gr,

Right gyrus rectus; a-2, right A-2 artery from which

the above-mentioned trunk arises;

l-fpa,

left fron

topolar artery; 2, left optic nerve;

ch.

optic chiasm;

a-I,

left (toP) and right

(bottom) A-

I arteries;

it,

lamina

terminalis;

01, op

tic tract; mem, membrane

of

Liliequist;

ac,

anterior clino

id

process;

ica,

internal

carotid artery;

col,

coltonoid. Note xanthochromic

pigment (bilirubin) from hemoglobin

of

recent sub

arachno id hemorrhage.



152

7.

T he Chiasmatic Cistern

and

Environs

Fig.

7.27. Allother example where chiasmatic,

carotid,

and

interpeduncular cisterns arc all seen

(from observer's left to righ t) . 2, Bo th optic nerves;

ch,

optic chiasm; 01, right optic tract;

ito,

internal

carotid artery; single-crossed

arrow,

hidden or igi n of

poste r ior co m m u nica

ti

ng

artery; dQu.ble-crossed arrow,

hidden ongm of anterior choroidal artery; ac, an

terior clinoid process; pc. posterior clinoid process;

bo,

basi lar artery;3.oculomotor nerve; un, uncus;

rei,

fron tal lobe retractor;

00,

artery

of

H

eub

ner;

a-I,

right (bottom) and left (toP) A- I arteries_ See next two

fi gures for anterior communicat ing artery complex.



Anatomy 153

Fig. 7.28. Same case as in Fig. 7.27. T}'pical variation

in anterior communicating artery complex illus

trated.

a-I,

L

eft (toP)

and right ( mllom) A

-I

arleries;

a-2,

left (top) and right (bol/o

.

m)

A-2

arleries; aea, an

terior communicating arlcry;

co,

connecting b

ri

dge

from anterior communicating arler}, to left

A-2

ar-

tery; in , arachnoid over interhemispher ic fissure;

lIa,

arler}'

of

Heubner; ar, arachnoid fibers; iea, inter

nal

carotid artery; sillgle-crossed

arrow,

origin

of

pos

terior communicating artery; *, bifurcation

of

inter

nal

carotid artery.



154

7. The

Ch

iasmatic Cistern

and

Environs

fig. 7.29. Same case as in Figs. 7.27 and

7.28.

An

terior communicating artery complex magnified.

foa,

Franto-orbital artery;

ilif,

arachnoid over i

n

terhem ispheric fissure; a-2, left (toP) and right

(bot

-

10m) A-2 arteries; a-1, left (lOP) and right (hoI/om) A-I

2

arteries; Ma, ante

rior

communicating artery; co, con

necting branch to the left A-2 artery; 2, both optic

nerves; ch,

op

tic chiasm;

ot,

op

tic tract; 1m, artery of

Heubner.



Anatomy

155

)

1' I

"

,.1

Fig. 7.30. Another case illustrating relationship

of

anterior communicating artery

(aca)

to chiasmatic

and lamina terminalis cisterns.

a-I,

Left

(toP)

and

right

(bottom)

A-I arteries;

a-2•

left

(lOP)

and right

(bot-

10m)

A-2

arteries;

00,

artery

of

u n e r and

branches covered

by

arachnoid and blood;

ar,

arach noid over interhemispheric

fi

ssure and cover-

a-I

ing a second anterior communicating

ar

ter

y; r-gr.

right gyrus rectus; rtl, frontal lobe retraClOr; I, olfac

tory tract;jl ,

ri

ght frontallobe ;fpa, left frontopolar

artery (low takeoff); foa, left f ronto-orbital artery;

l-gr,

left

gy

rus rectus;

2,

both optic ner

ves;

ts, tuber

culum sellae;

ch,

optic chiasm; 01, right optic tract;

It,

lamina terminalis.



156

7.

The

C

hiasmat

ic

Cistern

and Envil"Ons

Fig. 7.31. Another va riation of the anterior com

municating ar tery complex. Fr

om

the an

ter

ior com

municating artery (aca) arises both a connecting

br idge (co) to the left A-2 (sec

Fig. 7.32)

and an acces

sory

(t hi

rd) anter ior cerebral artery (ace) ascending

between the two

A-2

arteries. a·· I , Left

(toP)

and right

(bottQm) A- I ar lc i-ies; a-2, left (lOP)

and

right (OOllom)

A-2

arte

ries;

r-foa,

right

fronto-orbital

artCl-Y; I,

right

olfactory tract; r-gr, ri ght gyru s rectus; l-gr, left gy ru s

rectus; i-roa, left fronto-orbital artery; ar, arachnoid;

2, both optic nerves;

at,

a

nterior

clinoid process;

ica,

internal carotid arte ry;

*', bi

furcation of the internal

carotid artery (from

wh ich

unseen aneur

ysm

arises);

ot,

right optic tract; cit, optic chiasm; It, lamina ter

minalis.



Anatomy

157

Fi

g. 7.32.

5."lme

case as

in Fig. 7.31 wit

h right frontal

lobe d isplaced by retractor (rei). a-1, Left (lOP) and

ri

ght (hottom)

A-I

arteries;

a-2,

left

(loP)

and right

(bot-

10m) A-2 arter ies; aca, anterior commun

ica

ting ar

ter

y;

p, perforatOr;

co,

connecting branch from an

terior commu nicating artery to the left

A-2

artery;

V,

\'

ei

n;

ace

, accessory (third) anterior cerebr

al

artery;

foa,

left fronto-orbital arter

y; I-JUl,

l

ef

t artery

of

Heubner; 2, right optic nen'c; ac, right anterior

cl inoid process;

ch,

optic chiasm (lateral s

id

e);

ot,

right optic tract; it. lamina termina

li

s;

*,

bifurcation

of

internal carotid artery from w

hi

ch arises base of

aneurysm

(an); m-2, M-2

artery;

r-Iw,

right a rtery of

Heubncr.



158

7. The Ch iasmatic CiS lern and En"irons

Fig.

7.33. AnOlher case of anterior

communicating

artery (aca) duplication. a-I, Right A-I artery; M. ar

tery

of

Heubner; 0-2, right (bottom) and left (top) A-2

arteries; Ttl, right frontal lobe retractor;

ihf,

in

terhemispheric

fi

ss ure;gr, left gyrus rectus; I , left 01-

faclO ry tract; 2, both optic nerves; i-loa, left frolllo

orbital artery;

an,

aneurysm; Pit, pituitary stalk ; ica,

in ternal carotid a rtery;

. ,

bifurCllion

of

inlernai

carotid artery; 01, right optic tract; ii, lamina ter

minalis; ch, optic chiasm; p. perforator.



Anatomy

159

Fig

.

7.34. View of

underside

of

an anterior com·

municating artery co mplex in chiasmatic and lamina

terminalis cistern

s. s,

Suction tube;

ua,

internal

carolid artery;

ot, ri

ght optic tract;

fI,

lamina

ter·

minal

is;

p, hypothalamic perforators; a-J, right

(001-

t

om) and left (toP) A· I arte

ri

es;

a-2,

orig

in of

left

A-2

artery;

(Ua,

anterior communicating

ar

ter

y; ha,

left

artery

of

Heubner;

1-[00,

le

ft

fronto-orbital artery;

1,

left olfactol}' tract; 2, both

op

t

ic

nerves;

ts,

tuber

cul

um

sellae.



160

7. The Ch iasmatic Cistern and Environs

Fig. 7.35.

AnaLOmy

of lhe lamina terminalis and

chiasmatic cisterns. 2, B

ot

h optic nerves;

ar,

vascul

ar

arach noid betweell optic nerves; cit,

oplicc

hiasm;all,

aneurysm a

ri

sing from most of the internal carotid

artery; a-I, right (bottom) and left (lOP) A-I arte

ri

es; it,

lamina tcrminalis;

JUI,

artery

of

Heubner;

ret,

frontal

lobe retrano}";

0-2,

right (boltom)

and

left (lOP) A-2 ar

teries; ace, origin o f accessory anterior cerebral ar

tery; i/l[,

arachnoid

over interhemisphe ric fissure.



Anatomy

161

Fig.

7.36.

Same case as in Fig. 7.35 with magnified

viel\' of the lamina terminalis (It) between the right

A-I

artery (a-I) and artery of Heubner

(ha). The

lamina terminalis is bordcred latcrally by the optic

tract

(vi).

Note arachnoid bands

(or) and

many

P I ~

forating arteries (P). v,

Vein:

gr, gyrus reclus; all,

aneurysm.



162

7.

The Chiasmatic Cistern and Environs

Fig,

7.37.

Another example

of

carotid, ch iasmatic,

and lam ina tcnnina

li

s ciSlCrnal analOmy. ica,

in t

cr

nal carotid

artcry; Ie,

edge

of

anterior reflection

of

tentorium;

pc.

posteri

or

clinoid proccss; /KO, pos

terior co mmunica

ti

ng artcr

y; oclw,

anterior choroi

dal

artcry; m-I,

M-l

anc

r

)'; QI,

optic tract;

(1 1,

right

(hollom) and Icft (loP)

A-

I arteries; dr, arachnoid

b<

uld; II, lamina lerminalis;

dCd,

anterior com

municating artery;

hr,

bridging artcry from

left A-

I

loanterior cornmuni catingancry:Joo, left fronto-OI '

bital

ar

tery;

gr,

left gyrus rectus; lUi,

le ft anery of

Heubner;

eh,

optic chiasm; 2, both optic ncn'CS; p,

perforator

s.



Anatomy

163


in Fig.

7.37, different vi

ew. iea,

Internal carotid artery;

pea,

posterior communicat

ing artery: aelta. anterior choroidal

aner

y: mol, M- I

arter

y;

I-

I,

right (bottom) and left

(lOP)

A- I arteries;

P,

perforator ; ill; arachnoid band;

I··IUI,

right artery

of

H

eubner

and branches; r{oa . right fronLO-orbital

ar·

tery;a-2, origins

of

right

(bottom

) and left

(lOP)

A-2 ar

teries;

v, ve

in;

aea,

anterior communicating arter),; {-

100, left fronto-orbital arte ry;gr, left gyrus reclUS; 2,

bOlh

optic nerves; '·IUl, left artery of H

eubner

; 01,

optic

tr

act; fl, lamina tenninalis.



,

Fi

g. 7.3

9. A histor

ic, diagrammatic example

of

an

alllerior

com

municating ar ter

ial

complex form ing duplications and br id ges. On

( ither side

are

the right and left A-IIA-2junctions. Fl"Om BremerJL

(1943) Conge nital aneurysms of the cerebral

ancr ics.

An em

bryologic study. Arch Pathal 35: 81

9-83\;

copyright 1943, Amer

ican fo.'leclieal Association [I].

Fi

g. 7.40. Photograph

of

a plastic cast

(toP)

and d ia

gram

(bottom)

of the rec

ur

rent artery of Hcubnc r as

seen in front with two somewhat different projec

tions. In the diag ram the artery Heubncr is shown in

interrupted lines. From \Vcstbcrg C (1963) T he re

cur rent artery of Heubner and the ancrics of the

central ganglia. Acta Radiol (

Oi

agn) I:

949-954

[5].

164



8

The Ambient and Interpeduncular

Cisterns

Jntroduction

Thi

s chapter focuses

on

the pterional ap

pro

ach toward the amb ient

an

d inte

rpeduncu

lar cistern

s.

Th e surgica l orientati

on

of th e pa

tient's head (sec Fig. 4.8) is similar to th

at

for

the plerionai approach to the syivian, carotid,

and chiasmatic cisterns. However, the operat

ing microscope is s

hif

ted from a m

ore

rostr

al

direc tion (see Fig. 4.5) to a more ca ud al line-of

sight

(see Fi

g. 4.7).

T he amb ient ciste

rn

is a

ce

rebral spinal fluid

(CS

F)

compartment

made up of the

body

a

nd

wing

of the ambie

nt

cistern on each

si

de. T he

bo

dy is

bor

dered laterally by the medial su r

face of the temp

ora

l lobe and the med ial ed ge

of the tentorial notch. It is bordered media

ll

y

by

the latera l surface of the mi

dbr

ain and the

pont

omesencepha

li

c

jun

ction. T he wing (n

ot

seen ana tomi ca lly in this atJas) is a la teralexten

sion

of t

he

body a

nd

lies betwecn the pulvin

ar

of the thalamus

anter

iorly and the temporal

lobe pos ter iorl y. The body of the ambient cis

te

rn

as seen in this atlas contains those struc

t

ur

es foll

ow

ing the te

nt

orial e

dg

e and lying

within the space between the car

ot

id cistern

rostra

ll

y

an

d the interpe

dun

cul

ar

cistern cau

da ll y. Some of these structu res (such as th e an

te rior cho roidal arter

y)

arc assigned to a sepa

rate c

ru

ral cist

ern

by some authors [8}. T he

basilar ve in of Rosenthal and the ter minus of

the optic tract ca n be considered either to

li

e

within the ambient ciste

rn

or to make

up

pan

of the med ial wa ll of the cistern . The third

(oculomotor) nerve

li

es within both the inter

peduncu lar cist

ern

and the amb ient cist

ern

since the arac

hn oi

d memb rane of

Lil

ie

qu is

t

(sep

ara

ting the rostral chiasma

ti

c ciste

rn

from

the c

aud

al inte

rp

e

du

ncular

cis

tern) usua

ll

y is

adh erent along its latera l margin to the medial

and caud al side o f the oculomotor nerve. This

membrane m

ay

stop

at

or bef

ore

the

ocul

omo

t

or

nerve so that CS F in th e inter

pedu ncul

ar

ciste

rn

mixes with

CS

F in the am

bient cistern at a confluence lateral or medial

to the oculom

otor

nerve (

Fig.

8.1; also sec

Fig. 6.3). In some cases the Liliequist mem

brane extends lat

era

lly to the t

ent

orial edge

(see Fig. 8.

10

), a

nd

CS F fl

ow

must be t

hr

ough

per forati

on

s in th is ar ach

no

id me

mbr

ane. T he

poste

ri

or

co

mmuni

cating artery a

nd

the P-2

port ion of the posterior ce reb ra l a

rt

ery as we ll

as the f

ourth

(

tr

ochlea r) nerve and s

up

erior

ce rebe

llar ar

tery also are par

tl

y within the

body of th e ambie nt ciste

rn

.

Fig

ur

e 8.2 shows the anato my

at

the le,'e l of

the tentorial notch and midbrain. Figu re 8.3

diagrams the

anato

my of the auachmcnts of

the t

entorium a

nt

erio

rl

y to the posterior and

anter ior cl ino id processes. Dur ing the pter

iOlla l app roach to the inter pedun cul ar ciste

rn

,

the posteri

or

cli no id process is an

impon

ant

lan

dma

rk lateral

to

w

hi

ch is the oculomotor

nerve.

Within the inter pe

dun

cular cistern lie the

origins of the oculomotor ner ves, the tip of the

basilar artery (Fig. 8

.4),

the origins of the P-I

segments of the posterior cerebral a

rter

ies and

their poste

ri

or th alamic perforators (

Fi

g. 8.4),

and the origins of the s

up

erior cerebe llar ar

te ries. I n the case of a shor t P- l artery, the

caud al end of the posterior communicating a r

tery also may lie m

ore

medially and within the

interped uncu lar cistem.



1

66

8.

The

Ambient and Interpeduncul

ar

Cisterns

5u.p

lY

NeT""

(m.b

..

"

p.duncl.

Qu.adriq.mi

MI

pio.t.

Fig.

8.2. Incisura of the tentorium. The midbrain

was sectioned transversely, and the hemispheres

have been removed. Note r

el

ation

of

the bifurcation

of the basilar arte ry to the environs in terms

of

a pIer·

iO

llal

approac

h lO lhis region. From Taveras Jr ..[

Fig. 8.1. Diagram of sagittal sections of a normal

brain and the se llar region , looking to the right. M,

Mammillary body; LM, Lilicquist's mernbranc(mcm

brane

of

Key and Retzius); 3.

right

ocu lomOlOr

Ilene;

PC, right

p o ~ t c

i o l

clinoid process; DS, dor

sum sellae;

arrow, normal now

of CSF th

ro

ugh the

prepontine and inter peduncula r cisterns. From

JL, 0

(1980)

Suprasellar arachnoid

c)

's\s:

an extension

of

the membrane of Liliequis

l.

Neurosurgery 7: 615 -

618

(4).

"

opt.< <hi"""

1 ,{u.

ru\.. bulwn.

Ne:rve.

i-Bo.,ilor r u t . , . ~

, , - , -0, ," (.e:rt1.Cro..l

a:ftV" :I

ou.du.c.t

of

(1960) T

he

roentgen diagnosis of

intracra

ni al in

cisural space occupying lesions. Am

J

Roentgenol

84: 52-69 [7]. Copyright by American Roentgen

R'ly

SocielY. 1960.



A

Anatomy

167

Fig. 8.3. Rel ationship of posterior

cl

in oid process on

the left

(A)

and right

(B)

to the oculomo

tor

nerve

and circle of W

il

lis.

No

te relat

io

n

ofpo

steriorclino

id

process. posterior cOlllm un icating artery. 1'-

1

a rt er

y,

and oculomotor nerve t.o tip

of

bas ilar ar tery in

terms of the pter ional app roach \0 the interpedun

cul ar

cis

tern. Reproduced by per mi ss ion from Mal

kasian I) R. Rand

RW (19i8) 1\

'licrosurgi

ca

l anato

my,

in Ra nd R W (cd): Microl1tllroslllgtry. cd

St Lo uis,

CV 1\

losby Co, PI'

3i

-

iO

[6]. A. Superior

view

view

of the left se llar and p,uasell

ar

region de monstra t

ing the d ura l reneClions and the "ocul omotor

trigolle."

/.ines wilh adjaunl OfN'11

arrOW.J. bo

und

aries

of

the ocul

omotor tr

igone:

.t ,

medial renections of

the tentorium cerebc

lli

:

y..

poste

ri

or cl

inoid process;

ante

r

io

r clino

id

process; d. d ia phragm s

el

lae;

lal

tra/ slmighl

black

arrow. ostium

of

the ilUern al carotid

artc )':

cw"Vtd

(lITOU\

O\

'cr optic n

en

'e and

und

er fal

ci

form ligamcnt;dolltd Ii/It. ope ning to the optic fora

m

cn; m

td

ial slmiglit arrow

(b

l

ack

cMcurt'd),

opening in

d i:lphragm se

ll

ac for pituitary sta

lk

; broke71

r r ~

oculomotor ostium; long black arrOW/lead, ostium

of

the fou

rth

cran ia l ner\"c;

l'lI/all

black

arrows.

"Y" du ral

fold. B. Supe ri or

view of

the sella illustrating the reo

lationship of the a n ler

io

r cl i

no

id process

(11 ),

middle

cerebr:11 art

er

y (C). poste rior communicating arte ry

U), ocul omotor

Il

c n e (fl , trochlear nerve (D), pos·

ter

io

r cerebr

al

a

ne

ry

(C)

and tentorium cerebclli

Illed i<l l renectio ll ( :- /

). No

te that the oculomotOr

nerve is s

li

ghtly lateral and

inf

erior to the poster ior

communicating

an ery

at the oculomotor ostium as it

penetrates the du ra in the oculomo

tor

trigone. Ho

w

e\ 'er. as the oculomot

or

nerve

P.

1SseS inferior to the

post

erior

communicating artery (proximal to the

m

id

brain), it m

ay

be im med iat

el

y i

nferior

or slightly

medial to the poste

ri

or cerebral artery-postcr ior

communicaling

artery

ju

n

ct

ion.

Th

e ant

erior

choroid,ll artery has not been included. Unl1UJrked

falciform ligamell t o\"er the

op t

ic nen'c as

it

enters the optic ca nal; E, frce edge of the tentorium

cerebc

ll

i and its medial renection;

H,

basilar artery;

I , post

erior cl

i

no id

process;

K.

antc rior cerebral ar

tery.

8



168

8.

T he Ambient

and

Interpeduncular Cisterns

A

Fig. 8.5. Diagrams illustrating various r

el

ationships

of

the basilar

arter

y terminat ion to the dorsum se

lla

e

(A) and the th ird ventricle (B). From Greitz T,

1...O

f5-

Fig. 8.4. Lateral

vicw

of vertebrohasilar arteriogram

(s ubtraction techn ique) to show example of pos

terior thalamic pel-foratofs

(arrow)

arising from the

p

ol artery and the basilar ancry bifurcation. From

Fox

[2 ].

ted S (1954)

Th

e relationship between the third ven

tr icle and the basi l

ar

artcry. Acta Radiol4 2: 85- 100

[5].



Anatomy

169

Fig

. 8.6.

Two

cxampl

csofiopa

midol cislcrnography

wil

h axial

cr

sections at lel·eI

of

midbrain.

Thc

cis

tcrnal CSF is whitc. A. UIV)' black OrTout. from in·

tcrhcmisphelic fissure

to

cistern

of

thc lamina lcr'

millalis (poims

to

lamina tcrminalis behind which is

bla

ck unenhanced CSF

in

third ventricle):

sim igllt

solid black OITOW

lies at union

of

syl\'ian. chiasmatic

and ambient cisterns and points to optic tract;

wavy

wllile aITow p< lSses

from lateral syl\'ian cistern (fis

sure) to medial

sy

lvian cistem;

jlmigllt

solid

wllile

aITow lies

on medial temporal lobc and points

to

th e

body

of

the a

mbi

ent cistern lateral to midbra in :slum

.wiid wllilt Qrrow

lies on

vc

rm is

of

cercbellum and

pOill lS

10 (illad rigcmilia l cistern:

shorl o/lell

Muck

arrow

li

cs in interpcdunc

ul

ar

cis

tern and poims to mam-

A

8

mill

al

l '

body

of

hYj>othalamu s.

B. BfackaITuwhead li

cs

in j unction

of

ambient and intcrpedullcul

ar

cisterns

and poillts 10 oculomotor ner

ve

that separates the

se

cisterns;

doubit-headtd

aITOW lies in interpeduncular

cistcrn and points (a) anteriorly to pituitary stalk

(sur r

ounded

by

arachnoid enclosing less enhanccd

CS

F in hypophyscal cistern) and (b) posteriorly 10

ol1e of

the two ascending P_I afleries;so/id black aITOW

lies

in intcrpeduncular cistcrn and extends from

othcr asccnding P·l artery

to

postcrior clinoid pro

cess (whit

er

than

tllC

enhanced

CSF);solid whitton'OW

lies 011 peduncle of midbra

ill

and points to

bod y of

ambient cistern;

opm arrow lies

on anteri

or

cl inoid

process aud points to internal carotid artery.



170

8.

The

Ambienl and In terpedu ncular Cis terns

Within the interpeduncular cistern , the ter

minus

of

the ba

si

l

ar

a

rt

ery

may

have

va

rious

relat ionships wi th the dorsum se

ll

ae and its

posterior clinoid

pr

ocesses

as we ll

as with the

brainstem (

Fi g.

8.5).

The

imaged anatomy of

the str

uctur

es

about the ambient and inter

peduncular cisterns can be seen in cross-sec

tion on the computed tomography (CT) scan

after

instillation of

wa

ter-soluble

cont

rast

medium into the CSF (Fig. 8.6).

Fi

gure 8.7 is a

photogra

ph of

a plastic model of the brain

or

iented as the

neuro

s

ur

geon w

ill

sec the

brain stem, basilar an ery, superior cerebellar

arte

ry, oculomotor nerve, and posterior cere

bral a n e ry (P- I segment) .

In Ihis

view fro m the

plc

ri

onal perspective,

Lhe

right temporal lobe

and cerebellar hemis

ph

ere have been removed

(a

lso see

Fig

. 4.7).

Anatomy

Th

e s

urg

eon fo

ll

ows the posterior com

municating artery cauda

lly.

A

dhes

ions be

tween the uncus

of

the temporal lobe and

oculomotor nerve are removed.

The

tempora l

lobe and i

ts

uncus are retracted. After opening


Li

licqui st (mem

brane

of

Key and Retzius), the surgeon sees the

follow in g in a

ca

udal-to-rostral direction

(Figs. 8.8 and 8.9): the rostral pon

s, su

p

er

io r

cerebellar artery, oculomotor nen'e, posterior

cerebral

arte

r

y,

posterior communicating ar

tery and its anterior thalamic p

erfora

tors, an

I.erior choroidal artery. inl.ernal carotid artery.

and o

pt ic

nerve.

The

oc

ul

omotor nerve wi

ll be

seen passing imo the dura

of

the oculomotor

tr

igone (Fig. 8.3)

just

latera l to the

po

sterior

clinoid

pr

ocess. From there the oc

ul

omotor

nen

'e en ters the cavern ous

si

nu

s.

At

this stage

oft

he expos

ur

e, only the lateral

termination

of

the

P-I

artery wi ll be seen at its

ju n

ction with the

P-2

artery

and

the post

er

ior

communicating artery (Fi

g.

8.8).

Us

ually the

P-I artery is obscured

by

the ant

er

ior thalamic

perforators as the artery curves ca udally and

media

ll

y

away

from the s

ur

geon and lOward

the basilar a

rt

ery tip.

The

upper trunk

of

the

basilar a rtery may come into vi

ew

(Fig. 8.9).

At

times the

membrane of

Lili

equist w

ill be

thickened

and

imper

fo

rate from a previous

subarachno id hemorrhage

or

mening

iti

s

(

Fig.

8

.10),

resulting in an obstruction to the

fl

ow

of CSF and subsequent hydrocephalus.

An

in

cision in t

hi

s thickened membrane

(Fi

g.

8.

11

) w

ill

result in a s

udd

en

flow

of CSF

and relaxation

of

the brain. Note thal now the

amel'ior thalamic p

er

forators are seen on their

lateral

si

de whereas views of the carotid cis tern

earli

er

showed these sma

ll

arteries on their me

di al

si

de (sec Figs. 6.7 and 6.8).

In a rare patie nt the post

er

i

or

clinoid pro

cess and i

ts

dural cover ma y project up between

the caudal surfaces

of

the internal carotid ar

tery and optic nerve

or

chiasm

(F

i

g.

8 .1 2). In

the majority

of

patients the posterior clinoid

process projects

up wa

rd in

a parasagiual plane

late ral to the in ternal carotid artery (

Fig.

8

.1

3).

On

occasion both posteriorc linoid processes

and the top

of

the do

rs

um

sel

lae

ca

n be seen

(Fig. 8. 14).

Thi

s same figure shows the right


ar

tery clipped wi th

sma

ll

ma lleable clips (avoiding perforator

s)

prior to severing this

ane

ry between the

cl

ips.

The P·

2 artery passes laterally between the

temporal lobe an d oc

ul

omotor nerve.

The

P- I

artery takes its typical course

away

from the sur

geon; it loops superiorly, caudall

y,

and me

di a

ll

y lO

wa

rd the rostral tip of the b

asi

lar ar

tery. In

Fi g.

8.14 the middle half of the P- I ar

tery is hidden by the P-2 artery.

Figure 8

.15

is the

sa

me case after severing

of

the right posteri

or

communicating artery.

Th

is

is an

unu

su

al

view

of

both P- I arteries, both

1'

-2

arteries, and the left (opposite) posteri

or

com

municat ing a rtery.

Fig

ures

8

.16

a

nd 8. 17

are t

wo

se

parate exam

ples of previo

ll

s

su

barachnoid hemo

rrha

ges

that have caused adhesions in

the arachno

id

sh

eat

h encl

os in

g the a

nt

erior thalamic per

forators. T hese adhesions have

ca

used many

of

the perforators

to

stick together. This situa

ti

on

requires sl

ow,

delicate dissec

ti

on to

pr

event

p

erforator

injury.

Figures 8 .18 and 8 .19 are two se parate exam

pl

es

of ap pr

oaches to the int

erped

uncular

cis

tern where the intracranial internal carotid ar

tery is short. Retraction of the frontal lobe

brin

gs

A- I and M -I pe

rfor

ator s into "iew at the

bifurcation

of the

internal carot

id

artery. In

Fi

g.

8. 18 the uncus, which hides the P·2 artery,

is still ad herent to the oculomotor nerve. In

Fig.

8.

19 the

interna

l carotid artery hides the

posterior communicating arte r

y.



Anatomy

I i i

Fig.

8.7. Plas

tic model of brain: viewed as from a

right pterional appro.1ch to the anatomy around the

interpedunc

ul

ar cistern (see Fi gs. 4.6

and 4.i). The

right temporal lobe and ri ght cerebellum have been

removed, btu the view is similar to that after

wi

de

opening

of

sylvian

fiss ur

e. r-fl. Right front.allobe; J,

both olf.lclory tracts;

1-1l,

medial side of left (o ppo

she) temporal lobe;

p-J,

le ft Pol artery; i-sea, l

ef

t

supe rior cerebe

ll

ar artery; ), rig ht oculomotor

lIerve; ba,

b;:

lsilar

arter

y; '·va. le ft vertebral arte ry:

va

.

ri

ght I'enebral

artery;

//lcd,

medulla

ob

lon

ga

ta;

aiea, right anterior inferior cerebellar

ar

ter

y;

7 and

8. origins of facial and acoustic nerves; 6, right abd u

cent nerve ; 5. right t

ri

ge minal nerve arising from

POllS:

mep. sectioned middle cerebellar peduncle;

ebllll, medial surface of le ft cerebellum (right side cut

awa y);

r-

se

a,

right superior cerebellar artery; p·2,

right

1'

-2 ;1I·tel}'; I'ed. pedu ncle (pyram idal tract) of

midbrain: il'[. interpeduncular fossa

of

midbrain;

pea, right posterior communicating artery; pil, pitu

itary bod y; 2. right optic n

en

'e; lIIam, mamill

ar}'

bod

y.



172

8. The Ambient and Imerpeduncular Cisterns

Fi

gures 8.20 through 8.23 are examples of

the righ t latcral zone, middle zone, and left

eral zo ne

of

the inter peduncular cistern as

viewed progre

ssiv

ely from the right pterional

approach. In each res peClive case the micro

scope is tilted from a p

ar t

i

al

cauda-medi

al

di

reclion (ie,

direction

of

the

surge

on '

s view) to a

caudal, yet morc medial, direction. At thc sa me

time the right internal carOlid artery and the

proximal M-J arte ry arc displaced gently to the

l

eft

(media lly)

by

a l la lTOW self-retaining re

tracto

r.

Care is taken not to occlude the carotid

artery (especially i f vascular hypotension is

used) or fracture atherosclerotic

pl

aques in the

arte ry.

In

some cases

it

may

be

necessary to clip

(with sma

ll

ma

ll

eable

cli

p

s)

and sever the post

e

ri

or communicatin g artery (see

Figs

. 8

.1

4

an

d

8.

15), avoiding occlusion

of

anteri

or

thalamic

perforato rs by the clip

s.

In Fig. 8.20 a clear view

of

the oculomotor

nerve separat

in

g the super ior cerebe

ll

ar artery

and the P-2/posterior communicating junClion

is present. T his th ird crani al nerve begins, as it

typically does, as a broad neural band fro m the

midbrain in the interpeduncular fo

ss

a. This

broad band

gather

s together rostral to the

pons and passed forward

under

the tentorial

edge and into the oculomotor trigone (see

Fi

g. 8.3) ju st late ra l to the posterior clino

id

pro

cess. The midbrain, from whence the

oculomot

or

nerve originate

s,

is

hidden from

view owing to the buck

li

ng

of

the brainstem

during the embryoni c stage

of

development.

The forward buckling

of

the de

ve

loping pons

accoun ts fo r the ros tral pons being seen by this

surgica l ap

pr

oach.

With retraction

of

the in temal carotid

anery

and a more medial

til

t

of

the a

im of

the micro

scope

, the center of the interpeduncul

ar cis

tern

ca n be seen

in

Fi

g.

8.2

1.

An even s

harp

er

medial angulation

of

the microscope aimed

caudal to the carot

id

a

ner

y and hypotha lamus

permits the s

ur

geon to see beyond the inter

ped uncular midline as is revealed in Fig s. 8.22

and 8.23. In this circumstance the observer is

look

in

g

th r

ough the space between the back

of

the

dor

sum sel

la

e and clivus (see Figs. 4.7 and

8. 1) and the front

of

the brainstem (see

Fi

g. 8.7). With this

ri

ght pterional approach,

the

do

rsum se

ll

ae (Fig. 8.

14

)

li

es in the upper,

left-hand field

of

the observer's view, and the

basilar artery and ros tral pons

li

e

in

the lowe r,

right-h

and

field

of

the observer's vie

w.

De-

pending on the exaCl direction

of

the opti

cs

of

the microscope, the surgeon now sees bo th

superior ce rebellar arteries (origins), both

oculomotor nerves, both P- I arte ri

es (o

rig in s),

and the l

ef

t mesencepha

lic

peduncle (pyrami

daltract),

T he

anterior

(frolltobasal) surface

of

the up per basilar artery is viewed

by

the su

r

geon.

Figures 8.24 and 8.25 represent another

example

of

the transition from a view

of

the

junClion

of

the ambient and inte

rp

eduncular

cistern s (

Fig.

8.24) to a view

of

the center

of

the

interpeduncular

ci

stern (Fig. 8,2

5)

, Note how

the

P-1

artery on the right tul"llS caudally away

from the s

urgeon

whi le the P- I artery on the

left takes a more lateral co

ur

se. Large and vital

ante

ri

or and posterior thalamic perforators

are presen

l.

Figure 8.26 gives a view

of

the anatomy of

the lamina termi nal s, chiasmatic, carotid , am

bient, and interpeduncular cis tcl"Ils

in

one pa

tient. Figme 8.27 demonstrates anatomy about

the carotid, ambient, and prepontine cistel"lls.

Figures 8.28 through 8.30 represent

another example

of

transition from viewing

the lateral zone to viewi ng the central

zo

ne

of

the interpeduncular cistern in a case

of low

lying ba

si

lar artery bifmcatio

n.

Figures 8.31

through 8.33

il

lu

strate the many anterior

thalamic perforators arisin g from the internal

carotid and posterior communicating arte

ri

es.

They

lie

ensheat hed wi thin their own filmy

arachno id envelope. Th e anter ior choroidal ar

tery takes a pro

minent

course from the inte

r

nal carot

id

artery an d' disappears be hind the

uncus.

Fig

ur

e 8.33 additionally gives a panoramic

view

of

the anatomy

of

the lamina termina lis,

chiasmati

c,

carotid, ambient, and interpedun

cular cisterns. The relationshi p of the pos

terior communicming artery to the

P-I

and P-2

arteries is illustrated. Figure 8,34 gi

ves

a dear

vi

ew

from the bifurc

at

ion

of

the internal

carotid and adjacent optic tract to the bifmca

tion of the ba silar arter

y. The la

st two fi g

ur

es

dea

rl

y demonstrate that the pterional a p

proach permits access to lesions situatcd an y

where about the circle

of

Willis,

I t

is ideally

suited for multip le lesions (eg, aneurysms) pre

sent in diffcrent loci, ye t within reach from the

chiasmatic to the i

nterpedun

cular

ci

sterns.

The

approach req ui res significant removal

of

the sphenoid wing and , in many cases, a wide



Anatomy

173

opening of the sy lvian fissure. Additional de

ta

ils

of

the neurosurgical techniques used by

the author for lhis approach are given else

where [2].

B

ibli

ogra

ph

y

I. Fox J L (1979) f\Iicrosurgical exposure of intracra

nia l aneurysms.J Microsllrg I:

2-3

1

2. Fox J L (1983) Intracranial

Ancwysms, vo

l 2.

New

York.

Springer·Verlag, PP 877 -

1069

3. Fox JL (1985) Microsurgical exposure of vene

brobasi l

ar

aneurysms, in Rand RW (ed):

Micra'

neurosurgery,

cd

3.

St Louis, CV

]\

'Iosby Co,

PI' 589-599

4. "

ox

J L, AI-Mefty

0

(1980) Suprase llar arachnoid

cysts: an extension of the membrane of Lil iequisl.

Neurosurgery 7: 615-618

5. Greilz

T,

Uifsled S (1954) The relationshi p be

tween the third ventricle and the basilar anery.

Acta Radiol42: 85 - 100

6.

Ma

lkasian

DR,

Rand

RW

(1978) Microsurgical

anatomy, in Rand RW (ed):

Micronfuroslllgcry,ed 2.

St Louis, CV Mosbr Co, pp 37- 70

7. l avaras J M (1960) The roentgen diagnosis

of

in·

cis ural intracranial space occupring lesions.

Am

J

Rocntgenol84: 52- 69

8.

a ~ r g i l

MG, Kasdaglis

K,

J ain KK el al ( 1976)

Anatomical observations of the subarachnoid

cis

terns

of

the brain

during

surgery.

J

Neurosurg

44: 298- 302



174

8.

The

Ambient

an

d Interpeduncu lar Cisterns

Fig. 8.8.

Pl

crion

al approac

h

to

ambient and inter

peduncular cisterns (see

Fig

. 8.7 and Fi

g.

4.7). pr,

Probe retracting the ill ternal carotid artery

(ica); 2,

right

optic nerve; ac, anterior cl inoid process; aI',

arachnoid: pc, posterior clinoid process; Ie , tentorial

edge;), oculomotor nc n

c

at lateral oordcr

of

inter

pedu ncular cistern and emering cavernous sinus

through oculomotor ostium (see FIg. 8.3);

sea,

s

uper

"

jo l

"

cerebe

ll

ar

artery;

col,

cononoid:

rei,

tem-

\Xlra

lobe retractor;

pons,

rostral pan of pon

s; pea,

posterior communicating anery entering posterior

cerebral artery at the

pol (P- /)/P2(P-2)

junction;

p,

anterior

thalamic perforators;

lIIC, urlCUS:

adw, dup

licated anterior choroidal artery; v, \'cin. Note: P

-2

ar

tery

and

basal vei n

of

Rosenthal lie ill ambient cis

tcrn between pontomesencephalic region and tem

porallobe. From F

ox

lll.



A

na

to

m

y

1

7

fi

g .

8

.9

. S

a

m

e ca

se

a

s

i

n f

oig

8.

8.

P

ro

b

e (p

r)

isr

et

r

c

t-

i

ng

po

s

te

rio

r

c

om

m

u

n

ic

ati

n

g

a

r tc

"

y p

ea

)

to

s

ho

w

o

ri g

i

n o

f

su

p

er

i o

r

ce

re

b

el

la

r a

rt

e r

y

.s

ta

) f

ro

m

b

as

il

ar

a n

e

ry

ha

)

in

i

m

cr

p

cd

u

n

cu

l

r

cis

tc

l l

.

m

; A

r

ac

h

no

id

:

po

rl

S

r

o

st r

a

l

pa

rt

o

f

p

o n

s

; J

b

as

e

o

f

oc

u

lo

m

o t

or

ne

r

ve

n

r

in

g

o

u t

t

its

m

i

db

ra

in

or

ig

in

: /

1-

/,1

-

1

a r

-

t

er

) ;

p-

2

-2

a

r

te r

),

e

n t

c

rin

g

a

m

b i

en

t

c i

s t

e r

n

: Ii

-re

i

te

m

po

r

al

l

o b

e

re

tr

ct

o r

: a

c}

w

d

u p

li

ca

te

d

a

n t

er

io

r

c

h

or

oi

da

l

a

rte

r

y ;

Im

e

,

un

c

u

s;

V,

v

ei

n :

fl-

rr

t,

f

rO

ll

tal

lo

b

e

rc

tr a

c

t

O

l';

2,

o

p t

ic

n

er

v

c :

e

a,

in

te

rn

a

l c

ar

o

t id

r

t

cr

y:

pc

, p

o

s

te

ri o

r

c l

in

oi

d

p

ro

ce

ss

.



176

8.

The Ambient

and


Fig. 8.10 . Path

of

posterior communicating anery

(pea) in another case.

The

thickened

(horn

pre

vio

us

subarachnoid bleed) arachnoid membrane of

Liliequist

(mem)

se parates unseen interpeduncular

cistern from carotid cistern.

Th

e posteri

or

com

municating anery (pea) follows posterior extension

of

carotid cistern

to join

(*) the posterior cerebral ar

tery

(p-2)

in the ambient cistern.

The

1'-2 anery

(P-2)

ascends

in

the wing

of

the ambient

cistern. ica,

Internal carotid artery; at, alllerior clinoid process;

Ie, tentorial margin: 3, oculomotor nerve; /l·rel, tem

poral lobe retractor; p, anterior tha la mic per

forators;

ar,

arachnoid membrane ensheathing pos

terior communicating artery and its perforators (p);

rei,

re lr

actor

displacing M·l artery and carotid ar·

lery bifurcation median),;

a /,

ol 'igill of A·] ,trtery; 2.

right optic nerve; at, anterior clinoid process. From

Fox

[2].



Anatomy 177

Fig. 8.11. Same case as in

Fig

. 8.

10

. Membrane

or

Liliequist

(mem)

has been opened, revcaling intcr

peduncular cistern.

), Ri

ght oc ulomotor

ne n

'e;

p,

lateral medu

ll

ary perforators: bo, basilar artery; r-

sea,

right superior cere

be llar

artery;

p-2 , P-2

artery;

pea,

posterior communicating artery; INd, medial

side

or

lert (opposite) pedu ncle

of

midbrain. From

Fox [2).



178

8. The Ambiem and

Im

erpeduncular Cisterns

Fig. 8.12. Another case illustrating an unusual pre

sentation of the posteriordinoid proce

ss (PC) pr

oject

ing up between optic nerve (2) and internal carolid

artery

(ica). gr,

Gyrus rectus;

a-J, A-

I

ar

tery;

v,

vein;

unc,

UIlCUS;

J,

oculomotor nerve;

an,

collapsed

aneur

ys

m at posterior communicating artery; clp,

clip

on

aneurys

m; Ile, a

nter

io r clinoid

process.



Anatomy

li9

Fig. 8.13. Another case with view

through

ca rotid

cistern into interpeduncular cistern. m-l, t.

·I-1

arte ry;

a-

l ,

A- I artery;

ot,

op t

ic

tract; p, hypothalamic

and

anterior thalamic perfor,llors; ch,

opLic

chiasm; 2,

right optic nerve; ac,

am

erior clinoid process; ica, in

ternal carotid arterY;CTossed arrow, origin of posterior

communicating artery (pea); ac/uJ., anterior choroida l

artery; pol, P

_I

arte ry;

p-2,

P-2 arte ry; 3, oculomotor

nerve;

br, branch

from s

uperior

cerebellar

arte

ry

(sea); PO/IJ, rostral pons; an, aneurysm

of

basilar ar

tery (00) at ori

gi

n

of

s

uperior

cer

ebe

llar artery (sea);

pe, posterior cl inoid process;ds, lOp of dorsum sellae.



1

80

8. The Ambient and Interpeduncular Cisterns

Fig. 8.14. Same case

as in Fig.

8.13, looking leftward

across interpeduncular cistern.

fl.

Frontallobc;

ret,

retractor on internal cal"Olid artery

(ica)

and its bifur

cation; p, ilnte ri

or

thalamic perforators; 2, right

optic nerve; ac, amcrior clinoid process; l-pc, left

(op'

posite) posterior clinoid process; tis, LOp of dorsum

sellae; pc. right posterior clinoid process; I-sea, left

supe

ri

or cerebcll,ll" artery; ped, medial side of left

I·sea

peduncle of midbr.aiu; 3, left and right oculomotor

nerves; cmssed Ulnm',

one

of

twO

malleable clips on

posterior communicating an c

ry

(pea); b-Ul . base of

bifurcation aneurysm

of

basilar

anery

(00); /1-1,

right

pol

anery; /1-2, right

P-2

artery;

UIlC, uncus; If-ret,

tern

porallobe retractor; pons. rostral pon s;

an,

dome or

aneurysm at hidden origin

or

I'ight supcl·iorcerebcl.

lar artery (r-sea).



Anatomy lSI

Fig. 8.15. Same case asin Fig

s.

8.13 and 8.14. showing

posterior circle

of Willis

in

interpeduncular

cistern.

2, Right optic nerve;

iea,

internal carotid al· tery; ae,

anterio

r clinoid process;

i-pea

, left posterior com

municating ane ry:

p-2,

left and right P-2 arteries;

p-I.leftand

right - 1 aneries ;J, left (labeled twice)

and

right oculomotor nerves: l-pc, left posterior

clinoid process;

r-

pc, right posterior clinoid

pr

ocess;

00,

tip of basilar

artery;

an,

aneurysm at bifurcation

of hasilar artery;

p,

posterior thalamic perforators;

ped, medial side

of

left peduncle of midbrain;

sea,

right superior cerebellar artery: pons. rostral pons;

crossed r r ~ malleable clip on caudal

end

of severed

right posterior communicating arte ry; Inc, uncus.



182

8. The Ambient and Interpeduncular Cis terns

Fig.8.16. Another case illustrating the posterior


(pea)

and its amerior thalamic

perforators (p)

st

uck together by adhesions from

previous hemorrhage. WIC, Uncus; aeM, anterior

choroidal artery;

mol,

M-I artery;

pr,

probe retract

ing internal carOlid ar tery (ica);

a-I,

A-I artery; 2,

optic nerve; pc, posterior

cl

inoid process; mem, thick

ened membrane

of

Liliequist;;, ocu lomotor nene .



AnalOmy

183

Fi

g.

8.17.

Anothcr case wherc the

amer

i

or

thalamic

perforalOrs (p) are stuck IOgether by adhesions in

their c

ncl

os ing arachno

id

sheath. pr, Probe retr

ac

t

ing intcrnal carotid artcry (ita); acha, duplicated an·

terior choroidal artery and p

er

forators;

crossed arrow,

origi n of antcriorchoro idal

aner

),jan, aneurysms at

origin antcrior c

horoi

dal artcry (bottom) and pos·

terior co mmunicating artery (toP):

2,

optic

nc n

'c;

boo,

bif

ur

ca

ti

on

of

basilar artcry:

00,

tr

u

nk of

basilar

artcry;), oculomotor ncrve;sca, superior ccrcbellar

artcr),;

p-2,

P

-2

an ery; po

l,

P_I artcr

y; pea,

posterior

communicating

artcr

y;

II",

uncu

s.



184

8.

T he Ambient and I

nterpeduncular

Cisterns

Fig. 8.1 8. Following

posterior

comm unicating

artery

(pea) toward interped uncul ar cistern hidden behind

mem

brane

of Lil iequisl (mem). col, Coltonoicl;

rei,

tempora l lobe retraCLQr; J, oculomotor nerve; unc,

uncus;p, anterior thalamic perforators and A-I per

forators;

akl,

anterior temporal artery; mol, M-l af -

col

" I

tery;

a-I,

A-I ar tery; 2, optic nerve;

aeM,

atHerior

choroid al artery;

ica,

internal carotid artery; crossed

arrow,

origin of posterior co mmunicating artery

(pea); all,

aneurysm at

or

i

gi

n

of

posterior com

municating artery; It, tentorial margin;pc, post

erior

clinoid process.



Anatomy

185

II ret

Fig. 8.

19.

View ofrightlatcra

J portion of intcrpcdun

cular cistern after opening membrane

of

LiliequisL

jl-rtl.

Frontal lobe retractor;

p,

perforators from

bi

fu

rcation

of

internal ca rotid artery (iea);

01,

optic

tract; a-I, A-I artery; mem, medial

jX>rtion of

mem

brane

of

Liliequist;

pc,

posterior

cl

inoid process; 00,

basi

lar artery;

an,

aneurysm of basilar

ar

tery at ori

g

in of

superi

or

cerebe ll

ar

artery

(sea);

p-l, P

_I

artery;

p-2, P-2 artery; m-J, M-l artery; m-2,

M-2

artery; It-nl,

temjX>ral

lobe retractor; unc, uncus; 3, oculomotor

nerve;

fe,

tentor

ial

margin.



186

8. The Ambient

and

Intt:rpWuncular Cisterns

Fig. 8.20. Anothe r case with view

of

right lateral por

tion of interpeduncu lar cistern after remm'

al

of

mcmbr.mc of Liliequisl. Notc how oculomotor

nerve (J) gathers together from a broad band exiting

the midbrain. pons. Ro stral pons; sea, su perior cere

bellar artery;

00,

basilar artery near

its

bifurcation: Ie,

margin of tentorium;

/1,

temporal lobe;

col,

cot

lO

no

id

;

rei,

retractor:

p-2,

P·2 artery;

p, perforat

ors;

111-2.

M

-2

artery:

mol,

M-l

ar

ter

y;

ot, optic tract; a-I.

A-I artery; 2, opt ic nerve; mem, membrane

of

Liliequisl (anterior re nectio

ll around

pituitary

stalk); ial, internal carotid artery; pea, posterior com

municating artery;

aciUl,

anterior choroidal ar tery;

pol, P_I artery. Reproduced by permission from Fox

JL (1985) Micros

ur

gical expos

ure ofve

rtebrobasilar

ane

urysms, in Rand RW (cd): Micr

mleUrQS1I1gery,

cd 3.

Sf Louis, CV Mosby Co, pp

589-599

[3].



Anatomy

187

Fi

g. 8.21 . Same case as in Fig. 8.20. Internal

caro

tid

artery

(ica

), mid dle cerebral

ar

tery (m-I), and pos

teriorcomm unicating ar tery (pea) retracted medially

by

narrow retractor (rtt) to expose cemer or imer

peduncular cistern containing aneu rys m (an) at

bi rurcation

or

bas ilar

ar

tery (ba). Except at its base,

aneurys m is covcred by a

carpe

t or

fi

brin. p-I. Left

(loP) and

ri

ght (bottom) P-l arte

ri

es;sca, right superior

cerebe

ll

ar a

rt

ery: Ie, margin or tentorium : J,

oculomOlOr nen'C; pons. rostral pons; p. one or sev

eral anterior thalamic perrorators rrom postcrior

communicaling art.ery; 2.

opt

ic nerve; /le, anterior

cl

inoid process:pc, posterior

cl

inoid process. Repro

d uced by perm

is

sion rrom Fox

J L (1985)

Micro

neurosurgical exposu

re or

verte

br

obasilar an

eurysms. in Rand RW (cd): M icrotll'UfOsmgery,ed 3. 51

Louis. CV Mosby Co, pp 589- 599 [3).



188

8. The

Ambient and

Interpeduncular

Cisterns

Fi

g.

8.22. Example of ventral surface of

bas

ilar ar

lcry

(ha) in interpedunc

ular cistern flanked

by

oculomotor nerves (3). The membrane of Liliequist

has been removed. t-sea,

Left

superior cerebellar af

tef),; r-sea, right superior cerebellar artery; ], right

and left

oculomotor nerves; lie, right posterior

clinoid process; pol, left and right P-l arteries;

I),

cot

posterior thalamic perforators from

pol;

*, base of

basilar

tip aneurysm; ica,


ret,

rClraClOr displacing iea bifurcation medially; aelia,

anterior choroidal

arter

y; fl. frontal lobe;

col,

cot

tonoid;

/l-ret,

right temporal lobe re tractor; crossed

arrow, malleable dip on caudal end of severed right

posterior

communicating arte

r

y.

From

Fox [2J.





190

8. Th e Ambient

and


,.1

'01

Fig.

8.24. Another case

illustrating anatomy at j unc

tion of carotid,

interpeduncular

, and ambient cis

terns after removal

of

arachnoid mem brane

of

Lilicquist. rei, Retractor displacing internal carotid

a

rt

e l

)'

media

lly; CQl,

couono

id

s;

p,

perforators; mol,

M- I artery;aw, duplicated anterior temporal artery;

v, veins; pons, rostral

pons;),

oculomotor nerve;sco,

superior cerebe llar artery; 00, basilar artery; pea,

post

erior

communica ting artery in carotid cist

ern;

p-2, P-2 artery emering

wing

of ambient

cistern

be·

tween pons and lemporallobe ;p-J, p

ol

artery going

medially in interpeduncular cistern. From Fox [2J.



Ana{Qmy 191

.

co.

J

r

)

I

/

Fig. 8.25. Same case as in

Fig.

8.24. View of ventral

aspect

of

bifurcation of basilar artery (boo) and inter·

peduncular cistern between ocul

omO{Qr

nerves (3).

00, Basilar artery: sea. right superior cerebe llar ar

tery; p-l, right (labeled twice) and lef P_I arteries;

p-

2, right P-2 artery; pons, rostral pons; v, ve ins; ala, an-

terior temporal artery;

mol.

M-I artery; col, (ot

{Qnoid;

rel, retra({Qr on ica; p, posterior thalamic per

forators; i-sea, left superior cerebellar artery;

an,

aneurysm

of

tip

of

basilar

artery;crossed

arrow, caudal

end

of

severed posterior communicating artery

(with malleable dip s on

it).

From Fox

[2]

.





Anatomy

193

fi

g.

8.

27

. A vicw through carotid and interpeduncu

lar ciste

l'll

s into prepoilline cistern anterior to the

pons

(PO"s). ll·

rt

t ,

Temporal lo

be

retractor; co

l,

cot·

tonoid;

fl ·ret,

frontal lobe retrac

tor

;

clp.

shank of

aneurysm clip on an 3mcrio

rco

mmunicat ing artery

anc

urys

m;

a·l.

A-I artcr

y;

mol. M-l an ery;

tmc,

1I

.t

00'

uncus; sea, superior cerebe llar

anery

; an , aneurysm

of bas ilar artery

(1M)

at takeoff of amerior inferior

cerebellar anery ;J, oculomotor nerve;

pc

. posterior

cli

noid process; ic

a.

internal carotid artery. From

Fox

[2].



194

8. The Ambicni and Jnterpeduncular Cisterns

Fig. 8.28. Another case with view of carotid, inter

pe

dun

cular, and rostral

prepontine

cisterns.

Ie,

Mar

gin of tentorium; mem, remainder of membrane of

Lilicquisl (most removed): rti,

tempora

l lobe retrae

LO

r ; pons, rostral pons; J, oculomotor

ncn'c;jK.

post-

crior clin oid process; ac, anteriorclinoid process; ica,

jlllcrnal

carotid

artery; 2, optic nCl've; QI. optic tract;

a-I, A-

I

artery; m-l,

M-I

artery; p-2, P-2 artery;p-J. p.

I artery; crossed

arrou,

origin of posterior com

municating artery.



Anatomy 195

fig. 8.29. Same case as in 8.28 with medial re

traction

(1"(/)

of

the internal carotid artery

(ica).

2.

Optic ne

rv

e:

ac,

anteri

or

clinoid process;

pc, pos

terior clinoid process;p·l, left (obscured with blood)

and right P-

J

arteries; " bifurcation

of

basilar artery;

an, aneurysm

of

b.1si lar artery at takeoff

of

hidden

right su pcrior cerebella r artery;

),

oculomotOr n

en

'e

entering cavernous sinus;

POtU,

rostral pons;

p,

per

forator;

p-2,

right

P-2

artery:

pea,

posteri

or

com

municating artel")'; m-l, M·J artel")'; 0-1, A- I artery;

01, optic tract.



196


Fig.

8.30. Same case as in Figs. 8.28

and 8.29.

View of

bifurcation

of

bas ilar artery (boo) in center

of

imer

peduncular cistern. pol,

Left

and right po l arteries;

J, ocu lomotor ncn"c;

all,

aneurysm at o

ri gi

n of

superior cerebe llar artery (sea); Ie, margin of ten

LOr

ium; pons. rostral pons; *, bifurcation of imernal

carotid artery; ret, retractor d isplacing imernal

carotid artery media ll

y.





198


Fig. 8.32. Same case as in Fig. 8.31

at higher

magnifi

cation to show

anterior

thalamic perforators

(p)

from

postcfiorcommunicating

artery (pea) and thei r

ensheat

hi

ng arachnoid. ar, Thickened arachnoid

bands within envelope of arachnoid about per

fo

rators and posterior communicating arter

y; un"

uncus of right tern poral lobe; adm , anterior choroi

dal arter

y; ica,

interna l carotid

arter

y;

QI ,

optic tract.



AnalOmy

199

Fig.8.33. Same case as in Figs. 8.31 and 8.32.

Arachnoid membrane

of

Lil

ie

qu ist has becn dissect

ed

away.

Note how pterional approach can g

i\

·c

panoramic vicw

of

chiasmatic, lamina terminalis,

carotid, ambielll, and interpeduncular cisterns. 2,

Both optic nerves;

eh,

optic c

hi

asm;

It.

lamina ter

mi

nalis;

01,

right optic tract;

a.-I,

A-I arter

y;

p, pe r-

forators;

m-J, M-l

artery;

m-2,

M

-2

artery;

ar,

ar

achnoid sheath; aeM, anterior choroidal artery;

ita,


an,

aneurysm;

pea,

po

s

terior co mmunicating artery;

00,

basil

ar

artery;

p-

l ,

P-I

artery; p-2 ,

P-2 arter

y:),

oculomotor nerve;

sea,

orig

in

of

right superior cerebell

ar

artery.



200

8.

T he Ambient and Interpeduncular Cisterns

Fig. 8.34. Anoth

er

case illustrating bifurcation of

basi lar artery (boo) in interpeduncular cistern.

I-sea,

Left

superi

or

cerebell

ar

artery;

pc

. posterior clinoid

process;

),

left

(hid

den

in

shadows) and right

oculomotor nerves;

v,

vein;

r-sea,

origin of right

superior cerebellar artery;

{1-J,

right and left

pol

ar-

teries in interped uncular cistern;

pea,

posterior com

municating artery;

p-2,

origin

of

right P·2 arter

y; p,

perforators;

Il-ret,

temporal lobe retractor; unc,

uncus;

mol, r.1- 1

artery; ot, optic tran;

ha,

artery

of

Heubncr;jl, frontal lobe;

a-I,

A- I artery; aCM, an

terior choroidal artery;

ica,

internal carotid artery.



A

Abducens nerve, 171

Acoustic nerve, o

ri

gi

n of, 17 1

Adhesions

arachnoid membrane, 94

between frontal and temporal

lobe

s.

56,

71

ca rotid ar lery aneurys m to

oculomotor ne

rv

e,

111

fr

on

t

al

lobe

to

oplic tract,

10.

Ambient cistern, 165-200

anatomy of, 172, 199

body of, 169

junction with ca rotid and i

n

t

erped

unc

ul

ar cistern

s.

169, 172, 190, 192

junction

wi

th

sy

lvian and

chiasmatic

cis

terns, 169

Aneurys m

anterior cerebral ar te ry A-I,

92, 161

anlerior choro

id

al artery. 92.

108

at o rigin, 84, 115, 183

anterior co mmun ica ting ar·

lery, 124, 132, 137, 139,

140, 1

43-

144, 193

hypothalamic perfo rators

stuck to, 125, 149

basilar arte r

y_ Stt

Bas

ilar

af

te r

y.

aneurysm of

internal carotid a

rt

er y.

See

Caro

ti

d artery, in

terna

l,

a neurys m of

middle cerebral a

rt

ery M- I

al b

if

urcation, 76-77

dome in temporal lobe, 75

fl

anked b y tempora l and

frontal M-2 arte ries, 78 -

79

Index

posterior cerebral an ery P-I ,

120

posterior co

mmun

icating ar·

tery,

11

4. 178

at o rigin. 11

5-

11 6, 183-

184

,197

at

supe

ri

or cerebellar artery

ori gin , 180. 185, 196

Aqueduct of

Sy

lv

iu

s, 166

Arachnoi d, 156, 174- 175

anterior re fl ec

ti

on at pitu

itary sta lk , 125, 186

between frontal and temporal

lobes, 72

sc \'ered by microscissor

s,

56,84

between left

op

tic nerve and

frollta

l l

obe. 140

bet

wee

n op t

ic

nerves,

98-99.

10

2,

116, 132-134, 148,

160

covering internal carotid ar

tery and o pt ic ner

ve,

53,

74

disten

ded

by cerebrospinal

fl uid , 56.

59

at interhemisphe

ri

c

fi

ssure,

144, 150, 153-155, 160

at pituitary stalk, 138, 169

s

ur

gica l ope ll ing of, 57, 87-

88, 177

and se paratio n

by

fo rceps

blades, 64-65, 67

at sy lvia n fissure. 146

Arachno id bands or fibers, 57,

87.90-91,

11

7. 153

at anterior cerebral ar tery

A- I , 84, 127, 161- 163

in arachnoid envelope of tha

lam

ic

per

fo

rators and

posterior communica ting

artery. 198

be

tw

een hypothalamic

per

forators

and

o p

tic

tract,

81

between m id dle cerebral ar

tery branches, 56, 70-

73

betwee n middle cerebral M-l

a

rt

ery and te

mpor

al

lobe. 80

between sy lvia n vessels and

pi a, 63

at illlernal carotid artery, 67.

11 6

at lamina terminalis cistern,

125.14

1

at optic nerve/carotid artery

j unc

ti

on, 67

at posterior communicating

ar tery, 83

in subd ura l space, 56, 58,

60-6

1

at sy lvia n fissure base. 56,

65-66

Arachnoid membrane of

Lili

e

quist, 68-69, 93-94, 98-

100, 103-104. 107, 111 -

112, 116. 11 8. 125, 134,

138, 141 , 146- 148, 151,

165-166, 184

adhesions of, 94

attac

hm

ents of, 98

colorat ion of. 97

medial portion of, 185

at pituita ry sta lk , 125, 138.

147 - 148, 1

86

re flection of, 98

removal of, 188

surgical

ope

ning of. 177

thickening after hemorrhage.

170, 176, 182





tentorium of. See Tentorium

cerebe

lli

ve rm is of, 169

Cerebral arteries, anterior, 124,

1

67

A-

I artery, 77, 85, 91, 93- 94,

10

1,

11

0,

11

3-

115. 118,

120, 123, 124, 133-135,

178-179, 182, 1

93-195,

197, 199-200

ane urysm of, 92, 16 1

arachnoid band over, 84,

127, 161- 163

hypoplasia of, 125. 146-

147, 149

left,

11

9, 125, 126,

136-

140,143-

144,149- 157,

159-160. 162-163

bridgin g artery to anter-

IOr

communicating

artery, 127, 162

or i

gi

n of,

82-83.

100, 108.

11

7,176

perfo rators from, 57.

79 -

80,82,84,92,106.141-

142, 161 - 163, 170, 184,

186, 199

rel

at

ion to artery of Heub

ner, 95

right. 125. 126, 136- 140,

143-144, 1

50-

163

junction wit h right A-2,

11

2

tran ssy lvia n view of, 82-83

A-2 arter

y,

126, 156-157

and

common tru nk for ar

tery of Heubner and

ri

ght

frontopolar ar tery,

126, 15 1

left. 137. 139- 140, 144,

153

- 158, 160

bri

dg

in g artery from an

t

er

ior communicating

artery. 112, 126,

154, 157

or

igin of, 159. 163

right, 120, 137. 139- 140,

143,

149. 153-158, 160

junction wit h ante rior

communicating ar tery,

144

ju nction with right A- I ,

11 2

origin of, 163

accessory. 126, 1

56-

157

o

ri

gi n of, 127. 160

in

c

hi

asmatic ciste

rn

, 55

Index

Cerebral arteries, middle. 55

branches of, 56, 57,60,66,

70-71,75,86-90,133

M- I artery. 84-85, 93, 94,

118, 120, 123, 14 1- 142,

144, 1

62-163,

179,182,

193-195, 197, 199-200

aneurysm of

at bifurca tion, 76-77

dome in temporal lobe,

75

nan

ke

d by temporal and

frontal M-2 arteries,

78-79

deep in

sy

lvian fissure,

89

emering sylvian fissure, 81

frontal artery from, 75, 89

l

ef

t, 11 9

long, 67, 78

orig

in

of,

82-83,

106, 108,

112- 11 3,

11

5, 117

perforators from, 57.79-

8 1

,89-92,125,1

46- 147,

170, 181, 1

84-

187, 190-

191,200

short, 57, 79

tran ssy lvian view of, 82-83

vari

ations in, 57 ,

75

M-2 artery, 83,

90,157,

185-

186,199

aneu rysms at bi fu rcatio n at

M- I

.77

dee

p branches of, 87

frontal artery from, 61, 76,

80,88, 146

variations in, 57, 75

Cerebral arteries, posterior.

108-109, 1

66-

167

1'-1 artery, 1

75

, 179, 183,

185-186, 194

aneurysm of, 120

ascending. 169

course of, 170, 172, 190

left, 171, 181, 187- 189,

191. 195-196,200

ori gi n of. 165

perforators from, 165, 168,

1

81,188,195

right, 180-18 1, 187-189,

191, 195-196,200

short, 165

P-2

artery, 109, 114-1 15,

165, 176- 177,179. 183,

185, 192. 194

course of. 170

entering ambient cistern,

175, 190

l

ef

t, 181

perfo rators from, 186,

190--191

203

right, 171, 180- 18 1. 19 1,

195

origin of. 200

relation of

P-

1 and

1'

-2

to


artery. 170, 172, 174.

186,199

Cerebral peduncle, 166

Cerebrosp in al fluid

circulation of, 94

in distension of arachnoi d

membrane, 56, 59

drainage by lumbar punc

tur

e,

40-4

1

flow through interpedu ncu

lar cistern, 165, 166

in

m

id

brain

se<:t

ions, 169

Chair, surgeon's, 16

Chiasmat

ic

cistern. 93, 1

23-

164

anatomy of, 123-127. 172,

199

struc

tu r

es in. 126

union with

sylv

ian

and

am

bie nt cisterns, 169

Choroidal artery, anterior. 57.

77,80--82,85,91,107,

110, 112- 113,

11

8, 145,

1

62-

163, 179,182,184,

186, 188, 192. 198-200

aneurysm of, 92, 108

at origin , 84. 115, 183

cou rse of, 172. 197

duplicated, 174, 175, 183

origin of, 95, 100, 104, 134,

144, 152, 1

83

perforators from, 183

relation

to

uncus of temporal

lobe, 95, 105

Circle of Willis

posterior,

18

1

relat

io

n to poste

ri

or clinoid

process, 167

Clinoid process

of

sphenoid

bon'

anter

ior, 37-38, 4 1-44. 5 1,

69,83, 100, 107- 108,

11 0- 11 2. 116- 11 7. 123.

128, 1

34,141-142,

147,

1

51-

152. 156, 167, 169.

174, 176,178-18 1, 187,

194- 195

attachment to t

entor

ium,

165

righ

t,

140, 157



204

Clino id process (to'I/.)

posterior,

37-38, 42

-45,

66-

67 ,69,83,98,100, 106 -

10

8,

110-1

11

, lJ

8,

[20-

121, 1

38,152,

162, 167,

169 , 174-175, 179, 182,

1

84-185,

187, 193- 195,

200

attac

hment

to tCllloriutn,

165

dura on, 99, 102. 118

left , 170, 180--18 1

relation to internal carotid

artery. 96, 114- 115

right, 114, 166, 170, 180-

18 1, 188

unu

sual

pr

esentation or.

170, 178

Communicat in g artery. anter

io r, 11

3. 120, 150, 159,

163

aneurysm of,

124, 132, 137,

1

39-

140, 14 3- 144 , 193

hypothalamic perforators

stuck

to,

125, 149

bridging artery from left A·I,

127, 162

bridging ar tery to left A-2.

112 . 126 , 153 - 154, 157

duplicating, 126, 127, 134,

ISS, 158. 164

ju nction

with A·I

and A-2

arteries,

112, 144

perforators from , 11

2, 157

triplicating complex of, 125,

144

variations

in

complex of,

126.

127 , 1

53-

157

V-shaped. 126. 152- 154.

156-157

Communica ting artery. poster·

io r, 77, 85, 91, 99.

11

2-

11

3, 162- 163. 175,177.

195, 200

adjacent aneurysm, 114

aneurys

m

of

collapsed, 178

at origin, 115- 11

6, 183-

184, 197

in

carotid cistern, 190

caudal end in interpeduncu·

lar ciste

rn

, 165

clips on, 170, 178, 180- 18 1,

188, 1

91

course of, 176

ensheathed by arachno

id

membrane, [76

Index

hidden by internal carolid ar

tery, 192

junction with P· I and P·2 ar·

teries, 170, 17

2,

174 , 186

lateral direction of, 95, 106-

107

left ,

11

8- 119, 138

origin of. 95.

98.100-10

1,

104- 105.11 1. 134, 141-

142, 144,152- 153,179,

1

84,194

perforalOrs fr

Om

hypophyseal,95, 102

hypothalamic, 95. 102-

10

3

thalamic, anterior, 82-83,

95, 102- 103, 109- 110,

172.174,176

, 180, 184,

187.190, 192 , 1

97-

198

adhesions in arachnoid

sheath of. 170. 182-

183

in arachnoid sheath. 198

preane

ur

ysma l type of infun

dibulum. 95. 1[0

relation to P· I and P-2 arter

ies, 170 , 172. 174. 186,

199

right , 138, 17 1

sma

ll

, 95, 108

Cranimomy, right frontolateral,

39

Cribriform plate, 124, 130

Crista

ga lli

,

124

, 130-13 1

Cushing, Harvey. 2, 3. 4

D

Dahlgre n. Karl, 3

Dandy, Walter, 4, 5-6

De Martel, Thierry. 3-4

Diaphragm sellae, 106. 1

12

,

118

ope

ning for pituitary sta

lk

,

167

Dissecti ng instruments, 29, 30

Dorsum se

ll

ae,

166

front of. 115

relation to b

asi lar artery ter·

mination, 168

side of, 114- 1

15

top of, 114- 11 5, 170, 179-

180

Doyen, Emile,

3

Drake, Charles, 16, 18

Drills and bur r

s,

24, 41

Dura

of

crista g'd

lli

. 130

exposure o

f.

40, 49-50

frontal,49-50

margin of, 62

as optic c

ana

l margin, 128

of

orbital roof projections.

129, 13 1

of posterior

cli

noid process,

99, 102, 118

of

sphenoid wi ng, 65, 68, 72,

86

of sy lvian

fi

ssure , 50

tempordl, 50

venous

si

nus in , 114-115

Dural

flap,

4 1

E

Electrocautery, 24-26, 39. 40-

41

F

Facial nerve

fron talis branches of, 40

origin o f. 17 1

"alciform ligament, 167

Fi shhook retractors. 22-23, 39,

48

"1aps

cranial.

39-40

dural,41

scalp.

39. 47-48

Foramen ovale.

38

Forceps

electrocautery, 24-26

jewelers, 27, 29. 56. 62

to open and se parate arach

noid, 64-65, 67

" rontal M-2 arteries, 61, 70,

75-76.

88-89

microaneurys

llI

s of. 76

frolll middle cerebral M-I ar

tery. 75. 89

from middle cerebral M-2 ar

tery. 6

1,

76, 80, 88, 146

aneurysm flanked

by

,

78 -

79

Frontal

du r

a. 49-50

Frontal lobe. 53, 58-59, 6 1-64,

66,69.72,74-75,77,

81-83,85-87,91,180.

188.192

ad hes ion 10

op

tic

tr

acl,

104

adhesion to temporal lobe,

56,71

ba

se of,

131

c1 evillion of, 52, 124



left, 1

39-

140, 150

in quadrang

ul

ar

zo

ne of

chiasmatic cistern, 132-

133

righi , 139, 143, 150, 155, 171

Frontolaleral craniotomy, right,

'9

Fronto-orbita l arteries, 114,

124 , 1

32-

133, 13

7,

14 2,

14 7, 154

l

ef

t, 117, 133, 140, 143--144.

149- 15 1, 155-159,162-

163

ri

gh t, 14 3- 144, 156. 163

fo-rontoparieta l sutu re line, I , 37

Frontopolar arteries

left. 140, 149

low takeoff of. 155

low takeoff of. 125, 149, 155

right,

14

9

common trunk with anery

of H

eub

ner, 126, 15 1

Frontosphenoid al suture li ne,

1,37

Frontotemporal bone

nap

,

39-

40

G

Gigli saw, 3, 24, 40

Gyrus rectus, 65, 98, 105, 120,

123, 124. 128, 161, 178

initial exposure o f,

124

,

132-

13'

H

le f

t,

114 , 137, 142, 14 7-149,

155-156, 158. 162- 163

medial surface of, 133

right, 112, 11 4. 133, 136,

146- 147,151. 1

55-

156

vein on, 99, 143

Hayes, George, 5

H

ead

ho ld er, 1

3-16

H

emor

rh

age, subarachnoid

and adh esions in arachn oid

shea th of thalamic per

foralOrs, 170, 1

82-

183

th ic kened arach noid mem

brane

of

Lil iequist from,

170. 176

and xanthochromic pigment

from hemoglobin, 15 1

Heubner recurrent artery, 57,

80-8

1,9 1. 102, 1

05,108,

113, 134- 135, 142- 143,

Index

14 7, 1

52-

155, 158. 170 -

171

,200

adherent to aneurysm al ca

rotid ar ter y bifurcatio n,

85

cOlllmon trunk with right

fr

omopo

lar

ar

ter

y.

126.

15 1

co

ur

se o f, 127, 164

varia tions in, 125

large size of, 125, 14 6, 149

lef

t,

133, 136- 137, 140, 144,

149, 1

57,159,

162-163

perfo rator from, 83

rela tion to

anter

i

or

cerebral

artery. 95

righ

t,

136- 137. 139, 144,

150, 157, 163

Heuer, George,

4 , 5

Histo

ry

of pte

ri

ona a

pp

roach,

1-7

cranial saws in,

2-3

hypophyseal nap in , 5-6

osteoplastic method of Wag-

ner, 1-2

skin incisions in , 7

trephine and melal guide of

de Mar tel in, 3-4

Hydrocephalus. commu nicat

ing,

94

Hypoph

y.sea

l app roach of

Heucr and Dandy. 4,

5-

6

Hypophyseal artery, superior,

79,84, 95, 99, 102. 106,

120

Hypophyseal

ci

stern , 125. 138,

14 1,

169

Hypophyseal

per

forators

from imern

al

carotid artery,

95,99,

11

5, 125, 138

arachnoid sheath o f, 120

from posterior c

ommuni

ca t

in g ar tcr

y,

95, 102

Hypothala mic perforators

from

in

terna

l carotid artery.

81,95, 102- 103, 106,

11 8, 14

8, 159, 179

from post

er

io r commun ica t

in g artery, 95, 10

2-103

stuck to

anterior

communi

ca ting artery aneurys m,

125, 149

Hypothalamus. mammillary

body

of, 166, 169,

171

Hyrtl's ca nal, 41

205

I

Incisions in skin,

7.

39, 46

Instrumentat

io

n, 11-30

bone-re

mo

va

l, 24

dissccting, 29, 30

electrocautery, 24-26, 39,

4

0-4

1

external, 1

3-22

fishhook retractors, 22-23,

39, 48

intraoperat

iv

e,

22-30

jewel

ers'

fo rceps, 27, 29, 56,

62

mirrors, 29

opcrating microscope, 16-22

overhead table, 22

retf3clOrs, 26-27. 28. 48. 5 1-

52,56,58

scissors, 27, 29, 68, 74

suct

io

n

and

suct

io

ll

-i

rriga

ti

o n

devices, 23- 24, 41

surgeon's chai r, 16

television sys tcms. 22

Interhemispher ic fiss ure

(c

is

tern ), 123, 124. 133, 142,

14

7,

158, 169

arachnoid covcring of, 144,

150, 153-- 155. 160

Interpeduncular cistern, 69,

9l-94, 14 1, 152, 165-

200

anatomy of, 165- 173, 199

ap

pr

oaches to. 170. 1

84-

185

basilar artery bifurcation in.

189

center of, 172, 187, 194 -

196

fron

lO

latera l route

10,

98

j un

Ct

ion

wi

th ambient and

C.t rOlid cisterns. 169.

172,190, 192

right l

at

eral po

ni

on of, 1

85-

186

Interpeduncular fossa of mid

brain, 171

Irri

gat

in

g flu id, 23--24

J

J ewelers' forceps. 27, 29, 56, 62

K

Kempe. Ludwig, 6, 39

Kcy and Retzius membran

e.

Set

Arachnoid me

mb

rane of

Li li

equist



206

L

Lacrimal artery, 51

Lamina lerminalis, 85, 112-

11 3,

123.

124

,

12

5, 1

33-

14 8, 15 0- 151 , 155- 160,

1

62-

163, 192, 197

anatomy 0[, 172, 199

Lamina terminalis cistern, 93,

125

, 134- 136,

144

, 149,

16

9

anatomy of, 160-- 162

arachnoid bands

at marg

in

of, 125, 141

struc

ture

s in, 126

Liliequist membrane.

See

Arach

noid membrane of

Li li

e

quist

M

Mammillary body of hypothala

mu

s,

166,

169

, 171

Medu lla oblongata, 171

Medu llary perforators from

basilar artery. 115, 1

77

Meningo-orbital artery. 41, 51

Microscissors. 27.29.68,

74

Microscope, opera ting,

16-

22

advantages of, 17- 18

disadvantages of, 17

Midbrain

anatomy of, 165, 166

interpeduncular fossa of, 171

peduncle

of

(pyramidal

tr act), 169, 171 - 172, 189

left. medial side of, 177,

180- 181

Mirrors at tip of probes, 29

o

Obalinski, Alfred, 3

Oculomotor nerve

s,

65, 69, 94,

98-100,

102 . 104, 10

6-

1

10, 11

2,

11

5, 121, 152,

169, 176, 1

78-

1

79.182-

183. 185. 187, 190, 1

93-

194, 196, 199

adhesion to carotid artery

ane

ur

ysm, III

adhesion to uncus of tempo-

ral lobe, 170, 184

angulation of, 83

base of, 175

course of, 172

entering cavernous sinus,

170,174,192,195

Ind

ex

le ft ,

114

. 180-18 1, 188,200

origins of, 165

oSl ium of, 167, 174

relation to basilar artery bi

furcation. 19 1

right, 114 , 166. 171, 177,

180- 18 1, 1

88,200

separating superior cerebe

ll

ar

artery. 172, 186

Oculomotor trigone, 167, 172

Olfactory bulb, 124,

131

O lfactory cistern , 123, 124,

129

Olfactory nerves, 1

24

Olfactory stria, medial and lat

eral, 124

Olfactory trace, 53, 95, 98--99.

102, 105, 124, 132-133,

155, 17 1

lower portion of, 128

left. 158-- 1

59

middle portion of, 129

right, 156

upper

port ion of, 130, 13 1

Operating

microscope, 16-22

Operating room table.

13

Ophthalmic artery, 95

left, 148

origin of, 104, 148

Optic ca nal, 38, 167

dural

margin of, 128

Optic chiasm, 80-84, 9 1, 106,

112, 114, 11 7- 120, 123,

133, 136, 14

0-

144, 14

6-

152. 154-156, 158, 160,

162, 1

66,179,192,197,

199

lateral side of, 157

pr

e

fi

xed,

124

, 125-126, 134-

135, 150

Optic cistern , 124

Optic nerves, 52, 66, 69, 77,

82-83, 100-101, 103-

105, 107-

108,

110, 112,

11 4, 11 8--120, 167.175,

1

82-

184. 186-187,

194-

195

arachnoid band over, 67

arachno

id

between, 98--99,

102, 11 6, 132- 134,148,

160

arachnoid covering of, 53. 74

latera l portion in carotid cis

tern, 123

left, 106, 117, 133, 138, 140-

143, 146- 152, 154-156,

158--160,162, 192, 199

in orbit, 124

right, 98-99, 102, 106, 11 6-

117.121, 128,133.138,

141

-

14 3,

146--1

50,152,

154- 160,162,171, 174,

176, 179 - 181 . 19

2,199

unusual relation to posterior

cl inoid process, 170, 178

Optic tract,

79-85, 89-9

1, 106,

1

08-

110, 11 5, 120, 123,

135-136,

145 ,150-

15 1,

154, 1

61-

163, 169,179,

185-186, 194-195, 197-

198, 200

adhesion to frontal lobe, 104

right,

112

,

114

, 118, 133,

138--1 44, 146--149, 152,

155-159, 192, 199

terminus of, 165

view to internal caro tid ar

tery, 103

Or

bit

dura covering roof projec

ti

ons, 129, 13 1

in surgical position, 42-45

Orbital fissure,

super

ior. 38

Orbital gyru s, m

ed

ial. 123, 1

24

p

Parietosphenoid al suture line,

1,37

Parictotemporal suture line, I,

37

Peduncles

cerebe llar , middle, 17 1

cerebral, 166

interpeduncular cistern . Set

Interpeduncular cis tern

midbrain.

16

9, 1

71-172,

189

Perforated substance, anterior,

9.

front border of, 124

perforators to, 57, 79, 84, 89,

118

Perforat

in

g arteries

on a

neur

ysm dome, 78

from anterior cerebral

A-

I

ar tery, 57.

79-80,

82, 84,

92,106, 141- 142, 16 1-

1

63,170,184,186,

199

from anterior choroidal ar

tery, 183

from anterior commun icating

arter

y, 11

2, 157

to anterior perforated sub

stance, 57, 79, 84, 89,

11

8



arachnoid fibers from, 57,

90

from artery of Heubner, 83

hypophyseal. Su Hypophy

seal perforators

hypothalamic. Su Hypotha

lamic perforatOrs

from internal carotid artery.

Su Carotid artery. inter

nal, perforators from

medu llary, from basil

ar

ar

tery, 115, 177

from middle cerebral M-I ar

tery, 57, 79-81, 89-92,

125

,

146-147,170,181,

184-187, 1

90-191,

200

from posterior cerebral arter-

''''

_I, 165, 168, 188, 195

P-2, 186,

190-19

1

from posterior communicat

ing artery. Su Commu

nica ting artery, posterior,

perforators from

stria thalamic, 57, 89-92

thalamic. See Thalamic per·

foralO rs

Pericallosal cistern, 123

Periosteal patch elevated from

frontal bone, 39, 47

Petrous pyram id , 42-45

PhoLOgraphy, 33-35

curre

nt techniques in,

34-35

Pituitary gland, 97, 118, 140,

1

71

in

fu

ndibulum of. 166

Pituitary sta lk , 82, 95-96, 102.

104, 106,

11

0,

114

, 119,

12

1,125, 138, 1

40-

14 1,

146,149

opening for, in diaphragm

se

ll

ae, 167

portal veins of, 11 8

surrounded by arachnoid,

125, 138, 147-148, 169

Pons

rostral paft of, 115, 170, 172,

174-175,179-1 8 1,186-

187, 190-192, 1

94-

196

trigeminal nerve ar i

si

ng

from, 171

Positioning

of

patient, 39

importance of, II , 16

Prepontin e cistern, 193,

194

Psyc hopathic point, 6, 39

Pte rion, de finition of, 1,37

Pterygoid

pl

ates, 38

Index

Q

Quadrangular zone in chias·

matic ciste rn , 124. 133-

163

Quadrigeminal cistern , 169

Quadrigeminal plate, 166

R

Raney

dips

, 47

Recurrent artery of Heubner.

Set Heubner recurrent

artery

Reil is lan

d,

7 1

Retractors, 26-27, 28, 48, 5 1-

52, 56, 58

fishhook, 22-23, 39, 48

self· retaini ng. 26-27

Rongeurs, 24, 40

Rosenthal

ve in

, bas

il

ar, 165,

174

S

Saws, crania l, development of,

2-3, 24, 40

Scalp nap, 39.

47-4

8

Scissor

s,

types of, 27, 29, 68,

74

Sella turcica, 37-38

Ski n incisions, 7, 39, 46

Skull fixation, three·poim,

13-

16,39

Sphenoid wings, 37, 38,

42-43,

45

dura over, 65, 68, 72. 86

prior to removal,

49-50

removal of, 39, 40-41

Sphenoid otemporal su ture line,

1

,37

Sphenoparietal sinu

s,

bridging

veins to temporal lobe,

41,56,66.74

electrocoagulation of. 56, 68

Stria thalamic perforators, 57.

89-92

Subarachno

id

h

emor

rhage

and adhesions in arachnoid

sheath of thala

mi

c per

foralOrs, 170, 182-183

thickened arachnoid memo

brane of Liliequist from,

170, 176

and xanthochromic pigment

from hemoglobin. 151

Suction and suc

ti

on.irrigation

devices, 23-24, 4 I

Suture lines of sku ll , 1,37

207

Sy lvian aqueduct, 166

Sylvian fiss

ur

e (cistern), 52, 55-

92.93-94, 123

anatomy of. 56-57

arachnoid over, 146

dura over, 50

lateral, 169

medial, 169

s

ur

gical openin g of, 56-91

union wit h chiasmatic

and

ambient ciSlern, 169

veins in, 63, 66, 75-76, 78

branches of, 59

Sympathetic fibers on internal

carot

id

artery, 96, 116

T

Table

operat

ing room,

13

overhead, 22

Televis ion systems, 22

Temporal arteries

anterior, 70, 75, 77-79, 83,

88-89,91, 100, 134, 147,

184,19 1

dup

licated. 190

from middle cerebral arter

ies, 70

M·I, 75, 89

M-2. 61,76,80,88, 146

aneurysm nanked by, 78,

79

posterior, 76

superficial. 40

Temporal

lobe, 53, 56, 58-59,

6 1

-62,65-66.69-70,7

4,

85-87,9 1,186

adhesions

with carotid artery, 100

wit h frontal

lobe,

56, 71

aneurysm dome in, 75

br idging veins to sphe

nopa

.

rictal

si

nu

s, 41,56

.66,74

el

ectrocoagulation of. 56,

68

dura of, 49-50

elevation of, 52

left, medial side of,

11

7, 119,

171

medial , 169

right, 120

uncus of, 69, 102, 108-109,

11 2-113, 115, 121, 152,

174-1 75, 178, 180-183,

185, 192-193, 197-198,

200



208

Tcmporal lobe (conI.)

adherence to oculomotor

nerve, 170, 184

left, media l side of, 117

relation to

anterior

choroi

dal artery, 95, 105

retraction of, 83

vei

n on, 1

28

Tempora

l

is

muscle. incision of,

39,47

Tentorium cerebcUi, 166

anterior reflection of, 99, 162

attachments to clinoid pro

cesses, 165

caro

ti

d a rtery aneurysm

adhesion

to,

101

Index

Third ventricle, 145

cerebrospinal fluid in,

169

relation to b

as

ilar artery,

168

Toison, J ean,

2-3

Tre

mor. reduct i

on

of,

29

Trephin

es, development of, 3-

4

Trigemin

al

ne

rv

e.

ri

g

ht

, ar is

in

g

from pon

s,

171

Trochle

ar

nerve,

165, 166

ostium of,

167

Tubercu

lum se

lla

e, 37-38, 43-

44,117,135, 148, ISS,

159

in

interpeduncular cistern ,

190 - 1

91,200

in

lamina terminalis cistern,

127 , 161

portal, of pituitary stalk, 118

in

sulcus belween frontal lobe

and olfactory cistern,

129

in sylvian fissure, 59, 63, 66,

75-76, 78

on temporal lobe, 128

Venous d ra

in

age,

pr

eservation

of,41

Venous sinu

s,

dura

l,

114-115

Ventricle, third, 145

cerebrospinal fluid

in

,

169

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