University of Nigeria Research Publications

Aut

hor

KALU, Ochie.

REG NO: PG/PGD/97/20161

Title

Sonographic Evaluation of Splenetic Sizes in Normal

Adult Nigerians

Facu

lty

Medicine

Dep

artm

ent

Medical Radiography

Dat

e

2005

Sign

atur

e

DEGREE:

*ru

i revcrc (;od who deiennin

grateful to the I f e d of Ilepartn

cicpartmcnt mti this proprnrnmc o n 1

I n l w thank nll who pnvc me

day-to-day till thc last syilahlcs o f 1

usc this opport~mity to thank Mrs. ('

I,et me also thank my colleap

me. Agho. J.A, C'hie~wu I l,rncinlf

rcrnetnhcr n fallen col lcng~ir I 'a t r ick

the department of Medical Radl

1 Iniversity of Nip,cria, F3-wgtr Cnrnpt

Tcnchinyz J fospit~l , ( 1 INTI I ) I ~ ~ I I I ~ Z I I .

1;innlIy I thnnk (;or! for ~ t ~ r

fhtnilv.

Ikclirnfctf t o :

I)r. I..! Okoye. Prof'. H . ( ' Ijmerah

Prof. F.N h k . l l r . A.A Ofidilr

* nonr-rnl splenic s i m s for f l ~ c I ~ r n l i t v . ' I ' ~ c S ~ I C C ~ I was ITICASIII-CC~ i n the S I I ~ ~ I ~

position along the le f t mid sxillar-v lirw. The splenic volttme nntl weight wcre

c a l c ~ ~ l ~ t e d from existing fornmrrln. Age w n s corrclntetl with splenic Icrigtli.

weight anti volr~mc. 'T'hcre was significant difference hetlveen nwlc and

female sizes ( I ' < 0.05). No siani ficnnt difference ruistecl hrtwcrtl t h

splenic sizes of C'aucasians arid that o f the s t ~ d v grmtp ( P 0.05). h > r

correlations existed between age and splmic weight, vcrl~~rnc and Icr~pth. A

good correlations waq found hctwecn h d v weipht a n d ~p lcn i c weight, as

normdl sizcs will cnhancc CAI-lv dctc*c.t inn of spltriic. s i 7 ~ rl~nnnps it1 the

locality and this C O I I ~ I ~ he cr i t ical in evaluation of patholonies involving the

Tit le Page.. ........................

D~dir-3t ion

Approval Pape .....................

Acknowledgement.. ........ .. ... Ahtract

Tghlr nf Pnnfcnfc

CHAPTER ONF: RACKCRCI

1 1 Intrnrfrrctirrn

1 7 Statcm~nt nf Prnhlem

......... 1.3 Pirrpose of Study..

1.4 Significance of Study.. ....

1 .S Scope o f Study.. ...........

1.6 1.imitation.s of Study. ...... 1 7 1 itrrntrrrc Rcvir\rr

C1-I APTER TW(1: A N A T O M \

2.1 Imcation and Rclat ions of

. . 2.2 Stn~cture o f the Splecn..

.............. 2.3 Rlood Sitpply..

2.4 Functions o f the Spleen.. . .

2.5 Physiology of t h e Spleen..

2 . Absence o f the Spleen.. ...

Enlargement of the Splee n.. 15 .............................. 4*

f'arvz~c nf Snlenomenalv.. .................................. 16

MATERlALS AND

...... .3 Scanning Techniques..

4.4 Splenic Width and Thickhess ............................... ...... 4.5 Spelnic W e i ~ t , Area and Volume.. :. ............,...

f - Calculate splenic weight, splenic area and volwne of the different ages with

existing for111r11a and tilid their correlation with age.

- Establish any correlation between body weight arid splenic weight

- Establish rcIati011~11ip between meat1 splenic lengt h with subject Iieiglit.

- Compare tlie splenic length of Nigeria with Caucasians.

1.4 SIGNIFICANCE OF STUDY

- The result obtained from the study will show nonnal range of splenic sizes of

Nigeria11 adults to enable accurate evaluation of the spleen in pathologic

states.

- lt will show any similarity or dissimilarity between tlie splenic sizes of

Nigerians and Car~casinns,

- A population specifk riorrnopan of the splenic sizes will enable critical

clinical decisions to be made with more confidence.

- It will show the probable existence of tlie so-called "small spleen" in this

malaria endemic zme (Burns 1978, Grove 1978).

1.5 SCOPE OF STUDY

The study includes adults from the age of 20 - 75 years. The study was

carried out at the University of Nigeria Teaching Hospital @NTH) Enugu and

Bishop Slianalian Hospital, both in E r q y State of the southeast geopolitical

zone of Nigeria. i

concluded that abdominal palpation is a poor method for diagnosis of

splenornegaly

An ultraso~lograpliic splenic size of 130 x 80 x 30111111 WilS establislletl by

Bisset et a1 ( 1 990). He noted that the length and size of the spleen decreased in

middle and old age. Most studies are in agreement tl~at even tllorlgh the size of

the spleeri may vary, that generally the largest span is the lo~lgitudirlal

dimension, which sliould not be greater tllm 1301nm (Tatnayo et al 1993),

althongli Messhezy et a1 ( 1 997) repofled a inaxitnutn lengtli of I I G t m .

In their own study, Cllauhan et a1 (1996) evaluated the spleen of 90

- healthy adults and claimed that splenic recession rather then splenornepaly is

prevalent in adult patients wlio have sr~ffered fi-0111 falcipnn~t~~ malaria nr who

live in endemic falcipanm zones.

Lotus et al (1998) rtfter his study conclr~ded that racial differences in

splenic length could result iu incorrect interpretation of the splenic size. This

opinion also slrengthens the need for racial population specific splenic

nonnogalns.

Reviewed literature shows that some work has been done to evaluate the

effect of certain disease on the spleen. Hipenstein (1994) studied seven

neonates wlio were being treated with extracorporeal ~nei~~brane oxygeriation

(ECMO) and observed that rapid spleriic enlargement may be secondary to

sequestration of red blood cells, platelets and other Ile~natologic elements that m

I

have been datnnged. K a t h y (1998) also revealed that tioniial spleen may

become hyperactive mid prodr~ce a conditio~i kliowi as Iiypersplenisn~ it1 which

splenornegaly is a presentation.

In 45 heta-tlialnsearnia lreterozygotes and in 38 rioniial controls

Tassiopoulos et a1 ( I 995) determined by ~~ltrasoul~d the niaxim~in diameters and

volulnc of the spJee~~. 'They fou~id t l i ;~ t the volun~e of the splee~i is sigiificmt

m d bigger in I~cterozygotes as opposed to rior-rnals, il l 17.8% of heterozygotes a

palpable spleeri was found. This study lead to the hypothesis that in all

heterozygotes the final volrme of the spleen is it~creased, however, only in the

17.8% was a palpable spleeti found.

Dowriey (1992) assessed the predictability of the weight of resected

spleen From measr~re~nents obtained fiotii real titlie ultrasonograpliy scans. In a

. . . preliminary study of 12 spleens obtained at autopsy ruic'

ultrasonography, the product of the splenic length, width and

linearly related to splerlic weight (r = 0.92). Estirmtion of sl

therefore, possible by a simple calcr~latioti using these paratne

diseases (SCD) predisposes to splenic infection because of

hypospleriisn~, clefective phagocytic arid splenic fiinction. Splenic inL,.,.. ,,.

occr~r in patients who may be considered to have ahsent spleen (Cavenaugli et al,

Spler~ic Illass in patients will1 Iiae~iia~oblastosis wab revealed to be closely

related to the degree of Mastosis (Betimetter arid Abdul Kadyrov, 1993).

Accurate determination of change in splenic size thus appears to reveal a

wide variety of disorders especially linetnafologicnl disorders. If nonnogratns

are established for the population, sr~ch disorders, whicli affect splenic size, will

have enhanced detection.

Pozzato (1998) measured the altmsound splenic lengths of patients with

Iiver cirrhosis and portal liypertensioii pre and post transplant and found a

significant difference in splenic length after transplant, Studies done in the river

basin of Senegal sllowed that patients with intestinal scfiistoso~niasis had

splehomegaly compared with a co~itrol group (Rodriqrtes et al 1993).

Schistosominsis results in "pipe stern" type cirrhosis of the liver and thus can

lead to portal liypertensioti and eventr~ally spleaomegaly. Porcel (1998) deduced

that splenorrlegaly with small inul tiple liypoecl~oic lesions in AIDS patients

should raise the suspiciori of tuberculosis as the first diagnosis.

Grove (1978) and Bums (1978) note that Nigeria is in the malaria

endernic region of the world wllere there are titore likely occurrence of changes

in splenic sizes.

F~~rtliennore, M c ( h c e and Grove stated that sickle cell diseases tend to

occur in persons with origins in Amcan and equatorial cormtries. Nigeria is in

the zone where this disease is prevalent. Although, ultrasonopaohy is m

efficient, cheap and easy modality in the assessn~ent of spGnic size, no work is

known to have been done in the measurement of splenic sizes in the Nigerian

popdation. The researcher therefore, desires to determine a nonnograrn for the

Nigerian population, which is relevant in determining clmges in splenic sizes in

issr~es relating to splenic pathology.

. .

fonn lynpliatic follicles, wliich are sites of lynipliatic production, l'lie red pulp

is composed of erytlirocytes, lympl~ocytes, retic~~loelldotl~elial cells, wl~icll

sw-round nurnerous vascular sirir~soids tl~ror~gh wliicl~ the blood from the splenic

artery passes.

The splecn has a dinpliraguatic and visceral surface. On the rr~edial

visceral surface is the I~ilum tllrorrgli wliicl~ vessels arid nerves enter and leave

the spleen.

The visceral surf;ace faces dnwriwards arid lo the right towards tlie

abdominal cavity.

The visceral peritone~im or serious coat invests all surfaces gastric,

diaphragmatic nlid renal except the hilum. A m a l l area is in contact with the

splenic flexure. Its anterior harder is rlotchcd as a relic of the fusion of several

splenules from which the orgari arises ill the embryo.

2.3 BLOOD SUPPLY

,Yp/enic Arfeqr: This is the largest branch of the celiac tnrnk. It follows a tortuos

course along the superior border of tlie pancreas, posterior to the orner~tal bursa.

Between the layers of the splenorerlal ligament, tlie splenic artery divides into

five or lriore I~rariclies tlltlt enter withiti the liiliirn of the spleen.

Sp/cnic Vein: This is formed by several tributaries that emerge from the hilurn.

I t is joined by tlie inferiur tnesetlteric vein and n w posterior to the body and tail

I

The spleriic veil1 unites with the superior inesenteric vein posterior to the

neck of the pancreas to fonn tlie portal vein. The ~~orrnal calibre of the splenic

vein slior~ld rmt exceed 1 Omtn in AP diameter. I n portal hypertension the

diameter of the splenic vein is triore hatl 1Otn1n.

Lyrnplrntic Drni~rng~: The Iyi~pli drains inlo several nodes lyirig at the hilurn.

The splenic lymphatic vessels leave the lyrnpti nodes in the Iiilutn and pass

along tlie splenic vessel to the posterior sr~rface and superior border of the

pancreas.

Nerves: The nerves of the spleen derive from the celiac plexus and are

distributed mainly along branches of the spler~ic artery and they are vasomotor

in Function.

FIJNCTIONS OF TIIE SPLEEN I

Destrrrcfiorr of Red Dlood Cells: WIle~l the red cells iri the circ~~lation

hcconie old, they fragnierit and the reticdo rndolllelial cells of the spleen

take 1111 the fraginet~ts. The Iiaernoglobin from tile red cells is broken

down aiid the cot~stituents pass to the liver, where the iron is stored and

the pignerlts are excreted it1 the bile.

Forrtrntiorr of Red Blood Cells: From tlie 2nd to the 5th month of intra-

uterine lif'c, the spleen i s an imlmtant sife for pnduction o f red blood

cells (RRC).

Fornrnfiori of Ljwrplrocytes: The spleen fonns some of the lytnpliocytes

Forrttclfim of Antibodies nrrd Arttifo- in: The retic1110 erldotllelial cells of

tlic spleeri are together with other cells of the reticr~lo er~dothelial cells

system, respo~isihle for the production of antibodies a t i d arititoxins.

A Rescrrwir for /Ilood: The splccr~ car1 constrict mid push up tn 200mls of

blood illto the circulatiot~.

PHYSIOLOGY OF THE SPLEEN

Blood that circulates tlirougli the spleen comes frorri the spleriic artery,

wliich is a brrt~icli of the celiac tnlr~k, ~vllicli in fum is a brarich of tlie descending

aorta.

The portinti of arterial blood flint enters the spleen first ericow~ters the

white pulp, wliicli consists of r ~ i ~ s s e s of lyinplioid tissues containing

lyrnpllocytes and ~nacropllages.

The white pulp fonns clrunps aror~nd the splenic arterioles and is the main

site of immune and pl~;rgcxytic fr~rlctiori within the spleen. Here, the blood bonie

antigens encowiter lytnpliocytes, itiitiatilig the iml~lime response.

Some of the blood that enters the tenninal capillaries of the spleen

coiltinr~es through the ~nicrocirculatio~~ and enters lliglily distensible storage

areas called vellous sinuses. Most of the blood, however, oozes tlirough the

extremely permeable capillaty walls into the principal site of the splenic

filtration - the red pdp. Here the resident ~nacrophages of the mononuclear

pllagocyte system ( W S ) pliagocytose old damaged or dead blood cells (mainly

. erythrocyte), micro organisms and particle debris.

Haemoglol)in from plmgocytoserl erythrocytes is cntnbolised and the heme

(iron) is stored in the cytoplasm of the ~~lacropliages or

blood plasma, The macrophages also can remove certain particulate inclrisions

From the erythrocytes witliont l l a ~ ~ ~ i i ~ i g the Blood that filters

through the red pulp alrm fill& its way into the venous si~~rlses and hence into

;1 1011. the partial circul t '

! I

I

2.6 ABSENCE O F TIIE SPLEEN I

! Absence of the spleen from ally cause (ah-oplly, traurria, retrieval) leaves

I fhctional deficietlcies. For exarilple ler~kocytosis oftell occurs after .

I splcnectotny. This suggests that the spleen exerts some control over tlie rate of a

production of leukocytes, stem cells it1 the bone inarrow or their release into the

blood stream. Splenic al~setlce is also associated with decreased levels of iron in ' I

the circulation, reflecting splenic role i n the tlletabolisrn. Ilnmune function

decreases it1 the absence of spleen. Alltibody prodttctioti it1 response to sniall

doses of solrtble antigen diminishes.

The fhcfiorl of renloval of old and defective blood cells by the system

seems to be confirmed by the fact that the blood of asplenic individr~als contain

more ~norplrologically defective blood cells tlmi normal.

2.7 ENLARGEMENT OF THE SPLEEN (SPLENOMEGALY)

If the spleen enlarges, its long axes extetids downwards arid forwards

along the tenth rib in the direction of the utnbilicus and its anterior portio~i

approaclles the costal 111;1rgitl to the left of tlie greater crirvatttre of the stotnach.

The splccn must at least double its nortnal size before its anterior border

passes beyond the le'f? coastal tnargitl. Whatever the degree of enlargement the

spleen glides ill cotltact with the diaphragm and anterior abdolninal wall. No

colonic resonallce is formd on percr~ssion over the orgm.

The t~onl,:ll spleerl may he outlined by fat a d slc'l~ spleen is frequently

visible 011 the l ~ l a i ~ l radiographic film. Corlve~~tiotlal rad iopphy has difficulty

in outlining the spleen compared to ultrasonopaplry that shows the splenic

outline explicitly.

2.8 CAIJSES 01; SPI,ENOMEGAl,Y

Splenornegaly can be caused by circulatory disorder, infectio~~, connective tissue

disorders, lipoid storage disorders, hfiltrative disorders, turnours, trauma and

sarcoidosis.

Circulatory Disorder: The fillowiilg conditions are types of circrilatory

disorders that can cause spler~onlegaly.

Congestive cxcliac failwes

Portal hypertension

Portal or spler~ic vein tllrornbosis

Blood disorder

Hernolytic atlemia

Sickle cell disease

Splenornegaly can be caused by skeletal disorders like

Osteoporosis

Myelofibrosis

Infection: Tl~cse kinds of infectio~l can cause sple~~omegaly: typhoid,

tuberculosis, I~istoplns~nosis, bn~cellosis, nlalaria, scl~istoso~niasis, hydatid

disease.

- Con,nective ?'issue Disorders: Corirwtive tissue disorder wliich may result in

splenornegaly include:

- Systemic Ltipl~s Erytl~rexr~atosis (SLE)

- Polyarterititis riodosa

Lipoici Storage Discme: Gaucher's Disease

Inf i l t r:~tivc: Atnyloid

Tumours: Cysfs, ~nefaslasis, leukcrnia, ly~r~pl~otna

Trauma: In tmoina affecting the spleen, the spleer~ m y assutue increase in size

due to:

Conversely, the size OF spleen [nay becorne dinlinislied as a resolt of some

patlinlogies like:

- Sickle cell diseases

- Myelofibrosis

The pratlc of spleno~negnly is valllable in extrapolating likely cause of th *

cllange iri size.

I

I

CIJAPTER THREE

METHODOLOGY

3.1 DATA SELECTION

Duration:

The period of data collectio~~ was between Novetnber 200 1 and March

2003.

Population:

The poptilation consists of patients who were referred for abdominal or

pelvic ultrasou~ld to ' the University of Nigeria Teaching Hospital En~rgu and

Bishop Sliaiallan Hospilal, Nsukka, who met the exclusion criteria.

Sample Size:

A pilot study to estimate the feasibility o f the rr~airl study showed that

abo11t 20°4 of f i le patients met the exclusion criteria.

ple size of 245 was obtairled usi~lg the Ima

- Women who 113d recult abor-tio11.

- Subjects wlio Iiad recurring illness

- Patients who have had splenic resection

- Patients who have s~~ffered from any I~aemotologic disorder or disorders that

may compro~i~ise splcnic size including lytiplio~na, maeniia, etc.

- Patierit s with sytnpt oms of parasitic infectio~is like malaria or scl~isto~rliasis

- Patients who have sickle cell diseases.

Equipment

The equipne~it used for this study were SONOACE 3200 tdtrasotuid

eqdpment that has a frequency of 3.SMHz with sector probe and Concept niodel

of the dynamic imagi~lg ultrasound system with trmsducer freqwicy of 3.5MHz

and curvilinear probe. Both systerris are fitted with electronic calipers. Other

eqt~ipment used include ultrasound gel, weighing scale and 200m measuring rule

graduated on the wall.

The two t~ltrasor~ograpliic units were provided with printer fix purpose of

obtaining hard copy of t11e images.

3.3 SCANNING TECHNIQ1lE

On c7TTivid for the scan, tile lieiglit and weight of each patient were

obtained and recorded aIong with the age and sex. The patients were scariried in

the supine position and nieasurement of the spleen taketi in the same position.

Longitudinal ant1 transverses scans were carried out. For the Iotigitt~dinal scan

prohe was placed along the left axillmy line at the I'evel of the xipl~istenil~m

between ninth m d tenth tlioracic vertebrae, [lie probe was then rotated about 10'

posteriorly in order to bring the lorlg axis of the splee~i in f i l l1 view. The scan for

longitudinal measurement was rnnintgit~ed mtil a sharp outline of the spleen,

wliich cut across the I I ~ ~ I I I I I is vbtaiued. Tile longest supero-inferior diameter

from below the diaphragm superiorly, to l l~e inferior botder of the spleen was

taken.

Tlie probe was hien tunled tllror~gli 90° to the lot~gitr~dinal axis of the

spleen to ohtairi the trmsverse axis. Measurement of the width arid the thickness

were then obtai~~ed. Tht: t~seasr~re~nent s were then matched agailist the subject's

age, weight, height arid sex.

The population was the11 grouped into ~riales (34.4%) and females

(65.6%). They were also categorized into ten age groups with itlcretrretits of 5

years. Tlie sple~iic le~igtli, weight area slid vol~me were collated for both sexes

and varlous age goups.

Mean values wen: obtained for males and females and both compared for

differences using the z-tcst arld null Iiypothesis.

Splenic length, %eight, area allti volume were correlated with age using

the speannari's linear 'r' test.

': Posifion and orientation of the curvilinear probe for longitudinal section of the spleen

Fig 2: Position and orientation of the curvilinear probe : . . for transverse section of the spleen

Fig 3c: Splenomegaly filling the Screen Normal parenchymal echotexfure

CHAPTER FOUR

DATA ANAI,YSIS AN11 PRESENTATION

4.1 TARI,ES AND GRAPHS

Tahlr 1: Age and sex rlistrihrrtion of the sample poprlnlion

- - - - . . .-

I Total I

. - . -

Malt frequency

-1'ablc I shows that larger proportions of the sample were females ( 1 64 = 65.6%)

compared to males (86 - 34.4%).

'l'hc ape gi-oup of 30 - 34 years had the largest sample size ( 7 - 23.5%)

among - the age groups. - 'I.l~e ape group of 60 - h4 years had the least sample size

o f (2.4%) o f the total sample size.

Tahlc 1 1 : M e a n splcnic Icngih ( I , ) , wirlfh (1%'). fhickness ('1') with st:lntlarrl

Table 11 sliows a ~wrn~ogr-atn of !lie male nn( l r m n l e splenic lenp~h. width

and thickness as wcll as thcir standard deviation (SI)) in ccntirnetrcs. In th is

study group. the ~naxirnrtm male splenic lengtli of' 1 1 . 5 3 1 1 ~ v a s o f - d a i r d i l l the 31)

- - 39 years age group in the males.

M R ~ Splenic Size

i x n ~ t h 1 1 . 1 k 0.7cm, width 7.2 + 0.2rm and thickness of 4.2 + 0.2~111.

Thi? s t i ~ d v alsn ih~airictl n lkrnnlc splcnic mcnrl length o f 10.0 + 0.7~111. width of

6 .8 4 O 5i.m and thickncsq of 4.15 4: 0.2ctn.

Tahle 111: Rel~tionship between mean splenic Icnqth (cm) with heights (cm) r

o f fcrnrlle of 40 - 44 yenrs old

I SubJcct Jfeight (cm) Splenic I , e n ~ t h (cml I

The table shows relationship

shows a good correlation of r = 0.65

splenic lenpth (Spl).

Spl = 1.2 + 0.063F-I

between subject heieht and splenic length

I was noted between sub~ject height (FI) and

Tshlc 1V: &test comparison of the mcan splcnic length nf males and

fcmalep

----- --.-- 7-,r--$c[ I Mcan splenic T SD in

Comparison of mean splenic length of males and females

i n : There i s n o significant difference between the male and female splenic

length

I : There is a significant difference between the ~ m l e and femzle splenic

length.

Significant level: a - -- 0.05

5.0 > 1.96 (p < 0.05). fhercforc Hr, i s rejcctcd and 1-1, is accepted

The z-test for comparison of mean splenic length showed that the null

hypothesis were rejected and t h ~ t there is significant difference be twem the

male and female splenic Imjqth.

Table V: Distribution of splenic length equal or l ~ s s than 7.8crn in length

among the age grauprs in both sexes

5 subjects had splenic length equal or les than 7.8cm. Two were f o ~ ~ n d in I

the 20 - 24 ycars ape group arnonp rcrnalc and onc cnch in the 31) - 44 venrs age

group for both sexes.

Table V1: Proportion of spleen less than or eqlral (r, 7.8cm in length

. .- -. -~ - .- - - - . . - - 1 - - - - -- . . -- -

4 I -- -- - - ---.- - -- 4 ----------

Total 5 1 2.0% --- - . - - . ~ I - o 1

Table V and table VI slmw that onlv 5 sljhjects (2%) m t of the 250

subjects have splenic length eqrral or less than 7.8cm. Among the 5 suhiects

there was one male (0.4%) and 4 fernales (1.6%) who had splenic length equal

o r lerq than 7 8cm

Tahle V11: Sex distrihlrtion of mean splenic weight

'T'his table shnwc diqtrihution of splenic weight with gee. A mean splenic ,

weight of 145 + I I em f'nr rmlc 2nd 1.70 + 1 Iprv fbr f'crnnlr was ohtair~ed. In

both sexes, t h e rnaxi~num splenic weight was fnrsnd in the 40 -- 44 years age

group, 15Xgm for male and 156gm for female. In the rnalec 30 39 years age

group, the spleen weighed 157gm. close to the ~naximrrm weight of the 40 - 44

ycar ape group.

Table VIII: Comparison between male nnd fcrnale splrnic weight

weights.

difference bet-ween male and female splenic

HI: There i s n significance difference hetween inale and female splenic

weights.

The c f n t i d i ~ n l frd I J ~ J i~ 7-feet

The significance level = 0.05

The calculated z value = 6.98 > 1.96 (P < 0.05): therefore Hh is reiected

and H I acccptcd.

Thcrc is significant diffcrcnce between males and females splenic weight I

6.98 > 1.96 ( P < 0.05). A poor cm-relation is also noted hetween splenic wei~ht

and aRe for hoth sexes.

Table IX: Body weight a9 a function nf splenic w e i ~ h t in swh jecto o f 40 - 44

years old . ~ .- . .. . - .

/--Body wcieht (KET SpIcnic weight (gm) -7 I

t . - - --- - - I-- Mean 124 It 2Ogm 1 68 k 13gm __ _____l__l_ -I_----- -- - -- --I

Table IX shows body weight as a f ~ ~ n c t i o n of splenic weijzht in subject o f

40 - 44 ycars old age yrnnp.

Male mean splenic weiy,ht = It18 + 20pm a

Female mean splenic weight = 124 f 13gm X

Z vdue = 6.98 > 1.96

1 the male and female splenic

weight (P < -.-,,. ...,.-*- w,.w...w ..,.,,,, ,,,,,ed elf with M v weirrht (r =

0.6). Subjects whose body welght h 60kg and above (normal adult body ~eight)

showed better correlation of r = 0.75 thah with a w g e t e of all the body

weights. The female splenic weight showed poop codation with body weight

(r = 0.4). Using the spanman's linear 'r' moment.

splenic area of 64 f 3 .3cm2 for males and 58 f 5.8cm2 for females. Comparison I

Aa,e @earn) 20 - 24

25 - 29 .- I 30-34

35-39

wing z-test shows significant difference between the male and female .@c

1 Splenic Area (em3

Male 62.8 64.5

68.0

69.0

Ferdalc

56.6

60.4

61.5

62-5

Maximum normal splenic volume for male is 13.6rm' and 13.4rrn"m female.

area 15.7 > 1.96 (p < 0.051. 'l'he statistical test used i s z-tekt. A significance level f

o f 0.05 was used, the calculated z value = 15.7 (p < 0.05).

Table XI: Variation of rrplrnic volmne (ern3) with nee

-. - - --- -1

* -_--.l-__- _ - _ _ -

Agc (~cars ) Mnlc 1 k'crnalc -7

Table XI shows the distribution of splenic volt~rne with age. Male mean

splenic volume is 12.6 + 0.9cm' and female mean splenic volurne is 1 1.1 _+

1.5cm'. T h e ,graph shows non-linear nature.

A poor correlation is noted between age and splenic volrrme. The

maximum spleriic voltrrne for both sexes i s in the 40 - 44 vears age group.

Fig 4 Male m r t fernstle splenic volornt! with spt

Table XII: Body sr~rface area as a frrnctian of splenic vdrrrne in 40 - 44

years old apre group.

- - -- -

Body surfacc area (RSA)

___-____--.----- I . .

Mron V ~ r n g I c . R 9 A - 3 h2.

Mean male splenic vol[rrnc - 14.5crn ' 4 2.2

Mean female splenic vol~rmc - I 1.5cm' + 2.2

Male r = 0.9. female r = 0.8

S,V = 0.27 + h.hl3SA (crn')

'Thc male m t m horfv qlrrf;lcc nrea = 1 .%n2 wf~ilt- the female mean

body surface area (RSA) = 2.hm2. l'he study also showed that h e male mean

splenic volume = 14.45 + ?.5rm3 and the female mean qplmic volrme = 1 1.48 it.

2.2crn3. The coefficient of corrclatim of thc body wrfacc area aminct the

splenic voll~rne iq r = 0.7 fnr female, and r = 0.9 for male 11qinp the spearman's

linear 'r' mntnrnt

16

I 4

12

Splenic volt~rnr l fl 3 crn

8

T a hle X I 11: Comparison of splenic length of f hc ctrnd~ grnrrp nnd t h ~ t or the

HO: There i s no significant difference hetweer~ the splen i r lerwtli r ~ f the st~ldj.

proup and Carmqianq

4 : There is a s ienif icmt difference betweer1 fhe ql-rlrr~ic lerir~,th o f the s t~ldv

jzrtlup and Ca~~cas inns

0.67 < 1.96 ( P > 0.051. f l i ~ r e f o r e I l , , i q arcepterf

I lence the str~dy says that there i s no sigriificxrit diffcrencc hrtween the

splenic lenqlh o f the f'aircmian nnrl flint of thr s t r~dv ernllp (P > 0.05).

. - - - - - - -. .

Study group

4.2 I'llSCl ISClCINq

In thic; qtt~rfv, a sample ~ i 7 ~ o f 2 5 0 nrw I I ~ . 'l'here were 164 females

(65.6% o f the sample si7e) and 86 males (34.4%). The 30 - 34 veam w e group

had the l a r ~ c s t nlmhcr of partiripant9 wherca~: the leac;! wm the hO - 64 years

age grotlp for the hvth sexes.

4.3 SPJ ,ENIC I ,ENf;TIl

The splenic lennth for hnth sexes was the easiest dimension to measrtrc

t,he ~sses s rnen t n f thc splenic s i x . I n the male rnctan splenic lenqth was 1 I , 0

n

. - - 250

Splenic lerteifi

. - - .

11.5

0.7cm. Splenic lenath had a range nf 9.7cm to 12cm. though this valrre is in <

disa,qreernent with the work of Ijissct grid Khan, 1990, i t ;1qrees with Messinezy

(1997). The splenic lcngth ohtnincd in this sttdy s h v s n v stati~tical cliffcrcncc

(P > 0.05) between C'ar~ca~qian splenic len,pth, \vhic:h i s I I .6r1n, and 1 1.5cm fhr

the st~rdy wow.

The splenic length i n t h e male is ereatest in the 70 - 79 years age p,rnup

while the smallest splenic length in that sex is at 65 - 75 ymrs indicating

shrinkinp. Thc splenic length in the age Erorrp of 20 -- 39 vrars s I i t~ \v~d steady

increase with age and after 39 years it begins to shorten. Therefore, if the splenic

size is larger than the value in the nnrnnqratn for the aqc, pntholoay is str,~p,csted.

In the female, the ureatest splenic length i s in the 4n- 44 years w e group

as against 30 -- 39 ycarc in thc malc. The splenic Irneth of the fcrnale 20 - 44

years age proup also showed steady increase with ape and after 44 years when i t

started to dcclinc as a,qc incrtascc. While incrcasc in splenic length in the male

stops at about the age: o f 39 years. i t continues to increase in the female ti l l 5

years later.

1,ike in the male the smallest splenic length is fmmd at 65 years and

above. Therefore, the author deduced that splenic lenpth increasec with age and

at about middle a ~ c the length h c ~ i n s to decrease. Thiq is in agreement with

Dclnnd (1971)). In the rcrnalc. the splenic length start^ t o di~niniqh from 45 vears,

however. the m ~ t h n r did not investigate whethcr nnv relsltionship exist between -

splcnic size and rnenonarlse since 45 years i s a cornmon nerind of mennpauw 1

and the splccn also h c i n ~ ! a hacmotnlwic nrgan both in the innlc and thc female.

There i s a good correlation between subiect height and splenic lenath as also

reported by Deland, 1970. Female r = 0.65 (spl = 1.2440.fl67Il).

Spt = splenic length. f f = subiect height

It was ohqerved fhat 2% of the srhjects under qfr~riv h a w qp lmic lenqth

equal or less than 7.8cm as reported hv Cha~~han et 31 (1996). This i s aswciated

with natives of falciparum malaria endemic area. It was fi~rther nnted to be more

prevalent among women ( I .fiO/n of the stidy pop~llniion) and 0.4% fnr males.

The mean splenic width for males is 7.2 + 0.2crn and 6.8 + 0.5cm for

females. T h e splcnic width incrcnccs wi th aqe t i l l 3C) w a r s in the mnles hut

continues t i l l 49 years in the females. thereafter the width heains to decline with

c?Re in hoth mxle and fernale. When critical eval~rntinn o f fhe spleen iq required

in condition o f diminishing s~ len ic si7e before 49 years i t suggests pathology.

l Jnlike for splenic width, splenic thicknecs r e x h rnax im~~m dimension at

the same age group o f 40 - 44 years for hoth male and female and thereafter, the

splenic thickness stnrts to dirninish with age.

The splenic thickness obtained from the str~dv was 4.2 + O02c.m for males

I

4.5 SPI,ENIC* WFIGHT, A R E A AND VOI,IIMF

The splenic wei& was Iar~eqt in the 40 - 44 vears aRe arolrp for both -

sexes. The splenic mean weigl~t is 145 + 1 I Em and 130 + 1 ! em for males and

fcrnales respectively.

There was a statistically significant difference hetween mnle and female

splenic weipht (P < 0.05).

The range of snlenic weipht w a ~ fmnd to he between 120gm to 158gm

for both scxcs (P > 0.051, ;1 splcnic weight outside this range mav he si~rpected

to have a disorder in non-obese patients,

In the Caucasian. Dcland (1970) showed that mmirnrrrn splenic- weight

occurred at the ane of 20 - 29 years group m d thereafter ~rac-l~~allv declines.

While the maximum wriqllt obtained in this sturfv occr~rrt.d at 4 0 - 44 vcnrs age

group.

There was good correlation hetween cpl~nicr weight and aEe initiallv, as

ape increased splcnic weight decreased and this dccrcasc was not linear. A

similar characteriqtic wn5 notcd in the relationship of c;plenic area and ap,e. The

splenic area increased with age ti l l 39 years for male and 44 vears for fernfile.

Thc area of t h e spleen dccrcase in a non-lincar tnnnncr finer 39 years and this

accounted for the poor correlation between the age and the splenic area.

In thc annlvsi? of thc rtlniionqhip hetween hodv weight and splenic t

weiaht. a snecific ane p r o w (40-44) vears was choqen. al though the relgtinnship

between age and splenic weight was poor this amlvsis still exclwled the effect

of age. Therefore, the analvsis of the relationship between body weight and

splenic wciaht were independent of age. This 40 - 41) vegrs ap,e p,rollp has the

hiphest frequency in the sample pnprrlation and a l so i s the age wmrp where the

both qexes have the, largest splenic weight attictng the strrdv prorrps.

There is poor correlation between splenic weight and bodvwei~ht o f the

subiccts who arc t ~ n d c w c i ~ h t (59kg and less). Minirnv~m ntlnnal weip;ht for the

age range i s 60kg (Roper, 1975). Srrhjects whme w e i ~ h t are 6Okg and a h w e

showed correlation (r = 0.75). this suepests a strong: clinical relatintiship

between splenic weight and body weights of the s~~hjec t

The subiectq who weighed 60kq m d ahove hnd smne ct-raracterisfics with

Caucasians. When the r~ndenveight and t h e norrnnl s~rhier ts were combined. the

graph showed a poor correlation between splenic wcie;ht and hodv weight

showing that there was very poor cnrrelation between hody weight and splenic

weight of the underweight. 7'hereht-e. the splenic wei&t or size may he an

index to evaluate the well being of a person. This srrggests that work should be

carried out to show whether splenic size or weight can correlate with any levels

of cmaciafion. nody weight i s a useft11 factor in considering splenic weight.

In the s t ~ ~ d v o f Rody Surfgce Area (RSA) and qpl~nic vnflrme. the author

observed that males of 20 years and above have RSA of 1.5 to 2.5rn2 and the

females have 1.0 to 4.0m2. l h a t is. females have wider range of RSA than

males. Males hnve mean splenic voll~rne of 14crnJ while females hnve splenic

voltme o f l 0.?crn3. A ~ o o d corffirirnt of correlation w i s t i n e hptwrrn RSA and

splenic volumc was nhscrvcd. Fcm;llt r = 0.8. male r - 0.9, t~sine. the

Speannan's linear 'r' moment.

There was significant difference between the male ydenic vdrrrne and the

female splenic vol~~rne ( P < 0.05). C'or.rclatim h c t w ~ e n ope 2nd splenic vohrrne

was poor. Both male and female chow maximum splenir vol~rme at aEe groups

of 40 - 44 yenrs and therenfler the spleen begin? to shrink a.r; aRe increme. This

age group was used for comparison of body srjrface area (RSA) and splenic

vnlrrme. The graph of age and splenic volutnc: s h o w a non-tinearitv 3s age

lnrrrace

PFf APTFH FIVE

Medical ultrasonographv is a valuable tool for f he assecstnent nf splenic

size and pathological status of the spleen.

This studv has provided a nnclmal range of splenic size, which Ni,gerians

can use in the assessment of splenic size especially in matters relating to

p a t h o l o ~ y .

Splcnic length 9.5cm to 12.0crn

Width f,-.?rm tr, 7 4 r m

Small increase outside the rlormoRrarn may be a lead to unsuspected

disorder and cal Is for furlher invest i ~ a i ion.

The other splenic parameters, weight, vnlr~tne 3nt.l area are obtained from

these dimensions. For body weight o f 6Okg and above, (standard body weight),

the splenic dimensions have no difference with fhe Caucasian values. Significant

diffcrencc waq n o t d hptween m ~ l ~ nnd f ~ r n g l ~ dirn~ncinne

Subjects w h o are up to 30 years old and weigh 5 9 k ~ o r fess s h o w splenic

parameters that are less than their age group who weigh 6Okg and above. This

supgests splenic si7e as a strtlnp clinical marker. A normopram was obtained for

various paramctcrs of tlir spleen. Splenic' weieht may he val~~nhlr index in I '

assessing the well being of a patient.

Thc nonnojqam nbtaincd will hc 11sefi11 in assessinq manv disease

conditions in Nigeria, which manifest in spienornegaly nr diminution o f the ,

A small proportion of the study group shows 'small' splenic sizes, which

The correlation hetween age and splenic wei~ht , splenic length and

splenic volume are poor because the ~ r a p h was not linear. There are initial

steady increases with age t i l l middle age when the parameter starts to shrink

with aRe. The decrease as age increase arc irregular and not steady. hence

exhibit in^ poor correlations with age.

Splcnic length initially incrcmes and decline with ace. Splcnic weight

also increases with hody weight and hody surface area. while splenic volume

also increases with body surface area.

5.1 CONCI ,I ISION

This study stronglv recommends splenic length as the beqt predictive

parameter of splenic size hccat~sc:

- Splenic length i s easy to obtain

- Splenic length i s minimally ohstn~ctcd by Ras and rib shadows during scan

- Splenic length showed clear relationship .cvitli age, bodv weight and height

- Splenic length is an important factor in the determination of th r splenic

weight, volttme and area

- The splenic Icngth ohtaincd shows sensitivity in.dctcctin~ changes in splenic

- Rcscarch s t ~ ~ d i c s should he cnrricd r w f to find arly rrlntionship bctwccn

nutrition and splenic sizes.

- Studies should bc carried out to find how lonp i t tgkes fnr the spleen to be

restored to normal size after pathology is relieved. This will he nf cl inical

si~nificancc when there i s doubt about the cause of splenomej.yiIy. especially

after treatment has been given for a disorder.

- '1le researcher also su~nests stt~dies on he rates of' increase of splenic s i x

with time in various pathologic states affecting splenic size.

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APPENDIX - ,

Body surlace area (USA) i s acquired by the Lhhois and Dubois tbrmula

(Niedelran et a1 1983).

Weight x 1 kg x Hcight(crn1 x l x 6(rn2) 2.35 1.38

Splenic weight = 0.43 (length x width x thickness) grn

1992)

Splenic volurne = L x W x 'l'on' 27

Cross sectional area = 0.8 (I . , x W )

For a two sample test for mean:

'I'he correlations were analysed using the Spearman's linear 'r' test

A = y-bx

t3 = Sxx

Formula tor the sample size

P = Proportion trom previous work or pilot study (20Y0 or 0.2)

d - - 'l'olcrable error (0.05)

z = % value ot' specified level o f signi ticance ( 1.96)