Surgical Management of Petroclival Meningiomas

Schmidek chapter 40Khaled M. Aziz Sebastien,Froelich,Sanjay Bhatia,

Alexander K. Yu,Albino Bricolo,Todd Hillman,Raymond F. Sekula Jr.

Outline

• Natural history• Recurrence rate• Clinical picture• Neurologic evaluation• Anesthetic consideration• Intraoperative Neurophysiologic monitoring• Goal of surgical management• Surgical approach• Radiosurgery

Natural history• The position of cranial nerves VII and VIII is the critical

landmark to differentiate petroclival meningiomas from cerebellopontine angle meningiomas

• Petroclival meningiomas originate anterior to the IAC and displace cranial nerves VII and VIII posteriorly.

• Cerebellopontine angle meningiomas originate posterior to the IAC and displace cranial nerves VII and VIII anteriorly

• Slow growing skull base meningioma

Recurrence rate• Depend on location, cavernous sinus involvement, brain

stem infiltration, grade of resection, and histopathologic result

Simpson After 5 Yrs(%)

After 15 Yrs(%)

After 25 Yrs(%)

Grade 1 3.5 7-10 13-16Grade 2 4 11-15 15-20Grade 3 25 37-43 39-76Grade 4-5 36-45 63-100 -

Recurrence rate

Clinical Picture• Involvement of cranial nerves

– V, VIII, VI, VII, IX, and X

• Cerebellar compression– Gait ataxia

• Brain stem compression– Motor and sensory deficit

• Increased intracranial pressure– Dementia– Duu to secondary to hydrocephalus

Neurologic evaluation• CT for transpetrosal approach

– Anatomy of the inner ear– Height of jugular bulb– Pneumatization of mastoid bone

• MRI– T1 : delinate tumor,its relationship to other structure– T2 : arachnoid cleavage plane,brain stem edema and infiltration– Flow void : location of major vertebrobasilar vessel

• MRV– Torcula, transverse sinus, sigmoid sinus– Vein of Labbe(posterior temporal venous drainage)

Neuroradiologic evaluation• Cerebral angiography

– Tumor blood supply• meningohypophysial trunk of the internal carotid artery• the posterior branch of the middle meningeal artery• the meningeal branch of the vertebral artery• the clivus artery from the carotid siphon• the petrosal branches of the meningeal arteries• the ascending pharyngeal branches of the external carotid

artery

– Mass effect on vertebrobasilar systems

Anesthetic consideration• Brain relaxation• Monitor nerve and tract : Muscle relatant is not use• Remifentanil or sufentanil infusion for analgesia• Sevoflurane or propofol for hypnosis

Intraoperative Neurophysiologic monitoring

• Somatosensory evoked potentials (SSEPs)– Record peripheral nerve afferent

• Motor evoked potentials (MEPs)– Recording electromyogram activity in muscle

• Brain stem auditory evoked potentials (BSAEPs)– Cortical response to auditory stimuli

• EMG

Goal of surgical management• Goal of surgery is complete resection of the tumor

without causing additional deficits to the patient• Tumor with brain stem compression

– decompression with either total or subtotal excision• Tumor with neurovascular invasion

– Excision of tumor that leaves the part infiltrating the neurovascular structure

Goal of surgical management

Surgical approachs

• Clivus and petroclival zone• Anterior petrosal approach• Posterior petrosal approach• Lateral Suboccipital Approach

Clivus and petroclival zone

Clivus and petroclival zone• Zone I (upper zone)• dorsum sellae to the upper border of the IAC• retrosellar region, region medial to the trigeminal

impression down to the IAC• exposed via the Kawase approach (anterior petrosal

approach)• Zygomatic osteotomy can be added• If tumor involve only retrosellar region of zone I : trans-

sylvian transcavernous approach

Clivus and petroclival zone• Zone II (middle zone)• IAC to the upper border of the jugular tubercle• exposure provided via the posterior petrosal approach• tumor involve Zone I and II : combined petrosal

approach

• Zone III (lower zone)• jugular tubercle to the lower edge of the clivus• Exposed via lateral suboccipital–transcondylar

approaches 

Clivus and petroclival zone• Petroclival angle• angle between the petrous

bone and the clivus at the level of IAC

• Central clival depression• relationship between

intermeatal plane(superior) and jugular tubercle(inferior)

• The less obtuse the petroclival angle, the more difficult the exposure of the central clival depression

Anterior petrosal approach

Anterior petrosal approach• allows exposure

– the middle fossa floor– the petrous bone apex,– zone I of the petroclival region

• subtemporal or frontotemporal craniotomy and anterior petrosectomy

• lumbar drain

Anterior petrosal approach

• Position– Supine position and rotate 90 – Ipsilateral shoulder is elevated– Head tilt 15 degrees downward– Patient’s upper back is elevated 25-30 degrees

• Skin incision– initiated posterior to the midpoint of the mastoid

process extends superiorly and anteriorly– traversing the superior temporal line and ending at the

middle of the zygomatic arch for a subtemporal anterior petrosal approach

Anterior petrosal approach• Subtemporal approach

– Myocutaneous flap reflex inferiorly– Rectangular craniotomy along the squamosal suture– Zygomatic osteotomy– Drilled floor of middle fossa– Key : preserve dura and remain extradura

• Frontotemporal craniotomy approach– Skin flap extend anteriorly– Mycutaneous flap reflex anteroinferiorly– Sphenoid wing complete drill

Anterior petrosal approach• The dura is elevated from the middle fossa floor, and

petrous bone via a posterior to anterior approach; elevation starts at the arcuate eminence and proceeds anteriorly

• The middle meningeal artery is controlled with bipolar cautery and sectioned, the foramen spinosum is packed with bone wax

• Greater superficial petrosal nerve(GSPN) is identified and keep intact : dissection follows the GSPN from posterior to anterior until it courses under the third division of the trigeminal nerve (V3)

• Glasscock’s triangle– Laterally : foramen spinosum to the facial hiatus– Medially : GSPN– Base : V3

• Kawase’s triangle– Laterally : GSPN– Medially : petrous ridge– Base : Arcuate eminence

Anterior petrosal approach• Anteriorly, the mandibular division (V2) is identified at the

foramen rotundum• Dissection continues medially to the petrous ridge

indenting the superior petrosal sinus• Separation of the dura propia continues until the

connective tissues sheath over V2,V3 and the Gaserian ganglion is visible(Meckel’s cave)

Anterior petrosal approach• Kawase’s quadrilateral is drilled under microscope at

petrous ridge to identify the IAC– The arcuate eminence forms a 120-degree angle to

the GSPN (or the internal carotid artery), and the IAC bisects this angle

– Follow the geniculate ganglion to the labyrinthine segment of the facial nerve(high incidence of facial nerve injury)

• Drilling of the IAC continues to the bone crest dividing the facial nerve and the superior vestibular nerve (Bill’s bar)

Anterior petrosal approach• The bone overlying the cochlea is drilled until the

cochlea appears as a blue line• After identify of the dura covering the IAC posterior• the Kawase’s quadrilateral is drilled to the

– GSPN (preserved) laterally– the petrous segment of the internal carotid artery anterolaterally– V3 anteriorly– the superior petrosal sinus medially– the posterior fossa dura and inferior petrosal sinus inferiorly

Anterior petrosal approach• The inferior temporal lobe dura is open above and

parallel to the superior petrosal sinus. The dura is reflected inferiorly

• The superior petrosal sinus is secured with titanium hemoclips and is split

• The tentorium is cut medially toward the tentorial incisura posterior to the dural entry of the trochlear nerve

• The posterior fossa dura is further split inferiorly

Anterior petrosal approach• After completion of surgical resection• Watertight dural closure is demanding• The IAC bony opening is plugged with a small piece of

fat or muscle• The dura is approximated utilizing a synthetic dural graft

and is sprayed with fibrin glue. If there is a big filling defect, it can be judiciously obliterated with pieces of fat graft to prevent postoperative fluid collection and cerebrospinal fluid (CSF) leak

Anterior petrosal approach• Closure• Bone flaps are connected and fixed with titanium plates

and secures• Bony defects are filled with bone cement for cosmetic

reconstruction and prevention of CSF leak• We prefer to keep the lumbar drain in place for 48 hours

after obtaining an immediate postoperative CT scan

Posterior petrosal approach

Posterior petrosal approach• Temporal craniotomy + presigmoid craniectomy + a

small lateral retrosigmoid craniectomy• Depending on the preoperative hearing

– retrolabyrinthine or translabyrinthine bony temporal bone drilling is added

• Sectioning of the superior petrosal sinus and tentorium, and a relaxing incision in the dura above the lateral transverse sinus – frees the sigmoid sinus and allows mobilization of the sigmoid

sinus posteriorly to expand the presigmoid space : crucial step

Posterior petrosal approach• Position

– Same in anterior petrosal approach – Lateral oblique position

• Skin Incision– three fingerbreadths circumferentially around the

edge of the ear pinna

Posterior petrosal approach• The transverse sinus and the transverse–sigmoid

junction are dissected from the overlying bone• Retrolabyrinthine mastoidectomy• Landmark

– Spine of Henle : Antrum– After drilling the bone over the sinodural angle, the

sigmoid sinus, superior petrosal sinus, and posterior semicircular canal are exposed

– Floor of Antrum : Cortical bone of the lateral semicircular canal

Posterior petrosal approach• Landmark

– Follow lateral semicircular canal : posterior semicircular canal

– Follow posterior semicircular canal : superior semicircular canal

• The air cells of the mastoid tip are removed to expose the digastric ridge : landmark for the stylomastoid foramen and the beginning of the fallopian canal

Posterior petrosal approach• Dura openings

– Below temporal lobe : parallel to the superior petrosal sinus

– Posterior fossa dura in presigmoid space : longitudinally between superior petrosal sinus and the jugular bulb

– Gentle traction on temporal lobe and cerebellum : superior petrosal sinus is sectioned and clipped– Incision dura along transverse sinus– The tentorium is sectioned into the incisura at a point

posterior to entrance of the trochlear nerve

Posterior petrosal approach

Posterior petrosal approach• Closure

– Pericranium or a synthetic dural graft for close– Open mastoid air cell : wax– The antrum : muscle– The mastoidectomy : abdominal fat graft and sprayed

with fibrin glue– Bone flaps : titanium plates

Posterior petrosal approach• Closure

– Bony defect : bone cement– Temporalis m. is closed– Keep lumbar drain for 48 hrs– Immediate post-op CT scan

Lateral suboccipital approach

Lateral Suboccipital Approach• For

– petroclival meningiomas involving zones I, II, and III• Exposure

– posterior surface of the petrous bone– the anterolateral brain stem– craniocervical junction.

Lateral Suboccipital Approach• The lateral oblique position• Key hole : inferomedial to asterion to avoid injury to

transverse sigmoid junction• Mastoid bone is drilled to expose medial edge of the

sigmoid sinus and the inferior edge of sinus• For tumor extend to zone III : C1 laminectomy and

drilling of the posteromedial third of the occipital condyle and lateral mass of C1

Lateral Suboccipital Approach• V3 segment of vertebral artery : groove of the C1

lamina• Dural incision : C1, extends superiorly through the

foramen magnum, and extends superolaterally to the top of craniotomy edge

• Closure– dura is closed watertight– pericranial graft or a synthetic graft– suture line is sprayed with fibrin glue

Radiosurgery• < 3 cm in diameter• adjuvant treatment to prevent tumor regrowth and

recurrence after maximal safe surgical resection

Outcome• Increase post operative morbidity• Preoperative neurologic deficits (diminished

Karnofsky Performance Scale score• tumor size of 2.5 cm or more• multiple cranial fossae involvement and cavernous

sinus infiltration• absence of arachnoid cleavage plane

Outcome• brain stem compression and invasion, brain stem

edema• adhesions to and encasement of vascular structures• high vascularity and direct tumor blood supply from

the basilar artery• firm tumor consistency affecting the extent of tumor

resection