Schmidek

1. Surgical Management of
Petroclival Meningiomas
Schmidek chapter 40
Khaled M. Aziz Sebastien,Froelich,Sanjay Bhatia,
Alexander K. Yu,Albino Bricolo,Todd Hillman,Raymond F. Sekula Jr.

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

3. 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

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

5. Recurrence rate

6. 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

7. 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)

8. 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

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

10. 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

11. 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

12. Goal of surgical management

13. Surgical approachs
• Clivus and petroclival zone
• Anterior petrosal approach
• Posterior petrosal approach
• Lateral Suboccipital Approach

14. Clivus and petroclival zone

15. 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

16. 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

17. 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

18. Anterior petrosal approach

19. 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

20. 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

21. 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

22. 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)

23. • 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

24. 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)

25. 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)

26. 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

27. 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

29. 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

30. 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

31. Posterior petrosal approach

32. 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

33. Posterior petrosal approach
• Position
– Same in anterior petrosal approach
– Lateral oblique position
• Skin Incision
– three fingerbreadths circumferentially around the
edge of the ear pinna

34. 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

35. 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

36. 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

37. Posterior petrosal approach

38. 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

39. Posterior petrosal approach
• Closure
– Bony defect : bone cement
– Temporalis m. is closed
– Keep lumbar drain for 48 hrs
– Immediate post-op CT scan

40. Lateral suboccipital approach

41. 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.

42. 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

43. 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

44. Radiosurgery
• < 3 cm in diameter
• adjuvant treatment to prevent tumor regrowth and
recurrence after maximal safe surgical resection

45. 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

46. 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