Medial sphenoid wing meningioma

Introduction

Meningiomas are relatively common neoplasms that arise from arachnoid cap cells and account for approximately 20% to 30% of all primary intracranial tumors. Of all meningiomas, approximately 15% to 20% occur along the sphenoid wing that places them at a complex anatomic location, involving the optic nerve, cavernous sinus, and internal carotid and middle cerebral arteries. ^, Medial, as compared with middle and lateral, sphenoid wing meningiomas are closer to critical parasellar neurovascular structures, including the optic nerve, internal carotid artery (ICA), middle cerebral artery, and cavernous sinus, and surgery in these regions is associated with significant morbidity including vision loss, cerebral ischemia, and diplopia, among others. Complication rates range from 20% to 40% (vision loss varies from 20%–30%), with gross total resections as low as 60% in several series. In this chapter, we present a case of a dominant hemisphere medial sphenoid wing meningioma.

Example case

Chief complaint: left eye vision loss

History of present illness

A 33-year-old, right-handed woman with no significant past medical history presented with progressive left eye vision loss. For the past 5 to 6 months, she developed difficulty with seeing and has tried different glasses without improvement. She saw her optometrist who noted left optic nerve atrophy, and visual field testing revealed diminished vision in all quadrants in her left eye. Imaging was done ( Fig. 48.1 ).

Medications : None.
Allergies : No known drug allergies.
Past medical and surgical history : C-section.
Family history : No history of intracranial malignancies.
Social history : Secretary, no smoking or alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact except only counting fingers in left eye; No drift, moves all extremities with full strength.

	Gerardo Guinto, MD, Centro Neurologico ABC, Mexico City, Mexico	Rodrigo Ramos-Zúñiga, MD, PhD, University of Guadalajara, Guadalajara, Jalisco, Mexico	Shaan M. Raza, MD, Anderson Cancer Center, Houston, TX, United States	Harry Van Loveren, MD, University of South Florida, Tampa, FL, United States
Preoperative
Additional tests requested	CT and CTA Neuropsychological assessment	MR angiography DTI Neuropsychological assessment	Neuroophthalmology evaluation MRA or CTA	Cerebral angiogram Neuroophthalmology evaluation
Surgical approach selected	Left pterional orbitozygomatic craniotomy	Left pterional orbitozygomatic craniotomy, anterior clinoidectomy	Left modified orbitozygomatic craniotomy, anterior clinoidectomy	Left frontotemporal craniotomy, orbitozygomatic osteotomy, posterior orbitotomy, anterior clinoidectomy
Anatomic corridor	Left trans-Sylvian	Left frontotemporal	Left trans-Sylvian	Left trans-Sylvian
Goal of surgery	Simpson grade II	Simpson grade II, decompression of optic apparatus, restoration of ICA flow	Simpson grade II because of being type I clinoidal meningioma, decompression of optic apparatus	Simpson grade I pending intraoperative evaluation
Perioperative
Positioning	Left supine with 35 degree rotation to right	Left supine with slight right rotation	Left supine and right 30 degree rotation	Supine with right rotation
Surgical equipment	Surgical navigation Ultrasonic aspirator Reciprocating saw	Surgical microscope Ultrasonic aspirator	IOM (SSEP/EEG) Reciprocating saw Surgical microscope Ultrasonic aspirator	Surgical navigation Surgical microscope Micro Doppler Ultrasonic aspirator
Medications	Steroids Antiepileptics	Steroids Antiepileptics	Steroids Mannitol Antiepileptics	Steroids Antiepileptics Mannitol
Anatomic considerations	Orbit, anterior clinoid, cavernous sinus, ICA, MCA, frontal and temporal lobes	Optic canal, sphenoid wing, anterior clinoid, optic nerve and chiasm, cavernous sinus, ICA/ACA/ACOM and perforators	ICA, ophthalmic artery, PCOM, AChA, A1, M1, left optic nerve, optic chiasm, optic tract	ICA, MCA, ophthalmic artery, optic nerve and chiasms, hypothalamus, pituitary stalk, midbrain and cerebral peduncle, cranial nerves III/IV/VI, lateral cavernous sinus, superior orbital fissure
Complications feared with approach chosen	Injury to ICA and MCA, cavernous sinus, cerebral edema, seizures	Cranial neuropathy, optic nerve damage, neuroendocrine dysfunction	Injury to optic apparatus and vasculature	Retraction injury, stroke, brainstem injury, visual compromise
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Left pterional	Left pterional	Left pterional	Left frontotemporal
Bone opening	Left frontotemporal and orbit	Left frontotemporal and orbit	Left frontotemporal and orbit	Left frontotemporal and orbit, anterior clinoid, optic roof
Brain exposure	Left frontotemporal	Left frontotemporal	Left frontotemporal	Left frontotemporal
Method of resection	Frontotemporal skin flap with preservation of anterior branch of STA, subfascial temporalis opening to preserve frontalis nerve, frontotemporal craniotomy, orbitozygomatic osteotomy from supraorbital notch to posterior roof of orbit to lateral wall reaching inferior orbital fissure with an osteotomy in an inverted V-shape of the malar bone and osteotomy of zygoma, drilling of sphenoid ridge and anterior clinoidectomy to completely expose optic nerve, open dura, Sylvian fissure opening, begin tumor debulking, identify ICA and MCA and optic nerve early, dissect these areas from the tumor, if tumor stuck to these critical structures leave small fragments behind, make sure optic nerve completely free of tumor, debulk tumor until lateral cavernous sinus wall exposed with low voltage bipolar coagulation, removal of dura in contact with tumor and pericranium reconstruction	Left frontotemporal flap with preservation of STA, frontotemporal craniotomy, orbitozygomatic extension, extradural anterior clinoidectomy, open dura, intratumoral decompression, decompression of optic canal and nerve, leave cavernous sinus component alone, coagulation of skull base dura, closure with subgaleal drain	Left pterional incision to contralateral midpupillary line, preservation of pericranium, subfascial dissection to expose frontozygomatic process, pericranium and superficial temporalis fascia reflected anteriorly, temporalis reflected toward zygomatic arch, MacCarty keyhole, one-piece modified orbitozygomatic craniotomy, orbital osteotomy superior to IOF, drill sphenoid wing down to SOF, extradural clinoidectomy to unroof cavernous sinus and gain proximal control of ICA, unroof optic canal 270 degrees, open dura posterior to anterior along Sylvian fissure with T with one limb along SOF and other along optic canal, Sylvian fissure opening distal to where tumor involves vasculature, identify A1/AChA/ACOM, open dura of optic canal, trace optic nerve to chiasm and optic tract, resect tumor until plane until arachnoidal plane disappears likely near distal dural ring, papaverine soaked gelfoam laid over exposed vasculature, inspect anterior clinoid for communication with sphenoid sinus, close dura and use temporalis fascia to create subdural-epidural inlay-onlay along dural defect along optic canal and anterior clinoid followed by free pericranial graft along skull base, bolster closure with fibrin flue, titanium mesh to reconstruct sphenoid wing	Left frontotemporal flap, subfascial dissection to preserve frontalis nerve, MacCarty burr hole, frontotemporal craniotomy, zygomatic root cut anteriorly and posteriorly and left attached to masseter fascia, supraorbital nerve mobilized, orbitozygomatic osteotomy with mallet and chisel in one-piece with cut across medial supraorbital ridge/zygomaticofacial process near foramen/along the sphenoid from the burr hole to the IOF/across orbital roof with osteotome and mallet, sphenoid ridge is reduced, posterior orbitotomy with partial resection of the lateral orbital wall under microscopic visualization, optic canal is unroofed, extradural anterior clinoidectomy, Dolenc dural opening along Sylvian fissure, Sylvian fissure is opened, tumor debulked internally with ultrasonic aspirator, capsule mobilized from brain interface, circumferentially remove dura around lesion if possible to devascularize tumor, identify ipsilateral optic nerve then chiasm then contralateral optic nerve, tumor dissection to follow posteriorly to identify MCA and branches, once enough tumor is removed then dissect from cavernous sinus from front to back from SOF and bottom to top from foramen rotundum and ovale, dura cut along oculomotor nerve and removed along lateral wall of cavernous sinus, area inspected for residual, leave small remnants if cannot be dissected safely from neurovascular structures, fat graft if anterior clinoid cannot be repaired, synthetic orbital roof if necessary
Complication avoidance	Orbitozygomatic craniotomy, Sylvian fissure opening, identification of ICA/MCA/optic nerve early, leave small amounts of tumor if adherent to vessels	Orbitozygomatic craniotomy, extradural clinoidectomy, intratumoral decompression, optic canal decompression	Modified orbitozygomatic craniotomy, extradural anterior clinoidectomy, optic canal decompression, trace vasculature, recognition that the arachnoid plane between the tumor and the ICA may disappear near the clinoidal ring and limit the resection	Orbitozygomatic craniotomy, extradural clinoidectomy, intratumoral decompression, early identification of vessels, synthetic orbital roof to minimize enophthalmos
Postoperative
Admission	ICU	ICU	Intermediate care	ICU
Postoperative complications feared	MCA stroke, CSF leak, inadvertent opening of paranasal sinuses	Optic nerve injury, cavernous cranial nerve injury, vascular damage, cerebral edema	Optic apparatus injury, vasospasm, CSF leak, seizures	Retraction injury, cerebral edema, stroke, visual loss, CSF leak
Follow-up testing	CT within 6–8 hours after surgery MRI 6 weeks after surgery EEG 2 years after surgery Neuropsychological	CT within 12 hours after surgery MRI within 24 hours after surgery	MRI within 48 hours after surgery Neuroophthalmology evaluation 2–4 weeks after surgery	CT same day after surgery MRI within 24 hours after surgery
Follow-up visits	6 weeks after surgery	1 month after surgery	10–14 days after surgery	10–14 days after surgery 6 weeks after surgery
Adjuvant therapies recommended for WHO grade	Grade I–observation Grade II–observation Grade III–radiation	Grade I–observation Grade II–observation Grade III–radiation	Grade I–observation Grade II–radiation if residual Grade III–radiation	Grade I–observation Grade II–radiation for residual Grade III–radiation