Giant medial sphenoid meningioma

• The lateral transorbital approach to the medial sphenoid wing, anterior clinoid, middle fossa, cavernous sinus, and Meckel's cave: target-based classification, approach-related complications, and intermediate-term ocular outcomes
• Microsurgery for a medial left giant lesser sphenoid wing meningioma complicated by postoperative vasospasm of the ipsilateral supraclinoid carotid artery
• A giant aneurysm mimicking a medial sphenoid ridge meningioma
• Apoplexy Inside a Giant Medial Sphenoid Wing Meningothelial (Grade I) Meningioma: An Extremely Rare but a Potentially Dangerous Complication
• Surgical excision of large-to-giant petroclival meningiomas focusing on the middle fossa approaches: The lessons learnt
• Left orbital roof giant cell tumor of bone: A case report
• Surgical treatment of intracranial aneurysms via the pterional keyhole approach
• Large and giant medial sphenoid wing meningiomas involving vascular structures: clinical features and management experience in 53 patients

Giant medial sphenoid wing meningiomas (greater than or equal to 5 cm in maximum dimension) involve the dura of the greater and lesser sphenoid wings, the anterior clinoid process see clinoidal meningioma, the sphenoorbital bone and the middle cranial fossa.

In more extensive cases, they may also involve the cavernous sinus see cavernous sinus meningioma, the orbital apex and periorbita, the sellar region-suprasellar region and the pterygopalatine temporal infratemporal fossae ^{1) 2)}.

Thus, they are a surgical challenge due to their intricate locations and intimate relation to vital neural structures ^{3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13)}.

The most common clinical presentation of clinoidal meningioma and medial sphenoid wing meningiomas are headaches and visual disturbance such as blurred vision, visual field deficit, or optic atrophy (resulting from optic apparatus compression) or diplopia (resulting from oculomotor nerve distortion).

Based on the calculated volume; the degree of associated hyperostosis and/or more than 50 % calcification within the tumour mass; the degree of peritumoural oedema; the extent of tumour invasion to the surrounding region; and, the extent of cavernous sinus invasion, a score ranging between 1 and 12 was assigned to every patient ¹⁴⁾.

In patients who had a score of ≥7 out of a total of 12, a small residual tumour had to be left due to the significant risk of neurovascular injury if total excision had been attempted.

Criteria for scoring system: Volume (in cm2 )=(Length×width)2 /2: <400=1; 400 to 800=2; >800=3.

Based on method by: Kawamoto Y, Uozumi T, Kiya K, Fujioka Y, Kurisu K, Kawamoto K, Sugiyama K (1995) Clinicopathologic growth factors of acoustic neuromas. Surg Neurol 43:546–52 ¹⁵⁾.

Hyperostosis of anterior clinoid or the wing of sphenoid/>50% calcified mass within the tumour: Present=1; Absent=0. Oedema: None—0, Up to 2 cm—1, Lobar/hemispheric—2.

Cavernous sinus extension: Tumour abutting lateral wall of cavernous sinus—0.

Tumour touching cavernous internal carotid artery—1.

Tumour encasing cavernous internal carotid artery—2.

Tumour encasing and narrowing cavernous internal carotid. artery—3.

Tumour encasing and obliterating cavernous internal carotid artery—4.

Based on classification by: Hirsch WL, Sekhar LN, Lanzino G, Pomonis S, Sen CN (1993) Meningiomas involving the cavernous sinus: Value of imaging for predicting surgical complications. AJR Am J Roentgenol 160:1083–1088 ¹⁶⁾.

Extension to extra region (Sellar-suprasellar; Superior orbital fissure-orbit; and, Prepontine-Interpeduncular cistern-Posterior fossa): none–0, single–1, multiple–2, total score 1–12.

Grade Definition

I Complete removal of tumour and dural attachment with any abnormal bone

II Complete removal of tumour and coagulation of its dural attachment

IIIa Complete removal of intra- and extradural tumour without resection or coagulation of its dural attachment

IIIb Complete removal of intradural tumour without resection or coagulation of its dural attachment or any extradural tumour extensions

IVa Intentional subtotal removal to preserve cranial nerve or blood vessels with complete removal of its dural attachment

IVb Subtotal removal leaving <10% tumour volume

V Subtotal removal leaving >10% tumour volume or decompression with or without biopsy

Based on grading by: DeMonte F, Smith H, Al-Mefty O (1994) Outcome of aggressive removal of cavernous sinus meningiomas. J Neurosurg 81:245–251 ¹⁷⁾.

• The lateral transorbital approach to the medial sphenoid wing, anterior clinoid, middle fossa, cavernous sinus, and Meckel's cave: target-based classification, approach-related complications, and intermediate-term ocular outcomes
• Microsurgery for a medial left giant lesser sphenoid wing meningioma complicated by postoperative vasospasm of the ipsilateral supraclinoid carotid artery
• A giant aneurysm mimicking a medial sphenoid ridge meningioma
• Surgical excision of large-to-giant petroclival meningiomas focusing on the middle fossa approaches: The lessons learnt
• Left orbital roof giant cell tumor of bone: A case report
• Surgical treatment of intracranial aneurysms via the pterional keyhole approach
• Large and giant medial sphenoid wing meningiomas involving vascular structures: clinical features and management experience in 53 patients
• The "no-drill" technique of anterior clinoidectomy: a cranial base approach to the paraclinoid and parasellar region

The standard frontotemporal approach as well as the extensions of various skull base approaches were utilized for successful removal of giant medial sphenoidal meningiomas greater than or equal to 5 cm.

When the preoperative radiological score of Behari et al. was more than or equal to 7 out of a maximum of 12, there was considerable difficulty in achieving total excision of the tumour ¹⁸⁾.

An extension of the standard frontotemporal craniotomy using an orbitozygomatic osteotomy, as was done in 7 cases in our series, was found to be especially useful for tumours with extensive orbital, suprasellar and prepontine extensions

Cranial nerves are often directly invaded or stretched by the tumour so that it may be difficult to detect or preserve them

Behari et al. had a high incidence of preoperative hemiparesis often related to the large tumour size and extensive perifocal edema. Four of the patients developed extensive postoperative oedema. One of them in fact required a frontal lobectomy and bone flap removal in addition to mannitol and other dehydrants. Venous compromise during extradural drilling, coagulation of the pial, parasitized veins to these large tumours and retraction oedema may all have played a part ¹⁹⁾.

Mathios et al. performed a retrospective analysis of a consecutive series of lateral transorbital approach (LTOA) patients. Seven target zones were identified: 1) the orbit, 2) the lesser sphenoid wing and anterior clinoid, 3) the middle fossa, 4) the lateral wall of the cavernous sinus and Meckel's cave, 5) the infratemporal fossa, 6) the petrous apex, and 7) the anterior fossa. The authors used volumetric analyses of preoperative and postoperative MR and CT imaging data to calculate the volume of bone and tumor removed and to provide detailed ophthalmological, neurological, and cosmetic outcomes.

Of the 20 patients in this cohort, pathology was in zone 2 (n = 10), zone 4 (n = 6), zone 3 (n = 2), zone 1 (n = 1), and zone 5 (n = 1). Pathology was meningioma (n = 10), schwannoma (n = 2), metastasis (n = 2), epidermoid (n = 1), dermoid (n = 1), encephalocele (n = 1), adenoma (n = 1), glioblastoma (n = 1), and inflammatory lesion (n = 1). The goal was gross-total resection (GTR) in 9 patients, all of whom achieved GTR. Subtotal resection (STR) was the goal in 8 patients (5 spheno-orbital meningiomas, 1 giant cavernous sinus/Meckel's cave schwannoma, 1 cavernous sinus prolactinoma, and 1 cavernous sinus dermoid), 7 of whom achieved STR and 1 of whom achieved GTR. The goal was biopsy in 2 patient and repair of encephalocele in 1. Visual acuity was stable or improved in 18 patients and worse in 2. Transient early postoperative diplopia, ptosis, eyelid swelling, and peri-orbital numbness were common. All 9 patients with preoperative diplopia improved at their last follow-up. Seven of 8 patients with preoperative exophthalmos improved after surgery (average correction of 64%). There were no cases of clinically significant (> 2 mm) postoperative enophthalmos. The most frequent postoperative complaint was peri-orbital numbness (40%). There was 1 CSF leak. Most patients were satisfied with their ocular (84%-100% of patients provided positive satisfaction-related responses) and cosmetic (75%-100%) outcomes.

The LTOA is a safe minimal access approach to a variety of paramedian anterior skull base pathologies in several locations. Early follow-up revealed excellent resolution of exophthalmos with little risk of clinically significant enophthalmos. Transient diplopia, ptosis, and peri-orbital numbness were common but improved. Careful case selection is critical to ensure good outcome ²⁰⁾.