Endoscopic Transorbital Resection of Spheno-Orbital Meningiomas for Orbital Decompression

Intro: Endoscopic transorbital resection for spheno-orbital meningioma presents a less invasive alternative to craniotomy with reduced risk of post operative cosmetic deformity, with some studies citing equal or superior rates of gross total resection (GTR) than open approaches. When the primary goal of surgery is orbital decompression, with intracranial tumor resection as a secondary aim, transorbital endoscopic surgery may be a superior approach.

Methods: Case series of patients with spheno-orbital meningiomas who underwent transorbital surgery by neurosurgery and oculoplastic multidisciplinary teams at a single center from July 2023 to July 2024.

Results: Seven patients were identified; all patients were female. The mean (SD) age was 67.5 (24.7). Five patients initially presented to the oculoplastics service and were referred to neurosurgery for co-management. Five patients presented with proptosis, diplopia, or facial pain without deterioration of vision. Two patients presented with compressive optic neuropathy and vision loss for several months. All seven patients underwent combined transorbital decompression by neurosurgery and oculoplastics teams. Surgical procedure involved a lateral eyelid crease incision and subperiosteal dissection down to the lateral orbital rim with bony marginotomy, retraction of the temporalis, periorbita and globe. Surgical loupes were used for access and visualization of the superficial aspect of the hyperostotic bone, which was removed with a combination of coarse and fine drilling. The endoscope was utilized when visualization with loupes became limited, as resection transitioned to deeper bony drilling, intracranial tumor resection, and dural reconstruction. All patients achieved significant orbital decompression. There was gross total resection of both bony tumor and enhancing dural tail for two patients. Two patients underwent adjuvant radiotherapy after subtotal resection. Postoperative pathology was consistent with World Health Organization (WHO) grade 1 meningioma in six patients and WHO grade 2 disease in one patient. Both patients with compressive optic neuropathy achieved improvement in post operative visual acuity. Three patients developed transient post operative diplopia that resolved by post operative month six.

Conclusion: For patients with intraosseous spheno-orbital meningiomas, orbital decompression via an endoscopic approach can achieve meaningful tumor resection as well as reduce pain, decrease proptosis, and relieve compressive optic neuropathy. Bi-directional referral patterns and a collaborative approach between oculoplastics and neurosurgical services optimizes care for patients with these challenging skull base lesions. It also fosters cross-specialty evaluation of a symptom targeted approaches and identifies which patients are ideal surgical candidates for transcranial versus transorbital surgery ([Fig. 1]).

Fig. 1 Axial orbit computed tomography (CT) with hyperostotic sphenoid wing meningioma (A) and after trans orbital approach for post bony orbital decompression (B). Axial magnetic resonance imaging (MRI) T1-TSE sequence with enhancing dural component (C) and MP-RAGE sequence after gross total resection of bony tumor and dural component (D).