Endoscopic endonasal surgery for anterior skull base meningiomas

Abstract

Meningiomas of the tuberculum sellae, planum sphenoidale and olfactory groove region are relatively common. Traditionally these meningiomas have been approached through several transcranial approaches. More recently, keyhole approaches have been utilized with success even for large tumors. Endoscopic approaches are an extension of this philosophy, which, in carefully selected patients, may be an excellent alternative, offering a direct line of site from an endonasal approach without brain retraction. Furthermore, bilateral optic canal decompression can be safely and effectively accomplished. We propose that a majority of tuberculum sellae and posterior planum meningiomas may be removed via an endonasal approach, particularly those that are 3 cm or smaller in maximal diameter with minimal lateral extension beyond the supraclinoid carotid arteries and with medial optic canal invasion. A deepened sella is also a favorable factor for endonasal removal. In contrast, we propose that a minority of olfactory groove meningiomas are ideal candidates for endoscopic trans-cribriform removal given the higher risk of anosmia and cerebrospinal fluid leak via the nasal corridor. Instead, a majority of these tumors can be safely and effectively removed via a transcranial keyhole approach, such as the supraorbital "eyebrow" craniotomy or traditional pterional craniotomy with a higher rate of olfaction preservation.