Lateral orbitotomy for removal of sphenoid wing meningiomas invading the orbit.

Sphenoid wing meningiomas may growth and spread in different directions, such as cavernous sinus, sella turcica and orbit. The extension to the orbital cavity may occur through the bone, the optic canal and/or the superior orbital fissure, although in most invasive cases the pathway of tumor spread cannot be defined. Although most sphenoid wing meningiomas with bone involvement extend to the orbital roof and/or lateral orbital wall, only about half of the cases in the reported series show a defined intraorbital tumor mass. Sphenoid wing meningiomas with extension to the orbit are currently removed through several transcranial approaches. We report a series of 18 patients harbouring a sphenoid wing meningioma with extension in the lateral or superolateral orbital compartments, who underwent tumor resection via a lateral orbitotomy, thus avoiding the craniotomy. The approach consisted in the resection of the lateral orbital rim, lateral orbital wall and infiltrated sphenoid wing; the lateral part of the orbital roof was resected in 12 cases with superior orbital extension of the tumor. A seemingly complete resection (Simpson I), including the infiltrated bone, dura and periorbita, was obtained in 13 patients (72 %), whereas in 5 cases (28 %) the entity of dural resection could not be exactly defined (Simpson II). In three cases with the tumor reaching the lateral aspect of the optic canal, satisfactory decompression of the optic nerve was obtained. The advantages and limits of this approach are discussed.