Surgical Management for Medial Sphenoid Wing Meningiomas

Surgical Strategy by Compartment Formation Classification

Abstract

  Medial sphenoid wing meningioma, at the advanced stage of its growth, creates several compartments partitioned by the internal carotid artery, Willis arterial ring and its perforators, the optic nerve, and the tentorial edge. According to the classification type, which we newly propose takes into consideration the meningioma's main attachment on the skull base, each type has a characteristic compartment formation. For example when infra-Willis portions of the tumor make the main attachment on the skull base, total removal is often difficult because these tumors tend to form more complicated compartments. We discuss the operative techniques and resectability of these tumors and emphasize that the concept of compartment formation is important and that, in order to preserve the perforators, the tumor should be taken out via the route that the tumor came in.