Combined Occipital-suboccipital Craniotomy

Abstract

The most frequent location for meningiomas of the posterior fossa, in our experience, is on the posterior surface of the petrous bone (Fig. 28-1). The major blood supply to these very vascular tumors arises from short branches of the internal carotid artery as the blood passes through the carotid canal within the petrous bone. Additional vessels from the posterior branches of the middle meningeal artery and from meningeal branches of the vertebral artery feed the tumor. In medially placed tumors near the clivus, the blood supply may be identical to that for a clivus meningioma. These tumors are attached to the dura over the posterior surface of the petrous bone anterior and superior to the internal auditory meatus and to the undersurface of the tentorium. The tentorium may be perforated by the tumor just as the falx is often penetrated by meningiomas in that location.