Surgery of Basilar Top Aneurysm: Drilling of Anterior and Posterior Clinoid Processes

Abstract

Surgery of cerebral aneurysm confronts expected difficulty and unexpected happenings. To make difficult surgery easy, a surgical strategy as if operating in a shallow basin with the skull base technique is required. Extradural drilling of the anterior clinoid process is the most basic technique to obtain wide working space by mobilizing the internal carotid artery. We report a case of very high-positioned basilar top aneurysm treated with this technique. Drilling of the anterior clinoid process is a safe and quick technique. On the contrary, drilling of the posterior clinoid process poses the danger of unexpected massive bleeding from the venous plexus of the clivus. Preoperative estimation of how wide and deep the drilling can be performed is not easy. Hesitating go and obligatory stop limit this technique. We report 2 cases that encountered this situation.