Half Trans-Sylvian and Half Subtemporal Approach for Microsurgical Clipping of Basilar Apex Aneurysm

Basilar apex aneurysms (BAAs) are considered among the most challenging pathologies in open cerebrovascular neurosurgery.¹ While often managed endovascularly, complex BAAs or those in which endovascular therapy is not prudent may require microsurgical treatment. Microsurgical approaches include trans-sylvian, subtemporal, and pretemporal. Here, we present a case of a growing BAA in a 65-year-old man with a history of multiple intracranial aneurysms treated with stent-assisted coil embolization. His clinical picture was complicated by left vertebral artery dissection and occlusion during angiography. Due to apprehension toward further endovascular interventions, an occluded left vertebral artery, and the desire for definitive treatment, the patient opted for microsurgical management. We used a combined trans-sylvian and subtemporal approach, allowing for a wide operative corridor to the posterior circulation, increased proximal control, and optimized exposure of the aneurysm neck and surrounding perforators (Videos 1-11). The case presentation, relevant anatomy, operative technique, and postoperative clinical and imaging outcome are discussed, and the existing literature on microsurgical treatment of BAAs is reviewed.^2-12 The patient gave verbal permission for his case to be published. Because all patient identifying information has been removed, Institutional Review Board and Ethics Committee approval was not required.