Orbitozygomatic Approach for a Ruptured P1 Perforator Aneurysm: 2-Dimensional Operative Video

Perforator aneurysms are a rare cause of subarachnoid hemorrhage that are challenging to diagnose and treat. The posterior circulation is prone to perforator aneurysms, with reported cases including 57 basilar artery perforator aneurysms,^1-26 3 superior cerebellar artery aneurysms,^22,27,28 and 2 posterior choroidal artery aneurysms.^22,28 Approximately half of perforator aneurysms are diagnosed on the first diagnostic imaging,²⁹ and described management strategies include open treatment, endovascular treatment, or conservative management. We report a case and video of a ruptured perforator aneurysm arising from the P1 segment of the posterior cerebral artery (PCA). Preoperative imaging revealed an aneurysm in the region of the basilar apex but failed to reveal the parental source of the aneurysm. Therefore, a frontotemporal craniotomy with orbitozygomatic osteotomy was used to explore the region of the basilar apex, focusing on the perforators arising from the proximal PCA. In this video, we illustrate the steps used to increase the exposure to this deep corridor, successfully identify the causal perforator, and secure the aneurysm. We discuss how open treatment for basilar apex/PCA perforator aneurysms can be used to overcome the difficulty in identifying the source for perforator aneurysms on preoperative angiogram studies and successfully clip these challenging aneurysms. The patient consented for participation in this report.