Clip-Assisted Coiling of Large Partially Fusiform Internal Carotid Artery Terminus Aneurysm

Internal carotid artery terminus aneurysms can be complex entities that present a challenge for both surgical and endovascular treatment.^1,2 Definitive microsurgical treatment can be difficult due to anatomic features such as a wide neck, high density of perforators originating at this location, and proximity of vital arteries (e.g., the anterior choroidal artery) originating from the distal internal carotid artery. Conversely, endovascular treatment may be ineffective due to low complete aneurysm occlusion rates and high risk of recurrence. Hybrid surgical and endovascular treatment of complex aneurysms not readily amenable to treatment with a single modality has been described.³ In Video 1, we present a case of a 55-year-old woman found to have a large internal carotid artery terminus aneurysm, which was managed with a hybrid approach. The aneurysm was large, broad-based, and mostly saccular, but had a fusiform component at the base containing the origin of the anterior choroidal artery. Definitive microsurgical clipping was attempted, but ultimately was not possible as the anterior choroidal artery origin could not be preserved. The aneurysm was subsequently partially clipped, facilitating coil embolization of the saccular component with clip assistance.