Recanalization of a large supraclinoid carotid aneurysm via elicited vertebral artery-internal carotid artery anastomosis: a case report.

Proximal ligation of the internal carotid artery (ICA) with high-flow bypass is one of the surgical strategies for treating large, unclippable ICA aneurysms. We encountered a rare case of recanalization of a large ICA aneurysm that disappeared after high-flow bypass surgery, and subsequently reappeared via an elicited vertebral artery (VA)-ICA anastomosis (anastomosis between the anterior meningeal artery branching from the right VA, and the ascending pharyngeal artery branching (APA) from the right ICA). To the best of our knowledge, this is the first case report describing angiographical recurrence of a large ICA aneurysm after the surgery. Periodic long-term follow-up by neuroimaging may be necessary after this surgery, particularly in cases of ICA proximal ligation with the ICA aneurysm, when the APA has not been clearly identified as a branch from the ipsilateral external carotid artery on the preoperative angiogram.