Fenestration of the supraclinoid internal carotid artery is extremely rare and frequently associated with aneurysms at the fenestrated segment or other vascular anomalies. We present a rare case of fenestration of the right supraclinoid internal carotid artery in which a small fenestrated segment arose from the neck portion of the paraclinoid aneurysm and fused with the origin of the posterior communicating artery.
Keywords: Fenestration; cerebral aneurysm; internal carotid artery.