Fenestration of the supraclinoid internal carotid artery with associated aneurysm.

A 42-year-old woman presented with a rare case of fenestration of the supraclinoid internal carotid artery (ICA) with associated aneurysm manifesting as headache. Computed tomography (CT) found no abnormalities. Three-dimensional CT angiography showed fenestration of the left ICA with an associated aneurysm. Direct surgery was performed for the aneurysm, and the patient's postoperative course was uneventful. The present case of ICA fenestration associated with aneurysm indicates that surgical treatment should be considered for even small unruptured aneurysms arising from this location, because of the high risk of rupture.