Fenestration of the supraclinoid internal carotid artery associated with carotid bifurcation aneurysm.

Fenestration of the internal carotid artery is extremely rare. The authors describe a fenestration at the supraclinoid portion of the left internal carotid artery revealed after subarachnoid hemorrhage from an ipsilateral carotid bifurcation aneurysm. This is the third reported case of fenestration of the intracranial internal carotid artery. Fenestrated cerebral vessels and their possible genesis and surgical management are discussed.