Congenital absence of the common carotid artery in a patient with a ruptured anterior communicating artery aneurysm.

In a 41-year-old woman with a ruptured anterior communicating artery aneurysm, cerebral angiography incidentally showed an absence of the right common carotid artery. The right internal and external carotid artery originated from the ipsilateral inominate artery. The absence of the common carotid artery is extremely rare and association with a ruptured cerebral aneurysm is even less common. A description of the case and review of the literature are reported.