Agenesis of the internal carotid artery (ICA) is defined as a congenital absence of the carotid canal and occurs in less than 0.01% of the population. This anomaly is usually diagnosed as an incidental finding or after a cerebrovascular event. We present the case of a 36-year-old woman, with bilateral agenesis of the ICA who had suffered a subarachnoid hemorrhage due to ruptured aneurysm of the basilar artery. Therefore, agenesis of the ICA is a condition that, although rare, should be considered since there is a risk of coexistence with other life-threatening conditions such as aneurysms.
internal carotid artery; carotid artery diseases; intracranial aneurysm