Thromboembolic complication following neurointervention in ruptured anomalous hyperplastic anterior choroidal artery aneurysm.

The anterior choroidal artery (AchA) is an important cerebral artery despite its small diameter and relatively short course, because it provides blood supply to several important structures. Hyperplastic AchA is an extremely rare anomaly, and its clinical significance is the increased occurrence of intracranial aneurysm formation compared with an ordinary AchA. Because it has many small choroidal branches, subtle injury to the artery may result in severe complications. We describe a patient with a ruptured aneurysm in anomalous hyperplastic AchA, who developed an acute internal capsule infarction after coil embolization in spite of saving the parent artery.