Ruptured internal carotid artery aneurysm at the origin of a perforating artery associated with a hyperplastic anomalous anterior choroidal artery--case report.

A 65-year-old man presented with a hyperplastic anomalous anterior choroidal artery (AChA) associated with a ruptured internal carotid artery aneurysm at the origin of a perforating artery manifesting as sudden onset of headache and vomiting. The aneurysm was too small for endovascular embolization, so we performed open surgery via the left pterional approach. Aneurysm clipping with preservation of the perforator was impossible, so we clipped the aneurysm neck and sacrificed the perforator. We also performed dome clipping because dome puncture resulted in continuous bleeding. Head computed tomography obtained 3 days after the operation showed cerebral infarction at the territory of the sacrificed perforator, but the patient suffered no neurological deficits. This case of internal carotid artery aneurysm with a perforating artery arising from the aneurysm dome shows that sacrifice of the perforator may be necessary to prevent rebleeding.