多発性脳動脈瘤を伴った両側Infraoptic Course of ACAの1例

A Case of Bilateral Infraoptic Course of ACA Associated with Multiple Cerebral Artery Aneurysms

I．はじめに

　眼動脈分岐部付近の内頸動脈（ICA）より分岐し視神経の下方を横走した後，視交叉の前方を上行して前交通動脈（A-com）部に至る血管奇形は非常に稀で，infraoptic course of ACA，anomalousbranch of the ICA，carotid ACA anastomosisなどと呼ばれている^42）．

　今回われわれは，この血管奇形に多発性脳動脈瘤を合併した1例を経験したので，前大脳動脈（ACA）のA1部との解剖学的関係，脳動脈瘤との合併を中心に文献的考察を加え報告する．

Infraoptic course of anterior cerebral artery (ACA) is a rare cerebral vascular anomaly frequently associ-ated with intracranial aneurysm.

A 58-year-old woman suffered subarachnoid hemorrhage due to aneurysmal rupture. Carotid angiogra-phy revealed multiple aneurysms and bilateral infraoptic course of ACA. Usual A1 segments were notvisualized on both sides. These findings were also confirmed by craniotomy.

Only 46 cases have been reported including ours. In this paper, we reviewed previously reported casesand the cause of aneurysm formation was discussed.