Azygos Anterior Cerebral Artery Aneurysmの2例

Two Cases of Azygos Anterior Cerebral Artery Aneurysm

Ⅰ．はじめに

　下等哺乳動物の前大脳動脈は1本のazygos anteriorcerebral artery（以下azygos ACAと略す）からなっている．Baptista^1）の集計によれば，ヒトにおいても2,153例中23例（1.1％）にazygos ACAが認められている．一方，本動脈はしばしば中枢神経系の奇形や，脳動脈瘤と合併して認められている．われわれは，両側頸動脈写あるいは他側頸部圧迫による一側頸動脈写により，明確な前大脳動脈の造影が得られた末梢部前大脳動脈瘤症例37例中（うち多発動脈瘤18例）2例にazygos ACAを認めたので報告する．

Two cases with azygos anterior cerebral artery were reported from an analysis of 37 cases of distal anterior cerebral artery aneurysm. Case 1 was a 57-year-old woman. She had an attack of subarachnoid hemorrhage two months before admission to our clinic. The anterior cerebral artery was not demonstrated on the right caro-tid angiogram, and an azygos anterior cerebral artery was visualized on the left carotid angiogram. The ane-urysm was situated at the distal end of the azygos artery. Case 2 was a 71-year-old hypertensive woman. Subarachnoid hemorrhage occurred 6 days before admission to our clinic.