脳梁辺縁動脈非血管分岐部より生じた破裂脳動脈瘤の1例

An unbranched-site ruptured aneurysm of callosomarginal artery

I．はじめに

　前大脳動脈の末梢に発生する動脈瘤は比較的稀であり，その合併する血管奇形や特徴的な臨床症状などで興味ある疾患である．また，発生部位のほとんどが脳梁周囲動脈の血管分岐部であるが，今回われわれは，脳梁辺縁動脈上の血管非分岐部から生じた破裂脳動脈瘤によるくも膜下出血例を経験したので文献的考察を加え報告する．

A case of ruptured callosomarginal artery aneurysm was reported. A 47-year-old male was admitted to our hospital with disturbance of consciousness. CT scan re-vealed subarachnoid hemorrhage. No aneurysm was de-tected by initial angiography. His consciousness level deteriorated so we stopped the examination. CT scan after initial angiography showed intracerebral hemato-ma in the left frontal lobe. On day 15 severe vasospasm occurred and he presented with total aphasia and right hemiplegia. The third angiography disclosed a calloso-marginal artery aneurysm. Neck clipping of the aneurysm was successfully performed via unilateral in-terhemispheric approach. Postoperative course was un-eventful and the patient recovered well with mild right hemiparesis and motor aphasia. He was transferred to another hospital for rehabilitation. The incidence of dis-tal anterior cerebral artery aneurysm has been reported as being about 5%. The location of aneurysm in this case is very rare. In the present study we review the literature on aneurysms at the distal anterior cerebral artery and discuss the clinical and radiological f eatures.