くも膜下出血で発症した内頚動脈後壁blister-like aneurysmの1例

Blood Blister-like Aneurysm on the Posterior Wall of the Internal Carotid Artery Causing Subarachnoid Hemorrhage: A Case Report

Ⅰ．はじめに

　Blood blister-like aneurysm（BBA）は，一般的に動脈瘤壁が脆弱で裂けやすいため，通常のクリッピング術は難しく，その再破裂予防の標準的な治療法は確立していない^1,3,9)．BBAの多くは，いわゆる内頚動脈前壁動脈瘤と呼ばれるものであり，後壁に生じるものは極めて少ない⁹⁾．今回われわれは，くも膜下出血（subarachnoid hemorrhage：SAH）で発症し，その後ダイナミックな形状の変化を示し，治療に難渋した内頚動脈後壁のBBAの1例を経験したので，文献的考察を加えて報告する．

　We report a case of blood blister-like aneurysm（BBA）on the posterior wall of the internal carotid artery（ICA）causing subarachnoid hemorrhage（SAH). A 45-year-old man suffering from SAH（WFNS grade 5）was referred to our hospital. 3D-CT angiography showed a BBA on the posterior wall of the ICA. The aneurysm had been enlarged for a few days. Therefore we performed coil embolization. Four weeks after the operation, the aneurysm was found to have regrown. In the second operation the aneurysm was successfully treated by the ICA proximal occlusion with extracranial-intracranial bypass. Postoperative follow-up cerebral angiography detected no aneurysm. To our knowledge, BBA on the posterior wall of the ICA is rare. Radical surgery with bypass should be performed as soon as possible when the BBA is found to regrow. We discuss the clinical characteristics with a review of the literature.