トラッピングにて治療した破裂前下小脳動脈遠位部解離性動脈瘤の1例

Trapping of Ruptured Dissecting Aneurysm of Distal Anterior Inferior Cerebellar Artery―Case Report

はじめに

　前下小脳動脈（anterior inferior cerebellar artery:AICA）に発生する動脈瘤は，全頭蓋内動脈瘤のうち1％未満とされている^1）。また，遠位部に発生する頻度は0.03～0.5％と低く，非常に稀である^2）。今回われわれは，くも膜下出血にて発症したAICA遠位部解離性動脈瘤に対し解離部のトラッピングを施行し，術後聴力障害を認めず軽快した1例を経験した。AICA遠位部に発生する解離性動脈瘤の報告は渉猟しえた限りでは本例を含め9例のみであり，貴重な症例と考えられるので，文献的考察を加え報告する。

Abstract

　We report a rare case of dissecting aneurysm of the distal anterior inferior cerebellar artery (AICA).　A 63-year-old woman who complained of severe headache and nausea was admitted to our hospital.　A　computed tomography (CT) scan revealed subarachnoid hemorrhage, intraventricular hemorrhage, and acute hydrocephalus.　Left vertebral angiogram revealed a dissecting aneurysm at the meatal loop of the distal AICA.　On the next day, left suboccipital craniotomy was performed, and the fusiform aneurysm was trapped.　The patient did not exhibit cranial nerve palsy after the operation.　A left vertebral angiogram obtained after the operation showed that the dissecting aneurysm of the distal AICA had completely disappeared.

　Dissecting aneurysm of the distal AICA is a rare condition.　Thus far, only 9 cases have been reported in the literature.　We reviewed these cases and discussed the treatment for and outcome of dissecting aneurysms of the distal AICA.

(Received: November 6,2007,Accepted: September 30,2008)