中大脳動脈クリッピング時に中大脳動脈M2癒合による窓形成が明らかとなった1例

Middle Cerebral Artery Fenestration with M2 Fusion Detected during Aneurysm Clipping:A Case Report

Ⅰ．はじめに

　脳血管における窓形成の頻度は，前交通動脈，椎骨脳底動脈に多く認められ，中大脳動脈では非常に稀である¹⁾．また中大脳動脈窓形成の多くはM1近位に存在するとされている⁷⁾．今回，中大脳動脈瘤の手術の際にM2癒合による窓形成を認めた症例を経験したため報告する．

　We report a unique case of middle cerebral artery fenestration with M2 fusion detected during an aneurysm clipping. A 72-year-old woman was diagnosed with an unruptured aneurysm of the right middle cerebral artery, and middle cerebral artery fenestration with M2 fusion was detected during the aneurysm clipping surgery. It was difficult to identify this unusual vascular anomaly before the surgery. Therefore, neurosurgeons should be cautious of such hidden vascular anomalies and be prepared for the possible complications during surgery.