外傷により内頸動脈C1-2部に全周性に生じた解離性動脈瘤の1例

A Case of Traumatic Dissecting Aneurysm of the C1-2 Portion of the Internal Carotid Artery

I．はじめに

　頸動脈動脈解離は以前は非常に少ないと言われていたが，その概念の普及と診断技術の進歩により症例数は増加している^7）．頸動脈の中でも総頸動脈近傍での解離が多く，頭蓋内の内頸動脈に外傷により生じる解離性動脈瘤の報告は少ない．また，これらの外傷性解離性内頸動脈瘤は血管の閉塞による虚血症状で発症することが多く，破裂してくも膜下出血（SAH）にて発症する硬膜内内頸動脈の解離性動脈瘤の報告は極めて稀である^1）.

今回われわれは閉鎖性頭部外傷後，内頸動脈C1-2部に全周性に生じた頭蓋内外傷性解離性内頸動脈瘤を経験した．この症例はSAHをくり返した．出血で発症したこのような動脈瘤の報告はなく，その診断，治療法の問題点について検討した．

The authors report a case of traumatic dissecting aneurysm of the C1 - 2 portion of the internal carotidartery (ICA) in a 54-year-old woman. She suffered from traumatic SAH due to closed head trauma as a re-sult of a motor vehicle accident. Twenty-five days after this accident, traumatic dissecting aneurysm of the C1 - 2 portion of the ICA that was caused by closed head trauma was ruptured and increased in size, asrevealed by serial angiographic studies. In intraoperative finding, dissection involved the entire circumfer-ence of the C1 - 2 portion of the ICA. Clipping procedures were impossible, so internal carotid ligation andSTA-MCA anastomosis was performed. To our knowledge, this traumatic dissecting aneurysm of the C1 -2 portion of the ICA was the first case that presented with SAH. We discussed the mechanism of dissec-tion of the ICA and operative strategy suitable for this aneurysm.