脳動脈瘤クリップ後の再発

Recurrent Cerebral Aneurysm after Successful Clipping of Aneurysmal Neck

I．はじめに

　破裂すればくも膜下出血の主因となる脳動脈瘤の根治治療法としては，頭蓋内直達手術による脳動脈瘤柄のclippingが最も確実かつ安全な手術方法の代表と信じられ，広く用いられてきた．しかしながら最近われわれは，術中の確認はもちろん，術後の脳血管撮影でも動脈瘤柄を含めて動脈瘤の消失を確認ののち，数年を経て同部位に，より大きな動脈瘤の再発をみた症例を相次いで経験したので，脳血管撮影所見および組織学的に検討を加えてみた．

Neck clipping has been widely believed to be one of themost reliable and typical treatment of the cerebral aneurysm.Recently we experienced two cases of recurrence of cerebralaneurysm several years after surgery, in spite of confirmationof perfect neck clipping not only by intraoperative inspectionbut postoperative angiographical studies.

The histological findings demonstrated that the arterialwall at the clip edge changed into thinning, interruption,and atrophy both of the muscle layer and internal elasticlamina. Therefore, local fragility of the arterial walladjacent to clip edge seemed to cause formation of a newaneurysm.