脳動脈瘤塞栓術中に逸脱したコイルが，後に血管狭窄を引き起こした1例

Arterial Stenosis after Coil Migration in Embolization of an Aneurysm

Ⅰ．はじめに

　脳動脈瘤コイル塞栓術中に，瘤内に離脱したコイルが親血管内に逸脱してしまうことはしばしば経験される合併症である．親動脈へのわずかな突出であればそのまま経過観察することが多いと思われるが，親動脈に逸脱したコイルが長期的にどのような経過を辿るのかはあまり知られていない．

　今回われわれは，破裂脳動脈瘤塞栓術中に瘤内に離脱したコイルが動脈瘤外に逸脱し，回収せずに経過観察としたところ，半年後に血管狭窄を起こした症例を経験したので報告する．

　A case of arterial stenosis after coil migration in intracranial aneurysm embolization is presented. A 51-year-old woman suffered sudden onset of headache and unconsciousness. Computed tomography demonstrated diffuse subarachnoid hemorrhage and cerebral angiography disclosed a right internal carotid artery (ICA) bifurcation aneurysm and a right ICA-anterior choroidal artery aneurysm. The aneurysms were treated by endovascular embolization with Guglielmi detachable coils. During the embolization procedure of the ICA bifurcation aneurysm,a coil strand detached in the sac had migrated into the ICA. We did not retrieve the migrated coil,because the free coil strand was stable in the ICA and did not cause distal flow reduction. The patient suffered vasospasm of the right ICA and underwent intra-arterial infusion of fasudil hydrochloride and percutaneous transluminal angioplasty of the ICA on day 9. The patient experienced infarction in the territory of the right anterior cerebral artery area and needed a ventriculo-peritoneal shunt for hydrocephalus. The patient was discharged with mild right hemiparesis. Follow-up angiography after six months revealed right ICA and middle cerebral artery stenosis,but the free strand of the migrated coil had not moved in the right ICA. We suspect that the coil strand might have induced thrombosis or intimal hyperplasia of the proximal M1 segment and right ICA. Although late stenosis of the parent artery might be rare,it should be recognized as a long term complication of a migrated free coil strand in the endovascular treatment of intracranial aneurysms.