[Arterial stenosis after coil migration in embolization of an aneurysm]

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.