内頸動脈硬膜輪近傍動脈瘤の血管内治療

Abstract

Aneurysms arising around the carotid siphon, named juxta-dural ring aneurysms, are different from other cerebral aneurysms. These aneurysms are partially or totally covered with the dura mater and surrounded by the bone or the optic nerve. These anatomical specificity makes surgical access and clipping difficult, compared with other aneurysms. In our experience with endovascular treatment of the cerebral aneurysm over the past 4 years, 32 (28.8%) out of 111 patients harbored juxta-dural-ring aneurysms, including 5 males and 27 females whose age ranged between 33 and 76 years (average 57.5 years old). Seven patients suffered from subarachnoid hemorrhage, 3 in Grade 2, 3 in Grade 3 and 1 in Grade 4. Of 25 patients whose aneurysms were intact, 2 patients developed visual disturbance and 23 were asymptomatic. There were 28 small aneurysms and 4 large aneurysms. Giant aneurysms were not included in this study. Eight of them are broad necked. Twelve aneurysms arose distal to the origin of the ophthalmic artery and 20 did proximal, including 5 “carotid cave aneurysms.”“Extradural cavernous aneurysms”were excluded.Reasons of indication of endovascular treatment were surgically difficult case in 26, surgically unsuccessful case in 2, poor medical condition in 1 and patient's own will in 3. All these 32 aneurysms were occluded with detachable coils with preservation of the carotid artery. Angiographical results were complete occlusion in 12 (37.5%), dome filling in 13 (40.6%) and residual neck in 7 (21.9%). In the follow-up, complete occlusion was seen in 17 (53.1%), dome filling in 11 (34.4%) and residual neck in 4 (12.5%). Clinical results were good recovery in 29 (90.6%), moderately disabled in 2 (6.3%), severely disabled in 1 (3.1%) and dead in 0 (0%). Of 25 non-ruptured aneurysms, all the patients obtained GR, but there was no visual improvement in 2. Only 1 patient developed hemiparesis caused by embolic stroke due to inadequate heparinization in spite of complete occlusion of the aneurysm and intact carotid artery.Otherwise no serious complications occurred. In the follow-up period from 6 months to 4 years, no bleeding or rebleeding was observed. In our experience over a relatively short period, results are satisfactory. Considering surgical difficulty and results, we conclude that endovascular treatment is useful for carotid aneurysms around the siphon (juxta-dural ring aneurysm). However, special attention should be paid in choosing treatment of intact aneurysms, in which the risk of rupture is not high in the natural course.