Endovascular Retreatment of Cerebral Aneurysms Previously Treated with Endovascular Embolization

Objective Intracranial aneurysms treated with endovascular coil embolization may recur. We investigated the factors affecting aneurysmal recurrence after embolization and effects of endovascular retreatment within 1 year. Methods In 3 years, 1,335 patients with 1,385 intracranial aneurysms were treated with coil embolization. Factors affecting aneurysm recurrence and the effects of endovascular retreatment were analyzed. Results Angiography immediately following embolization showed total occlusion in 1,030 aneurysms (74.4%), neck remnant in 207 (14.9%), and partial occlusion in 148 (10.7%), with a total peri-procedure complication rate of 4.2%. Overall, 145 patients with 151 aneurysms recurred within 1 year and the other 1,234 aneurysms remained occluded (89.1%). A significant (p < 0.05) difference existed in aneurysm size, rupture status, use of stent and immediate occlusion outcome between the two groups, with significantly (p < 0.05) lower recurrence rates in aneurysms with smaller sizes, no rupture and stent-assistance coiling. Neck remnant, partial occlusion, coiling without stent assistance, large and giant aneurysms were significant (p < 0.05) risk factors for aneurysm recurrence during the first year. The rate of recurrence was 4.7% (11/232) in aneurysms with total occlusion and 35.9% (23/64) in aneurysms with neck remnant and partial occlusion. Of the 34 recurrent aneurysms, 6 were re-embolized with detachable coils alone, 12 with stent-assisted coiling, 8 with balloon-assisted embolization, and the remaining 8 aneurysms with covered stents, resulting in total occlusion in 28 aneurysms and neck remnant in 6. Conclusion Recurrence of previously-coiled cerebral aneurysms is significantly affected by aneurysm size, use of stent and degree of immediate occlusion. Endovascular retreatment with balloon-or stent-assisted techniques or with covered stents can be safe and effective for recurrent cerebral aneurysms.