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 ( < 0.05) difference existed in aneurysm size, rupture status, use of stent and immediate occlusion outcome between the two groups, with significantly ( < 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 ( < 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.