Intracranial aneurysms that repeatedly reopen over time after coiling : imaging characteristics and treatment outcome

We report imaging and clinical characteristics of patients with aneurysms that repeatedly reopened over time and were coiled three times or more during a follow-up period of 2-11 years. At angiographic follow-up of 624 of 827 aneurysms coiled between 1995 and 2005, 74 aneurysms (8.9%) reopened and were additionally coiled. During an extended follow-up, 12 aneurysms (1.5%) in 12 patients repeatedly reopened and were repeatedly coiled. Initial aneurysm sizes ranged from 15 to 30 mm. Four aneurysms contained intraluminal thrombus. Eight aneurysms were associated with subarachnoid hemorrhage and two with a mass effect, and two were incidentally discovered. The locations of aneurysms were basilar artery (eight), carotid artery (two), anterior communicating artery (one) and middle cerebral artery (one). Altogether, 49 coil treatments were performed in the 12 aneurysms, ranging from three to six coil treatments per aneurysm. Of the 49 coil treatments, 20 (41%) were performed with a supporting device. There were no procedural complications (0%, 97.5% CI 0-5.7%). The mean clinical follow-up period was 70.6 months (median 60, range 25-135 months). All 12 patients are neurologically doing well (GOS 5). Reopening was by compaction in nine aneurysms and by migration of coils into intraluminal thrombus in three aneurysms. In two aneurysms, late regrowth became apparent at 76 and 95 months after the previous coiling. Aneurysms that reopen over time and need to be coiled for a second time should be imaged at regular intervals to detect repeated reopening or regrowth. The treatment strategy of regular follow-up and additional treatments when necessary is effective and safe.