Late Adverse Events in Coiled Ruptured Aneurysms with Incomplete Occlusion at 6-Month Angiographic Follow-Up

BACKGROUND AND PURPOSE: Patients with coiled ruptured aneurysms with incomplete occlusion at 6 months are not only at risk for rebleed during further follow-up but also for complications of angiographic follow-up and retreatment, and for progressive mass effect by uncontrollable aneurysm growth. We assessed the frequency and outcome of all these possible aneurysm-related events in 124 patients with incompletely occluded aneurysms at 6 months during a follow-up of 419 patient-years.

MATERIALS AND METHODS: Between 1994 and 2007, 901 ruptured aneurysms were coiled and 713 (79%) had 6-month angiographic follow-up, of which 124 were incompletely occluded (17%). These 124 patients were followed for a mean of 41 months (median, 30 months; range, 1–150 months).

RESULTS: During follow-up, 307 angiograms were obtained without complications. Of 124 aneurysms, 88 were retreated (71%). Fifteen aneurysms were retreated more than once. Altogether, 124 additional treatments were performed, and no complications occurred (0%; 95% CI, 0.0–3.6%). Four aneurysms rebled, causing death in 2 patients. Another 4 patients experienced progressive mass effect by growth of the coiled aneurysm, leading to death in 1. The annual event rate was 1.9%, the annual mortality was 0.7%, and the annual rebleed rate was 1.0% (8, 3, and 4 in 419 patient-years).

CONCLUSIONS: In this study of patients with coiled ruptured aneurysms with incomplete occlusion at 6 months, a strategy of imaging follow-up and retreatment when possible leads to a low incidence of serious adverse events. Rebleeding and progressive mass effect of the aneurysm were responsible for these events, not complications from additional treatment or angiographic follow-up.