Late adverse events in coiled ruptured aneurysms with incomplete occlusion at 6-month angiographic follow-up

Abstract

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.

Fig 1.

Flow chart showing patient selection.

Fig 2.

Cumulative incidence of late adverse events in incompletely occluded aneurysms at 6-month follow-up.

Fig 3.

Cumulative mortality from late adverse events in incompletely occluded aneurysms at 6-month follow-up.

Fig 4.

Flow chart of all treatments.

Fig 5.

Late mass effect by continuous growth of a large basilar tip aneurysm despite repeated coiling in a 39-year old man. A−C, MR imaging after 2 (A), 4 (B), and 8 (C) years shows gradual enlargement with brain stem compression and edema (arrow in C). D, Angiogram of the 17-mm basilar tip aneurysm at first presentation after SAH. E, Angiogram after 8 years and 4 coiling procedures at the time of presentation with new mass effect (compare with C). F, Angiogram after the fifth coiling with stent placement shows adequate aneurysm occlusion.