Long-Term Follow-Up of 1036 Cerebral Aneurysms Treated by Bare Coils: A Multicentric Cohort Treated between 1998 and 2003

BACKGROUND AND PURPOSE: The endovascular treatment (EVT) of cerebral aneurysms has experienced a revolution since 1991 with the introduction of platinum coil technology. During the past 10 years, there has been significant study of the feasibility of this technique, and clinical results of EVT have been published. The long-term durability of Guglielmi detachable coil (GDC) embolization of cerebral aneurysms still remains unknown. The purpose of this study was to evaluate the stability of anatomic occlusion of aneurysms and to assess the rate of recanalization and retreatment of these aneurysms.

MATERIALS AND METHODS: Between January 1998 and December 2003, 1036 aneurysms (804 ruptured and 232 nonruptured) were treated consecutively with GDC coils in 5 neuroradiology centers. Procedural feasibility, acute angiographic occlusion results, morbidity, and mortality associated with this technique were assessed. All patients were regularly followed by digital subtraction angiography and MR imaging each year after treatment.

RESULTS: Initial acute angiographic results in 1036 aneurysms demonstrated total occlusion in 731 patients (70.5%), subtotal occlusion in 252 (24.3%), incomplete occlusion in 20 (1.9%), and failures in 33% (3.3%) aneurysms. A remodeling technique was used in 10%. A second procedure was performed for 72 aneurysms (7%). The total aneurysm follow-up time was 49,923 months (4160.25 aneurysm-years). The retreatment period was either in the months following initial treatment in aneurysms incompletely occluded or in years due to recanalization or de novo aneurysms. Fewer than 5 patients rebled during 10 years of follow-up. Long-term follow-up angiograms were obtained in 899 aneurysms, with 646 total, 230 subtotal, and 23 incomplete results.

CONCLUSIONS: Long-term follow-up of cerebral aneurysms is necessary to depict recanalization. Only 7% of the aneurysms were retreated. Use of bare coils gives a good long-term level of occlusion.