Contemporary Results of Bare Platinum Coil Embolization for Wide‐Necked Ruptured Aneurysms: A Subset Analysis of the SMART Registry

Abstract

Background Rupture status and presence of a wide neck are important factors that adversely impact angiographic occlusion after endovascular coiling. A potential strategy to improve occlusion rates in wide‐necked, ruptured aneurysms (WNRA) is modification of coil technology. Methods WNRA were chosen from the SMART registry that comprises 905 intracranial aneurysms treated with SMART bare platinum coils (Penumbra Inc., Alameda, USA) in the US and Canada. WNRA were defined as neck ≥4 mm, dome‐to‐neck ratio <2, or both. Clinical and angiographic data at presentation and follow‐up were assessed. Outcomes included adequate occlusion rate (Raymond–Roy occlusion class I or II), occlusion at 1 year, and good functional outcome (modified Rankin score 0–2) at 1 year. Angiographic outcome was compared for neck ≥ 4 mm versus <4 mm. Results A total of 143 patients (mean age 59.3, 74.1% female) with 143 WNRA were included. Median aneurysm size was 5.8 mm. 46.2% had a neck ≥ 4 mm. Balloon remodeling was used in 35.7% (51/143) and stents in 10.5% (15/143). Intraoperative thromboembolic complication rate was 7.0% (10/143). Overall immediate adequate occlusion rate was 78.3% (112/143); postprocedure occlusion rates were lower (62.1%, 41/66 versus 92.2%, 71/77) for aneurysms with necks ≥4 mm than those with necks <4 mm. At 1 year follow‐up, adequate occlusion was achieved in 82.4% (75/91) patients. Aneurysm occlusion improved in 31.9% (29/91) but worsened in 20.9% (19/91) of all patients at 1 year. Retreatment rate among patients who completed the study was 20.2% (20/99). One instance of intraoperative rupture (0.7%) was noted. Good functional outcome was achieved in 57.7% (41/71). Conclusion These results suggest that successful embolization of WNRA with new generation SMART coils can be achieved safely. WNRA continue to require assistive techniques at presentation and also retreatment over time. In addition, neck width may have an adverse impact on angiographic outcome.