Large and giant intracranial aneurysms: outcomes from the multicenter prospective SMART coils registry

Background Endovascular coiling for intracerebral aneurysms has been evolving. Yet, large and giant aneurysms (LAGA) remain a significant challenge in any treatment modality and carry high rates of morbidity and mortality. Method The SMART registry, a prospective, multicenter site-adjudicated trial, was used to identify patients with LAGA (Sac 10–25 mm for large and >25 mm for giant) treated with the Penumbra SMART COIL (SMART) system and compare their outcomes to patients with smaller aneurysms (SA; Sac ≤ 10 mm). Aneurysm occlusion per Raymond-Roy (RROC) scale, recanalization, retreatment, mortality, and serious device-related adverse events (SAEs) were analyzed. Results A total of 133/905 (14.7%) enrolled patients had LAGA with a mean (SD) aneurysm size of 13.7 (3.59) mm for LAGA and 5.8 (1.95) mm for SA. LAGA were more likely to be non-saccular (24.1% vs. 12.3%, p = 0.0007) and wide-necked (69.9% vs. 59.7%, p = 0.0268) compared to SA. Primary coiling was the main treatment modality for LAGA and SA (43.6% vs. 43.3%; p = 1.0). However, LAGA were more likely to be treated with flow diversion in addition to coiling (6.0% vs. 1.0%, p < 0.001). At 1-year follow-up: (i) RROC I-II was 82.7% in LAGA and 91.2% in SA; p = 0.0166, (ii) recanalization rates were 13.8% vs. 12.7%; p = 0.7417, and retreatment rates were 11.5% vs. 6.4%; p = 0.0648, for LAGA and SA, respectively, and (iii) all-cause mortality was 9.8% in LAGA vs. 4.7% SA; p = 0.0222. The device-related SAEs rates were low and comparable between the two study groups (4.5% vs. 4.1%; p = 0.8153). Conclusion The SMART registry demonstrated that endovascular coiling can be feasible and safe in patients with LAGA, however randomized controlled studies are needed for comparative effectiveness. Clinical trial registration https://clinicaltrials.gov/study/NCT02729740 .