Background: Flow diversion has revolutionized the management of wide-necked intracranial aneurysms (IAs). We aimed to assess the effectiveness and safety of the new generation 64-wire Surpass Evolve for the treatment of unruptured small/medium-sized IAs.

Methods and results: This is a subanalysis from the SEASE (Safety and Effectiveness Assessment of the Surpass Evolve) registry, an observational cohort study including 15 academic institutions in North America and Europe between July 2020 and October 2022. Patients with wide-necked saccular IAs, measuring <12 mm along the internal carotid artery and vertebrobasilar system, and treated with the Surpass Evolve were included. Primary effectiveness was complete occlusion (Raymond-Roy class 1) at follow-up (core laboratory adjudicated), and primary safety was major stroke (ischemic/hemorrhagic) in the territory supplied by the target artery or death. A total of 129 cases with 135 IAs were included (median age 59 years, 85.3% women). Median maximum IAs size and neck size were 5.1 and 3.9 mm, respectively. Most IAs were in the internal carotid artery C6 (65.9%, 89/135) and C7 (14.1%, 19/135) segments. At a median follow-up time of 10.2 months (interquartile range, 6.4-12.8), complete occlusion was 77.1% (101/131), ≥50% in-stent stenosis was 8.8% (11/125), and retreatment was 0.8% (1/125). Major stroke and mortality were reported in 2 (1.6%) patients and 1 (0.8%) patient, respectively. Size was the only factor associated with higher odds of incomplete occlusion (adjusted odds ratio, 1.2 [95% CI, 1.02-1.5]; P=0.03).

Conclusions: Patients with small/medium-sized IAs can be effectively treated using the Surpass Evolve, a new generation, 64-wire, cobalt-chromium flow diverter.