563 Post-Approval Three Year Outcomes Study of the Neuroform Atlas Stent for Treatment of Wide-Neck Intracranial Aneurysms

Abstract

INTRODUCTION: Favorable safety and effectiveness outcomes were presented previously for the Neuroform Atlas Stent following the completion of its pre-market study (ATLAS trial [Safety and Effectiveness of the Treatment of Wide Neck, Saccular, Intracranial Aneurysms with the Neuroform Atlas Stent System]) in anterior and posterior cohorts. METHODS: The ATLAS post-approval study was a multicenter, prospective, single-arm, open-label study of wide neck (neck ≥ 4mm or dome-to-neck ratio <2) intracranial aneurysms in the anterior and posterior circulations treated with the Neuroform Atlas Stent and approved coils. The primary effectiveness endpoint was complete occlusion (Raymond-Roy class 1) on angiography in the absence of retreatment or significant parent artery stenosis (>50%) through 3 years post-procedure. The primary safety endpoint was occurrence of major stroke, ipsilateral stroke, or neurological death through 3 years post-procedure. Independent adjudication of primary endpoint outcomes was completed by an Imaging Core Laboratory and Clinical Events Committee. RESULTS: A total of 146 anterior and 101 posterior cohort subjects from the pre-market study population were enrolled for continued follow-up. Subject demographics and aneurysm anatomy were representative of pivotal trial findings. For anterior subjects, the mean aneurysm size was 6.1±2.4 mm and the mean dome-to-neck ratio was 1.2±0.3 mm. In posterior subjects, the mean aneurysm size was 7±2.7 mm and the mean dome-to-neck ratio was 1.2±0.4 mm. At 3-year follow-up, the percent of target aneurysm progressive occlusion rated the same or better was 84.4% (95% CI, 67.2% - 94.7%) of anterior subjects and 90.0% (95% CI, 73.5% - 97.9%) of posterior subjects. A primary safety event was reported in 0.7% (1/146) of anterior and 1.0% (1/101) of posterior subjects, respectively, with no neurological deaths. CONCLUSIONS: The results of the ATLAS post-approval study demonstrate durable treatment effectiveness and favorable safety outcomes.