Post-approval study 3-year outcomes of the Neuroform Atlas stent for the treatment of wide-necked intracranial aneurysms

INTRODUCTION: The ATLAS trial was a prospective, multicenter, single-arm, investigational device exemption (IDE) study to evaluate the safety and effectiveness of the Neuroform Atlas Stent System for the treatment of wide-necked bifurcation aneurysms. This analysis presents the 36-month follow-up data for the anterior and posterior cohorts. METHODS: Of the 182 patients in the IDE anterior cohort, 146 consented to participate in the post-approval study (PAS) and, of the 116 patients in the IDE posterior cohort, 101 consented to participate in the PAS. The primary effectiveness endpoint was core laboratory adjudicated (Raymond-Roy 1; RR1) without retreatment or parent artery stenosis (>50%) at 36 months post-procedure. The primary safety endpoint was Clinical Event Committee-adjudicated major ipsilateral stroke or neurological death through 36 months. RESULTS: There were 146 patients in the anterior cohort and 101 patients in the posterior cohort. At 24 months the composite effectiveness endpoint was 77.3% (34/44) in the anterior cohort and 65.5% (19/29) in the posterior cohort and at 36 months these rates were 92.3% (24/26) and 75.0% (18/24), respectively. RR1 rates at 24 months were 84.1% (37/44) in the anterior cohort and 70.0% (21/30) in the posterior cohort; at 36 months they were 96.3% (26/27) and 79.2% (19/24), respectively. By 36 months the primary safety endpoint occurred in 4.1% (6/146) of patients in the anterior cohort and 5.0% (5/101) in the posterior cohort. CONCLUSION: The results of the long-term assessment of the Neuroform Atlas Stent System demonstrate favorable safety and effectiveness in the treatment of wide-necked bifurcation aneurysms without a single treated target aneurysm rupture beyond 12 months post-procedure.