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 widenecked bifurcation aneurysms. This analysis presents the 36-month follow-up data for the anterior and posterior cohorts. Methods Of the 182patients in the IDE anterior cohort, 146 consented to participate in the post-approval study (PAS) and, of the 116patients 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 36months post-procedure. The primary safety endpoint was Clinical Event Committeeadjudicated major ipsilateral stroke or neurological death through 36months. Results There were 146patients in the anterior cohort and 101patients in the posterior cohort. At 24months the composite effectiveness endpoint was 77.3% (34/44) in the anterior cohort and 65.5% (19/29) in the posterior cohort and at 36months these rates were 92.3% (24/26) and 75.0% (18/24), respectively. RR1 rates at 24months were 84.1% (37/44) in the anterior cohort and 70.0% (21/30) in the posterior cohort; at 36months they were 96.3% (26/27) and 79.2% (19/24), respectively. By 36months 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 12months post-procedure.