RT Journal Article SR Electronic T1 Aneurysm treatment with WEB in the cumulative population of two prospective, multicenter series: 3-year follow-up JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP 363 OP 368 DO 10.1136/neurintsurg-2020-016151 VO 13 IS 4 A1 Pierot, Laurent A1 Szikora, Istvan A1 Barreau, Xavier A1 Holtmannspoetter, Markus A1 Spelle, Laurent A1 Herbreteau, Denis A1 Fiehler, Jens A1 Costalat, Vincent A1 Klisch, Joachim A1 Januel, Anne-Christine A1 Weber, Werner A1 Liebig, Thomas A1 Stockx, Luc A1 Berkefeld, Joachim A1 Moret, Jacques A1 Molyneux, Andy A1 Byrne, James YR 2021 UL http://jnis.bmj.com/content/13/4/363.abstract AB Background WEB treatment is an endovascular approach for wide-neck bifurcation aneurysms that has demonstrated high safety and good efficacy in mid-term follow-up. While evaluating safety in the long term is important to determine if delayed adverse events occur affecting late morbidity and mortality, the most important point to evaluate is the long-term stability of aneurysm occlusion. The current analysis reports the 3-year clinical and anatomical results of WEB treatment in the combined population of two European trials (WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm Therapy) and WEBCAST-2).Methods Aneurysm occlusion was evaluated using a 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant.Results The safety population comprised 79 patients. The efficacy population comprised 61 aneurysms. Aneurysm locations were middle cerebral artery in 32/61 aneurysms (52.5%), anterior communicating artery in 13/61 (21.3%), basilar artery in 9/61 (14.8%), and internal carotid artery terminus in 7/61 (11.5%). No adverse events related to the device or procedure occurred between 2 and 3 years. At 3 years, complete occlusion was observed in 31/61 (50.8%) aneurysms, neck remnant in 20/61 (32.8%), and aneurysm remnant in 10/61 (16.4%). Between 1 year and 3 years, aneurysm occlusion was improved or stable in 53/61 (86.9%) aneurysms and worsened in 8/61 (13.1%). Worsening was mostly from complete occlusion to neck remnant in 6/61 (9.8%) aneurysms. The retreatment rate at 3 years was 11.4%.Conclusions This analysis confirms the high safety profile of WEB. Moreover, evidence demonstrates the great stability of aneurysm occlusion with adequate occlusion (complete occlusion or neck remnant) in 83.6% of aneurysms.Clinical trial registration URL: http://www.clinicaltrials.gov. WEBCAST and WEBCAST-2: Unique identifier: NCT01778322.