Introduction WEB is an endovascular device allowing treatment of wide-neck bifurcation aneurysms. WEB 17 has been developed to make easier the treatment and to manage smaller aneurysms.

Aim of Study CLEVER objective is to provide safety and efficacy data on the WEB 0.017 in treatment of ruptured and unruptured bifurcation aneurysms at 12 months.

Methods CLEVER is an observational, prospective multicenter study conducted in 17 European sites.

Data collected are 100% monitored and primary endpoints independently evaluated (adverse events adjudicated by CEA, occlusion rates by Corelab).

Data were analyzed on the full population as well as separately for ruptured and unruptured aneurysm. Sample size calculation is based on objective performance approach for safety and efficacy rates.

Results 163 patients were enrolled with 103 unruptured aneurysms and 60 ruptured aneurysms.

Aneurysms treated were ranging from 2 to 9.2 mm.

The primary safety endpoint, defined as the proportion of patients with death of any nonaccidental cause or any major stroke within the first 30 days after treatment or major ipsilateral stroke or death due to neurologic cause from day 31 to the 1 year after treatment, was 1.8%.

The primary efficacy endpoint, defined as the 12-month rate of adequate occlusion without retreatment, was 82.2%.

Detailed description of endpoints will be provided with a specific attention to the aneurysm initial presentation (ruptured vs unruptured).

Conclusion These results show good efficacy and safety results at 12 months, and no WEB related mortality, confirming safety and efficacy of WEB 0.017 use in unruptured and ruptured aneurysms.

Disclosure of Interest Istvan Szikora has a consulting agreement with Microvention. I Szikora, Chr Cognard and L Spelle served as research coordinators for the CLEVER study