Background Flow Disruption with WEB is an innovative endovascular approach for wide-neck bifurcation aneurysms. Multiple prospective, multicenter good clinical practice (GCP) studies to date (WEBCAST, French Observatory, WEBCAST 2) have shown a low complication rate with good efficacy.

Objective To report demographic, procedural data and initial 30 day safety follow-up of the US IDE pivotal study for assessment of safety and effectiveness for the WEB treatment of wide neck bifurcation aneurysms: the WEB Intrasaccular Therapy Study (WEB-IT).

Methods WEB-IT is a prospective, multicenter, GCP (Good Clinical Practice) study dedicated to the evaluation of safety and effectiveness of WEB treatment, conducted in 25 centers in the United States, and 6 OUS centers in Canada and Europe. Inclusion criteria were ruptured and unruptured wide-neck aneurysms located in basilar artery, middle cerebral artery, anterior communicating artery, and internal carotid artery terminus. Independent study oversight and data integrity methods include: patient data monitoring, clinical event adjudication by medical monitor, core lab evaluation of the primary effectiveness endpoint, and study oversight by data monitoring committee (DMC). The study’s primary effectiveness endpoint is the proportion of subjects with complete aneurysm occlusion without retreatment, recurrent subarachnoid hemorrhage, without significant parent artery stenosis (>50% stenosis) at one year after treatment. A subject will be considered an effectiveness success upon meeting all of the above criteria. The study’s primary safety endpoint is the proportion of subjects with death of any nonaccidental cause or any major stroke (defined as an ischemic or hemorrhagic stroke resulting in an increase of 4 points or more on the National Institutes of Health Stroke Scale) 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. A subject will be considered a safety failure upon meeting any of the above criteria.

Results The study population is 150 patients with 150 aneurysms. The demographics report will include gender distribution, aneurysm location, aneurysm size, and relevant medical history will be described. Technical success, total fluoroscopy time, total WEB procedure time, periprocedural neurologic events, major strokes and 30 day morbidity and mortality will be reported.

Conclusions The WEB-IT pivotal study provides the largest prospective study of safety and effectiveness data for the WEB aneurysm occlusion system. Demographics and safety follow-up to 30 days provide initial safety information: the primary safety and effectiveness endpoints at 1 year will be reported in a subsequent abstract.

Disclosures D. Fiorella: 1; C; Sequent Medical, Penumbra, Microvention, Seimens. 2; C; Sequent, Microvention, Medtronic, Penumbra, Codman. A. Arthur: 1; C; Sequent Medical. 2; C; Sequent Medical. A. Molyneux: 1; C; Sequent Medical. J. Byrne: 1; C; Sequent.