Purpose WEB Flow disruption is an innovative endovascular treatment for wide-neck bifurcation aneurysms. Three prospective multicenter GCP (Good Clinical Practice) studies were conducted in Europe (WEBCAST, French Observatory, WEBCAST2). Safety and efficacy data are analyzed in the cumulated population of these 3 studies.

Methods Patients with wide neck bifurcation aneurysms were included in these 3 studies. An independent medical monitor independently analyzed adverse events. Follow-up imaging was obtained at 6 and 12 months in WEBCAST study and at 12 months in French Observatory. An independent expert in Interventional Neuroradiology evaluated anatomical results using the 3 grades scale: complete occlusion, neck remnant, and aneurysm remnant. In WEBCAST, the reader was also directly comparing evolution of anatomical results between 6 months and 12 months classified as improved, stable, or worsened.

Results A total of 168 patients (112 females, 66.7%) with 169 aneurysms including 14 ruptured (8.3%) were included in the 3 studies (51 patients in WEBCAST, 62 in French Observatory, and 55 in WEBCAST2). Eighty-six out 169 aneurysms were located at middle cerebral artery (50.9%), 36/169 at anterior communicating artery (21.3%), 30/169 at basilar artery (17.8%), and 17/169 at internal carotid artery terminus (10.1%). Placement of the WEB device was feasible in 163/169 aneurysms (96.4%). Morbidity and mortality at one month were reported in 4/168 patients (2.4%) and 0/168 patients (0.0%), respectively. At 6 months, morbidity and mortality were reported in 1/99 patients (1.0%) and 3/99 patients (3.0%), respectively (there was no follow-up at 6 months in French Observatory).

Anatomical results at 6 months (WEBCAST and WEBCAST2) were complete aneurysm occlusion in 51/90 aneurysms (56.6%), neck remnant in 23/90 aneurysms (25.5%), and aneurysm remnant in 16/90 aneurysms (16.7%). Anatomical results at 12 months (WEBCAST and French Observatory) were complete aneurysm occlusion in 56/100 aneurysms (56.0%), neck remnant in 26/100 aneurysms (26.0%), and aneurysm remnant in 18/100 aneurysms (18.0%).

Conclusion This analysis in the large cumulated population of 3 GCP studies confirms the high safety of WEB treatment with low morbidity and mortality at one month and 6 months. At 6 and 12 months, adequate occlusion (complete aneurysm occlusion and neck remnant) was obtained in a high percentage of aneurysms (82.2% and 82.0%, respectively).

Disclosures L. Pierot: 2; C; Sequent. A. Molyneux: 2; C; Sequent. J. Byrne: 2; C; Sequent.