The WISE Study - WEB Implant Safety and long-term Effectiveness: a pooled analysis of seven clinical trials – 1-year unruptured aneurysm results

Introduction: The Woven EndoBridge (WEB) Embolization System is the first intrasaccular device developed for the treatment of wide-necked bifurcation aneurysms (WNBAs). Here we report the 1-year outcomes for the unruptured aneurysm cohort of the WISE Study (WEB Implant Safety and long-term Effectiveness) database, a pooled analysis of subject-level data from seven prospective WEB trials. Methods: Individual subject-level data from seven prospective, multicenter, core laboratory adjudicated, externally monitored studies evaluating the WEB device for the treatment of unruptured WNBAs were pooled. The included aneurysms had a mean dome width of 6.5 mm. All studies shared the same core laboratory, and five of the seven shared the same clinical events committee. Subject demographic and aneurysm characteristics, procedural data, and effectiveness and safety outcomes were combined and evaluated as a single population. Adequate occlusion was defined as complete occlusion or residual neck on core laboratory assessment. Results: A total of 449 unruptured aneurysms were successfully treated within WISE. The 1-year rates of complete occlusion and adequate occlusion were 54.7% (223/408) and 82.8% (338/408), respectively. Aneurysm recurrence was 6.4% (19/298) and the retreatment rate was 2.5% (11/449). All-cause morbidity was 1.2% (5/416) and treatment-related morbidity (device- and/or procedure-related) was 0.5% (2/416) at 12 months. No ruptures were observed after WEB treatment through 1 year. Complete occlusion was less likely for anterior circulation aneurysms, larger aneurysm height and width, and wider neck. Complete occlusion was less likely for anterior circulation aneurysms and for aneurysms with larger height, width, and neck size (all p<0.05). Greater WEB lateral compression was associated with higher rates of complete occlusion (OR 1.289 for absolute difference and OR 7.042 for ratio, p≤0.0066), and with higher rates of adequate occlusion (OR 1.288 and 8.846, respectively). Retreatment was associated with larger aneurysm height and width, and smoking history. Conclusion: The WEB device is safe and effective for the treatment of unruptured intracranial aneurysms with high rates of adequate occlusion, low rates of recurrence and retreatment, and reliable protection from rupture.