Aneurysm clipping on WEB device: A feasibility study using a human ex-vivo aneurysm model

Background and objectives: The Woven EndoBridge (WEB) device is a breakthrough in brain aneurysm treatment, widely used for intracranial wide neck and complex aneurysms, especially at bifurcations. Although effective, aneurysm recurrence can occur post-treatment and the impact of clipping angle on the WEB mesh remains unclear. In this study, using a human placenta-based ex-vivo aneurysm model, we simulated the application of aneurysm clipping on WEB-treated aneurysms to elucidate the technical aspects and nuances, particularly the influence of the angle of clip application on WEB collapse. Methods: Human placentas were used to create aneurysms by suture-closing of the placenta vessels. The WEB devices were positioned in the aneurysms under fluoroscopic guidance, and different clip positions/angles on the WEB device were tested. Imaging was used to monitor the effects of clipping on the WEB device and aneurysm. Results: All clipping positions achieved complete aneurysm occlusion, collapsing the WEB mesh with no flow observed into the aneurysm. Despite the WEB device's displacement within the sac, no significant morphological changes to the aneurysm were identified, and the presence of a neck remnant did not affect the adequacy of blade apposition. Conclusion: Microsurgical clipping reliably collapses the WEB device, regardless of its placement or orientation. Our model suggests that clipping can effectively address in-vivo recurrences and persistent aneurysm filling of aneurysms treated with the WEB device. The model does not assess the influence of WEB healing within the aneurysm. Operators should be aware of possible WEB shape changes when clipping its mesh.