Management of WEB device migration and mal-position in endovascular treatment of cerebral aneurysms

With increasing advances in technology, the breadth of aneurysms that are treatable via an endovascular approach has increased. Wide necked aneurysms remain difficult to treat but the emergence of dedicated intrasaccular flow disruption devices such as the Woven EndoBridge (WEB, Micorvention) has increasingly seen previously ruptured and unruptured wide necked aneurysms successfully embolised and secured from the circulation using a single device.We are reporting two cases of WEB device treatment from the earliest experience with this device at our institution. These were complicated by partial extrusion in one case and remote migration of the WEB device in another case. Our initial cases highlight the importance of case selection and the need for accurate WEB sizing which are paramount to ensure complete occlusion of the aneurysm without complications of dislocation or extrusion into the parent vessel. Since then, we have performed over 170 cases with the WEB device. We also present a comprehensive review of the limited literature available on the management of mal-positioned and dislocated WEB devices. This allows us to reflect on how to avoid these complications and the different management options at the disposal of the neuro-interventionalist once such a complication has already occured. Rescue devices and manoeuvres that we reflect on include microcatheter manipulation, alligator retrieval device, stent retrievers, microsnares, aspiration, and stenting. Ultimately, each case needs to be individually evaluated and the best strategy selected depends on the context and specific circumstances.