A New Method for WEB Sizing Achieving Higher Neck Compression and Improved Occlusion Rates: Clinical Series and Analysis of 73 cases

Introduction: The Woven Endo Bridge (WEB) was developed for the treatment of Wide Neck Based Aneurysms. Selection of the appropriate size and shape of the device is paramount for optimizing long term outcomes. The width and height of the device are interrelated, with most sizing methods relying on aneurysm dome width and anticipated WEB height. In our institution we have developed a different sizing method emphasizing neck diameter as a more important factor at the expense of device height (width weighted method, WWM).
We sought to explore the impact the of our sizing method on device selection, configuration, angiographic flow disruption and occlusion rates.

Methods: The authors reviewed the first 73 cerebral aneurysms (from February 2019 to July 2022), treated by WEB using initially the standard IFU based sizing method and later cases with the WWM. Clinical, angiographic and geometric device-related data were collected as well as functional outcomes.

Results: A total of 73 aneurysms were included. Embolization was successful in 72 (98.6%) aneurysms. IFU-based sizing method was used in 20/73 cases (27.3%), and the rest were sized by our WWM (53/73, 72.6%). WWM led to different size selection compared to predicted device using the IFU (delta of +1 in width, -1 in height, p< 0.05) in 33/53 cases (62.2%). Significantly higher device neck compression (35% vs 26%, p< 0.05) and less need for changing the device (2/53 vs 6/20, p< 0.05) were noted. Follow-up (mean 9.8 months) was available for 62/73 patients, adequate occlusion seen in 54/62 (87%), IFU method 11/15 (73.3%), WWM 43/47 (91%), p< 0.05. Contrast stagnation beyond the top of the WEB was found to be correlated with adequate occlusion.

Conclusion : Width weighted sizing method, led to selection of larger-width devices, more compression and less need for changing device, compared to IFU sizing method, with improved occlusion rates. This technique may offer a maximization of width and neck compression impacting WEB sizing. Future studies are required to assess the long-lasting impact of this method on WEB recanalization rates.