Outcome Analysis and Early Concept Development to Identify the Most Suitable Woven EndoBridge Size Based on Various Shapes of Cerebral Aneurysms.

Purpose: The selection of the appropriate Woven EndoBridge (WEB) size is the most critical aspect of the decision-making process in aneurysm WEB embolization. However, there are currently no precise criteria for measuring WEB size that correspond to each aneurysm. This study presents a process that includes a WEB index for determining the exact volume based on various aneurysm shape types.

Materials and methods: Sixty consecutive aneurysms treated with WEB device were included. The volume measurements of the aneurysms, based on their column configurations, were compared with WEB volume to assess the accuracy of the fit within each aneurysm. After categorizing the aneurysms into symmetric and asymmetric shapes, they were further classified into 5 types according to their configurations. We estimated outcomes, including any events or recurrences, and calculated WEB index (WEB volume/aneurysm volume) along with the median and interquartile range to evaluate differences based on shape type. A statistical analysis was conducted to identify associations between various variables and stenting and/or recurrence.

Results: Symmetric aneurysms (n=39, 65%) were more prevalent than asymmetric aneurysms (n=21, 35%). Among the 5 shape types, the column shape was the most common (n=32, 53%), followed by submarine (n=9, 15%), sphere (n=7, 12%), boots (n=6, 10%), and mitten (n=6, 10%) shapes. The median WEB index was 0.96. Asymmetric aneurysm shapes were associated with stent-assisted procedures (oversizing) (P=0.029) and the presence of sac remnants or recurrence (undersizing) (P=0.033). There were no adverse events reported, except for 1 non-procedure-related death at 7 months and 2 retreatments among 3 recurred aneurysms during a mean magnetic resonance angiography follow-up of 8 months (range, 3-21 months) and a mean clinical follow-up of 12 months (range, 3-30 months).

Conclusion: Outcome of WEB embolization depended on aneurysm configuration (shape types) and the measurement of aneurysm volume (WEB index).