Woven EndoBridge device apposition and compression using Sim&Size virtual simulation correlate with aneurysm occlusion status: a retrospective cohort study.

Background: Virtual simulation is increasingly used for aneurysm treatment. This study aimed to explore whether mechanical behavior biomarkers of the Woven EndoBridge (WEB) device as computed by Sim&Size simulation software were associated with aneurysmal occlusion status at follow-up.

Methods: Consecutive patients with aneurysms treated with WEB were retrospectively enrolled (January 2014 to December 2021). Aneurysms were included if three-dimensional digital subtraction angiography and follow-up imaging were available. Device apposition and compression within the aneurysm sac were retrospectively calculated by Sim&Size simulation software. Mean global and maximum compression, mid-device and neck compression, and the Spruce index of heterogeneity of deformation of the simulated device were calculated. A multivariate Lasso regression was performed.

Results: A total of 81 aneurysms in 80 patients (56 females; mean age 60±12 years) were analyzed. At a mean radiological follow-up of 3±2 years, 62 (77%) showed an adequate occlusion. Mean apposition in the inadequate and adequate occlusion group was 42.9±11% and 53.97±12%, respectively (P=0.002), mean global compression was 4.95±3% and 7.85±6% (P=0.035), respectively, and maximal compression was 13.44±6% and 20.73±11%, respectively (P=0.009). Compressions at mid-level and neck level were comparable between the two groups. The Spruce index was higher in the inadequate occlusion group (0.16±0.05 vs 0.20±0.05, P=0.005). Multivariate analysis showed that wall apposition, maximum compression and the Spruce index were independent prognosticators of aneurysm occlusion.

Conclusions: Wall apposition, maximum compression and the Spruce index computed by Sim&Size software predicted the likelihood of aneurysm occlusion at follow-up, after WEB treatment.