E-208 Results of volume-based sizing of the woven endobridge (WEB) device

Abstract

Introduction The Woven EndoBridge (WEB) device, an intrasaccular flow-diverter, was recently approved by the FDA to treat wide-neck bifurcation aneurysms. Accurate sizing of the WEB device is of critical importance as it determines procedural safety and successful occlusion. Oversized devices can protrude into the vessel lumen and lead to thromboembolic events, while undersized devices result in inadequate aneurysm occlusion. Conventionally, size selection of the WEB device is based on measurements of the fundus height and neck width on 3D rotational angiography. However, even multiple, orthogonal linear measurements incompletely describe the three-dimensional morphology of intracranial aneurysms and may mislead size selection of the WEB. An alternative method is volume-based segmentation, minimizing measurement error. The aim of this study was to assess the ability of auto-segmented aneurysm volume to assist in appropriate WEB size selection. Materials and Methods All patients with an intracranial aneurysm treated with the WEB SL or WEB SLS device between March 2019 and August 2019 were identified for this retrospective study. Aneurysm volumes were determined by using a three-dimensional volume segmentation software on an independent Syngo workstation (Siemens Healthineers AG). Pearson correlation coefficients were calculated for aneurysm auto-segmented volumes and WEB volumes, as well as for aneurysm height × width and WEB height × width at the time of initial treatment. Patients underwent follow-up angiography at least 6 months after embolization. Results Thirty-three aneurysms were evaluated by 3D rotational angiography. By volume, the largest aneurysm was 916.4 mm3, and the smallest was 14.0 mm3, with a median volume of 84.7 mm3. The smallest WEB device used was 4 × 2.6 SLS and the largest WEB device was 11 × 8 SL. The correlation with WEB size was larger for auto-segmented aneurysm volumes (r=0.979) compared to height × width (r=0.867). Using Fisher r-to-z transformations, we found the difference between the two correlations to be statistically significant (p=0.0007). Out of the patients who have undergone follow-up angiography thus far, 91% (10/11) have achieved adequate aneurysm occlusion (complete occlusion or residual neck). Conclusion Aneurysm volumes are highly correlated with WEB volumes, with auto-segmentation volumes displaying statistically significant difference against conventional height by width measurements. These results suggest that the WEB device is more accurately sized using auto-segmented aneurysm volumetric measurements rather than height and width measurements, which may improve long-term occlusion rates. Disclosures K. Shah: None. T. White: None. I. Teron: None. A. Dehdashti: None. J. Katz: None. H. Woo: None.