Reliability and applicability of angiographic outcome scales in WEB device-treated aneurysms: a systematic review

Various angiographic assessment scales have been used to report the results of endovascular treatment with the WEB device. We aimed to review the use and reliability of these scales.

We systematically reviewed studies reporting angiographic outcomes of WEB-treated aneurysms from January 2010 to May 2023. We identified the studies that reported the reliability of the various scales. Data from eligible studies were extracted and evaluated by two independent reviewers, with discrepancies resolved by a third reviewer.

The review identified 138 studies that used 12 different occlusion scales. The non-specific Raymond-Roy occlusion classification (RROC) was most commonly used (94/138 (68%)), followed by the Bicêtre Occlusion Scale Score (BOSS; 21/138 (15%)) and the Web Occlusion Scale (WOS; 16/138 (12%)), both specifically adapted to the WEB. Six reliability studies were identified, which included 16-30 cases evaluated by few (2-7) raters. Studies were too heterogenous to proceed with a meta-analysis. Substantial agreement in reporting angiographic results was shown in one study using the WOS (K = 0.70; 0.64-0.75), and one using the BOSS (K = 0.82; 0.68-0.96), but only when categories were dichotomized as complete versus incomplete occlusion. Most classifications can be translated into the RROC, allowing comparisons with other devices and treatment modalities. The RROC reached substantial agreement, but only between 2 raters in a small 26-patient study (k = 0.69; 0.46-0.93).

More agreement studies are needed to validate the reliability of angiographic outcome scales that can be used to compare WEB with other endovascular or surgical treatments.