Development of a scoring system to predict endovascular crossing of femoropopliteal artery chronic total occlusions: the Endo VAscular CROSsing Score for Chronic Total Occlusions (EVACROSS-CTO).

Objectives: To develop a predictive score for the prediction of successful endovascular crossing in femoropopliteal artery chronic total occlusions (CTOs).

Methods: In this retrospective study, 84 patients were divided 70%:30% into a training and a testing cohort. Parameters such as cap morphology, side branches, bridging collaterals, flush occlusion, and length were derived from pre-procedural CT angiography. Lesions were segmented and calcification burden was assessed by thresholding. A score (EndoVAscular CROSsing Score for Chronic Total Occlusion [EVACROSS-CTO]) was built based on multivariate logistic regression. Receiver operating characteristics (ROC) curve analysis determined the optimal score threshold, with reported accuracy, sensitivity, specificity, and area under the curve (AUC).

Results: Factors including age > 50 years (P = .036, odds ratio (OR) = 53.7), calcification percentage >10% (P = .011, OR = 16.63), the presence of a flush occlusion (P = .02, OR = 15.564), the presence of a distal side branch (P = .018, OR = 9.879), and the presence of a proximal side branch (P = 0.064, OR = 23.369) were identified as suitable for inclusion in the score. Score values were assigned based on the relative odds ratio for each factor with a maximum score of 22. EVACROSS-CTO was able to predict the success of endovascular recanalization with an AUC-ROC of 79.8% (95% CI, 58.5%-100%). A score >16 yielded a sensitivity of 75% with a specificity of 70.6% for the prediction of treatment failure.

Conclusions: A score was developed by incorporating variables derived from pre-procedural CT angiography, demonstrating promising predictive capacity in determining the success of endovascular recanalization of CTOs.

Advances in knowledge: EVACROSS-CTO incorporates imaging variables for the prediction of endovascular recanalization success. This score will allow improved pre-procedural planning for femoropopliteal CTO management.