Predictors of Successful Extravascular Ultrasound-Guided Wiring for Femoropopliteal Chronic Total Occlusions Within 30 Minutes

OBJECTIVE: Extravascular ultrasound (EVUS) has been reported to be a feasible modality for facilitating guidewire passage in femoropopliteal (FP) chronic total occlusions (CTOs). However, predictors of procedural success remain uncertain. We aimed to identify the lesion and imaging characteristics associated with successful EVUS-guided wiring within 30 minutes and to develop a simplified scoring system. METHODS: We retrospectively analyzed 299 FP-CTO lesions in 250 patients who were treated with EVUS-guided wiring between April 2012 and December 2023. Successful wiring was defined as the guidewire passage under EVUS guidance within 30 minutes. Clinical, angiographic, and EVUS parameters were assessed, including the "Doppler flow sign," which is defined as ultrasound detection of intraluminal flow within the CTO. Multivariate logistic regression analysis was performed to identify independent predictors, and a simplified EVUS CTO score was developed. RESULTS: Successful wiring within 30 minutes was achieved for 140 lesions (47%). Independent predictors were shorter lesion length (odds ratio [OR] = 0.89, 95% confidence interval [CI] = 0.86-0.92), absence of calcification (OR = 0.30, 95% CI = 0.14-0.64), presence of a Doppler flow sign (OR = 2.45, 95% CI = 1.17-5.10), and absence of popliteal involvement (OR = 0.47, 95% CI = 0.24-0.94). The EVUS CTO score (range, 0-4) demonstrated stepwise increases in success rates as follows: 14% (0-1 point), 39% (2 points), 72% (3 points), and 90% (4 points). CONCLUSIONS: The EVUS CTO score serves as a useful tool for stratifying lesion complexity, predicting early procedural success, and aiding in case selection, operator training, and procedural planning for FP-CTO interventions.Clinical ImpactThis study identifies key predictors of successful extra-vascular ultrasound (EVUS)-guided wiring within 30 minutes in femoropopliteal chronic total occlusions and introduces a simple EVUS CTO score. This scoring system allows clinicians to stratify lesion complexity and predict early technical success, thereby improving case selection and procedural planning. By anticipating procedural difficulty, EVUS-guided intervention can be performed more efficiently, potentially reducing procedure time and radiation exposure. These findings support a more structured and practical approach to EVUS-guided peripheral intervention.