Safety-Oriented Endovascular-First Revascularization for Proximal Subclavian Artery Chronic Total Occlusion: Real-World Strategy Selection and Mid-Term Outcomes

PURPOSE: To report real-world outcomes of a safety-oriented, endovascular-first strategy for proximal atherosclerotic subclavian artery chronic total occlusion (CTO) and to develop a pragmatic computed tomography angiography (CTA)-based open-first consideration aid for anatomically unfavorable cases. MATERIALS AND METHODS: This single-center retrospective study included consecutive patients treated between January 2020 and December 2024. Endovascular-first revascularization was pursued when feasible, with bypass used as primary therapy or after failed endovascular attempts. Computed tomographic angiography morphology was assessed using prespecified definitions. Factors associated with endovascular technical success were evaluated using logistic regression. Hemodynamically significant restenosis during follow-up was defined as recurrence or progression of inter-arm systolic blood pressure difference ≥20 mm Hg relative to the post-discharge baseline. Time-to-event outcomes were assessed using Kaplan-Meier analysis. A CTA-based open-first consideration score (0-4) was derived among patients undergoing definitive revascularization (bypass vs successful endovascular repair). RESULTS: Among 122 patients, endovascular-first treatment was attempted in 101, with technical success in 75 (74.3%); definitive revascularization was achieved in 112 patients (91.8%) after inclusion of bypass. Right-sided laterality, absent proximal stump (<3 mm), and severe calcification were independently associated with endovascular technical failure. Periprocedural morbidity was low, with no clinically apparent stroke or transient ischemic attack; 1 localized type B aortic injury after endovascular repair and 1 lymphatic leak after bypass were managed conservatively. During a median follow-up of 26 months, estimated restenosis was approximately 10% at 1 year and 22% at 3 years, whereas clinically driven reintervention remained low at approximately 3% and 6%, respectively. The CTA-based open-first consideration score showed good discrimination for bypass selection (area under the curve, 0.887), with ≥2 points serving as a high-specificity prompt for bypass consideration. CONCLUSIONS: In proximal subclavian CTO, a safety-oriented endovascular-first strategy achieved acceptable technical success, low clinically apparent neurologic morbidity, and low reintervention during mid-term follow-up. A CTA-based open-first consideration score may help identify anatomically unfavorable cases for bypass consideration and define escalation boundaries, and warrants external validation.Clinical ImpactThis study supports a safety-oriented, endovascular-first approach for proximal subclavian artery chronic total occlusion, while emphasizing that endovascular and surgical revascularization should be considered complementary rather than competing strategies. Preprocedural CTA can identify anatomically unfavorable lesions in which prolonged endovascular escalation may reduce the procedural safety margin. The proposed CTA-based open-first consideration score provides a simple framework to support treatment planning, patient counseling, and predefined stopping boundaries. Clinically, this approach may help operators avoid unnecessarily aggressive recanalization attempts while preserving endovascular therapy for patients with favorable anatomy.