Clinical and anatomical correlates of significant subclavian artery stenosis in thoracic outlet syndrome: Insights from dynamic CT angiography

Purpose To evaluate subclavian artery (SCA) stenosis in thoracic outlet syndrome (TOS) and investigate associations with clinical presentation, anatomical predisposing factors, and costoclavicular space (CCS) dimensions using dynamic CT angiography (CTA). Materials and methods In this retrospective single-center study, dynamic CTA examinations performed for TOS between July 2023 and November 2024 were reviewed. SCA stenosis was graded as < 25 %, 25–<50 %, 50–<75 %, and ≥ 75 %. Significant stenosis was defined as ≥ 50 % narrowing and non-significant as 25–<50 %. Associations with clinical presentation, stenosis location, anatomical factors, and CCS dimensions were assessed accounting for within-patient clustering. Results Overall, 208 thoracic outlets from 108 patients were included. SCA stenosis was identified in 100/208 outlets (48.1 %), including 59/208 (28.4 %) with significant stenosis. After adjustment for anatomical factors, age, sex, and laterality, symptomatic status was independently associated with significant stenosis (aOR, 5.26; 95 % CI, 2.00–13.86; P = 0.001), but not with non-significant stenosis (P = 0.207). Significant stenosis was associated with mixed, neurogenic, and vascular presentations, but not atypical symptoms, and was predominantly located within the CCS (45/59, 76.3 %). Minimal and maximal CCS distances progressively decreased from outlets without stenosis to those with non-significant and significant stenosis (both P < 0.001). Anatomical predisposing factors were independently associated with significant stenosis (aOR, 5.76; 95 % CI, 1.08–30.65; P = 0.040). Conclusion Significant SCA stenosis was independently associated with symptomatic status, clinical presentation, anatomical predisposing factors, and smaller CCS dimensions. Non-significant stenoses showed less consistent clinical associations, supporting ≥ 50 % narrowing as a clinically relevant threshold for arterial compression in TOS.