Effectiveness of Doppler ultrasound in the evaluation of venous thoracic outlet syndrome: A bivariate diagnostic meta-analysis.

Abstract

Background: Doppler ultrasound is a widely used non-invasive imaging modality for evaluating venous thoracic outlet syndrome (vTOS), a condition marked by subclavian vein compression that can lead to complications such as thrombosis and pulmonary embolism. Despite recommendations from the American College of Radiology (ACR) supporting its use as a screening tool for vTOS, the available evidence derives mostly from small, non-randomised studies.

Methods: We performed a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Diagnostic Test Accuracy (PRISMA-DTA) guidelines. Diagnostic accuracy measures such as sensitivity, specificity, likelihood ratios (LRs), diagnostic odds ratio (DOR), and area under the curve (AUC) were pooled using a bivariate random-effects model. We also assessed heterogeneity, threshold effect, and publication bias. The review protocol was prospectively registered in the PROSPERO under registration number CRD42024621782.

Results: Five studies with 293 patients were included. The pooled sensitivity and specificity were 91.4% (95% CI: 83.5-95.7; I² = 25.4%) and 91.1% (95% CI: 63.8-98.3; I² = 82.0%), respectively. The AUC was 0.919 (95% CI: 0.80-0.94), and the DOR was 54.1 (95% CI: 13.6-215.5; I² = 57%). The positive LR (LR+) and negative LR (LR-) were 10.3 (95% CI: 2.15-49.6) and 0.10 (95% CI: 0.06-0.2), respectively, indicating strong diagnostic performance. Sensitivity heterogeneity was resolved (I² = 0%) after excluding one outlier study, yielding a revised pooled sensitivity of 88.6% (95% CI: 81.0%-93.1%). Deeks' funnel plot asymmetry test showed no evidence of publication bias (p = 0.60). Fagan's nomogram showed that a positive test increased the post-test probability from 25% to 77%, while a negative test reduced it to 3%. LR scatterplots confirmed high diagnostic utility.

Conclusion: Doppler ultrasound shows high accuracy and is a valuable first-line tool for the initial assessment of vTOS in symptomatic patients. Its non-invasiveness and bedside use make it ideal for early triage. However, broader clinical implementation requires standardised scanning protocols, training to reduce interobserver variability, and harmonisation of diagnostic criteria across centres to ensure reproducibility and reliability.