Spontaneous subclavian vein thrombosis (Paget Schroetter Syndrome, PSS) has been attributed to venous compression at the thoracic outlet and traditionally diagnosed on basis of venography. Intravascular ultrasound (IVUS) affords a multi-dimensional view of vascular structures, and may be more accurate in diagnosing venous compression. The goal of this project was to compare venography, and IVUS in patients presenting with PSS to assess the relative accuracy of each modality.
Patients presenting for evaluation of PSS between 2013 and 2019 were evaluated for subclavian vein (SCV) compression with venography and IVUS. Venogram and IVUS measurements of stenosis were made of index, and contralateral limbs in both neutral and stress (arm overhead) position. IVUS data included SCV diameters in anterior-posterior (AP) plane, cranio-caudad (CC) plane, and cross sectional area (A). Stenosis was reported as percentage reduction from a reference point (lateral margin of first rib) for venogram and IVUS data.
Of 35 subjects, the average age was 35 years, women were 57% of the cohort, 20% presented with a documented pulmonary embolus, and 70% were treated initially with thrombolysis. Venography demonstrated SCV occlusion in three (16%) patients with the index limb in neutral position, and 18 (54%) in stress position. The average stenosis in index limbs was 41.5% (Venogram), and the average IVUS stenosis was 41.9% (CC), 61.8% (AP), and 74.5% (A) (p<0.05). Subset analysis revealed that in 28% (10/35) of cases where venography identified no significant stenosis (average 10%), IVUS identified significant stenosis (33.5% CC, 54.3% AP, and 68.7% A) (p<0.05).
IVUS proved more sensitive than venography in detecting significant stenosis leading to subclavian vein thrombosis. Reduction in cross sectional area was the most sensitive measure of stenosis. IVUS identified significant stenosis in cases where venography failed to do so. The greatest utility of IVUS is in evaluation of PSS cases where venography shows no evident compression.

Copyright © 2020. Published by Elsevier Inc.