A retrospective cohort study of the clinical safety of endobronchial ultrasound in patients with superior vena cava obstruction.

Superior vena cava obstruction (SVCO) is a radiographic finding in patients with mediastinal masses, which may be accompanied by features of superior vena cava syndrome (SVCS). SVCS is associated with physiologic impairments that increase procedural risk. Data regarding the risk of complications following endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in patients with SVCO is limited. To assess whether rates of procedural complications from EBUS-TBNA are increased in patients with SVCO. A retrospective observational study was performed on all patients undergoing EBUS-TBNA by the respiratory department at major Australian tertiary center from January 1 to December 31, 2021. Imaging review identified radiographic SVCO, which was classified by anatomical location and degree of obstruction following a grading system previously described in the literature. Clinical features of SVCS were noted, alongside and procedural outcomes and complications. The primary outcome for this study was the rate of complications. Data was assessed with simple statistics and chi-square analysis. 245 linear EBUS procedures were performed. Radiographic SVCO of moderate severity or greater (>50% obstruction) was present in 11 (4%) patients, mild severity (<50% obstruction) in 13 (5%), indeterminate but likely in 4 (2%), indeterminate but unlikely in 20 (8%), and absent in 197 patients (80%). Rates of major complications were low across the cohort (7% in patients with SVCO, 8% in patients with SVCO), and were independent of SVCO (P = .34). Amongst the 24 patients with SVCO, the original radiology reports mentioned obstruction in only 4 patients, and overall clinical features of SVCS was rarely documented or assessed. SVCO is underreported and under-assessed in our cohort of patients both clinically and radiologically, however SVCO does not appear to be associated with a greater risk of complications following EBUS-TBNA. This study demonstrates that EBUS-TBNA can safety be performed in patients with radiological SVCO.