Study protocol for a multicentre, randomised controlled trial in China to evaluate the efficacy and safety of precise subsegmental bronchoscopic thermal vapour ablation treatment in severe emphysema.

introductionBronchoscopic thermal vapour ablation (BTVA) is a bronchoscopic lung volume reduction technique, also recommended by the global initiative for chronic obstructive lung disease (GOLD) guidelines. Previous studies on BTVA have primarily focused on segmental treatment, targeting the most severely affected lung segments while preserving healthier areas. However, there is considerable variability in the severity of emphysema within subsegments of these lung segments, suggesting that a more precise approach could potentially improve treatment outcomes. This study aims to evaluate the efficacy and safety of subsegmental BTVA, which may better preserve healthy lung tissue while more accurately targeting the most severely affected regions in patients with severe emphysema. METHODS AND ANALYSIS: This is a prospective, multicentre, randomised, controlled, open-label clinical trial conducted in China. A total of 100 patients with severe emphysema, who continue to experience significant symptoms despite optimal medical therapy according to GOLD guidelines, will be enrolled. Participants will be randomly assigned in a 1:1 ratio to either the experimental group (subsegmental BTVA) or the control group (segmental BTVA), both receiving optimal medical therapy. BTVA will be performed in two separate procedures, with the second procedure occurring at least 6 weeks and no more than 6 months after the first. The primary endpoint is the change in forced expiratory volume in 1 s at 6 months following the second procedure. Secondary endpoints include changes in lung volumes, quality of life (measured by the St. George's respiratory questionnaire for chronic obstructive pulmonary disease patients), other parameters in pulmonary function tests, and 6 min walk distance at 6 and 12 months, etc. ETHICS AND DISSEMINATION: The trial protocol was approved by the Ethics Committee of Shanghai Chest Hospital (IS23073). Additionally, study approval was obtained from local regulatory boards at each site before the study commenced. The results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: This trial was registered on ClinicalTrials.gov on 16 November 2023 (NCT06152107).