DOI: 10.6084/m9.figshare.30266679.v1
title: Lung Volume Reduction Therapies in Patients with Emphysema: A Systematic Review and Network Meta-Analysis

description: Severe emphysema, a major chronic obstructive pulmonary disease (COPD) phenotype characterized by hyperinflation, is associated with significant morbidity and mortality. Lung volume reduction (LVR) therapies, including surgical (LVRS) and bronchoscopic techniques (e.g. endobronchial valves (EBVs) and coils (ECs)), aim to reduce hyperinflation and improve outcomes, but their comparative efficacy and safety are unclear. This network meta-analysis compared LVR therapies. We systematically evaluated LVRS, EBV, EC, intrabronchial valves (IBV), sealants (ELS), vapor ablation (BVA), or airway bypass stents (ABS) in adults with severe emphysema. The primary outcomes were early and overall mortality. The secondary outcomes included lung function (FEV1, RV reduction), exercise capacity (6MWD), quality of life (SGRQ), and adverse events. Bayesian analysis using R/BUGSNet was used to assess their effects and rankings. Twenty-six RCTs (4418 patients) were included. No LVR therapy significantly reduced mortality compared with standard medical care (SMC) (early mortality, 1.6%; overall mortality, 10.9%; and highest rates of LVRS). Compared with SMC, LVRS and EBV significantly improved FEV1, RV reduction, and the 6MWD; LVRS consistently ranked most effectively. After excluding the impact of collateral ventilation in the subgroup analysis, EC significantly improved the SGRQ and 6MWD, and a reduction in residual volume and IBV improved the SGRQ. LVRS, EBV, and EC had significantly higher adverse event rates than SMC did. While no LVR therapy improved survival over SMC, LVRS and some bronchoscopic techniques (EBV, EC) significantly enhanced lung function, exercise capacity, and quality of life in severe emphysema patients. LVRS offers the greatest efficacy benefits but carries the highest risks. Bronchoscopic options (EBV, EC) provide safer and more effective alternatives, particularly for symptoms and functional improvement. Careful patient selection on the basis of fissure status and emphysema pattern is paramount. This network meta-analysis provides a comprehensive assessment of surgical and bronchoscopic lung volume reduction therapies for severe emphysema. The key findings are as follows:Compared with standard medical care, no LVR therapy significantly reduced mortality.LVRS and EBV are the most effective interventions for improving lung function (FEV1, RV reduction), exercise capacity (6MWD), and health-related quality of life (SGRQ). LVRS offers the greatest magnitude of benefit but carries the highest degree of procedural risk.EC is an effective alternative, particularly for improving symptoms and exercise tolerance, and may be suitable for patients with homogeneous disease or incomplete fissures where valves are less effective. The IBV also showed a potential benefit in SGRQ for selected patients.Patient selection is critical. Fissure integrity is paramount for the efficacy of endobronchial valves (EBV, IBV). LVRS requires careful assessment of surgical risk and emphysema patterns.Bronchoscopic techniques (EBV, EC and IBV) present a significantly safer alternative to LVRS in terms of mortality risk, expanding treatment options for higher-risk patients.However, evidence for other bronchoscopic techniques (ELS, BVA and ABS) remains limited. Compared with standard medical care, no LVR therapy significantly reduced mortality. LVRS and EBV are the most effective interventions for improving lung function (FEV1, RV reduction), exercise capacity (6MWD), and health-related quality of life (SGRQ). LVRS offers the greatest magnitude of benefit but carries the highest degree of procedural risk. EC is an effective alternative, particularly for improving symptoms and exercise tolerance, and may be suitable for patients with homogeneous disease or incomplete fissures where valves are less effective. The IBV also showed a potential benefit in SGRQ for selected patients. Patient selection is critical. Fissure integrity is paramount for the efficacy of endobronchial valves (EBV, IBV). LVRS requires careful assessment of surgical risk and emphysema patterns. Bronchoscopic techniques (EBV, EC and IBV) present a significantly safer alternative to LVRS in terms of mortality risk, expanding treatment options for higher-risk patients. However, evidence for other bronchoscopic techniques (ELS, BVA and ABS) remains limited.