Efficacy and safety of endobronchial valves for advanced emphysema: a meta analysis

A meta-analysis was undertaken to evaluate the efficacy and safety of bronchoscopic lung volume reduction with endobronchial valves (EBV) for advanced emphysema.

A systematic search was performed from PubMed, EMBASE, CNKI, Cochrane Library database. Randomized control clinical trials on treatment of emphysema for 3-12 months with the EBV compared with standard medications and sham EBV were reviewed. Inclusion criteria were applied to select patients with advanced emphysema treated with EBV. The primary outcome was the percentage of the forced expiratory volume in the first second (FEV1%). Secondary outcomes included St George's Respiratory Questionnaire (SGRQ) score, the distance of the 6-minute walk (6MWD) test, the Modified Medical Research Council (MMRC) dyspnoea score, cycle ergometry workload, and the rate of the six major complications at 3 or 12 months. Fixed- or random-effects models were used and weighted mean differences (WMD), relative risks (RR) and 95% confidence intervals (CI) were calculated.

Three trials (565 patients) were considered in the meta-analysis. EBV patients yielded greater increases in FEV1% than standard medications (WMD =6.71; 95% CI, 3.31 to 10.10; P=0.0001), EBV patients also demonstrated a significant change for SGRQ score (WMD =-3.64; 95% CI, -5.93 to -1.34; P=0.002), MMRC dyspnoea score (WMD =-0.26; 95% CI, -0.44 to -0.08; P=0.004), and cycle ergometry workload (WMD =4.18; 95% CI, 2.14 to 6.22; P<0.0001). A similar level was evident for 6MWD (WMD =11.66; 95% CI, -3.31 to 26.64; P=0.13). EBV may increase the rate of hemoptysis (RR =5.15; 95% CI, 1.16 to 22.86; P=0.03), but didn't increase the adverse events including mortality, respiratory failure, empyema, pneumonia, pneumothrax. The overall rates for complications compared EBV with standard medications and sham EBV was not significant (RR =2.03; 95% CI, 0.98 to 4.21; P=0.06).

EBV lung volume reduction for advanced emphysema showed superior efficacy and a good safety and tolerability compared with standard medications and sham EBV, further more randomized controlled trial (RCT) studies are needed to pay more attention to the long-term efficacy and safety of bronchoscopic lung volume reduction with EBV in advanced emphysema.