Endoscopic Volume Reduction in COPD-a Critical Review

Background: Chronic obstructive pulmonary disease (COPD) is common in Germany, with a prevalence of 13.2%. The available treatments are exclusively symptomatic, except for lung transplantation, from which no more than a few patients can benefit. Over the past decade, endoscopic lung volume reduction (ELVR) has broadened the therapeutic spectrum for patients with advanced pulmonary emphysema. Method: We review pertinent publications that were retrieved from Pubmed using the search terms "endoscopic lung volume reduction," "endobronchial valves," "endobronchial coil," and "bronchoscopic thermal vapor ablation," along with current data from the annual meeting of the German Respiratory Society (Deutsche Gesellschaft fur Pneumologie). Results: ELVR is now performed with three different techniques. Endoscopic valve implantation has been studied in three randomized controlled trials (RCTs) and several noncontrolled trials, which have shown a benefit from valve therapy particularly for patients who have only a small amount of interlobar collateral ventilation or none at all. A reduction of lobar lung volume by 56-80% was found, in association with a significant improvement of lung function (a 16-26% increase of forced expiratory volume in one second [FEV1]). The main complication of valve therapy is pneumothorax, which arises in up to 23% of cases. Coil implantation has been studied to date in only a single RCT, which revealed a significant improvement in quality of life as the primary endpoint (St. George's Respiratory Questionnaire [SGRQ]: -8 points). Bronchoscopic thermoablation has been studied only in noncontrolled intervention trials; in patients with emphysema mainly affecting the upper lobes, it has been found to reduce lobar volume by an average of 48%. Conclusion: Endoscopic lung volume reduction has broadened the therapeutic spectrum for selected patients with advanced pulmonary emphysema. Further prospective trials are needed to evaluate the benefits, risks, and long-term effects of the available techniques for ELVR.