BackgroundDespite optimal therapy many patients with emphysema remain significantly breathless and limited. Bronchoscopic lung volume reduction (BLVR), using valves placed to allow air to leave but not enter the worst-affected areas of the lung, has been proposed as a way to improve lung function in these patients, but response is variable because interlobar collateral ventilation prevents the devices from working. Based on retrospective analysis of clinical trials, patients with heterogeneous emphysema and intact interlobar fissures are most likely to benefit.ObjectivesTo establish whether or not it is possible to identify patients prospectively who will reliably benefit from endobronchial valve placement.DesignProspective, randomised, parallel-group, double-blind, sham-controlled trial.SettingThe study was performed at a single specialist centre.ParticipantsAdult patients with heterogeneous emphysema and a target lobe with intact interlobar fissures were eligible if they had significant gas trapping (total lung capacity > 100% predicted, residual volume > 150% predicted), breathlessness [Medical Research Council (MRC) dyspnoea score of ≥ 3] and exercise limitation (6-minute walk distance of < 450 m). Participants were on optimised pharmacotherapy and were non-smokers.InterventionsStudy participants were randomised to either unilateral lobar endobronchial valve placement aiming to achieve lobar atelectasis or bronchoscopy and ‘sham’ valve placement.Main outcome measuresThe primary end point was improvement in forced expiratory volume in 1 second (FEV1) in the treatment arm compared with the control arm measured 90 days post procedure. Secondary end points were change in lung volumes, gas transfer, exercise capacity (both walking and endurance cycle ergometry) and health-related quality of life.ResultsIn total, 50 patients were recruited, 25 to each arm; 62% were male and mean (standard deviation) FEV1% predicted was 31.7% (10.2%). The primary end point of the study was met as FEV1increased by 24.8% [95% confidence interval (CI) 8.0% to 41.5%] in the treatment arm and by 3.9% (95% CI 0.7% to 7.1%) in the control arm [between-group difference 20.9% (95% CI 4.3% to 37.5%);p = 0.033]. There were both statistically and clinically significant improvements in lung volumes and carbon monoxide gas transfer as well as endurance time and dynamic hyperinflation during cycle ergometry. Two deaths occurred in the treatment arm and one control patient was unable to attend for follow-up assessment because of a prolonged pneumothorax. Two pneumothoraces occurred in the treatment arm.ConclusionsWith appropriate selection of patients through a multidisciplinary team it is possible to produce a significant improvement in lung function through lobar occlusion with endobronchial valves in heterogeneous emphysema. Prospective trials are needed to compare the effect of BLVR with surgical approaches in terms of magnitude and duration of benefit.Trial registrationCurrent Controlled Trials ISRCTN04761234.FundingThis project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and NIHR partnership.
Endobronchial valve placement in emphysema: When is it lung volume reduction?
