Use of Endobronchial Valves in Non-Upper Lobe Heterogeneous Emphysema

Inclusion Criteria: * Age 18-80 years * Ex-smoker with smoking cessation confirmed by exhaled carbon monoxide (CO) levels * Moderate to severe airflow obstruction FEV1 \<50% Predicted * Severe dyspnoea - mMRC ≥2 * Hyperinflation - total lung capacity (TLC) ≥100% predicted, RV ≥150% predicted * SWT ≥75m * Optimum COPD treatment for at least 6 weeks * No COPD exacerbation for at least 6 weeks * Less than 4 admissions for exacerbation in the preceding 12 months Exclusion Criteria: * Patient unable to provide informed consent * Patient without clear targets for airflow re-distribution * Total lung CO uptake (TLCO) \<15% predicted and FEV1 \<15% predicted * pO2 on air \<6.0kPa * pCO2 on air \>8.0kPa * Neurological, rheumatological or other cause of exercise limitation * Other major medical illness, e.g. lung cancer that will limit participation * Production of purulent sputum more often than not (more than 50% of days) * Clinically significant bronchiectasis * Large bulla - more than 1/3 of hemithorax volume (i.e. where bullectomy would be more suitable) on CT scan * Arrhythmia or cardiovascular disease that poses a risk during procedure or exercise * Prednisolone dose greater than 15mg a day * Significant pulmonary hypertension - RVSP ≥45mmHg * Left ventricular failure - left ventricular ejection fraction \<45% or left ventricular fraction shortening \<23% * Prior LVRS or lobectomy * Lung nodule requiring surgery * Subject completed or is participating in a standard pulmonary rehabilitation program within 3 months of enrolment * Female of childbearing age with positive pregnancy test * Subject participated in a research study of investigational drug or device in prior 30 days * Subject taking clopidogrel, warfarin, or other anticoagulants and unable to abstain for 5 days pre-procedure