The investigators plan to perform a randomized controlled trial that compares bilateral lung volume reduction surgery (LVRS) with bronchoscopic lung volume reduction (BLVR) using endobronchial valves in terms of efficacy and patient safety.

Advanced lung emphysema has a considerable impact on quality of life in patients with chronic obstructive pulmonary disease. There are positive reports of surgical as well as bronchoscopic volume reduction in selected patients, but data comparing LVRS and BLVR is unfortunately lacking to date. The investigators therefore anticipate that their study will make an important contribution to the worldwide efforts in better understanding selection and management of surgical and bronchoscopic treatment of emphysema patients and that it will be of high public interest.

Inclusion Criteria:

• Patients suffering from emphysema (all morphologies, uni- or bilateral distribution) potentially qualifying for both study procedures, LVRS or BLVR (if possible, perfusion scintigraphy within < 6 month of screening, CT scan within < 4 months of screening)
• Age ≥ 30 and ≤ 80 years
• Body Mass Index (BMI) ≥ 16, but ≤ 35 kg/m2
• Non-smoking for 3 months prior to screening interview
• Patient is able to understand and willing to sign a written informed consent document.

Exclusion Criteria:

• FEV1 more than 50% predicted
• TLC less than 100 % predicted, RV less than 175% predicted, RV/TLC less than 58% predicted, and DLCO ≤ 20% predicted in homogeneous emphysema and DLCO ≤ 15% in heterogeneous emphysema, respectively
• PaO2 ≤ 6.0 kPa (45mm Hg) at ambient air (only applicable for homogeneous morphology!)
• PaCO2 ≥ 6.6 kPa (50 mmHg) at ambient air (only applicable for homogeneous morphology!)
• Patients with incomplete interlobar fissures as revealed by quantitative computed tomography analysis with StratX® (fissure completeness ≤ 80%)
• Patients with collateral ventilation as evidenced by bronchoscopic Chartis® measurement (only performed if fissure completeness according to StratX® is < 95%)
• 6-minute walking distance ≥ 470m
• More than two COPD exacerbation episodes requiring hospitalization in the last year
• More than two instances of pneumonia episodes in the last year
• Unplanned weight loss ≥ 10% within 90 days prior to enrollment
• Pulmonary hypertension as evidenced by Delta Psyst RV-RA > 35 mmHg on recent echocardiography (within 3 months prior to screening) and confirmed by RHC (mPAP ≥ 35 mmHg) and signs of moderate to severe RV dysfunction.
• Evidence of left ventricular ejection fraction (LVEF) less than 45% on recent echocardiography (within 3 months prior to screening)
• History of exercise-related syncope
• Myocardial infarction or congestive heart failure within 6 months of screening
• Clinically significant arrhythmias that might put the patient at risk in regard to the interventions
• Prior LVR (any method), bullectomy, or lobectomy
• Clinically significant bronchiectasis with expectoration of ≥ 2 tablespoons/day.
• Pulmonary nodule requiring surgery
• Unable to safely discontinue anticoagulants or dual antiplatelet therapy for 7 days
• Patients with a life expectancy of less than one year