Prolonged air leak is reported in up to 60 to 75% of patients after lung operation in the presence of severe lung emphysema. The effect of the non-powered AEONTM Endostapler as compared to the Echelon FlexTM Powered plus stapler on the volume and duration of air leak and on the time to chest drain removal after lung operation in the presence of severe lung emphysema will be investigated in a randomized, prospective, single-blinded clinical trial.

Patients with severe lung emphysema Grad III or IV scheduled for an operation by video-assisted thoracic surgery (VATS) or open method at the Department of Thoracic Surgery at the University Hospital Basel will be pre-screened in terms of inclusion and exclusion criteria. Before the operation, a randomization envelope is opened in the operation room, in which it is specified on which side and with which method the lung tissue will be closed. If bilateral surgery is planned, the other side is automatically closured using the other method. If for example the non-powered AEONTM Endostapler is randomly allocated to the left side, the right side is automatically operated with the Echelon FLEXTM Powered plus Stapler and vice versa. In cases of a unilateral surgery a random stapler as stated in the envelop would be allocated for that side in question. On the day of the operation, postoperative air leak will be measured quantitatively in ml per minute immediately, 2h, 4h, 8h, and 12h after skin closure. Starting on the first postoperative day, this is done twice a day at 8 am and 5 pm until the air leak stops or another surgery must be performed. Cessation of air leak is the case when a value of 0ml/min or two consecutive values under 30 ml/min by use of thoracic drainage Medela- Topaz™ system are read by the investigator.

Inclusion Criteria:

• Informed Consent signed by the subject
• Patients discussed in the interdisciplinary emphysema treatment board and found to have the indication for a LVRS or patients who meet the criteria in agreement with pneumology recommendation for bilateral or unilateral LVRS with pulmonary emphysema (all morphologies including chronic obstructive pulmonary disease (COPD) GOLD III and IV) or patients operated for other Pathology other than lung emphysema requiring lung resection in the presence of severe lung emphysema.

Exclusion Criteria:

• non-bullous pulmonary emphysema
• Severely impaired carbon monoxide diffusing capacity (≤ 20% of predicted value, One-second capacity (FEV1) ≤ 20% of predicted value with a homogeneous emphysema morphology
• Patients with severe pulmonary arterial hypertension (mPAP > 35 mmHg) and are symptomatic
• Significant (i.e. clinically relevant and symptomatic) Coronary Arterial Disease (CAD)
• Inability to follow the procedures of the study, e. g. due to language problems, psychological disorders, dementia, etc. of the participant
• Enrolment of the investigator, his/her family members, employees and other dependent person
• Current enrolment in another clinical trial studying an experimental treatment
• Pregnancy

Only the Patient is blinded to the study. Patients do not know which stapler they are being treated with on which side because they are under anesthesia in the operating room and also do not have access to information regarding the stapler being used afterwards.