Trial Evaluating the Rate of Pneumothorax in Severe Emphysema Secondary to Endoscopic Volume Reduction With Two-stage ZEPHYR® Valves Versus Endoscopic Volume Reduction With One-stage ZEPHYR® Valves

The Zephyr® valve was first implanted in 2001. Since then, 5 important studies have proven a clinical superiority compared to the existing standard of care. Bronchoscopic lung-volume reduction with the use of one-way endobronchial valves is a potential treatment for patients with severe emphysema. Loss of lung elastic recoil leads to airflow obstruction, gas trapping, and increased operating lung volumes. Lung volume reduction surgery (LVRS), resection of the most affected of the lung, has been clearly shown to improve outcomes in selected patient groups. The surgical intervention is, however, associated with significant morbidity and an early mortality rate of about 5%. Therefore, there is considerable interest in developing novel treatment approaches that can reduce lung volume and gas trapping, either more safely than LVRS or in patients for whom LVRS is not an option. In the present study, 244 patients will be randomized. After the selection process, they will all be hospitalized in order to undergo an endoscopic lung volume reduction with Zephyr® valve under general anesthesia. Half of them, the experimental group, will be treated according to Limoges' treatment algorithm (2 stages). For the other half, the control group, the entire lobe will be treated during one procedure will. Both groups will receive the standard of care treatments, according to the Global initiative for chronic Obstructive Lung Disease recommendations (GOLD). Both groups will be followed for one year: * All the patients will undergo a thorax CT scan 45 days after implanting the last valve. Three follow-up consultations are planned at 45 days, 6, and 12 months. During these consultations, each patient will complete a Saint-George Respiratory Questionnaire (SGRQ) Test, a plethysmography and a 6-minutes walking test. * Patients randomized in the experimental group will undergo a plethysmography and a thorax CT scan one day before the second procedure.