Management of primary spontaneous pneumothorax (PSP) remains unclear. Primary therapeutic goals for PSP include removal of air from the pleural space an prevention of recurrences. The absence of generally accepted and methodologically sound recommendations may account for the extensive variation in practice for air evacuation techniques. Air evacuation may be achieved by simple aspiration (exsufflation) or conventional chest tube drainage. Chest tube thoracotomy remains the most popular technique.Aspiration is a more simple technique, that allows possibility of ambulatory management. The purpose of the present study is to compare simple aspiration performed with a specific thoracentesis device, versus conventional chest tube drainage. Comparison will be performed on immediate efficacity of resolution of the pneumothorax.The hypothesis is that simple aspiration performed with a specific device is not inferior to chest tube drainage for management of a first episode of large size primary spontaneous pneumothorax. A second goal is to measure the efficacy at one week, and the recidive at one year. The trial is randomized, controlled and will include 200 patients for each group. The patients will be enrolled in 29 hospitals in France. Emergency department, thoracic surgery and pulmonary departments of each hospital were primarily contacted for agreement to participate to the study.

Inclusion Criteria:

• patients aged more than 18 years and less than 50 years
• first episode of pneumothorax
• primary pneumothorax (absence of known pulmonary disease)
• large size of pneumothorax : presence of a visible rim of air between the lund margin and the chest wall, from the apex to pulmonary base

Exclusion Criteria:

• impossibility to obtain patient consent for psychiatric disease
• patients under justice control
• âgé less than 18 years, or more than 50 years
• impossibility of medical follow de for geographic, social or psychic reasons
• pregnant women
• pneumothorax with acute respiratory insufficiency or bad tolerated
• recidive of pneumothorax
• traumatic pneumothorax
• pneumothorax with pleural effusion
• bilatéral pneumothorax
• pneumothorax with pulmonary disease