Does external pleural suction reduce prolonged air leak after lung resection? Results from the AirINTrial after 500 randomized cases

Background: External pleural suction is used after lung resection to promote lung expansion and minimize air leak duration. Published randomized trials failed to prove this advantage but they are limited in number and underpowered in many cases. The aim of the AirINTrial study was to test the hypothesis that external pleural suction may reduce the rate of prolonged air leak in a large, randomized cohort. Methods: All candidates for lung resection (with the exception of pneumonectomy) were considered eligible for this single-center study. At the end of operation, patients were stratified by the type of resection (anatomic versus nonanatomic) and randomly allocated into the external suction arm (-15 cmH₂O, group A) or into the no external suction arm (control arm, group B) in a 1:1 ratio. Chest drains were maintained for 3 days and then they were either removed or connected to an Heimlich valve, when an air leak was present. The main endpoint was to compare groups in terms of prolonged air leak (defined as the rate of patients having a chest drain still in place by postoperative day 7). Results: Starting on February 2011, 500 patients were randomized over a 21-month period, 250 in group A and 250 in group B. Twenty-one patients in group B (8.4%) required pleural suction owing to large pneumothorax or diffuse subcutaneous emphysema. On postoperative day 7, the chest drain was still in place in 25 patients in group A and in 34 patients in group B (10% and 14%, respectively; p = 0.2). Subgroup analysis showed that external pleural suction reduced the prolonged air leak rate in the subgroup of patients who underwent anatomic resection (n = 296, 9.6% in group A and 16.8% in group B; p = 0.05). Conclusions: Results from the AirINTrial showed that the routine use of external suction reduces the rate of prolonged air leak after anatomic lung resection. More accurate strategies of pleural suction based on the amount of air flow and the degree of lung expansion should be probably established to improve its effectiveness.