Characterization and Prediction of Prolonged Air Leak After Pulmonary Resection: A Nationwide Study Setting Up the Index of Prolonged Air Leak.

Background: The objective of this study was to better characterize prolonged air leak (PAL), defined as an air leak longer than 7 days, and to develop and validate a predictive model of this complication after pulmonary resection. Methods: All lung resections entered in Epithor, the French national thoracic database (French Society of Thoracic and Cardiovascular Surgery), were analyzed. Data collected between 2004 and 2008 (n = 24,113) were used to build the model using backward stepwise variable selection, and the 2009 data (n = 6,813) were used for external validation. The primary outcome was PAL. Results of the predictive model were used to propose a score: the index of PAL (IPAL). Results: Prevalence of PAL after pulmonary resection was 6.9% (n = 1,655) in the development data set. In the final model, 9 variables were selected: gender, body mass index, dyspnea score, presence of pleural adhesions, lobectomy or segmentectomy, bilobectomy, bulla resection, pulmonary volume reduction, and location on upper lobe. In the development data set, the C-index was 0.71 (95% confidence interval [CI], 0.70 to 0.72). At external validation, the C-index was 0.69 (95% CI, 0.66 to 0.72) and the calibration slope (ie, the agreement between observed outcomes and predictions) was 0.874 (<1). A score chart based on these analyses has been proposed. The formula to calculate the IPAL is the following: gender (F = 0; M = 4) - (body mass index-24) + 2 × dyspnea score + pleural adhesion (no = 0; yes = 4) + pulmonary resection (wedge = 0; lobectomy or segmentectomy = 7; bilobectomy = 11; bulla resection = 2; volume reduction = 14) + location (lower or middle lobe = 0; upper = 4). Conclusions: Surgeons can easily use the well-validated model to determine intraoperative preventive measures of PAL. [ABSTRACT FROM AUTHOR]