Risk Factors for Prolonged Air Leak After Pulmonary Resection: A Systematic Review and Meta-Analysis

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The aim of this study was to identify risk factors for prolonged air leak (PAL) after pulmonary resection and summarize the quality of evidence.


PAL frequently complicates recovery after pulmonary resection. Studies examining risk factors for PAL are highly variable in study population, design, and findings.


We searched MEDLINE and EMBASE from database inception to December 31, 2017; studies reporting on risk factor (s) for PAL after pulmonary resection for malignant or benign pathology were included. Data on study characteristics, quality, and outcomes were extracted. Study quality and quality of evidence supporting risk factors were rated. Previous significance of risk factors was summarized. For the meta-analysis, pooled odd ratios or mean difference and I heterogeneity were calculated using a random-effects model.


The systematic review included 37 studies, whereas 26 studies provided data for the meta-analysis, including 37,118 lung resections; 3546 had PAL occurrence. After meta-analysis, 17 risk factors were found to be significant; based on larger effect size, non-significant heterogeneity, and at least low quality of evidence or higher, the most strongly associated with PAL were forced expiratory volume in 1 second percent of predicted [mean difference = 8.84; 95% confidence interval (CI), 7.27-10.42], previous smoking history [odds ratio (OR) = 2.05; 95% CI, 1.63-2.58], major anatomic lung resection (OR = 2.82; 95% CI, 2.36-3.37), and pleural adhesions (OR = 1.94; 95% CI, 1.77-2.12). Modified GRADE quality of evidence was low or very low for the majority of risk factors.


A large number of perioperative factors are associated with PAL. Our review can guide risk-reducing interventions, clinical prediction rules, and patient-specific treatment and management strategies for PAL.