Persistent air leak: from evaluation to management

PURPOSE OF REVIEW: Persistent air leak remains a major source of morbidity after lung resection and in secondary spontaneous pneumothorax, yet management is still commonly driven by duration rather than mechanism. This review examines recent advances in objective air leak assessment, pressure-dependent leak physiology, localization, and phenotype-directed intervention. RECENT FINDINGS: Digital drainage improves reproducible measurement of air leak trajectory, although no universal threshold predicts healing or permits tube removal. Pressure-dependent air leaks related to residual pleural space or lung-thoracic cavity mismatch may resolve after reducing drainage intensity or removing the tube in selected patients. Computed tomography and ventilation SPECT/CT can support anatomical and functional localization when targeted treatment is planned. Recent studies support individualized low-pressure drainage, autologous blood patch or glucose pleurodesis, and bronchoscopic valves, spigots, blood patching, sealants, or plugs, but most comparative evidence remains limited and heterogeneous. SUMMARY: Persistent air leak should be classified by air leak trajectory, lung expansion, pleural pressure behavior, anatomical source, infection, and operative fitness. Phenotype-directed escalation may reduce unnecessary procedures while identifying patients who require early bronchoscopic or surgical source control.