Bronchopleural fistula (BPF) is a sinus tract between the main stem, lobar, or segmental bronchus and the pleural space. It can be a potentially catastrophic complication following pneumonectomy or other pulmonary resection. Morbidity ranges between 25% and 71%, and diagnosis and management is often a challenge for physicians. Other common causes of BPF include pulmonary infection causing necrosis, persistent spontaneous pneumothorax, chemotherapy or radiotherapy from malignancy, and tuberculosis. Treatment for BPF ranges from medical management to bronchoscopic procedures for critically ill patients and surgical intervention for those deemed at highest risk. There is a lack of consensus regarding optimal management due to varying therapeutic success. Varoli et al. described the time of onset following surgical intervention to classify fistulas as early (1 to 7 days), intermediate (8 to 30 days), or late (more than 30 days). Although fistulas almost always occur within 3 months after surgery,  BPF following pleuropulmonary infection can occur at any point.
Salik, I. +., & Abramowicz, A. E. +. (2018). Bronchopleural fistula. Statpearls (). Treasure Island, (FL): StatPearls Publishing LLC. doi:NBK534765 Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK534765/