Causes of Bronchopleural Fistula
Bronchopleural fistula most commonly occurs as a postoperative complication following pulmonary resection (1.5-28% incidence), but also arises from inadequately treated bacterial pneumonia with necrotizing infection, tuberculosis, lung abscess, trauma, and malignancy. 1, 2
Postoperative Causes
- Pulmonary resection surgery is the leading cause, occurring in 1.5-28% of cases, with highest risk after pneumonectomy for cancer, aspergillosis, or bronchiectasis 1, 2
- The mechanism involves failure of the non-resected lung to fill the pleural cavity, leading to pneumothorax space infection and subsequent breakdown of the sutured bronchus 2
- Postoperative fistulas typically develop within 2-3 months after the procedure 3
- Bronchoscopic resection of malignant endobronchial lesions can cause immediate BPF formation 4
Infectious Causes
- Inadequately treated bacterial pneumonia with progression to necrotizing pneumonia is a critical infectious cause, particularly with Pseudomonas and Aspergillus organisms 5
- Tuberculosis accounts for a significant proportion of spontaneous fistulas 2
- Lung abscess that erodes into the pleural space creates direct communication 2
- Necrotizing pneumonia should be treated medically, as surgical intervention or trocar chest tube placement increases BPF risk 3
Traumatic Causes
- Penetrating thoracic trauma can create combined esophageal-pleural and bronchopleural fistulas 6
- Blunt trauma with parenchymal disruption may lead to delayed fistula formation 6
Other Causes
- Malignancy causing direct bronchial wall invasion or post-radiation necrosis 4, 2
- Aortobronchial fistula represents a distinct vascular etiology with fistulous communication between thoracic aorta and tracheobronchial system, associated with mycotic aneurysm, atherosclerotic aneurysm, or trauma 3
Critical Risk Factors
The key pathophysiologic mechanism in postoperative cases is the combination of:
- Incomplete pleural space obliteration after resection 2
- Subsequent infection of the residual space 2
- Breakdown of bronchial stump closure under infected conditions 2
Common Pitfall
Do not confuse bronchopleural fistula with aortobronchial fistula—the latter presents with hemoptysis and sepsis, carries virtually 100% mortality if untreated, and requires urgent vascular intervention rather than pulmonary management 3