What are the causes of a bronchopleural (broncho-pleural) fistula?

Causes of Bronchopleural Fistula

The most common causes of bronchopleural fistula (BPF) are post-surgical complications following pulmonary resection, followed by lung necrosis from infection, persistent spontaneous pneumothorax, cancer treatments (chemotherapy/radiotherapy), and tuberculosis. 1

Primary Etiologies

Post-surgical Causes (Most Common)

• Pulmonary resection complications, particularly after pneumonectomy
  • Right pneumonectomy carries higher risk than left pneumonectomy 2
  • Technical factors increasing risk:
    • Long bronchial stump 3
    • Overzealous bronchial dissection 3
    • Stapled bronchial closure 2
    • Inadequate tissue to fill pleural space 3
    • Tumor in bronchial stump 3

Infectious Causes

• Necrotizing pneumonia 4
• Pulmonary abscess 4
• Empyema 5
• Tuberculosis 3, 2
• Poorly treated empyema 4

Malignancy-Related Causes

• Recurrent carcinoma at bronchial stump 2
• Lung necrosis following chemotherapy or radiotherapy for lung cancer 1
• Prior radiation therapy to chest 2, 6

Traumatic Causes

• Persistent spontaneous pneumothorax 1
• Penetrating chest injuries 4

Iatrogenic Causes

• Prolonged mechanical ventilation (barotrauma) 2, 6
• Invasive respiratory procedures 7

Risk Factors Contributing to BPF Development

Patient-Related Factors

• Advanced age 6
• Diabetes mellitus 6
• Positive sputum in tuberculosis patients undergoing resection 3
• Corticosteroid treatment 6
• Contamination of pleural cavity during procedures 3

Clinical Presentation

• Cough (often with purulent expectoration)
• Fever
• Dyspnea
• Pneumonia
• Empyema
• Persistent air leak

Diagnostic Approach

Imaging

• CT chest with IV contrast is the gold standard for detecting BPF 4
  • Direct sign: visible fistulous tract between bronchus/lung and pleural space
  • Indirect sign: air bubbles beneath bronchial stump or suspected fistula 4

Bronchoscopy

• Useful for direct visualization of the fistula
• Can be enhanced by retrograde instillation of methylene blue via chest tube 6
• May also be therapeutic in some cases 5

Management Considerations

Surgical Options

• Surgical drainage is essential for effective treatment 3
• Bronchial stump resuture (limited success) 3
• Thoracoplasty combined with drainage 3
• Myoplasty with limited thoracoplasty (highest success rate) 3
• Vascularized pedicle flaps (omentum most effective, especially after radiation) 2

Endoscopic Management

• Option for non-operable patients or as bridge to surgery 5
• Small fistulas: ethyl-2-cyanoacrylate 5
• Large fistulas: combination of silicone spigots and sealants 5
• Various glues, coils, and sealants have been used 1

Conservative Management

• Generally unsuccessful when used alone 3
• May include retrograde instillation of sclerosing agents like doxycycline 6
• Spontaneous ventilation to avoid barotrauma 6

Prognosis

• Historically high mortality (19.5% in older series) 3
• Success rates vary by treatment approach
• Multiple procedures often required (average 3.3 procedures per patient) 2
• Omental flap coverage shows highest success rates (23/25 patients) 2

Prevention

• Avoid pulmonary resection in tuberculosis patients with positive sputum 3
• Careful bronchial dissection and stump management 3
• Minimize contamination of pleural cavity 3
• Ensure adequate tissue remains to fill pleural space 3

BPF remains a challenging complication with significant morbidity and mortality. Treatment approach should be based on fistula size, location, and patient's clinical status, with surgical management offering the best chance of definitive resolution in suitable candidates.