Management of Bullous Lung Disease on CT
When bullous changes are identified on CT imaging, management depends primarily on whether the patient is symptomatic, the size and extent of the bullae, and the presence of complications such as pneumothorax or infection. 1, 2
Initial Assessment and Imaging
CT scanning is the gold standard for evaluating bullous lung disease, providing superior detail compared to plain radiography for assessing the extent of bullous changes, differentiating bullae from pneumothorax, and evaluating the quality of surrounding lung parenchyma. 1, 3
CT is particularly valuable when differentiating a pneumothorax from complex bullous lung disease, when aberrant tube placement is suspected, or when the plain chest radiograph is obscured by surgical emphysema. 1
Bullae are defined as sharply demarcated air-filled spaces with thin walls measuring ≥1 cm in diameter, while blebs are typically smaller (<2 cm) subpleural lesions. 1, 3
CT detects bullae and blebs in up to 80-90% of cases where they may not be visible on chest radiography, including contralateral pathological changes in approximately two-thirds of patients. 1, 3
Risk Stratification Based on Clinical Presentation
Asymptomatic or Minimally Symptomatic Patients
For patients with incidental bullous changes who are asymptomatic or minimally symptomatic, conservative management with observation is appropriate. 2
Mandatory smoking cessation counseling should be provided, as smoking plays a major role in the pathogenesis of bullous disease and increases lifetime pneumothorax risk to 12% in men (versus 0.1% in non-smokers). 1
Serial follow-up imaging may be considered given the potential association between bullous lung disease and lung cancer development, particularly in smokers. 4
Symptomatic Patients Requiring Intervention
Surgical evaluation is indicated when:
Bullae occupy >30% of the hemithorax with compression of adjacent healthy lung tissue causing incapacitating dyspnea. 2
Complications develop including recurrent pneumothorax, infection within bullae, or hemoptysis. 2
Progressive dyspnea occurs despite medical management in patients where even modest improvement in pulmonary function would provide significant clinical benefit. 2
Preoperative Evaluation for Surgical Candidates
Complete pulmonary function testing is mandatory, including:
Spirometry with lung volumes by whole body plethysmography
Diffusion capacity (DLCO)
Arterial blood gas analysis 2
Outpatient pulmonary rehabilitation and smoking cessation must be completed preoperatively. 2
High-resolution CT with thin slices provides optimal assessment of bullous extent and surrounding parenchymal quality to guide surgical planning. 1, 2
Surgical Approach
Video-assisted thoracoscopic surgery (VATS) is preferred when technically feasible, as it offers quicker recovery and less postoperative pain compared to thoracotomy. 2
The surgical principle is limited resection of large bullae while preserving all functional lung parenchyma—lobectomies should be avoided whenever possible. 2
Modified Monaldi-type drainage procedures are effective alternatives for high-risk patients who cannot tolerate excisional procedures. 2
Management of Pneumothorax Complicating Bullous Disease
When pneumothorax occurs in the setting of bullous disease:
For breathless patients or those >50 years with a rim of air >2 cm on chest radiograph, intercostal drain placement is indicated. 1
For smaller pneumothoraces (<2 cm rim) in younger, non-breathless patients, aspiration may be attempted initially. 1
CT scanning is particularly valuable when plain radiography cannot reliably distinguish pneumothorax from complex bullous disease. 1
Suction may be required if initial drainage is unsuccessful, with surgical referral after 3-5 days if air leak persists. 1
Special Considerations and Pitfalls
Avoid unnecessary aspiration or drainage of bullae mistaken for pneumothorax, as this can be dangerous—CT clarification is essential when uncertainty exists. 1
In patients with severe bullous lung disease and suspected pneumothorax, CT scanning prevents potentially harmful interventions by accurately differentiating emphysematous bullae from true pneumothoraces. 1
Arterial blood gas abnormalities are common, with PaO2 <10.9 kPa (80 mmHg) in 75% of patients with pneumothorax complicating bullous disease. 1
The presence of underlying lung disease predicts the degree of hypoxemia and influences management decisions. 1
Bullous lung disease may be a complication of severe pneumonitis (including COVID-19), requiring observation and follow-up rather than immediate intervention. 5
Long-term surveillance is warranted given the potential association between bullous disease and subsequent lung cancer development, particularly at bulla sites. 4