Risk Factors for Pneumothorax After Treatment With Endobronchial Valves: A Cohort Study.

Background and objectives: Pneumothorax (PTX) is the most prevalent and serious adverse event associated with endobronchial valve (EBV) treatment in chronic obstructive pulmonary disease (COPD) with emphysema. This study aimed to compare preoperative characteristics and 30-day outcomes in patients with COPD with and without PTX.

Method: This retrospective nationwide cohort study included patients treated with EBV between 2017 and 2023 at all EBV centres in Denmark. Data were retrieved from medical records.

Results: A total of 228 patients were included, of whom 46 (20.2%) had PTX. The median time to PTX was 7 h (IQR 2-22) and the median drain treatment duration was 13 days (IQR 8.5-22). The risk of PTX was significantly higher when EBV treatment was performed in the upper lobes than in the lower lobes (adjusted RR 6.32, 95% CI 2.56-15.60). High target lobe volume (adjusted OR pr 100 mL increase 1.12, 95% CI 1.02-1.22) and high residual volume (adjusted OR pr 10%pt. increase 1.11, 95% CI 1.01-1.23) were independent risk factors for PTX. More PTX patients had atelectasis after 2 h compared to patients without PTX. The risk of pneumonia (RR 4.5, 95% CI 1.7-11.8), empyema (p = 0.0047) and ICU admission (RR 9.89, 95% CI 1.98-49.4) were significantly higher in the PTX patients than in the patients without PTX.

Conclusions: PTX was more prevalent when EBV treatment was performed in the upper lobes and with high residual volume and target lobe volume, leading to prolonged hospital admission and risk of hospital-acquired pneumonia.