Pleural Adhesion Assessment as a Predictor for Pneumothorax after Endobronchial Valve Treatment

Abstract

Background: Pneumothorax after bronchoscopic lung volume reduction using one-way endobronchial valves (EBVs) in patients with advanced emphysema occurs in approximately 20% of patients. It is not well known which factors predict the development of pneumothorax. Objective: To assess whether pleural adhesions on pretreatment high-resolution computed tomography (HRCT) scans are associated with pneumothorax occurrence after EBV treatment. Methods: HRCT scan analyses were performed on all patients who received EBV treatment in a randomized controlled trial. Three blinded readers scored adhesions by number and by measuring the longest axis of each pleural adhesion in the treated lung. The Pleural Adhesion Score (PAS) was calculated by adding 1 point for each small pleural lesion (<1 mm), 5 points for each medium-sized lesion (1-5 mm), and 10 points for each large lesion (>5 mm). Results: The HRCT scans of 64 treated patients were assessed, of whom 14 developed pneumothorax. Patients who developed pneumothorax had a higher median number of pleural adhesions, 2.7 (IQR 1.9-4) compared to 1.7 (1-2.7) adhesions in the group without pneumothorax (p < 0.01). The PAS in the group with pneumothorax was higher compared to that in the group without: 14.3 (12.4-24.1) versus 6.7 (3.7-11.2) (p < 0.01). A threshold PAS of ≥12 was associated with a higher risk of pneumothorax (OR 13.0, 95% CI 3.1-54.9). A score <12 did not rule out the occurrence of pneumothorax. Conclusion: A higher number of pleural adhesions on HRCT with a subsequent higher PAS in the treated lung is associated with a higher occurrence of pneumothorax after EBV treatment.

Endobronchial valves for severe emphysema

“…These efforts could also result in more insight to predict patients who are at risk of a pneumothorax after treatment. Currently, the predictors of the risk of a pneumothorax are not clear and studies reported even contradictory results [28,29].…”

Endobronchial valve therapy for severe emphysema: an overview of valve-related complications and its management

“…pleurodesis or pleurectomy) are most often excluded for endobronchial valve treatment [22]. Adhesions may be visible on CT-scan, but currently it is not known whether this correlates to treatment success or the ability to achieve an atelectasis [23]. If there is no effect after treatment with valves, there is no presence of collateral ventilation and revision bronchoscopy did not show evidence of valve dysfunction, adhesions may be the cause of the treatment failure.…”

Bronchoscopic interventions for severe emphysema: Where are we now?

“…33 Improved patient selection has significantly improved patient outcomes but it is also evident that the main adverse event as a result of inducing lobar atelectasis or volume reduction is a secondary pneumothorax. 19,34,35 This is presumably due to the remodelling that occurs with volume loss, further decreasing pleural pressures and any areas where the lung is adherent to the pleura may lead to a tear and cause a pneumothorax. This risk ranges from 20% to 25% in the clinical trials and is reflective in clinical practice.…”