Endobronchial Valve Treatment Improves Regional Specific Ventilation in the Target Lung

Introduction: Previous studies yielded inconsistent results regarding whether bronchoscopic lung volume reduction using endobronchial valves (EBVs) improves pulmonary ventilation. The aim of this study was to evaluate changes in ventilation following EBV treatment using a novel technique for assessing specific pulmonary ventilation: X-ray velocimetry (XV LVAS, 4DMedical, Los Angeles, CA, USA).

Pulmonary ventilation was assessed using XV pretreatment and 6 weeks after treatment. The main outcome was mean specific ventilation (MSV) (mL/mL) which is defined as the volume change in a lung region (from start to end of inspiration), divided by the volume of that region at the start of inspiration.

Nineteen patients were included (79% female, mean FEV₁: 30% of predicted, median RV: 207 %pred). After EBV treatment, RV decreased significantly by 0.90 L (interquartile range: -1.2 to -0.67, p < 0.001). EBV treatment resulted in a significant increase in MSV of the whole lung. When stratifying by treated and non-treated lungs, a significant increase in MSV was found in the treated lung, while a significant decrease was found for the non-treated (contralateral) side. No significant associations were found between changes in X-ray velocimetry (XV) measurements and changes in clinical outcomes.

For the first time, XV was utilized to measure specific pulmonary ventilation before and after EBV treatment. Our results demonstrate an overall increase in pulmonary ventilation across the whole lung, driven by an increase in the treated lung, despite a decrease in the non-treated lung. No association was observed between changes in pulmonary ventilation and changes in clinical outcomes.