The ventilation–perfusion differential index assists target lobe selection and improves V/Q redistribution for endobronchial valve lung volume reduction: a prospective study

Abstract

Identifying the optimal target lobe remains a challenge for bronchoscopic lung volume reduction (BLVR) with endobronchial valves (EBVs). The ventilation/perfusion differential index (VQDI) has been identified as a possible tool for target lobe selection in BLVR. Twenty-four individuals suffering from severe emphysema underwent V/Q imaging. In each case, the lobe exhibiting the lowest VQDI was prioritized for EBV intervention. Over the 6-month follow-up period, changes in pulmonary function, exercise capacity assessed using the 6-min walk distance (6MWD), health status assessed using the St George’s Respiratory Questionnaire (SGRQ), and regional V/Q distribution were evaluated. Paired comparisons and Pearson correlation analyses were performed as appropriate. Significant reductions in ventilation, perfusion, and volume were observed in the target lobe (− 80.27%, − 76.09%, and − 32.72%, respectively; all p < 0.01), with compensatory increases in ipsilateral nontargeted regions. At 6 months, patients showed significant improvements in forced expiratory volume in 1 s (FEV 1 ) (+ 0.19 L), 6MWD (+ 71.8 m), and SGRQ scores (− 18.7 points) (all p < 0.01). A lower baseline VQDI predicted greater improvements in diffusing capacity of the lungs for carbon monoxide (DLCO) and dyspnea scores ( p < 0.05). Furthermore, the change in VQDI correlated positively with improvements in DLCO (r = 0.615), FEV 1 (r = 0.573), and 6MWD (r = 0.520) (all p < 0.01). VQDI-assisted target selection was associated with favorable clinical and physiological outcomes following BLVR with EBVs. These findings support the feasibility of this functional imaging approach and warrant validation in larger prospective comparative studies. Trial registration ClinicalTrials.gov (NCT05775588), first posted on 20 March 2023.