Functional Lung Imaging in Patients With Respiratory Compromise Undergoing Endobronchial Valve Placement

Bronchoscopic lung volume reduction (BLVR) using endobronchial valves is effective in improving quality of life in patients suffering from emphysema. BLVR treatment in advanced emphysema requires targeted segmental or sub-segmental placement of endobronchial valves (EBV) to achieve total lobar occlusion to induce effective lobar volume reduction. BLVR procedure success rate declines in patients with incomplete lobar fissure integrity due to the potential for collateral ventilation to circumvent EBV lobar occlusion. Current methods that assess lobar collateral ventilation as a correlate of fissure integrity are imperfect, resulting in a significant percentage of patients having equivocal assessment, leading to suboptimal selection of patients and potential for inappropriate selection of patients for BLVR. Additionally, methods used to select the target lobe for EBV placement predominately rely on the extent of emphysematous destruction. There is also a need to select based on the extent of physiological disturbance at the lobar level. Distribution of ventilation or regional ventilation heterogeneity may be associated with collateral ventilation. Therefore, in this study we wish to quantify lobar distribution of ventilation and ventilation heterogeneity in patients undergoing investigation for BLVR to determine the additive contribution of functional lung imaging for assessing lobar physiological derangement and suitability for EBV treatment.