A Study In Application Of Quantitative CT Analysis In The Endobronchial Valve Treatment For Chronic Obstructive Pulmonary Disease

Objective:The investigation aimed to observe changes of lung volume, airway and pulmonary vascular and to explore feature changes of pulmonary structure and functions in chronic obstructive pulmonary disease(COPD) patients with endobronchial valve(EBV) treatment by quantitative CT analysis(QCT). The mechanism of EBV therapy was explored by studying the correlation of QCT changes with pulmonary function and exercise capacity before and after EBV treatment. Through the analysis of the feasibility of preoperative QCT index to predict EBV efficacy, the QCT indicators were screened to improve the EBV efficacy and the prognosis of patients with severe COPD.Materials and methods:Twenty-four patients with severe COPD was treated with EBV therapy during October 2010 to July 2015 in respiratory medicine of PLA General Hospital. Lung CT images before and after EBV treatment were analyzed under three dimensional reconstructions by FACT medical imaging quantitative diagnosis system, and QCT changes of lung volume, airway and pulmonary vascular were recorded. The predictive valves of the preoperative screening indicators were compared and screening strategy was optimized with QCT indicators. The mechanism of EBV treatment was revealed by analyzing the QCT characteristics of patients with significantly improved lung function and exercise capacity. By describing the QCT characteristics of patients with success EBV treatment, the preoperative QCT indexes, which could effectively predict the efficacy of EBV, was screened.Results:1. The EBV treatment resulted in decreased volume of target lobe, increased volume of ipsilateral non-targeted lobe, and increased volume of whole lung vessels. There was asignificant correlation between the improvement of lung function with target lobe volume reduction and the increase of ipsilateral non-treated lobe volume after EBV treatment. The improvement of exercise capacity was significantly correlated with the increased volume of whole lung vessels, independent of target lung volume reduction. The improvement of lung function after EBV treatment was significantly related to the high volume of the target lobe and the low volume of the ipsilateral non-targeted lobe before treatment. The improvement of exercise capacity after EBV treatment was significantly related to the preoperative low volume of whole lung vessels.2. The fissure integrity and collateral ventilation had high accuracy in predicting whether the target lobe was significantly reduced, but poor accuracy in predicting significantly improved lung function and exercise capacity. The combination of two methods increased the rate of significant target lobe volume reduction with a loss of patients. The heterogeneity of target lobe had a poor accuracy in predicting TLVR, lung function and exercise capacity. The incidence of significant improved lung function and exercise capacity was higher in patients with TLVR?350mL than that in patients with TLVR<350mL. The lung function and exercise capacity were also significantly improved in some patients with TLVR<350mL after EBV treatment. The main changes of QCT indexes were the increased volume of ipsilateral non-treated lobe and whole lung vessels.3. For patients with inconsistent results of fissure integrity and collateral ventilation assessment, the preoperative low volume of ipsilateral non-targeted lobe and whole lung vessels could predict the improvement of lung function and exercise capacity after EBV treatment.Conclusion:1. The EBV treatment resulted in decreased volume of target lobe, increased volume of ipsilateral non-targeted lobe, and increased volume of whole lung vessels.2. The decrease of target lobe volume, the increase of ipsilateral non-targeted lobe volume and the increase of whole lung vessels volume might be main mechanisms of lung function and exercise capacity improvement in EBV treatment.3. Preoperative high target lobe volume, low ipsilateral non-targeted lobe volume and low whole lung vessels volume might be the main characteristics of EBV benefit population.4. For patients with inconsistent results of fissure integrity and collateral ventilation assessment, the preoperative volume of the ipsilateral non-targeted lobe and whole lung vessels might be of some value in predicting the efficacy of EBV treatment.