Radiology of pulmonary emphysema and lung volume reduction surgery

Abstract

Lung volume reduction surgery (LVRS), which involves the bilateral wedge resection of 20% to 30% of the most diseased lung through a median sternotomy, is emerging as a promising treatment option for select patients with severe, debilitating emphysema. This article details our observations and preliminary investigations related to the imaging evaluation of patients including selection criteria, postoperative findings, and structural changes in the thorax after surgery. Routine preoperative evaluation includes inspiratory and expiratory chest radiographs, computed tomography (CT) examination, and nuclear medicine lung scan. Investigational studies include quantitative CT to assess disease severity and dynamic magnetic resonance imaging to study respiratory movements. Postoperative improvement in FEV1, oxygenation, and exercise tolerance correlate with the degree of heterogeneity, hyperinflation, lung compression, upper lobe severity, and percentage of retained mildly diseased lung shown on preoperative imaging studies. Postoperative radiographic monitoring is important for detection of complications. Postoperative follow-up examinations show reduced thoracic distention, improved coordination of respiratory movement, and increased diaphragm curvature and excursion, supporting the hypothesis of improved respiratory mechanics as a major contributing factor to the success of LVRS.