Abstract
OBJECTIVES: Predicted postoperative forced expiratory volume in 1 s (ppoFEV1) and predicted postoperative diffusing capacity of the lungs for carbon monoxide (ppoDLco) are the two most significant parameters for predicting the risk of cardiopulmonary complications after major lung resection for lung cancer. Although the severity of pulmonary emphysema on computed tomography may be an important risk factor for postoperative complications, the clinical significance of measuring the severity of pulmonary emphysema, in combination with ppoFEV1 and ppoDLco, has never been evaluated. METHODS: We measured the severity of pulmonary emphysema, representing the percentage of low-attenuation area (< -950 Hounsfield units), in the whole lung field, in addition to ppoFEV1 and ppoDLco, in 451 patients who underwent major lung resection for primary lung cancer. We also measured the volume of the upper and lower lobes of emphysematous and non-emphysematous lungs. RESULTS: Postoperative cardiopulmonary complications developed in 60 patients (13.3%). According to a receiver operating characteristic curve analysis for the diagnostic potential of postoperative complications, the area under the curve was highest for the severity of emphysema, followed by ppoDLco and ppoFEV1. According to a stepwise multivariable logistic regression analysis, the severity of emphysema and ppoDLco was identified as independent risk factors for postoperative complications. Neither the heterogeneous distribution of emphysema nor that of non-emphysema was associated with the occurrence of complications in patients with upper lobe disease or in patients with lower lobe disease. CONCLUSIONS: The severity of emphysema on computed tomography is a relevant risk factor for cardiopulmonary complications after major lung resection. CLINICAL REGISTRATION NUMBER: The study was approved by our institutional review board of No. 240077.