Prediction of postoperative pulmonary complications in older patients undergoing lobectomy for lung cancer based on skeletal muscle mass

BACKGROUND: This retrospective study was designed to evaluate preoperative pulmonary function test (PFT) results and skeletal muscle mass, represented by the erector spinae muscle (EM), as predictors of postoperative pulmonary complications (PPCs) in older patients undergoing lobectomy for lung cancer. METHODS: The medical records, including preoperative PFT, chest computed tomography (CT) and PPCs, of patients older than 65 years undergoing lobectomy for lung cancer were retrospectively examined at Konkuk University Medical Center from January 2016 to December 2021. The sum of cross-sectional areas (CSAs) of the right and left EMs at the level of the spinous process with the 12(th) thoracic vertebra was used as the skeletal muscle mass (CSA(Both)). RESULTS: Data from a total of 197 patients were included in the analyses. In total, 55 patients had PPCs. The preoperative functional vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) showed significantly poorer values and the CSA(Both) had significantly lower values in patients with than in those without PPCs. The preoperative FVC and FEV1 showed significant positive correlations with CSA(Both). Multiple logistic regression analysis identified age, diabetes mellitus (DM), preoperative FVC and CSA(Both) as risk factors for PPCs. The areas under the curves for FVC and CSA(Both) were 0.727 (95% CI, 0.650–0.803; P<0.001) and 0.685 (95% CI, 0.608–0.762; P<0.001), respectively. The optimal threshold values of FVC and CSA(Both) to predict PPCs based on a receiver operating characteristic curve analysis were 2.685 L (sensitivity =64.1% and specificity =61.8%) and 28.47 mm(2) (sensitivity =62.0% and specificity =61.5%), respectively. CONCLUSIONS: PPCs in older patients undergoing lobectomy for lung cancer were associated with lower preoperative FVC and FEV1 values and a lower skeletal muscle mass. Skeletal muscle mass, represented by the EM, was significantly correlated with the preoperative FVC and FEV1. Therefore, skeletal muscle mass may be useful for the prediction of PPCs in patients undergoing lobectomy for lung cancer.