Impact of reduced skeletal muscle volume on clinical outcome after esophagectomy for esophageal cancer: A retrospective study

The aim of the study was to clarify the impact of reduced skeletal muscle volume on the morbidity of patients who underwent esophagectomy for esophageal cancer. Malnutrition and reduced skeletal muscle volume, that is, presarcopenia, are reportedly associated with a high frequency of postoperative complications after esophagectomy. However, it remains unclear whether the reduction of skeletal muscle volume following esophagectomy may affect clinical outcomes including pneumonia occurred beyond the preoperative period. From February 2009 to June 2015, in 123 patients, we retrospectively evaluated the postoperative changes of the psoas muscle index (PI) on computed tomography and assessed their impact on the incidence of pneumonia after esophagectomy. There was a significant reduction in the PI 6 months after surgery compared to the preoperative value. The incidence of pneumonia as of 6 months after surgery was 23.6%, which was higher in patients of advanced age (P = .02), those with a lower body mass index (P = .02), and those with a greater reduction of PI during 6 months after surgery (P = .03). It was not associated with preoperative nutritional data, pulmonary function, operative procedure, and preoperative PI. Multivariate analysis demonstrated that age and postoperative PI reduction were independently associated with the incidence of pneumonia 6 months after surgery (hazard ratio [HR] = 2.92, 95% confidence interval [CI] 1.16–7.32, P = .02; HR = 3.25, 95% CI 1.15–9.15, P = .03, respectively). Patients with pneumonia 6 months after surgery had significantly poorer overall survival than those without pneumonia at that time. Postoperative reduction of skeletal muscle volume was independently associated with the occurrence of pneumonia beyond the preoperative period, which might indicate the importance of a postoperative nutritional support after perioperative period in esophageal cancer patients.