Relationship of preoperative low muscle mass with postoperative loss of independence after hepato-biliary-pancreatic surgery in elderly patients: a single-center retrospective study

Numbers of patients undergoing hepato-biliary-pancreatic (HPB) surgery are increasing worldwide. However, elderly patients may experience loss of independence (LOI) postoperatively due to the marked invasiveness of surgical procedures. This retrospective cohort study aimed to investigate clinical characteristics of elderly patients including preoperative low skeletal muscle mass before HPB open surgery for malignancy, and the association between low skeletal muscle mass and LOI postoperatively. Patients aged 65 or older who underwent open curative resection for HPB malignancies in our institution between September 2021 and October 2024 were selected. Skeletal muscle index was measured preoperatively using bioelectrical impedance analysis. Characteristics of patients with low muscle mass (< 7.0 kg/m² for males or < 5.8 kg/m² for females) and risk factors for LOI were evaluated retrospectively. Of 148 eligible patients, 15 (10.1%) experienced postoperative LOI. The rate of LOI in patients with low muscle mass was significantly higher than in those without it (8 (20%) vs. 7 (6.5%); p = 0.0306). Prolonged surgical time (OR = 2.63; 95% confidence interval [CI], 1.40–5.60; p = 0.0016), severe postoperative complication (OR = 2.40; 95% CI, 1.32–4.50; p = 0.0039), preoperative loss of muscle mass (OR = 1.98; 95% CI, 1.06–3.80; p = 0.0303) were independent factors for postoperative LOI. Patients with low skeletal muscle mass tend to experience LOI. Measurement of muscle mass might help identify patients at risk of postoperative LOI.