A Systematic Review and Meta-Analysis of Perioperative Muscle Wasting Following Major Abdominal Surgery

Muscle wasting in the perioperative period is a frequent and clinically significant complication following major abdominal surgery and is associated with adverse outcomes, including increased postoperative complications, prolonged hospitalisation and worsened mortality. Despite its prevalence, the magnitude and course of perioperative muscle wasting (POMW) remain incompletely understood, and current interventions are limited. Current definitions applied to sarcopenia do not suitably apply to cohorts undergoing major abdominal surgery, and therefore, we propose the concept of POMW, defined as POMW within 6 weeks of surgery. These systematic review and meta-analysis aim to assess the extent of POMW and synthesise evidence on its clinical impact and potential interventions.

The electronic databases MEDLINE, EMBASE and Cochrane CENTRAL were searched from their inception to June 2025. Studies with preoperative and postoperative assessments of muscle wasting and/or function within 6 weeks of major abdominal surgery were included. Methodological quality and risk of bias were assessed with the Revised Cochrane model and Newcastle-Ottawa Scale, where appropriate. Meta-analysis was conducted using a random-effects model, with standardised mean changes (SMCs) as effect size metrics. The primary outcome was change in skeletal muscle mass/size within 2 and 6 weeks postoperatively, and the secondary outcome was change in muscle strength.

A systematic review identified 45 studies (n = 5283 patients) evaluating perioperative changes in skeletal muscle mass/dimensions and/or function within 6 weeks of major abdominal surgery. A meta-analysis of 17 studies (n = 2213 patients) was conducted, and significant reductions in muscle mass/size were observed at ≤ 2 weeks (SMC = 0.34; 95% CI: 0.19-0.49) and 3-6 weeks postoperatively (SMC = 0.39; 95% CI: 0.24-0.54). Muscle strength, primarily assessed via handgrip dynamometry, also declined significantly (SMC = 0.79; 95% CI: 0.12-1.46). Heterogeneity was high but findings remained robust in sensitivity analyses. Functional impairments and greater muscle wasting were consistently associated with poorer clinical outcomes.

POMW is common, rapid in onset and clinically relevant. Current management strategies are inadequate. There is an urgent need for early identification, standardised monitoring and targeted interventions to prevent postoperative functional decline and improve surgical outcomes. PROSPERO Registration: CRD420250606177.