Associations of CT-Detected Sarcopenia and Myosteatosis With Postoperative Outcomes After Emergency Abdominal Surgery: A Systematic Review and Meta-Analysis.

Emergency abdominal surgery, including emergency laparotomy, is associated with substantial postoperative morbidity and mortality. Preoperative computed tomography (CT), when already obtained for diagnostic purposes, can provide opportunistic information on skeletal muscle quantity and quality that may be relevant to perioperative risk assessment. This systematic review and meta-analysis evaluated the associations between CT-detected sarcopenia, myosteatosis, and related CT-derived muscle measurements and postoperative outcomes in adults undergoing emergency abdominal surgery. Eligible observational studies assessed CT-derived muscle measurements and reported at least one postoperative outcome. Ten CT studies were retained in the overall evidence synthesis. Across the available evidence, study-defined low muscle quantity (often termed sarcopenia) and low muscle quality or myosteatosis were associated with increased postoperative mortality and severe complications. Methodological and clinical heterogeneity, particularly variation in CT assessment methods and diagnostic thresholds, limited certainty. Opportunistic CT-derived muscle assessment may provide complementary risk information alongside established perioperative risk-assessment tools rather than replace them, but standardized definitions and prospective validation are required before routine clinical implementation.