Sarcopenia and Myosteatosis as a Predictor of Post-Operative Outcomes in Patients Undergoing Laparotomy for Abdominal...

Background: Emergency laparotomy (EL) is related to a high risk of morbidity and mortality. Sarcopenia (low skeletal muscle mass) and myosteatosis (poor muscle quality) have emerged as prognostic indicators in various clinical contexts. This study evaluated the impact of these conditions on postoperative outcomes in patients undergoing EL for abdominal emergencies. Methods: A retrospective analysis was conducted on 242 patients who underwent EL between January 2016 and December 2023. Skeletal muscle index (SMI) and muscle radiation attenuation (MRA) were measured using CT imaging at the L3 level. Sarcopenia was defined as SMI ≤ 41.6 cm²/m² for men and ≤ 32 cm²/m² for women. Myosteatosis was defined as MRA ≤ 29.3 HU for men and ≤ 22 HU for women. Outcomes included 30-day mortality, hospital length of stay (h-LOS), severe complications (Clavien-Dindo ≥ 3), and Intensive Care Unit (ICU) admission. Results: Of the 242 patients (median age: 70; 51.2% men), 42.6% were sarcopenic and 78.1% had myosteatosis. Sarcopenia was not significantly associated with any postoperative outcomes. Conversely, myosteatosis was significantly associated with longer h-LOS (17 vs. 8 days; p < 0.001), higher rates of severe complications (37.1% vs. 22.7%; p = 0.048), and ICU admission (48.2% vs. 28.3%; p = 0.010), but not with 30-day mortality. Multivariate analysis confirmed myosteatosis as an independent predictor of prolonged hospital stay (HR 0.59, 95% CI: 0.42-0.84 p = 0.003). Conclusions: Myosteatosis, rather than sarcopenia, is associated with worse postoperative outcomes following EL for abdominal emergencies. Including myosteatosis in preoperative risk assessments may improve the identification of high-risk patients and guide perioperative management.