Loss of muscle mass: a significant predictor of postoperative complications in acute diverticulitis

Severe muscle mass depletion, sarcopenia, has been shown to be associated with poor operative outcomes. However, its impact on emergency abdominal operations remains unclear. The purpose of this study was to examine the association between low muscle mass (LMM) and outcomes after emergency operations for acute diverticulitis.

Patients ≥18 y requiring an emergency operation for acute diverticulitis between January 2007 and September 2014 were included. On preoperative computed tomography, the cross-sectional area (CSA) and transverse diameter (TVD) of the right and left psoas muscle were measured at the level of the third lumbar vertebral body. Sensitivity analysis was performed to determine appropriate CSA and TVD cutoff values defining low skeletal muscle mass. Clinical outcomes of patients with low muscle mass (LMM group) were compared with the non-LMM group.

A total of 89 patients met our inclusion criteria. Median CSA and TVD were 794 mm² and 24 mm, respectively. There was a strong correlation between the CSA and TVD (R² = 0.84). In univariable analysis, significantly higher rates of postoperative major complications (63% versus 37%, P = 0.027) and surgical site infection (47% versus 19%, P = 0.008) were identified in the LMM group. After adjusting for clinically important covariates in a logistic regression model, patients with LMM were significantly associated with higher odds of major complications and surgical site infection.

Preoperative assessment of the psoas muscle CSA and TVD on computed tomography can be a practical method for identifying patients at risk for postoperative complications.