Sarcopenia, as Assessed by Psoas Cross-Sectional Area, Is Predictive of Adverse Postoperative Outcomes in Patients Undergoing Colorectal Cancer Surgery

Abstract

Background: Frailty and sarcopenia are important concepts in surgical practice because of their association with adverse postoperative outcomes. Radiologically assessed psoas muscle mass has been proposed as a surrogate for sarcopenia and may be predictive of poor postoperative outcomes. Objective: This study aimed to determine the association between sarcopenia, as assessed by psoas cross-sectional area, and postoperative outcomes in patients undergoing colorectal cancer surgery. Design: This was a retrospective review of patient records from 2014 to 2016. SETTINGS: This study was conducted at a single tertiary center. Patients: Patients undergoing elective resection of colorectal cancer were included. Main Outcome Measures: Sarcopenia was assessed using the total psoas index, calculated by measuring the cross-sectional area of the psoas muscle at the third lumbar vertebra and normalized for patient height. Preoperative and intraoperative variables, including the presence of preoperative sarcopenia, were evaluated as potential risk factors for adverse postoperative outcomes. Results: Of 350 patients, 115 (32.9%) were identified as sarcopenic. Sarcopenia was associated with a significantly increased length of stay (13 days vs 7 days; OR, 1.31; 95% CI, 1.23-1.42; p < 0.01) and 1-year mortality (13.9% vs 0.9%; OR, 16.2; 95% CI, 4.34-83.4; p < 0.01). Sarcopenia was also associated with a significant increased risk of any complication (85.2% vs 34.5%; OR, 15.4; 95% CI, 8.39-29.7; p < 0.01) and of major complications (30.4% vs 8.9%; OR, 15.1; 95% CI, 7.16-33.2; p < 0.01). Limitations: This study was limited by its retrospective design and by being conducted in a single institution. Although reduced muscle mass is suggestive of sarcopenia, it does not assess a patient's physical function or other components of the frailty phenotype. Conclusion: Radiological sarcopenia is an important predictive risk factor for adverse postoperative outcomes in surgical patients. Computed tomography scans, which are routinely performed as part of staging, provide an opportunity to assess for sarcopenia preoperatively.