A Semi-Automated Assessment of Radiographic Sarcopenia Using Psoas Area and Density Predicts Outcomes after Pancreaticoduodenectomy for Malignancy

Abstract

INTRODUCTION: Sarcopenia has been associated with increased adverse outcomes after major abdominal surgery. Radiographic sar-copenia defined as decreased muscle volume or increased fat infil-tration may be a proxy for frailty. In conjunction with other preoperative clinical risk factors, radiographic measures of sarcope-nia using both muscle size and density may enhance prediction of outcomes after pancreaticoduodenectomy (PD) for malignancy. METHODS: Preoperative CT scans of patients undergoing PD for malignancy were analyzed from a prospective pancreatic surgery database. Sarcopenia was assessed both manually and with a semi-automated technique by measuring the total psoas area index (TPAI) and average Hounsfield units (HU) at the L3 lumbar level to estimate psoas muscle volume and density, respectively. Adjusting for known preoperative risk factors, preoperative sarcopenia measurements were analyzed relative to perioperative outcomes. RESULTS: On univariate analysis of 116 patients, lower TPAI (odds ratio [OR] 0.34, p=0.009) and HU (OR 0.84, p=0.002) measurements were predictive of discharge to SNF, but not major complications, length of stay, readmissions, or recurrence. Higher TPAI increased the risk of organ/space surgical site infection (SSI) including pancreatic fistula (OR 3.12, p=0.019). On multivariate analysis, the semi-automated measurements of TPAI and HU remained as inde-pendent predictors of organ/space SSI including pancreatic fistula (OR 3.33, p=0.036) and discharge to SNF (OR 0.79, p=0.02). CONCLUSIONS: When combined with preoperative clinical as-sessments in patients with pancreatic malignancy, semi-automated radiographic sarcopenia metrics may enhance prediction of outcomes after PD such as pancreatic fistula and discharge to a SNF and help guide clinical management.