Total psoas area predicts medium-term mortality after lower limb revascularization.

ABSTRACT

BACKGROUND: Analytic morphometry is a novel concept in perioperative risk assessment. Low core muscle mass assessed by morphometry is associated with frailty and has been demonstrated to be an independent predictor of postoperative complications and mortality in oncologic, transplant, and aneurysm surgery. We aimed to study associations between core muscle mass and complication rates, length of hospital stay, and survival after surgical lower limb revascularization. METHODS: In this retrospective cohort study, 263 patients considered for surgical lower limb revascularization between January 2013 and December 2014 underwent cross-sectional imaging. Total psoas area (TPA) was measured on computed tomography angiograms at the level of the fourth lumbar vertebra by two independent observers blinded to clinical details. Clinical information was collected from patients' notes and the electronic medical record. Cox and logistic regression analyses were used to estimate the effect of clinical factors and psoas muscle area on survival, complication rates, and prolonged hospital stay after surgical lower limb revascularization. RESULTS: Data from 263 patients were analyzed. The American Society of Anesthesiologists score (hazard ratio [HR], 3.05; confidence interval [CI], 1.69-5.50; P < .001), emergency status (HR, 2.26; CI, 1.21-4.22; P = .011), lowest TPA quartile (HR, 1.89; CI, 1.07-3.35; P = .028), and Fontaine stage (HR, 1.63; CI, 1.04-2.53; P = .031) were found to be independent predictors of survival. Low TPA was not associated with increased rate of postoperative complications or prolonged hospital stay. CONCLUSIONS: Psoas muscle area may help identify patients with a shorter life expectancy after lower limb revascularization, but its role in predicting postoperative complications or length of hospital admission seems to be limited.