Preoperative Nutritional Status is an Independent Predictor of the Long-Term Outcome in Patients Undergoing Open Bypass for Critical Limb Ischemia

Abstract

The nutritional status before treatment has been reported to be significantly associated with the prognosis of patients with various diseases. The aim of this study was to examine whether or not this applies to patients undergoing open bypass for critical limb ischemia (CLI). The preoperative nutritional status of patients who underwent de novo infrainguinal bypass for CLI from January 2000 to December 2017 was retrospectively evaluated using the geriatric nutritional risk index (GNRI) and controlling nutritional status (CONUT) score. Patients were divided into 4 groups based on the GNRI or CONUT score; group I, normal nutrition; group II, mild malnutrition; group III, moderate malnutrition, and group IV, severe malnutrition. The amputation-free survival (AFS), overall survival (OS), and limb salvage (LS) rates up to 5 years were calculated by Kaplan-Meier method and a Cox proportional hazard regression analysis was performed to elucidate whether or not the nutritional indices were independently associated with these outcomes. A total of 373 patients were included. The median observation term was 969days. There were significant differences in the AFS and OS of the 4 groups divided based on the GNRI and CONUT score. The 2- and 5-year AFS rates of groups I, II, III, and IV, divided based on the GNRI, were 81% and 56%, 72% and 48%, 56% and 27%, and 56% and 12%, respectively (P<0.001), while those based on the CONUT score were 75% and 55%, 72% and 41%, 50% and 6%, and 30% and 30%, respectively (P<0.001). The GNRI (groups III+IV) was an independent predictor of AFS (Hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.27-2.69; P<0.001) and OS (HR, 2.26; 95% CI, 1.50-3.41; P<0.001), while the CONUT score (groups III+IV) was also an independent predictor of AFS (HR, 1.68; 95% CI, 1.13-2.49; P=0.011) and OS (HR, 1.64; 95% CI, 1.07-2.49; P=0.024). However, neither nutritional index was an independent predictor of LS. The preoperative nutritional status, as measured by the GNRI or CONUT score, was significantly associated with AFS and OS in patients undergoing infrainguinal bypass for CLI.