An Evaluation of Pre-Operative Nutritional Assessment Methods in Patients with Chronic Limb Threatening Ischaemia Having Distal Bypass

Abstract

The purpose of this study was to evaluate the influence of pre-operative nutritional status on long term outcomes of patients with chronic limb threatening ischaemia (CLTI) after distal bypass. Patients who underwent distal bypass for CLTI from 2011 to 2020 at a single centre were reviewed retrospectively in Japan. Comparisons were made between patients with malnutrition and normal nutrition, as diagnosed by four nutritional assessments: Controlling Nutritional Status (CONUT), Geriatric Nutritional Risk Index (GNRI), Glasgow Prognostic Score (GPS), and Prognostic Nutritional Index (PNI). The primary endpoint was survival, and the secondary endpoints were graft patency, limb salvage, and wound healing. A total of 314 distal bypasses were performed in 249 patients (169 males; median age, 76 years; diabetes mellitus, 70%; and end stage renal disease with haemodialysis, 40%). Malnutrition was observed in 103 patients (41%) evaluated by CONUT, 129 (52%) by GNRI, 76 (31%) by GPS, and 114 (46%) by PNI. The survival rates in the study cohort were 81% at one year, 55% at three years, and 47% at five years. Malnutrition in all assessments was statistically significantly associated with reduced survival rate (CONUT, p < .001; GNRI, p= .002; GPS, p < .001; PNI, p < .001). In multivariable analysis, CONUT was the best predictor of mortality (p= .014). Malnutrition did not affect graft patency and limb salvage, but malnutrition based on CONUT, GNRI, and GPS was statistically significantly associated with reduced wound healing (CONUT, p= .002; GNRI, p= .006; GPS, p= .011). In multivariable analysis, CONUT tended to be the best predictor of wound healing (p= .061). Malnutrition in patients with CLTI with distal bypass was associated with overall mortality and incomplete wound healing. CONUT assessment was most effective for prediction of survival and wound healing. Distal bypass for CLTI patients with malnutrition may be suboptimal, and endovascular treatment may be recommended as an initial revascularisation method.