Elevated Preoperative Neutrophil-lymphocyte Ratio is Asociated with Poor Patency and Major Adverse Limb Events After Infrainguinal Bypass Surgery Revascularization

Abstract

Introduction: High neutrophyl-lympochyte ratio (NLR) is associated with the pro-inflammatory status that surrounds atherosclerosis. NLR has also been related to the clinical severity and prognosis of peripheral arterial disease. Our aim is to analyse the influence of this pro-atherosclerotic marker on infrainguinal bypass surgery patency and clinical outcomes. Methods: Retrospective analysis of 150 infrainguinal bypasses. The clinical indication was critical limb ischemia in n=100 (66’7%) procedures. A preoperative blood sample of each patient was obtained 24 hours before the procedure was performed. These samples were used to calculate NLR. Our cohort was stratified in 4 group according to NLR interquartile ranges. (Quartile 1 [Q1] n=37; Quartile 2 [Q2] n=38; Quartile 3 [Q3] n=38: Quartile 4 [Q4] n=37). Patency and amputation rates at 30 days were compared between groups using the Chi-Square test. Patency, limb salvage and overall survival at 24 months were calculated by means of Kaplan-Meier test. Freedom from “major adverse limb events” (MALE) and from “major adverse cardiovascular events” (MACE) at 24 months were also analysed. Comparisons between groups were performed using Log-Rank test for a P < .05 in 2-tailed test. Results: Patency and amputation rate at 30 days were similar between the studied groups. Primary patency of the Q4 group at 24 months was inferior to the primary patency observed in the rest of the cohort (47% vs. 67%; p=0.01). We also found a tendency towards a lower assisted-primary patency at 24 months in the Q4 group (62% vs. 75%; p=0.08). Limb salvage (70% vs. 85%; p=.03) and freedom from MALE (62% vs. 79%; p=0.01) at 24 months were inferior in the Q4 group. Freedom from MACE and overall survival rates were similar between groups. Conclusion: Preoperative NLR is associated with major adverse limb events and lower long term patency rates after infrainguinal bypass surgery revascularization. Future prospective studies are required to determine its clinical utility.