Histological analysis of arterial and venous grafts used in coronary bypass for patients with renal insufficiency: A prospective multicentre observational study

Objectives: Chronic kidney disease (CKD) is associated with metabolic dysfunctions that accelerate atherosclerosis, posing significant challenges for patients undergoing coronary artery bypass grafting (CABG). In this population, arterial calcification and reduced saphenous vein patency are common complications. This multicentre prospective study aims to evaluate the impact of renal dysfunction on the histological characteristics of arterial and venous grafts used in CABG. Methods: Vascular graft specimens collected during CABG were prospectively analysed and stratified into 3 groups based on renal function, according to established publications: Group 1 (glomerular filtration rate [GFR] ≥90 mL/min/1.73 m ²), Group 2 (GFR 60-89 mL/min/1.73 m ²), and Group 3 (GFR ≤59 mL/min/1.73 m ²). Formalin-fixed samples were histologically assessed for intimal thickening (Grade 0-3), fibroelastosis, and vasa vasorum density. Results: A total of 324 arterial grafts (Group 1: 100; Group 2: 134; Group 3: 90) and 289 vein grafts (Group 1: 86; Group 2: 119; Group 3: 84) were analysed, including 5 arterial and venous grafts from dialysis patients. No significant structural differences were observed between groups. Intimal thickening rates were comparable across renal function stages. Fibroelastosis was more prevalent in venous grafts (56%-64%) than in arterial grafts (10%-15%). Conclusions: This study assesses graft histology in CABG patients stratified by renal function. At surgery, CKD does not appear to significantly alter graft structure. Further studies are warranted to explore long-term graft outcomes in this population.