Comparative Study On The Morphometry And Molecular-Biology Of Radial Artery Conduits In Patients Undergoing Coronary Artery Bypass Grafting With Diabetes Mellitus

The radial artery (RA) has become a popular conduit for coronary artery bypassgrafting (CABG), particularly as part of an “all arterial” grafting strategy. It has beenshown that RA has good early and mid-term patency,[1]and may have superiorlong-term patency.[2,3]Coronary artery disease is more common in individuals with diabetes mellitus(DM) than in those without, and a large population of the former needs CABG.Although DM is considered a risk factor for RA disease, the incidence of disease inthe diabetic RA has not been widely investigated, and the effects on its molecularbiology are even less clear. In this study, we compared RA pathology between CABGpatients with DM and non-diabetic patients using hematoxylin and eosin (H&E) staining and transmission electron microscopy. We also sought to investigate whetherDM has any negative effects on RA endothelial function in diabetic patients bydetermining the expression of endothelial nitric oxide synthase (eNOS), andendothelin-1(ET-1) and von Willebrand factor (vWF) mRNA.We studied the impact of diabetes mellitus (DM) on the radial artery (RA) in30patients with DM and30non-diabetic patients undergoing coronary artery bypassgrafting with autologous RA. The RA was normal in26.7%of diabetic and76.7%ofnon-diabetic patients (P=0.000298). Intimal thickness index and intima:media ratiowere higher in the former than in the latter (0.89±0.26vs.0.30±0.27, t=8.62, p <0.05;0.89±0.22vs.0.39±0.20, t=9.21, p <0.05). Electron microscopy scores werelower in the non-diabetic group (1.38±0.2vs.4.53±0.3, t=27.63, p <0.001); eNOSprotein expression and optical density were higher(1.33±0.25vs0.54±0.10, t=9.82,p <0.001). von Willebrand factor and endothelin-1mRNA levels were higher in theDM patients (t=5.14, p=0.006807; t=9.81, p=0.000780). The quality of the RA inpatients with DM was thus inferior to that in non-diabetic patients.In this study, there exists intimal hyperplasia in diabetic radial arteryaccompanied by atherosclerotic damage. It was possible that these morphologicalchanges related to the low level of eNOS and high levels of vWF and ET-1. It mayprovide molecular biologic therapeutic targets for the postoperative narrow of radialartery conduits in diabetic patients.