Supplementary Material for: Preserving endothelial integrity in human saphenous veins during preparation for coronary bypass surgery

While multiple factors influence coronary artery bypass graft (CABG) success rates, preserving saphenous vein endothelium during surgery may improve patency. Standard preparations include saphenous vein preparation in heparinized saline (saline), which can result in endothelial loss and damage. Here, we investigated the impact of preparing saphenous graft vessels in heparinized patient blood (blood) vs saline. Saphenous vein tissues from a total of 23 patients undergoing CABG were split into 2 groups: 1) saline and 2) heparinized patient blood. Excess tissue was fixed for analysis immediately following surgery. Level of endothelial coverage, oxidative stress marker 4-hydroxynonenal (4HNE), and oxidative stress protective marker nuclear factor erythroid 2-related factor 2 (NRF2) were evaluated. In saline patient veins, histological analysis revealed a limited luminal layer, suggesting a loss of endothelial cells (EC). Immunofluorescent staining of EC markers vascular endothelial cadherin (VE-cadherin) and endothelial nitric oxide (eNOS) identified a significant improvement in EC coverage in the blood vs saline groups. Although both treatment groups expressed 4HNE to similar levels, EC blood samples expressed higher levels of NRF2. Our data indicate that use of heparinized patient blood helps preserve the endothelium and promotes vein graft health. This has the potential to improve long-term outcomes in patients.