Intraoperative storage of saphenous vein grafts in coronary artery bypass grafting

Background: Saline is not biocompatible with saphenous vein grafts and does not protect against ischemia reperfusion injury. We compared normal heparinized saline with DuraGraft, a new graft-storage solution, in in-vitro and ex-vivo assays to evaluate the effects on cells and vascular graft tissue.Methods: Human saphenous vein (HSV) segments and isolated pig mammary veins (PMVs) were flushed and submerged in heparinized DuraGraft or heparinized saline for prespecified times. Following exposure, HSV segments were evaluated for viability and tissue morphology, and PMVs underwent histological assessments, to evaluate vein morphology and effects on the vascular endothelium. The performance of saline versus DuraGraft was compared in an ISO-compliant biocompatibility assay for cytotoxicity.Results: Loss of HSV graft-cell viability was observed as early as 15 minutes post-exposure to saline whereas viability was maintained up to 5 hours’ exposure to DuraGraft. Histological analyses performed with PMVs demonstrated endothelial damage in PMVs stored in saline. Cytotoxicity assays demonstrated that saline-induced microscopically visible cell damage occurred within 60 minutes. DuraGraft-treated cells did not show evidence of damage or reactivity.Conclusions: Normal saline caused damage to vascular endothelium, loss of graft cell viability, and mediated cell damage; no evidence of damage or reactivity was observed in DuraGraft-exposed cells.