New Preservation Method Enhances Long-Term Success of Vein Grafts in Coronary Bypass Surgeries

In severe cases of coronary artery disease, blood flow to the heart is impeded, which can lead to a heart attack and heart damage. Surgeons improve blood flow to the heart by using veins from the leg to reroute the blood flow in the heart. During these procedures, surgeons remove a section of the vein and typically preserve it in a saline solution for two to four hours until it is needed. A decade or more after surgery, however, 50% to 60% of those grafts fail. Now, researchers have discovered that by preserving large superficial leg veins intended for coronary bypass grafting in a mixture of the anticoagulant heparin and blood, rather than heparin and saline, the veins were better protected from cell and tissue damage.

The findings of the collaborative study by researchers at the Fralin Biomedical Research Institute at VTC (Roanoke, VA, USA) and Carilion Clinic (Roanoke, VA, USA) could significantly impact surgical practices and improve the longevity of vein grafts in coronary bypass surgeries. These findings are expected to influence clinical practice and the development of new solutions for using saphenous vein grafts in the millions of patients who undergo coronary artery bypass graft procedures annually. For the study, surgeons and operating room staff at Carilion Clinic employed standard techniques to harvest blood vessels from patients’ legs for use during coronary bypass procedures. In about half the surgeries, veins were preserved in a heparinized saline solution, which is the standard care, and the remaining veins were preserved in heparinized arterial blood. Heparin is commonly used to reduce clotting.

The research indicated that preserving veins in heparinized arterial blood provided better nutrients while the veins were outside the body awaiting use as a bypass graft, resulting in a healthier endothelium. Microscopic analysis of saphenous vein graft tissues showed damage in saline-treated veins, while endothelial coverage improved when using the patient’s own heparinized arterial blood. The heparinized patient blood also offered protection against oxidative stress or tissue damage. In heart bypass surgery, success hinges on the health and quality of the saphenous veins. While some endothelial damage is inevitable, further research could help the veins remain as healthy, open, and unobstructed as possible.

“This particular study will shape our practice clinically,” said Mark Joseph, a cardiothoracic surgeon with Carilion Clinic. “It will set up additional studies in finding the optimal solutions to maintain and improve the health of saphenous vein integrity, and hopefully translate to improved outcomes for patients. In addition, it may also affect other aspects of patient care where saline is often used as a common intravenous solution and inform us of any detrimental effects it can potentially cause to other organ systems.”

Related Links:
Fralin Biomedical Research Institute at VTC
Carilion Clinic