Development of an ex vivo model to investigate the effects of altered haemodynamics on human bypass grafts

Abstract

The insertion of vein grafts into the arterial circulation may contribute to vessel wall thickening and accelerated atherosclerosis, a common feature of late vein graft failure. We aimed to develop a model suitable for investigation of the effects of altered haemodynamics on human saphenous vein following its implantation into the arterial circulation. Segments of human saphenous vein obtained from patients undergoing coronary artery bypass surgery were sutured at each end to PTFE and placed into a flowsystem. Pressure and flowrates to stimulatethe arterial and venous systems were achieved. A theoretical model of the flowchamber was created and computational fluid dynamics software (FLOTRAN, Swanson Analysis Systems) was used to determine the flowprofile within the model. In summary, a flow model has been developed to investigate the effect of altered haemodynamics on the molecular and pathological changes that occur in vein grafts incorpor-ated into the arterial circulation.