Arteries differ from veins both in morphology and physiology. Thus the way they behave as in vivo conduits when used in coronary artery bypass grafting is also likely to be different. This may partly explain the predisposition of veins used as coronary conduits to accelerated atherosclerosis in comparison with the internal mammary artery grafts. There are presently few data describing the properties of the radial artery as an in-vivo coronary conduit over the longer-term.