Choice of conduits for coronary artery bypass grafting: craft or science?

Long-term patency of a bypass graft is an important determinant in reducing morbidity and increasing survival after coronary bypass surgery. The purpose of this review is to analyse factors contributing to improved outcomes of commonly used conduits. Progress has been limited by the lack of uniform definitions of graft failure and development of appropriate statistical models. Evolving techniques for assessing patency at more frequent intervals has provided insight into the time and sites of early disease. The explosion of scientific knowledge of graft physiology has added to improving harvest, storage and early protection procedures thereby reducing early morbidity. Similarly, the understanding and management of risk factors have contributed to graft durability and possibly survival. Conduits have different characteristics and applications, which are patient dependent. Competitive flow remains a problem especially with arterial conduits; functional studies as opposed to anatomy of the target artery may improve understanding of the contribution of the collateral circulation. Selected patency data provide comparison between grafts. The role of the second internal thoracic artery graft is the subject of the Arterial Revascularisation Trial. Off-pump bypass procedures and patient characteristics affect conduit selection. Stroke is a major complication, which can be minimised by avoiding the aorta especially during off-pump surgery. There are few randomised controlled trials on the late outcomes comparing different bypass grafts and between bypass grafting and current percutaneous intervention methods. Accurate reporting of outcomes of graft patency will improve the scientific content and emphasise the importance of surgery in the management of coronary disease.