What is the best choice for third conduit when using bilateral internal mammary arteries for coronary artery bypass grafting—radial artery or saphenous vein graft?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'What is the best choice for third conduit when using bilateral internal mammary arteries for coronary artery bypass grafting-radial artery or saphenous vein graft?'. Altogether >525 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Overall, there was no survival benefit demonstrated with the use of a radial artery over the use of a saphenous vein graft as a choice of third conduit following bilateral internal mammary artery grafts for coronary artery bypass grafting. The main limitation of the current evidence available is the restricted follow-up periods and the high attrition rates with small sample sizes affecting the strength of conclusions that can be drawn beyond 10 years of follow-up. We conclude that despite previous evidence supporting improved long-term patency of radial arterial grafts, there is no strong evidence that the use of a radial artery, over a saphenous vein graft, has any survival benefit when used as the third conduit following bilateral internal mammary artery grafts.