Which is the best graft for the right coronary artery?

摘要

Abstract Bilateral internal mammary arteries directed to the left coronaries are gaining popularity; an increasing level of evidence nowadays supports this surgical strategy. On the other hand, composite right internal mammary artery, radial artery, and gastroepiploic artery targeting high-grade stenotic lesions in the right coronary artery system may confer improved mid-and long-term patency compared to long saphenous veins. This analysis looks into the evidence comparing data of the third best available conduit for grafting the right coronary artery, and by extrapolating this report, compares total arterial revascularization vs. conventional coronary artery bypass grafting. Although there are no available results of randomized trials regarding the superiority of the 2 internal mammary arteries (IMA) directed to the left coronary system, it is becoming evident that there is superiority of a right IMA graft compared to saphenous vein and radial artery (RA) as a second conduit, especially when bypassing severe native coronary disease.1'2 Flow competition has been the limiting factor of arterial conduits, and proximal coronary stenosis is the surrogate for competitive flow.3 The RA as well as the right gastroepiploic artery (GEA) supports much less flow competition than the IMA, leading to spasm and occlusion.4 Therefore, these two arterial conduits should be used only in critical lesions, to avoid graft occlusion. Saphenous vein grafts (SVG) on the other hand, are the only conduits not significantly affected by flow competition. So, if we agree that both IMA directed to the left coronary system provide optimal left-side revascularization, in this review, we will examine the existing evidence to answer the question as to which is the best available conduit to bypass the right coronary artery (RCA).