Role of venous grafts in combination with arterial grafting

Abstract

Since the first successful coronary artery bypass grafting (CABG) was performed using a saphenous vein graft at the Cleveland Clinic, the saphenous vein has become widely used as a coronary artery bypass graft [1]. From 1968, the internal mammary artery (IMA) became more widely applied as new surgical techniques evolved. Green [2] and Favaloro [3, 4] used a combination of single and bilateral IMA grafting, alone and in combination with saphenous vein grafting (SVG). However, the patency rates of SVG in the early reports were unsatisfactory. The occlusion rate of SVG in the first year is 10~26% [5, 6]. By 10 years, 50% of grafts are occluded [7-9] and of the grafts still patent, 50% show marked atherosclerotic changes [7]. In contrast, in an early study, the patency of the IMA within 5 years of operation was 97% with only 2% occlusion and 2% stenosis, compared to the patency rate of 82%, 5% stenosis or irregular, and 13% occlusion in SVG [9]. These reports confirmed the superior patency of arterial grafting and promoted the search for arterial conduits other than the IMA. Most recent reports from large series continuously support the superiority of IMA grafting. A report by Tatoulis and colleagues in Melbourne [10] has clearly shown in 2,127 arterial to coronary conduits over 15 years a LIMA patency at 5 years of 98%, 95% at 10 years, and 88% at 15 years. On the other hand, the average number of grafts in a patient is 3~4. Although the LIMA has been established as the first choice of the graft for coronary artery, other arterial grafts such as the right IMA, the gastroepiploic artery (GEA), the inferior epigastric artery (IEA), and the radial artery (RA) are routinely used by fewer surgeons. This means that SVGis stillwidely used in combination with arterial grafts. Recognizing the lower patency of SVG compared to arterial grafts, surgeons aremore cautious with the protection of the SVG during harvesting and in the careful choice of the target vessel. A number of techniques have been developed to protect the graft particularly the endothelium of the graft [11]. With these improved techniques, the patency rate for SVG has been reported to be better than that reported previously. Further, with the most important coronary branch - the LADgrafted by LIMA, the SVG is often grafted to other branches. Under such circumstances, the patient's survival is improved [12]. The role of SVG in the current practice of CABG should therefore be updated. © Springer-Verlag Berlin Heidelberg 2006.