Should right coronary bypass grafts be anastomosed proximal or distal to the crux? A comparison of graft patencies

Abstract

Aim: Late occlusion of bypass grafts is one of the main issues associated with long-term survival after coronary artery bypass grafting (CABG) surgery. Left coronary system is generally revascularized using arterial conduits, whereas saphenous venous grafts are used for right coronary system. We investigated the prognostic factors that are related to the patency and risk of occlusion of saphenous venous grafts used for revascularization of diseased right coronary arteries.

Patients and method: 92 patients who underwent CABG operation including a right coronary artery (RCA) bypass using saphenous venous graft (SVG) between January 2003 and July 2010 were evaluated retrospectively. Mean time of follow up was 66.9 ± 27.2 months (range 104-13 months). Grafts patencies were investigated using coronary angiography, and associated risk factors for mortality and morbidity were determined during the mid-term and long-term follow up. During the data collection phase, a significant association was noticed between patency of right coronary bypass grafts and site of distal anastomoses on RCA. Thus, patients were divided into two groups, according to the site of anastomosis. Right coronary anastomoses were performed either proximal (Group A, n = 44) or distal (Group B, n = 46) to the crux of the RCA (PDA).

Results: Patency rates were similar in-group A (50% occluded and 50% patent) whereas patency rates were significantly higher in-group B (occluded 16.7%, patent 83.3%, p = 0.001). Mean age was significantly higher in-group A compared to Group B (p <0.05); however, there was no statistically significant difference between the two groups with regard to risk factors associated with cardiovascular disease (p >0.05). Also, mean diameter of the target vessel was significantly higher in-group A (p <0.01).

Conclusion: Based on the results of our study we suggest that even though an appropriate segment for anastomosis is available proximal to the crux of the RCA, right posterior descending artery (PDA) should be preferred for revascularization when RCA is the target vessel in CABG.