The right internal thoracic artery graft - benefits of grafting the left coronary system and native vessels with a high grade stenosis

Objective: The left internal thoracic artery (LITA), when grafted to the le ft anterior descending artery (LAD), is generally accepted as the conduit o f choice for coronary artery bypass grafting (CABG). In contrast, the role and efficacy of the right internal thoracic artery (RITA), despite its long -term use as a coronary artery graft, is relatively less understood. Accord ingly, in this study, we sought to assess the utility of the RITA as a coro nary conduit by examining the long-term patency of both in situ and free RI TA grafts and analyzing the association between intraoperative graft and co ronary artery variables. Methods: Nine hundred and sixty-two patients (LITA 962, RITA 432) who had CABG between 1985 and 1998 and underwent re-angiogr aphy for evidence of myocardial ischemia were included in this observationa l analysis. The diameter of the internal thoracic artery (ITA), the presenc e of a proximal anastomosis with the aorta, the location of the anastomosis with the coronary artery, and the coronary artery diameter, were recorded at the initial procedure. The follow-up was 67.0 +/- 39.4 months (mean +/- SD, range 0.1-169.5). The relationship between intraoperative variables and graft patency was assessed using Cox proportional hazard models. Results: Highest RITA failure rates were associated with grafting a native coronary artery with a stenosis of less than 60% compared with 80-100% (RR 3.8 (95% CI, 1.9-7.2) P = 0.0001). Grafts to non-LAD arteries had a higher risk of f ailure, the highest risk ratio being associated with grafting the right cor onary artery (RR 4.0 (95% CI, 0.9-17.4) P = 0.06)). Free compared with in s itu grafts were also associated with a higher risk of failure with this res ult bordering on statistical significance (RR 1.9 (95% CI, 1.0-6.0) P = 0.0 6)) Conclusion: Preference should be given to grafting arteries with a high grade stenosis or occlusion, to grafting left rather than right coronary a rteries, and to using in situ rather than free ITA grafts. Passing the RITA to the left, either anterior to the aorta or through the transverse sinus, did not influence patency. (C) 2000 Elsevier Science B.V. All rights reser ved.