Long-term outcome of revascularization with composite T-grafts: Is bilateral mammary grafting better than single mammary and radial artery grafting?

Objective Bilateral internal mammary artery (BIMA) grafting is associated with improved survival. However, many surgeons are reluctant to use this technique, owing to the potentially increased risk of sternal infection. The composite T-graft with radial artery (RA) attached end-to-side to the left internal mammary artery (IMA) provides complete arterial revascularization without increased risk of sternal infection. The purpose of this study is to compare outcomes of these 2 strategies. Methods Patients who underwent BIMA grafting using the composite T-graft technique, between 1996 and 2010 (n = 1329), were compared with 389 patients who underwent composite grafting with a single IMA + RA during the same time period. Results Patients undergoing single IMA grafting were older, more often women, and more likely to have diabetes, peripheral vascular disease, and COPD, and to need an emergency operation. Congestive heart failure, left main disease, and recent myocardial infarction were more prevalent with bilateral grafting. Propensity-score matching was used to account for differences between groups in preoperative patient characteristics. The 268 matched pairs had similar characteristics. The median follow-up time was 14.19 (95% confidence interval 13.43-14.95) years. Operative mortality and Kaplan-Meier 10-year survival of the 2 matched groups were similar (3.4% vs 3.7%, and 61.6% vs 64%, for the groups treated with BIMA and single IMA, respectively). Cox-adjusted survival was similar (P =.514). Age, chronic renal failure, and performance of <3 bypass grafts were independent predictors of decreased survival. Conclusions This study suggests that long-term outcomes of arterial revascularization with a composite T-graft constructed using left IMA and RA are not inferior to outcomes after BIMA grafting.