BACKGROUND: Composite grafting techniques for coronary artery bypass grafts (CABG) have been widely used. However, it remains unclear whether this technique provides similar blood flow to the left coronary artery when compared to the conventional alternative. We sought to compare the total blood flow to the left coronary branches that are revascularized with left internal thoracic (LITA) and radial artery (RA) grafts using composite and non-composite techniques. METHOD: A total of 42 patients were randomly assigned to three groups according to the CABG technique to be used: Group A or composite LITA-RA in a Y format (n=14); Group B or modified composite LITA-RA [intercoronary graft with RA and LITA to RA at the level of the left anterior descending artery (LAD), n=14)]; and Group C or pedicled LITA to the LAD and aorto-coronary RA (n=14). The patients were submitted to postoperative blow flow velocity analysis using a 0.014 inch 12 MHz Doppler flowire. Coronary flow reserve (CFR) was calculated by determining the average hyperemic peak velocity (APV) after an injection of adenosine. RESULTS: Proximal LITA baseline APV was 28.4±4.8 cm/s in group A, 34.4±7.9 cm/s in group B (p=0.0384 x C) and 25.8± 8.6 cm/s in group C. The CFR was 2.1 ± 0.4, 2±0.3 and 2±0.4 in groups A,B and C respectively (p=0.7208 A, B x C). The total Q to LCA branches was 110±30 in group A, 145±59 in B and 133±58 mL/min in C (p=0.3232 A, B x C). CONCLUSIONS: The LITA-RA composite graft maintains an adequate CFR and conveys similar blood flow to the left coronary artery branches when compared with conventional CABG technique.
Mammary arteries; Radial artery; Blood flow velocity; Cardiovascular surgical procedures; Myocardial revascularization
