λ Graft with the radial artery or free left internal mammary artery anastomosed to the right internal mammary artery: Flow dynamics

Background. The aim of this study was to evaluate the outcome and flow dynamics of the λ graft configuration, relative to a second arterial graft. Methods. From 1998 to 2000, 47 patients (mean age 55.5±4.7 years) with triple-vessel disease underwent arterial revascularisation using the λ graft. The in situ left internal mammary artery (LIMA) and right internal mammary artery (RIMA) were anastomosed to the left anterior descending (LAD) and obtuse marginal arteries, respectively. In 21 patients (group I) presenting proximal or middle-third LAD or right coronary (RC) arterial stenoses, the λ graft was constructed by anastomosing the distal LIMA, as a free LIMA graft, to the RC and proximally to the in situ RIMA. In the other 26 patients (group II) presenting with middle-distal third LAD or RC arterial stenoses, the radial artery (RA) was used to construct the λ graft. All patients underwent transthoracic echo color Doppler before and after an adenosine test at 1 week and 3 months after operation. Results. There were no hospital deaths. Overall, 47 λ grafts were constructed. There was no difference between baseline and maximal flows and coronary flow reserve (CFR) between groups. CFR at IMA stems increased in both groups within 3 months versus 1 week [^LIMACFR=2±0.3 vs 2.3±0.3 (p=0.002) and ^RIMACFR=2.2±0.4 vs 2.5±0.3 (p=0.009) in group I, and ^LIMACFR=2.12±0.33 vs 2.4±0.35 (p=0.005) and ^RIMACFR=2.17±0.32 vs 2.52±0.26 (p=0.001) in group II]. At 3 months versus 1 week, the ^RIMAdiameter_i (mm) at rest was 1.69±0.32 versus 1.48±0.2 (p=0.015) in group I and 1.66±0.3 versus 1.47±0.2 (p=0.01) in group II. At 6±2.4 months, all patients were free of angina. Conclusions. These data, almost identical for free LIMA and RA to RIMA using the λ graft, demonstrate that RIMA flow reserve is adequate for multiple coronary anastomoses irrespective of the second arterial graft.