Background : The use of both ITA as a Y-graft configuration has been proposed as a technique allowing complete arterial revascularization. Controversy however remains about the capacity of this Y-graft configuration to provide sufficient blood flow to the whole left coronary system and about possible steal phenomenon.
Methods and Results : To evaluate graft conductance six months after Y-graft revascularization of the left coronary system with both ITAs, 11 consecutive patients were studied during cardiac catheterization. Pressure and fractional flow reserve (FFR) were recorded distally in the left ITA main stem close to the proximal anastomosis of the free right ITA (ITA-stem), and in the distal part of each ITA branch at the site of their implantation to the LAD (ITA-LAD) or LCX (ITA-LCX) system. At each of these sites, the pressure gradient between aorta and the graft was measured in basal condition and during maximal hyperemia. In basal conditions, the pressure gradient was minimal between the aorta and the ITA-stem (2 ± 2 mmHg), the ITA-LAD (3 ± 3 mmHg) and the ITA-LCX (3 ± 2 mmHg; NS versus ITA-LAD). During maximal hyperemia, the pressure gradient increased to 7 ± 2 mmHg in the ITA-stem, to 9 ± 5 mmHg in the ITA-LAD and to 9±3 in the ITA-LCX (NS versus ITA-LAD). The FFR was 0.93 ± 0.03 in the ITA-stem, 0.91±0.04 in the ITA-LAD and 0.91 ± 0.03 in the ITA-LCX.
Conclusion : A Y-graft configuration with a free right ITA attached to a pedicled left ITA allows an adequate revascularization of the whole left coronary system. with an even distribution of perfusion pressure in both distal branches.