Background: Saphenous vein grafts (SVG) and pedicled gastroepiploic artery grafts (GEA) are routinely used to revascularize the right coronary artery (RCA). Little is known about the predictive value of objective angiographic parameters on the 6-month graft patency.
Methods: We prospectively enrolled 154 consecutive patients candidates to coronary revascularization. Revascularization of the RCA was randomly performed with SVG in 77 patients and with the GEA in 77 patients. All patients underwent a systematic angiographic control 6 months after surgery. Angiographic parameters included minimal lumen diameter (MLD), percent stenosis and reference diameter of the RCA measured by quantitative angiography (CAAS II system), location of the stenosis, run off of the RCA and myocardial viability. The endpoint was graft patency and flow pattern.
Results: Flow patterns were categorized as graft-dependent (n=109), balanced (n=20), native-dependent (n=11) or occluded (n=14). In multivariate analysis, only MLD and run off were significantly associated with a graft-dependent flow pattern in patients treated with a GEA. In these patients, patency was significantly improved when MLD was below a threshold value of 0.76 mm. In patients treated with a SVG, multivariate analysis failed to demonstrate any significant association between angiographic parameters and flow pattern.
Conclusion: MLD of the RCA below 0.76 mm and a large run off predict a favorable flow pattern in GEA, whereas the commonly used criteria (percent stenosis and reference vessel size) do not. In SVG, the flow pattern is not influenced by any of these quantitative angiographic parameters.
Which angiographic parameters predict 6 month patency of bypass grafts implanted on the right coronary artery. A prospective randomized comparison of gastroepiploïc artery and saphenous vein grafts.