Background: The radial artery (RA) is being employed as coronary artery bypass graft with good results, but when it is proximally anastomosed to the ascending aorta, undergoes substantial hemodynamic changes which could lead to significant graft intimal hyperplasia. The aim of this study was to investigate the evolution of RA graft morphology over time.
Methods: We studied 20 patients with a perfectly patent RA graft at both 1 and 5 year angiography after coronary artery bypass graft.
Results: Both RA graft and grafted coronary artery diameters, assessed by quantitative coronary angiography, significantly increased at 5 years, in comparison to 1 year angiography (2.08 +/- 0.45 vs 2.54 +/- 0.53 mm, +22%, p < 0.001 and 1.92 +/- 0.47 vs 2.18 +/- 0.41 mm, +13.3%, p < 0.001, respectively).
Conclusions: Hemodynamic changes following RA employment for coronary artery bypass graft stimulate a remodeling of RA graft itself and of the grafted coronary arteries. The progressive increase of diameters observed in RA grafts strongly argues against the development of flow-limiting graft intimal hyperplasia when RA is proximally anastomosed to the ascending aorta. Moreover, grafted coronary artery dilation suggests that hemorrheologic changes following coronary artery bypass graft could play a major role in the development of RA remodeling over time.