Histopathologic changes of the radial artery wall secondary to transradial catheterization

OBJECTIVE The immediate effects of transradial access on the radial artery wall are unknown. In this study we sought to assess the histological changes induced by catheterization on the radial artery. METHODS Thirty-four patients undergoing coronary artery bypass grafting (CABG) had radial arteries harvested to serve as bypass conduits. The proximal and distal ends of the radial artery conduits were sectioned and embedded in paraffin. Both ends of all specimens were evaluated by a blinded pathologist for intimal hyperplasia, medial inflammation, medial calcification, periarterial tissue or fat necrosis, adventitial inflammation, adventitial necrosis, and adventitial neovascularization. Fisher's exact test was used for statistical analysis. RESULTS Fifteen previously catheterized radial arteries (TRA group) were compared with 19 noncatheterized arteries (NCA group). The distal ends of the TRA group showed significantly more intimal hyperplasia (73.3% vs 21.1%; p = 0.03), periarterial tissue or fat necrosis (26% vs 0%; p = 0.02), and more adventitial inflammation (33.3% vs 0%; p = 0.01) than the distal ends of the NCA group. The distal ends of the TRA group also showed significantly more intimal hyperplasia (73.3% vs 26.6%; p = 0.03) and adventitial inflammation (33.3% vs 0%; p = 0.01) than the proximal ends of the same arteries. There were no histological differences in the proximal ends of the two groups. CONCLUSION Transradial catheterization induces significant histological changes suggestive of radial artery injury limited to the puncture site in the form of intimal hyperplasia, medial inflammation, and tissue necrosis. Both the proximal and distal ends of the radial artery show a spectrum of atherosclerotic changes independent of its use for transradial catheterization.