Angiographic results of the radial artery graft patency according to the degree of native coronary stenosis

Abstract

Objective: Radial arteries are gaining widespread acceptance as complementary arterial conduits for surgical myocardial revascularization, but there are limited reports about its angiographic patency compared with that of the internal thoracic artery or saphenous vein according to the degree of native coronary stenosis. Therefore, we tried to evaluate the mid-term angiographic results of the radial artery graft patency focusing on the native coronary stenotic status in a prospective manner.

Methods: From March 2000 to September 2006, a total of 488 patients underwent coronary artery bypass grafting using radial artery graft at our institution. From this group, 123 patients (mean age of 59.02+/-8.9 years (range 34-73 years)) were enrolled in the present study, and underwent a postoperative angiography after surgery (mean 32 months). The angiograms were assessed visually and quantitatively.

Results: A total of 382 distal anastomoses were performed and 352 anastomosis remained patent (92.1%). Left internal thoracic artery showed the most excellent patency in all of the conduits (128/129, 99.2%). Overall the radial artery graft patency was 92% (160/174). In the univariate analysis, patency was significantly worse for targets of the right coronary system (left coronary system 129/135, 94.4% vs right coronary system 31/39, 79.4%. p<0.05) and the radial artery graft showed a higher patency rate in the case of a severe stenotic lesion that preoperatively revealed more than 90% stenosis (defined as critical stenotic lesion) than in the case of a less severe lesion (50%<stenosis<90%) (100/102, 98% vs 60/72, 83.3%. p<0.05). The methods used for proximal anastomosis failed to affect radial artery patency (p=0.123). Multivariate analysis revealed the target vessel stenotic degree (50%<stenosis<90%) was closely related to radial artery graft failure (p=0.002, Exp (B)=0.067, CI=0.012, -0.373).

Conclusions: Regardless of the small study population, our data revealed that the radial artery conduit showed good midterm patency when it grafted to the critical stenotic lesion (over 90%). One might pay attention to the grafting strategy when the preoperative coronary angiogram reveals less than 90% of coronary stenosis, especially in the right coronary system but a larger and well-designed study should be warranted to confirm these findings.