Radial Artery Comparable to Internal Mammary Artery for Coronary Bypass

The flow-mediated dilation and endothelial function of a radial artery graft is similar to that of a pedicled left internal mammary artery graft when used for coronary artery bypass, British investigators report.

Dr. Mahmoud Al-Bustami and colleagues from Harefield Hospital in the UK, evaluated angiographic findings in 36 patients 3 weeks and 6 months after they had undergone coronary artery bypass graft surgery (CABG) with grafts of both the radial artery and the left internal mammary artery.

As reported in the Journal of the American College of Cardiology for February 20, the first angiographic procedure showed that the baseline diameter of the radial artery increased by 0.170 mm with pacing at a sub-Wenckebach rate, and by 0.310 mm after intragraft injection of glyceryl trinitrate. For mammary artery, the corresponding increases were 0.206 mm and 0.304 mm.

At 6 months, the differences were 0.112 mm and 0.274 mm for the radial artery, while for the mammary artery they were 0.098 mm and 0.218 mm.

“These findings indicate that the thick wall of the radial artery has no detrimental effect on the baseline size of the radial artery, and that the artery is capable of responding to a long-term persistent increase in demand by increasing its baseline size,” the investigators write.

They point out that the time-dependent improvement in vasomotor response of the radial artery “could have implications for its performance as a coronary conduit.”

J Am Coll Cardiol 2002;39:573-577.