Digital blood flow after radial artery harvest for coronary artery bypass grafting

Despite widespread use of radial artery as a bypass conduit in coronary artery bypass surgery, flow readjustment that takes place in the hands and fingers after the removal of the radial artery is poorly understood.

Using pulse volume recording plethysmography, a semiquantitative measurement of digital blood flow was carried out in 24 patients 7 days after harvesting of radial artery for coronary artery bypass grafting. Measurements taken from the fingers of the operated arms were evaluated and compared with those taken from the opposite or the control arms.

Postoperatively, there was an overall decrease in blood flow to all the fingers of the operated arms. At the same time, there was evidence of redistribution of digital blood flow favoring the first two fingers over the last two, the same distribution pattern as seen in the fingers of the control arms. The pulse amplitude studies, likewise, showed a significant drop in all fingers of the operated arms, with the decrease most pronounced in the fourth and fifth fingers. None of the patients showed signs of digital ischemia postoperatively.

The study showed that there was an overall decrease in digital blood flow after radial artery harvesting. The resulting blood supply by way of the remaining ulnar artery still provided more flow to the first two fingers over the last two fingers, indicating the existence of an autoregulatory mechanism operating to satisfy the physiologic needs of the fingers.