Coronary bypass revascularization with radial artery and internal mammary artery grafts

To evaluate radial artery (RA) and internal mammary artery (IMA) grafts in coronary artery bypass and the use of color Doppler ultrasound in the peri-operative evaluation of IMA and radial-ulnar collateral circulation.

From June 1998 to June 2000, sixty cases of coronary bypass revascularization with RA and IMA were performed. Preoperatively, the radial-ulnar collateral circulation was evaluated with the modified Allen's test, color Doppler ultrasound and noninvasive oxygen saturation measurement. The IMA lumen and blood flow were measured at the first intercostal space with color Doppler ultrasound preoperatively and postoperatively.

One patient (1.7%) died of serious cardiac arrhythmia on the fourth postoperative day. There were no arterial graft harvest related complications. Before harvesting, the ulnar artery blood flow was 30.78 +/- 9.71 ml/min, and it increased to 43.36 +/- 13.98 ml/min (40.87% increase, P < 0.01) after the operation. Compared with the baseline, there was no obvious change of IMA blood flow postoperatively (P > 0.05), but the systolic/diastolic flow ratio markedly decreased from 8.57 +/- 3.98 ml/min to 3.41 +/- 4.87 ml/min (P < 0.01).

Arterial grafts can be safely used for coronary bypass revascularization with good results. The ulnar artery blood flow can increase compensatively after RA harvesting. The diastolic blood flow of grafted IMA markedly increased postoperatively. Color Doppler ultrasound was very helpful both in evaluating the radial-ulnar collateral circulation before RA harvesting and in assessing the patency of the grafted IMA after coronary artery bypass grafting (CABG).