Effect of target artery location and severity of stenosis on mid-term patency of aorta-anastomosed vs. internal thoracic artery-anastomosed radial artery grafts.

Objective: To verify the effect of location and severity of stenosis of the target coronary artery (TCA) on mid-term patency of aorta-anastomosed vs. internal thoracic artery (ITA)-anastomosed radial artery (RA) graft.

Methods: During a 3-year period 228 consecutive patients received an RA graft at our institution. In 131 cases the RA was anastomosed to the aorta whereas in 97 the proximal anastomosis was performed on a mammary graft. The two groups were comparable in terms of preoperative variables and TCA characteristics. At a mean follow-up of 6.5 years 128 cases of the aorta-anastomosed and 95 of the mammary-anastomosed group were submitted to control angiography.

Results: Mid-term patency and perfect patency rates were 92.1 and 89.8% (118/128 and 115/128) for aorta-anastomosed RA vs. 86.3 and 84.2% for mammary-anastomosed grafts (82/95 and 80/95; P=0.81 and 0.82). The location of TCA did not influence graft patency in the two groups. The severity of the TCA stenosis strongly influenced graft patency in both groups but the threshold for failure was clearly higher in the mammary-anastomosed group.

Conclusions: ITA-anastomosed RA grafts are more vulnerable to the detrimental effect of chronic native competitive flow and should be used only for target vessel with subocclusive stenosis. The location of the distal anastomosis does not influence long-term RA patency.