Effect of venous valves on grafts for coronary artery bypass.

The effect of venous valves on blood flow and patency in grafts of the long saphenous vein for coronary artery bypass is examined. Our experimental model involved both diastolic-predominant blood flow and transient systolic regurgitation, and the waveform was similar to that of in vivo coronary circulation. In this model, blood flow was assessed in the presence or absence of venous valves. It was found that coronary artery blood flow was significantly greater in the presence of venous valves. Angioendoscopy showed that the movement of the graft valves was strong and rhythmic. It seems that valve preservation may be desirable in grafts for coronary artery bypass.