Improvement in forward coronary blood flow by using a reversed saphenous vein with a competent valve.
Reversed segments of saphenous vein have been the grafts of choice for aortocoronary bypass (ACB). Internal mammary arteries and free radial autografts have recently been shown to have a higher ppatency rate, but flow is usually lower. Normally forward coronary blood flow ceases and retrograde flow occurs during cardiac systole. Prevention of retrograde flow with a rapidly acting valve proximal to the coronary artery anastomosis should improve forward coronary blood flow. Thirty-nine reversed saphenous veins containing a competent valve were implanted in 32 patients undergoing ACB. After accurate zero flow was determined and a resting state achieved, mean (22 veins) and pulsatile (17 veins) flows were measured distal to the valve with the valve competent and temporarily incompetent. A competent valve in 10 right coronary artery vein grafts increased mean flow by 29.7% (+41 ml/min; p less than 0.005) and pulsatile flow in 6 veins by 17.7% (p less than 0.001). A competent valve in 12 left coronary artery vein grafts increased mean flow by 31.3% (+34 ml/min; p less than 0.01) and pulsatile flow in 11 veins by 13.7% (p less than 0.001). This study suggests that a portion of reversed saphenous vein containing a competent valve provides greater coronary artery blood flow than veins without valves and may be the conduit of choice for coronary artery revascularization.
D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass / Q000379:methods*; D003326:Coronary Circulation; D005069:Evaluation Studies as Topic; D006801:Humans; D012501:Saphenous Vein; D014182:Transplantation, Autologous; D014680:Veins / Q000637:transplantation*