Biologic fate of valves in reversed and nonreversed arterial vein grafts.

The cusps of valve-bearing segments of canine cephalic, femoral, and jugular veins were completely divided and were used in interposition grafts in the femoral and carotid arteries in the nonreversed position. Three control grafts had intact valves in the reversed position, and one control graft in the reversed position had division of the leaflets. Nine grafts were studied up to 2 months postoperatively with gross and microscopic observations. The cusp tissue, which shrinks immediately after complete division, disappears very early in the postoperative period in the reversed and nonreversed positions. Two reversed intact valves were still grossly microscopically normal 5 and 7 weeks postoperatively. The complete disappearance of the divided valve with a nonreversed coronary graft 101/2 months postoperatively has been documented at autopsy for the first time in a human subject. The significance of these findings and the superiority of the valveless nonreversed autogenous vein graft in clinical cardiovascular surgery has been discussed.