Effect of diminished distal blood flow on the morphologic changes in autogenous vein grafts.

Histologic changes in canine autogenous femoral veins were studied after interposition into the femoral artery. After a 50 per cent reduction of distal blood flow, marked fibrosis of the intima, causing narrowing of the intima and focal destruction of the internal elastic membrane and media, were found in the vein graft and the adjacent arterial segment. These changes are probably due to abnormal intraluminal pressure of femoral artery and interposed vein graft following constriction.