A quantitative study of endothelial cell injury in aorto-coronary vein grafts.

Criteria indicating injury of endothelial cells (craters, protrusion, denudation) in saphenous veins for aorto-coronary bypass grafting have been examined and quantitated by use of light-(LM), scanning electron (SEM) and transmission electron microscopy (TEM). The specimens were fixed either by immersion or under pressure. It was shown that the conventional way of handling saphenous vein grafts prior to implantation results in serious damage of the endothelial lining. The factors responsible are presumed to be hypoxia, manual flushing and distension with isotonic saline for blood removal, control of leakage, and counteracting spasm of the graft. Even samples collected by a "no touch" technique and exposed to a short hypoxic interval sometimes revealed slight injury.