An improved technique for preservation of endothelial morphology in vein grafts.

Scanning electron microscopy was performed on 29 canine and two human veins prepared for vein grafting by means of various techniques. Endothelial morphology was best preserved when veins were pretreated with papaverine before excision, when a warm solution was used for dilatation, when the grafts were stored up to 1 hour either in a warm, nutritive medium (Dulbecco's modified eagles) or a cold, nonnutritive solution (saline), and when the grafts were maintained in the distended state. Distending pressure up to 500 mm Hg did not cause injury to veins prepared by these techniques. The use of cold solutions to distend veins was especially harmful.