Scanning electron microscopic study of endothelial damage resulting from vein graft contraction during preparation

Preservation of the endothelial lining of veins during preparation as grafts appears likely to play a critical role in subsequent early graft patency rates. 82 cephalic veins from 41 dogs were divided into 6 major groups by the type of heparinized vein preservation solution used. Veins were soaked for 5 min. or 1 hr. at either 10 degrees C or 20 degrees C in one of the following solutions with or without 60mg/100 ml of papaverine added: Plasma-Lyte 148 autologous blood, or Fluosol DA (an oxygenated perfluorocarbon emulsion). A segment was removed from each vein as soon as it was dissected free and perfused with fixative at 30 mm Hg as a control. In 4 additional dogs both cephalic veins were perfusion fixed in situ as further controls. SEM examination of the vein grafts' luminal surface after storage in the various preservation solutions showed that the greatest single cause of endothelial cell damage or loss was the extent to which the vein was permitted to undergo vigorous contraction during preparation and storage prior to use as an arterial graft. Preparation solutions which contained the smooth muscle cell relaxant papaverine, therefore, minimized endothelial protrusion and loss. In this regard Plasma-Lyte plus papaverine maintained at 20 degrees C was the most satisfactory of the solutions tested.