University of wisconsin solution and human saphenous vein graft preservation: Preliminary anatomic report

Endothelial damage of human saphenous vein (HSV) during the preparation for bypass grafting could affect graft patency. Improving the preservation of HSV could provide a longer and better patency of coronary artery bypass grafts. An electron microscopic comparative analysis of the effects of three different preservatives on HSV morphology was carried on in order to determine the best method to prevent or minimize possible endothelial damage. Distal segments of HSVs were harvested from 15 patients with a “no-touch” technique. Each segment was divided into seven specimens after a low pressure distension with saline solution. The first of them was fixed immediately after harvesting with 2.5% glutaraldehyde solution, for basal evaluation. Three were fixed after 30 min and three after 5 h preservation at 4 OC in a) autologous, oxygenated, and heparinized blood (AOHB), b) heparinized saline solution with papaverine (HSSP) and c) University of Wisconsin solution (UWS). The specimens preserved in AOHB showed marked endothelial cell detachment and endothelial celI loss after both preservation times (30 min and 5 h). The specimens preserved in HSSP for 30 min showed no alteration in endothelium in 12 cases, while a partial endothelial detachment with intracellular edema was present in the last 3 cases; all 5 h specimens showed only a few remnants of endothelial cells. The specimens preserved in UWS for 30 min showed a morphology comparable to specimens preserved in the saline solution for the same time; in the 5 h specimens a well preserved endothelium was found in 11 cases and partial endothelial detachment and subendothelial edema in the other 4. These data suggest blood solution as the least likely to preserve venous endothelium. Saline and Wisconsin solutions show analogous data after 30 minutes preservation, while UWS was better after 5 h.