Short-term preservation of autogenous vein grafts: Effectiveness of University of Wisconsin solution

Background. Suboptimal preservation of autologous veins in storage solutions causes endothelial cell damage that can contribute to graft failure. The purpose of this study was to compare the effects of short-term storage of veins in autologous whole blood (AWB), 0.9% normal saline solution (NS), and University of Wisconsin solution (UWs) on vein structure and function after grafting. Methods. Autogenous jugular and femoral veins were atraumatically harvested from mongrel dogs. One vein segment was immediately implanted to serve as a control, and the other segments were stored for 45 minutes in AWB, NS, or UWs. The veins were implanted as reversed interposition graft in the carotid or femoral arteries. After 6 weeks light and scanning electron microscopy and isometric tension studies were performed on explanted vein grafts. Results. Morphologic studies revealed an intact endothelium that stained positively for factor VIII. Intimal thickness was similar between controls (42 ± 12 μm) and veins stored in UWs (53 ± 8 μm) (p = not significant), but it was significantly increased in veins stored in AWB (151 ± 29 μm) and NS (149 ± 18 μm) (p < 0.05). Sensitivity and maximum contraction to norepinephrine were not altered in veins preserved in UWs (6.0 ± 0.1 μmol/L and 0.19 ± gm/mm²) but were significantly reduced (p < 0.05) in those stored in AWB (7.2 ± 0.1 μmol/L and 0.08 ± 0.02 gm/mm²) and NS (7.0 ± 0.3 μmol/L and 0.09 ± 0.02 gm/mm²) compared with controls (5.9 ± 0.2 μmol/L and 0.20 ± 0.02 gm/mm²). The sensitivity and maximum relaxation to acetylcholine and sodium nitroprusside of veins preserved in AWB, NS and UWs were similar to controls (p = not significant). Conclusions. Vein storage in UWs preserves smooth muscle cell function compared with veins stored in NS or AWB. Therefore UWs is a more suitable medium for short-term preservation of veins in cardiovascular operation.