Abstract
This study was carried out to investigate if the University of Wisconsin solution (UWs) is suitable for long-term preservation of autogenous vein grafts (AVG) prior to transplantation, compared to autologous whole blood (AWB) and normal saline (NS). Autogenous jugular and femoral veins were harvested from adult mongrel dogs, using a "no-touch" technique. One segment of vein was immediately implanted to serve as a control, while other segments were stored for 24 hr at 4°C in AWB, NS, or UWs. The control and the preserved veins were implanted as reversed interposition grafts in the common carotid or femoral artery positions. After 6 weeks, scanning electron microscopy revealed an intact endothelial cell monolayer in all vein grafts that was stained positively for factor VIII. The degree of intimal thickening, as assessed by light microscopy in the middle position of the grafts, was similar in controls (52.0 ± 15.8 μm) and in veins stored in UWs (58.5 ± 16.1 μm), but it was significantly increased (P <0.05) in veins preserved in NS (198.9 ± 19.5 μm) and in AWB (312.0 ± 171.6 μm). Isometric tension studies revealed that maximum contraction and sensitivities (assessed by EC50) to norepinephrine were significantly reduced (P <0.05) in AVG stored in AWB (0.05 ± 0.02 g/mm2 and 5.5 ± 2.8 μM), but not in UWs (0.16 ± 0.03 g/mm2 0.92 ± 0.34 ±M) and NS (0.09 ± 0.03 g/mm2 and 3.0 ± 1.1 μM), compared with controls (0.17 ± 0.03 g/mm2 and 0.99 ± 0.38 μM). Acetylcholine (Ach)-induced maximum relaxations were similar in all of the veins. However, vessels stored in AWB were found to be more sensitive (P <0.05) to Ach (0.004 ± 0.002 μM) than those stored in UWs (0.042 ± 0.018 μM). Sodium nitroprusside produced similar responses in all of the veins. These data demonstrated that storage of veins in UWs for 24 hr prior to transplantation is more suitable than storage in AWB and NS for preserving the morphology and functional integrity of the smooth muscle and endothelium.