FUNCTIONAL AND MORPHOLOGICAL EVALUATION OF CANINE VEINS FOLLOWING PRESERVATION IN DIFFERENT STORAGE MEDIA

Injuries of endothelial and smooth muscle cells of autologous vein due to preservation in standard storage media may be responsible for graf t failure, The effects of vein preservation with University of Wiscons in solution (UWs) on endothelial and smooth muscle cell function and m orphology were compared to the effects of preservation with autologous whole blood (AWE) and normal saline (NS), which are frequently used i n cardiovascular surgery. Canine external jugular and common femoral v ein segments were preserved in the different solutions at 4 degrees C for 45 min and 24 hr, Rings (4-5 mm in length) from control and preser ved veins were evaluated by isometric tension studies at 37 degrees C and by scanning and transmission electron microscopy, Differences betw een groups were evaluated by Student's t test or Mann-Whitney U test a nd by analysis of the variance, and considered to be significant at P < 0.05. Sensitivities to norepinephrine (NE) showed that a 45-min vein storage in AWB (5.7 +/- 0.2 mu mol/L) but not in NS (5.8 +/- 0.2 mu m ol/L) or UWs (6.5 +/- 0.2 mu mol/L) had a deleterious effect on functi on of smooth muscle (P < 0.05) when compared to control veins (6.6 +/- 0.2 mu mol/L). Maximum contractile responses and sensitivities to NE were significantly altered (P < 0.05) after 24-hr vein storage in AWE (0.09 +/- 0.02 g/mm(2) and 5.4 +/- 0.07 mu mol/L) and NS (0.12 +/- 0.0 3 g/mm(2) and 5.6 +/- 0.08 mu mol/L) but not in UWs (0.36 +/- 0.06 g/m m(2) and 6.4 +/- 0.07 mu mol/L). With both storage times, acetylcholin e-induced endothelium-dependent maximum relaxations and sensitivities were significantly reduced (P < 0.05) in veins stored in AWB and NS, b ut not in UWs, compared with controls. Similarly, transmission electro n microscopy revealed marked neutrophil migration beneath the intimal surface of vessels and extensive separation and desquamation of endoth elial cells with exposure of subendothelial structures in veins stored in AWB and NS, The results suggest that UWs is a suitable storage med ium when compared to AWE and NS. (C) 1997 Academic Press.