PRESERVATION OF HUMAN LIVER GRAFTS IN UW SOLUTION - ULTRASTRUCTURAL EVIDENCE FOR ENDOTHELIAL AND KUPFFER CELL ACTIVATION DURING COLD ISCHEMIA AND AFTER ISCHEMIA-REPERFUSION

Biopsies taken from 13 human liver grafts at different stages of the t ransplantation process were used for study of the morphology of sinuso idal cells prior to harvesting (5 biopsies), after preservation in UW solution (10 biopsies), and after complete revascularization (13 biops ies). The mean cold ischemic period was 12 h 30. Immediate follow up w as uneventful and the mean peak of post-operative transaminases below 1300 IU/l. Biopsies were perfusion-fixed by the transparenchymal route to ensure satisfactory ultrastructural results. There were no loose s inusoidal endothelial cells in the lumen and no signs of cellular deat h. Some endothelial cells presented signs of activation at the end of the preservation period, and even more after revascularization, with n umerous lucent vacuoles resembling endosomes in the cytoplasm. Kupffer cells also presented signs of activation, particularly after reperfus ion. The retraction of endothelial cell processes which formed large g aps during cold ischemia proved to be partly reversible after reperfus ion. Signs of endothelial cell damage with gaps and partial rupture of the plasmic membrane were also observed, particularly after revascula rization, in areas which contained numerous inflammatory cells adherin g to the wall. The Disse space was not generally enlarged and containe d no inflammatory cells. The sinusoidal pole of hepatocytes was occasi onally damaged with the formation of blebs. These results strongly sug gest that any drug or perservation solution that will inhibit endothel ial and Kupffer cell activation could be beneficial in the prevention of preservation and reperfusion injury.