The impact of liver preservation in HTK and UW solution on microcirculation after liver transplantation

Severe microcirculatory disturbances due to endothelial cell damage and leukocyte adherence during reperfusion of transplanted livers are considered to contribute to early graft failure. Since the degree of reperfusion injury after liver transplantation depends on the length of preservation time and the solution used for preservation, the aim of our study was to assess three solutions with respect to microvascular perfusion and leukocyte adhesion. Therefore, rat livers were stored up to 24 h in Euro-Collins (EC), University of Wisconsin (UW), or histidin-tryphtophan-ketoglutarate (HTK) solutions prior to orthotopic transplantation. The livers were studied in situ 60 min postoperatively using intravital fluorescence video microscopy. Using simple syringe flushing (10 ml), sinusoidal perfusion decreased below 50% in EC preserved livers after 8 h preservation, in HTK preserved livers after 16 h preservation, and remained higher than 70% in livers preserved in UW up to 24 h. Permanent adhesion of leukocytes was increased more rapidly in organs after 1, 8, 16, and 24 h preservation in HTK (16%, 15%, 34%, and 49.7% +/- 4.7%) compared to those preserved in UW (15%, 18%, 17%; and 32.7% +/- 3.3%; P<0.05). Using a 10-fold volumn of the organ weight of HTK solution during the harvesting procedure, with an 8 min equilibration period, sinusoidal perfusion (39.6 +/- 4.7%) and leukocyte adhesion (42.7 +/- 3.1%) were not improved after 24 h. In contrast, equilibration with a volumn of approximately 40-times the liver weight improved sinusoidal perfusion (70.8% +/- 2.7%; P < 0.01) and leukocyte adhesion (24.9% +/- 3.1%; P < 0.01) significantly. Thus, using HTK solution, simple flushing prior to long-term cold storage resulted in microcirculatory disturbances when compared to UW solution. Larger volumns of HTK solution with an additional equilibration period of 8 min, however, reduced leukocyte adhesion and improved sinusoidal perfusion to a similar degree as UW solution.