Comparison of HTK- and UW-solution for liver preservation tested in an orthotopic liver transplantation model in the pig.

The aim of this experimental study was to compare the preservation potency of University of Wisconsin (UW) and HTK (Bretschneider) solutions in an orthotopic liver transplantation (OLT) model in pigs. Livers were harvested using an in situ perfusion technique, where organs were flushed with the solution being tested, stored on ice--cold storage (CS)--for 2 or 24 h and then transplanted. Parameters monitored were liver enzymes in serum, hepatic water content, high energy phosphates, nuclear magnetic resonance (NMR) relaxation time T2, light microscopy and bile production. CS for 24 h is an extreme in pig liver preservation and is not compatible with animal survival. Biopsies showed drastic morphological changes and grafts did not produce bile in either group. (Bile production 2 h CS: HTK, 5.6 +/- 1.8 ml/h; UW, 4.7 +/- 2.3 ml/h) Enzyme release after reperfusion (deltaSGOT, deltaLDH) was higher in long-term preservation. Hepatic tissue water content significantly decreased during CS in UW preserved livers. Edema alter reperfusion (deltaH2O: HTK 24 h = +5.6%, UW 24 h = +4.8%) and regeneration capacity after reperfusion (UW 2 h = 63%, HTK 2 h = 55%, UW 24 h = 30%, HTK 24 h = 30%) were not significantly different. However, we did not observe major differences in preservation potency between the solutions tested. Differences were correlated, rather, with length 9 time of CS, than with the solution used. Therefore, HTK solution seemed to be a low potassium containing alternative to UW solution.