PRESERVATION OF CANINE LIVER GRAFTS USING HTK SOLUTION

HTK (histidine tryptophane-ketoglutarate) organ preservation solution has been shown to be effective in human kidney transplantation, but th e efficacy of HTK for extended liver preservation has not been determi ned. In this study, canine livers were preserved in HTK and compared w ith livers preserved in University of Wisconsin solution. First, the r ight and left liver lobes in dogs were flushed separately with cold HT K and UW, respectively, according to a double-flush method. After spli tting the liver, the right and left lobes were stored at 4 degrees C i n either solution for 24 hr and 48 hr and assessed microscopically for parenchymal cell swelling, and enzyme histochemically for 5'-nucleoti dase (5'-NT) as a marker of ischemic liver injury. Unlike livers prese rved in UW (n=5), HTK-preserved livers (n=5) showed progressive parenc hymal cell. swelling after 24-hr and 48-hr storage. The 5'-NT scores i n HTK livers were lower than in UW livers, indicating increased storag e injury (0-5% and 66-85% in HTK- and UW-preserved livers, respectivel y, after 48-hr storage). Second, graft function was tested in an ortho topic liver transplantation model in the dog. Whole livers were flushe d in situ with cold HTK or UW and stored at 4 degrees C for 24 hr or 4 8 hr. Liver grafts stored in HTK were not washed out prior to reflow i n the recipient, in contrast to grafts stored in UW. Livers preserved for 24 hr using HTK showed life-supporting function after transplantat ion (n=5, survival 12 hr-8 days). Ah grafts preserved for 48 hr in HTK did not function (n=5, survival <10 hr). UW-preserved grafts all func tioned after 24-hr storage (n=5, survival >6 days), as well. as after 48-hr storage (n=6, survival >6 days). Peak serum glutamic oxaloacetic transaminase (SGOT) values after transplantation of 24-hr and 48-hr H TK-preserved livers did not differ from peak SGOT values of UW-preserv ed livers after similar preservation times. In conclusion, UW solution is more effective than HTR solution in extended preservation of canin e liver grafts: 24-hr storage of livers preserved with HTK solution is feasible, whereas 48-hr storage results in a nonfunctioning graft.