Influence of warm ischemia injury on hepatic functional status and survival of liver graft in rats

Objectives: To investigate the changing patterns of functional and histological status, observe the posttransplantation survival of liver graft under different warm ischemia time (WIT) in rats, and determine the maximum limitation of liver graft to warm ischemia. Methods: According to WIT, the rats were randomized into 7 groups, with WIT of 0, 10, 15, 20, 30, 45, 60 minutes respectively. Serum concentrations of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were measured at 1, 2, 3 and 5 days after orthotopic liver transplantation respectively. Liver graft specimens were observed histopathologically at the same interval. The rats' survival in each subgroup was observed. Results: In terms of graft survival, there was no significant difference between subgroups within 30-minute WIT. In the group with 30-minute WIT, the recipient rats' survival rate was 83.3% (10/12) at one week, 58.3% (7/12) at one month. and 50.0% (6/12) at 3 months. In the group with 45-minute WIT, the recipient rats' survival rate was 66.7% (8/12) at one week, 33.3% (4/12) at one month, and 8.3% (1/12) at 3 months, whereas only 8.3% (1/12) of the rats had one-week survival in the group with 60-minute WIT. Conclusions: These results indicate that rat liver graft could be safely subject to warm ischemia within 30 minutes. When WIT is prolonged to 45 minutes, the recipients long-term survival is severely insulted, and both function and histological structure of liver graft may develop irreversible damage when WIT is prolonged to 60 minutes.