Amelioration of rewarming ischemic injury of the pancreas graft during vascular anastomosis by increasing tissue ATP contents during preservation by the two-layer cold storage method.

Rewarming ischemic injury during vascular anastomosis severely compromises posttransplant pancreas graft survival because the graft has already been subjected to warm and cold ischemia before vascular anastomosis. We examined whether preservation of the pancreas graft by the two-layer method ameliorates rewarming ischemic injury of the graft during vascular anastomosis and also investigated the energy metabolism of the pancreas graft before, during and after rewarming ischemic period. After flushing with cold University of Wisconsin solution (UW), the pancreas grafts were preserved by the two-layer (UW/perfluorochemical [PFC]) method (group 1) or simple cold storage in UW (group 2) for 24-hr and then autotransplanted. In control, the pancreas grafts were flushed out with cold UW and immediately autotransplanted without preservation (group 3). After completion of vascular anastomosis, vascular clamp was not released until 90, 120, or 150 min of rewarming ischemia, including anastomosis time, has elapsed. After 90 min of rewarming ischemia, graft survival rates were 5/5, 100%, 5/5, 100%, and 5/5, 100% in groups 1, 2 and 3, respectively. After 120 min, all the grafts in groups 2 and 3 failed (0/5, 0%, and 0/5, 0%, respectively), however, all the grafts in group 1 survived (5/5, 100%). Even after 150 min, 1 of 3 grafts in group 1 survived (1/3, 33%). After 24 hr preservation, tissue adenosine triphosphate (ATP) and total adenine nucleotides (TAN) levels of the grafts in group 1 were about 2-fold the reference values before harvesting and significantly higher compared with group 2(p < 0.05; p < 0.05). After 120 min of rewarming ischemia, tissue ATP levels in group 1 were 84% of the reference values and significantly higher compared with group 2(p < 0.05). TAN levels of group 1 were also significantly higher compared with group 2(p < 0.05). Two hours after reperfusion, ATP and TAN levels in group 1 were significantly higher than group 2(p < 0.05). There were no remarkable difference between group 1 and group 2 concerning adenosine diphosphate (ADP), adenosine monophosphate (AMP) levels. We conclude that the two-layer (UW/PFC) method ameliorates rewarming ischemic injury of the pancreas graft during vascular anastomosis by increasing tissue ATP concentration and TAN levels during preservation and maintaining tissue ATP and TAN levels during vascular anastomosis. Consequently, ATP levels are rapidly recovered after reperfusion and the graft survives.