Limited survival of rat small bowel transplants preserved in University of Wisconsin solution for 48 hours

We have previously shown that rat small bowel may successfully be transplanted after preservation for 24 hours. In this study, syngeneic rat small bowel transplants were studied by light microscopy and transmission electron microscopy during and after preservation in University of Wisconsin (UW) solution for 48 hours. A total of 6 transplants were carried out using a previously described, standardized technique. In most cases, the bowel appeared histologically well preserved at the end of the 48 hr storage period (prior to implantation). Upon revascularization, however, reperfusion injury was dramatic, with loss of villi and crypts and inflammatory cells in all layers. The bowel was abnormal grossly as well as microscopically. This injury was irreversible with persistently abnormal histology for up to 1 week in all but 2 cases. We conclude that UW solution alone may allow satisfactory preservation of intestinal grafts for 48 hours only in isolated cases, and is therefore not adequate for predictable, satisfactory 48 hr preservation. Attempts to prevent reperfusion injury with oxygen-free radical scavengers are in progress.