M. Finotti1,2, T. Lysyy1, R. Morotti1, A. S. Munoz-Abraham1, A. Bertacco2, R. Agarwal1, C. Ibarra1, R. Patron1, A. Alkukhun1, F. D’Amico1,2, M. Rodriguez-Davalos1, D. Mulligan1, J. Geibel1 1Yale University School Of Medicine,Surgery,New Haven, CT, USA 2University Of Padua,Transplantation &Hepatobiliary/Surgery,Padua, PADUA, Italy
Introduction:
Human intestinal grafts intended for transplantation require optimal preservation to reduce ischemic injury. Hypothermic preservation is crucial in decreasing ischemia, and the type of solution used in cold preservation could influence graft survival. In this study, we used the Park/Chiu histological damage score to compare the efficacy of two solutions (UW and HTK solutions) in preserving human intestine under two different conditions: static storage and continuous hypothermic perfusion using an intestinal perfusion unit (IPU).
Methods: 18 human intestines were used, 14 were procured by our surgical team, with a Cold Ischemia Time (CIT) between 1-4 hours; and 4 were shipped with a CIT between 5-9 hours. The type of solution was randomized: UW or HTK was used to perfuse the intestine graft. In 4 intestines Lactate Ringer (LR) was used to flush the luminal intestine after harvesting, then the graft were stored in static preservation solution. Duplicate samples from the jejunum and ileum were collected before the initiation of cold storage (T0 samples). After mean 8.6 hours of static (T8) or continuous perfusion preservation (PT8), we sampled each intestinal section (jejunum and ileum) in duplicates (total of 208 samples collected).
Results:
HTK and UW were used for the initial luminal flush and subsequent cold storage in six and eight intestines respectively. In four intestines, LR was used to flush the lumen and then specimens were stored in a solution of UW. At T0 there was no difference between solutions. The jejunum had a mean score of 1.06, 1.75 and 0.87 with UW, HTK and UW+LR respectively. In the ileum, the mean ischemic scores were 0.93, 0.83 and 1.33 with UW, HTK and UW+LR respectively. At T8 jejunum maintained in UW had a lower histological damage score in comparison to HTK (mean 1.75 with UW vs 3.16 with HTK, p<0.0193). The same pattern occurred when the IPU was used (PT8): the mean ischemic score in jejunum was 1.5 with UW vs 3 with HTK (p<0.0287). In the ileum, no statistically significant difference was seen at T0, T8 and PT8.
Conclusion:Small intestine ischemic damage during the hypothermic preservation before transplantation may depend on the choice of preservation solutions. In the present study, we demonstrated that in the jejunum, UW solution is associated with less ischemic damage in comparison to HTK after 8 hours of storage, both in the static and in continuous perfusion. In the ileum, there is no significant difference in ischemic damage in specimens preserved with UW and HTK. Furthermore, we showed that at the time of intestinal harvest, LR is viable option to flush, clean, and prepare the intestine for transport with no apparent increased histological damage. These results remain consistent whether the intestine is continuously perfused or maintained in a static 4oC environment.