01.07 A Hypothermic Ex-vivo Intestinal Perfusion Unit that limits ischemia reperfusion injury

A. Flores Huidobro1, C. Ibarra1, A. S. Munoz-Abraham1, A. Bertacco1, R. Patron-Lozano1, A. Alkukhun1, R. Morotti1, J. Zinter1, F. D’Amico1, D. Mulligan1, J. Geibel1, M. I. Rodriguez-Davalos1  1Yale University School Of Medicine,Surgery,New Haven, CT, USA

Introduction: Intestinal function may be compromised for several reasons leading to a high number of adult and pediatric patients with intestinal failure. In an effort to reduce injury we have developed multiple animal and human models for extracorporeal perfusion using our intestinal perfusion unit (IPU). We previously published a feasibility study, here we present a comparison between transportation modalities: cold ischemia times, and a variety of preservation solutions. 

Methods: Twelve human intestines were procured from our two regional organ procurement organizations using our approved IRB protocol. Eight intestines were procured and connected to the IPU on site. Four intestines were procured, packed in static cold preservation and delivered to our institution within an average time of 8 hours and 42 minutes and the intestines were all connected proximally to jejunum and distally to the ileum, as well as to the superior mesenteric artery in a dual pump system (luminal and vascular). The human intestines were connected to the IPU and perfused with UW (University of Wisconsin) solution, HTK (Histidine-tryptophan-ketoglutarate) and a combination of UW + Ringer Lactate. Samples were taken at 8, 10 and 12 hours in hypothermic perfused conditions. Pathological analysis was determined using the Park/Chiu (P/C) scoring system for intestinal injury (0=normal, 8=transmural infarction). 

Results:Histological analysis of intestines shipped and then connected to the IPU showed a P/C score of jejunum (2.3) and for ileum (2.8). Intestines connected to the IPU on-site: P/C score of jejunum (1.85) and for ileum (1.23).. Average cold ischemia time (CIT) for recovered intestines by our team was 2.16 hours and CIT for intestines by other teams was 8.42 hours. Of the 12 total intestines, six were perfused with UW solution, five with HTK and one with UW + RL.  UW perfusion had an average P/C score of 1.6 and 1.77 in ileum and jejunum respectively. HTK had a P/C score average of 1.78 in ileum and 2.27 in jejunum. The combination of UW and RL had the poorest score, 2.33 in both the ileum and jejunum. 

Conclusion:Continuous hypothermic perfusion of intestinal tissue with UW solution proved to be the best source for limiting ischemia reperfusion injury. Lower ischemia injury scores were seen in the Ileum in comparison to Jejunum. This study demonstrates the advances of the IPU project and the variables that can significantly impact the preservation of the intestinal tissue. The results show that if possible, the intestine should be connected at the procuring site in order to achieve maximal preservation.