The small bowel is protected by the presence of luminal preservation solution during cold storage in a brain-dead rat model

TRENTADUE G; VECCHIO LE; KATS-UGURLU G; HAVEMAN JW,; FABER KN,; LEUVENINK H; RUMBO M; DIJKSTRA G

Veldhoven

Congreso; Dutch Digestive Days 2021; 2021

Dutch Association for Gastroenterology

Intestinal transplantation (ITx) is performed a handful of times a year, and graft survival rates are disappointing. Thus, animal models are needed to understand the mechanisms occurring before, during and after the procedure. The intestine, donated after brain death (DBD), is viable for up to 10 hours of storage, shorter than other abdominal organs which are preserved in the same way. There have been no developments in the way the graft is treated, stored and transported. The protective effects of luminal perfusion (LP) with an ice-cold solution have been consistent in previous studies in small and large animals, but none of these models include DBD. The aim of our study is to investigate whether the beneficial effects of LP occur also in a DBD model. Wistar rats (N=9) underwent brain death induction and kept stable for 2 hours. Donor vessels were then perfused with University of Wisconsin solution (UW) and the small intestine explantated. The explant was then divided into three pieces for cold storage (CS). One segment was kept empty (control), and the rest were filled with either UW or polyethylene glycol 3350. All segments were then tied shut and stored in ice-cold UW. Analysis time points were procurement and after 4 and 8 hours of CS. Samples were evaluated by histopathological scoring of preservation injury (IPI), percentage of absent epithelial lining and presence of oedema. Luminal UW showed a statistically relevant improvement on IPI after 4 hours of CS, while all other samples showed a tendency to lower damage for the duration of the experiments. 50% of the epithelial lining is detached from t=4 in control, while in luminally preserved intestines with UW is 30%. Increasing amounts of oedema beneath the epithelial layer in the the latter group reflects the largely conserved mucosal surface in comparison to other groups. Luminal perfusion of the small intestine is protective of the mucosa in the brain-dead rat. The LP solution with the best effect is UW for up to 4 hours of static cold storage. These results show less effect of LP than previously described, when using non-DBD models. More attention should be paid to the effect of DBD in the grafts viability on further studies.