Intestinal transplantation: an overview of the recent experimental studies

Abstract

Purpose of review Experimental intestinal transplantation (ITx ) has generated invaluable knowledge that has ultimately benefited the clinical activity. Herein, we appraise the recent publications pertaining to experimental ITx and highlight the main current research topics. Recent findings During the recent years, ischemia-reperfusion injury (IRI) and Graft-versus-host disease (GVHD) have gradually replaced acute rejection as the main research topic. New additives to established preservation solutions and relatively novel approaches such as luminal interventions during cold storage may prolong the storage time and alleviate IRI. High donor age does not seem to worsen preservation injury. The ischemic susceptibility seems to differ between species, which may impact the translatability of the experimental findings. A new experimental model of modified multivisceral transplantation including the donor spleen may offer a new tool with which to study GVHD, besides the classical Lewis–Brown Norway rat combination. Flushing the graft with fludarabine may mitigate GVHD in rats. T-cell activation inhibitor—mitochondrial was downregulated in the peripheral blood leukocytes before other signs of acute and severe chronic rejection could be observed. Summary Experimental research in ITx has largely shifted focus from acute rejection to IRI and GVHD. Several lines of research have matured toward clinical translation, yet no breakthrough is imminent.

Luminal Preservation Protects the Small Intestine in a Brain-dead Rat Model

“…Compared with results of previous studies in LP, particularly in animal models, 5 the effects of brain death seem to generate irregular injuries along the whole intestine, an effect reflected in the seemingly better-preserved sections that underwent control treatment for a prolonged period (8 h of CS). The present study shows higher damage already at the beginning of the donation procedure than what other studies without DBD have presented, with the absence of epithelial lining and increased presence of debris in the lamina propria (Supplementary Results, Figure S2 , SDC, http://links.lww.com/TXD/A453 ).…”

“…The bowel has also fallen behind regarding preservation techniques in the clinics, as there have been no developments in the way the organ is treated, stored, or transported. 5 …”

“…The protective effects of flushing the lumen of the bowel with an ice-cold solution have been consistent in previous studies in small and large animals and trials on human tissue. 5 What is surprising is the fact that DBD has been not a part of these models. The aim of this study is therefore to see whether LP also has beneficial effects in a rat model of DBD.…”

“…The bowel has also fallen behind regarding preservation techniques in the clinics, as there have been no developments in the way the organ is treated, stored, or transported. 5 Even though DBD provides the best quality organs, 6 these donors are presented naturally with a less than pristine condition. 7 After thorough analysis by the transplant surgeon both at procurement and implantation, the bowels might seem adequate, but the silent insults they suffer could add up after intestinal transplantation.…”

Experimental Assessment of Intestinal Damage in Controlled Donation After Circulatory Death for Visceral Transplantation

“…Decision to compare DCD-derived intestinal grafts with a no-touch waiting time of 5 min (similar to the clinical scenario of pediatric transplantation) with LD ITx procedures is based on two justifications: as reported by Oltean, in the experimental field of ITx in rodents, all published work where transplantation is performed use LD. Also, we considered that the great challenge for DCD was to compare it with the “gold-standard” donor situation regarding solid organ transplantation ( 27 ).…”