Small bowel transplantation under oral immunosuppression: experimental study in the pig

Immunosuppression for in vivo research: state-of-the-art protocols and experimental approaches

Almost every experimental treatment strategy using non-autologous cell, tissue or organ transplantation is tested in small and large animal models before clinical translation. Because these strategies require immunosuppression in most cases, immunosuppressive protocols are a key element in transplantation experiments. However, standard immunosuppressive protocols are often applied without detailed knowledge regarding their efficacy within the particular experimental setting and in the chosen model species. Optimization of such protocols is pertinent to the translation of experimental results to human patients and thus warrants further investigation. This review summarizes current knowledge regarding immunosuppressive drug classes as well as their dosages and application regimens with consideration of species-specific drug metabolization and side effects. It also summarizes contemporary knowledge of novel immunomodulatory strategies, such as the use of mesenchymal stem cells or antibodies. Thus, this review is intended to serve as a state-of-the-art compendium for researchers to refine applied experimental immunosuppression and immunomodulation strategies to enhance the predictive value of preclinical transplantation studies.

Modifications in combined liver-small bowel transplantation in pigs

AIM: To introduce combined liver-small bowel transplantation in pigs.

METHODS: Eighteen transplantations in 36 large white pigs were performed. Three modifications in combined liver-small bowel transplantation model were applied: Veno-venous bypass was not used. Preservation of the donor duodenum and head of pancreas in continuity with the combined graft to avoid biliary reconstruction. The splenic vein of donor was anastomosed end-to-end with the portal vein of recipients by the formation of a “cuff”.

RESULTS: Without immunosuppressive therapy, 72-hour survival rate of the transplanted animals was 72% (13/18). Five of 18 pigs operated died of respiratory failure (3 cases) and bleeding during hepatectomy (2 cases). The longest survival time of animals was 6 days.

CONCLUSION: Our surgical modifications are feasible and reliable, which have made the transplantation in pigs simpler and less aggressive, and thus these can be used for preclinical study.