The Development of Newborn Porcine Models for Evaluation of Tissue-Engineered Small Intestine.

Short bowel syndrome (SBS) is a major cause of morbidity and mortality in the pediatric population, for which treatment options are limited. To develop novel approaches for the treatment of SBS, we now focus on the development of a tissue-engineered intestine (also known as an "artificial intestine"), in which intestinal stem cells are cultured onto an absorbable bioscaffold, followed by implantation into the host. To enhance the translational potential of these preclinical studies, we have developed three clinically relevant models in neonatal piglets, which approximate the size of the human infant and were evaluated after implantation and establishment of intestinal continuity over the long term. The models included (1) a staged, multioperation approach; (2) a single operation with a de-functionalized loop of small intestine; and (3) a single operation with an intestinal bypass. The first model had complications related to multiple operations in a short time period, including surgical site infections and wound hernias. The second model avoided wound complications, but was associated with high ostomy output, local skin breakdown, and systemic dehydration with associated electrolyte imbalances. The third model was the most effective, although resulted in stoma prolapse. In summary, we have now developed and evaluated three operative methods for the long-term evaluation of the artificial intestine in the piglet, and conclude that a single operation with a de-functionalized loop of small intestine may be an optimal approach for evaluation over the long term.