Graft length affects outcome in fetal small bowel transplants

Multiple studies have demonstrated the ability of the fetal rat small intestine to be transplanted successfully as a free graft, devoid of its mesentery. While maintaining normal histologic architecture, portal circulation, and digestive and absorptive properties, the initial myeloelectric activity is delayed. The purpose of this study was to investigate how abnormal early motility affects functional outcome and survival. Using a syngeneic model, fetal rat small intestine segments were transplanted into adolescent rat recipients as free grafts into the omentum. After a maturation period, viable segments measuring 1 or 2 cm were placed into continuity with the native intestine after a standardized resection of either jejunum-ileum, ileum-cecum, or cecum. Control animals had native intestinal resection without graft interposition. Survival, daily weight gain, oral intake, and fecal output were monitored. In this model, overall survival was improved with the use of the shorter 1-cm graft segment compared with the 2-cm and more distal interpositions. No animals survived with proximal graft placement after jejunal-ileal resection. Nutrient use was improved in the transplant recipients compared with nontransplant controls but did not differ between the two graft lengths. These data suggest that outcome in this model is improved using shorter fetal intestine graft lengths. The use of multiple segments in multistaged procedures and early defunctionalization may improve results.