Small-bowel transplantation permits survival in rats with lethal short-gut syndrome

The functional integrity of transplanted bowel would most convincingly be demonstrated if transplantation after an otherwise lethal intestinal resection permitted survival and growth. In this experiment, we proposed to define the extent of bowel resection necessary for lethality and to show that transplantation allows salvage of these animals. Adult Brown-Norway rats (250 g) underwent extensive small-bowel resection (SBR) (ligament of Treitz to ileocecal valve) (n=5), cecectomy only (CEC) (n=3), SBR plus CEC (n=6), or SBR plus CEC and syngeneic transplantation of 25 cm of jejunum (n=6). All animals with SBR or CEC alone survived and grew; all animals with SBR plus CEC died within 2 weeks (mean, 6.4 days); and 6 of 6 animals with SBR plus CEC and transplant survived and grew. The difference in survival between the lethally resected rats and those with an intestinal transplant was highly significant (P<0.01). Dietary intake was similar in all groups. We conclude that in the rat, extensive small-bowel resection alone is not sufficient to be lethal; most of the small bowel and the cecum must be resected to obtain a lethal model. We have also shown that transplantation of small bowel into rats with an otherwise lethal extent of bowel resection will allow the animals to survive and grow. These results suggest the need for caution in correlating survival after intestinal transplantation in the rat with transplant function, since the preservation of too much native gut might permit survival even if the transplant has no nutritional function.