TRANSPLANTATION OF SEGMENTAL RAT INTESTINAL GRAFTS INCLUDING THE ILEOCECAL VALVE AND THE ASCENDING COLON

Extrinsic denervation and lymphatic disruption impair nutrient absorpt ion after small bowel transplantation. The present study was undertake n to determine whether adding the ileocecal valve with or without the ascending colon would improve the function of a segmental intestinal g raft. Five groups of Lewis rats (n=10/group) were studied. Group I had a sham laparotomy. Groups II, III, IV, and V had the native jejunum, ileum, and cecum replaced with a graft. Inbred Lewis rats were used as isogeneic donors for the transplants to avoid the confounding effect of graft rejection. Group II had the entire jejunum and ileum transpla nted. Group III had 20 cm of terminal ileum transplanted. Group IV had 20 cm of the terminal ileum including the ileocecal valve transplante d. Group V had 20 cm of the terminal ileum, the ileocecal valve, and t he ascending colon transplanted. The terminal ileum-transplanted and t erminal ileum/ileocecal valve-transplanted groups lost more than 25% o f their preoperative weight by the end of the second postoperative wee k; most of these animals were killed because of inanition. In contrast , the sham laparotomy, jejunum/ileum-transplanted, and ascending colon -transplanted groups remained healthy until completion of the study on the 28th postoperative day. The ascending colon-transplanted group ha d slower intestinal transit and less bacterial contamination of the te rminal ileum compared with the terminal ileum-transplanted and termina l ileum/ileocecal valve-transplanted groups (P<0.05). Transplantation of the ascending colon and the ileocecal valve significantly improves the function of segmental small bowel isografts in rats. These data su ggest that adding a colonic segment may be a simple method to improve the function of short-segment cadaveric and living-related intestinal grafts in humans.