The Rat Heterotopic Small Bowel Transplant Rejection And Immune Tolerance In Experimental Studies

Objective To establish successful models of heterotopic small bowel transplantation (SBT) and intestine-spleen co-transplantation in rat, and summarize our experience.Methods The graft removed en bloc consisted of entire small intestine, portal vein and aortic segment with superior mesenteric artery, or consisted of spleen, entire small intestine , portal vein with splenic vein, and aortic segment keeping with superior mesenteric and celiac artery with splenic arteric branching in intestine - spleen co-transplantation. The graft was perfused in situ and the gut lumen was irrigated during the operation. Blood circulation was reconstructed by microvascular end-to-side anastomosis between the donor aortic segment and recipient abdominal aorta, and end-to-end anastomosis between the donor portals vein and the recipient left renal vein with cannula technique. Both ends of the intestinal graft were exteriorized as stomas. The donor and recipient were receiving intravenous administration of Ringer's solution. Results A total of 165 tests in rats were performed. 41 transplantations were involved in experiment group,including 8 spleen-intestine co-transplantations, and the survival rate was 73.2%. The failure causewere included: 2 cases of arteric stoma bleeding, 2 cases of abdominal cavity infection, 2 cases of arteric stoma thrombosis and 5 cases graft intestinal bleeding in 3-5 day of post-transplantation. The cold ischemic time was less than 60 min, warm ischemic time was 24±11 min. A single operator, lasting about 4 hours, performed the whole operation.Conclusion Graft harvest, vascular anastomosis, maintenance blood volume and reducing warm ischemic time of graft are the key surgical technique. A resistant model of intestine-spleen co-transplantation by this method, microvascular end-to-side anastomosis between the donor aortic segment with superior mesenteric artery, celiac artery keeping with splenic arteric branch and recipient abdominal aorta, end-to-end anastomosis between the donor portal vein with splenic vein and recipient left renal vein utilization of cannula technique.