Surgical technique for combined liver/intestine transplantation in rats

Improved techniques for kidney transplantation in mice

Improved microsurgical techniques for kidney transplantation in the mouse are described. Left renal transplantation is performed with end-to-side anastomoses of the donor renal vein to the inferior vena cava and the donor aortic cuff to the aorta. Urinary tract reconstruction is accomplished by suturing the donor ureter with a bladder patch to the recipient bladder. With these modifications, it is possible to achieve success rates as high as 90%. This stable and reproducible model provides a useful tool to study the immunological mechanisms of kidney allograft rejection at the molecular level.

Host immune suppression after small bowel/liver transplantation in rats

Simultaneous liver grafting in the Lewis (RT1)-to-DA (RT1) rat strain combination protects small intestinal grafts from rejection. The present study examined host immune responses after combined small bowel/liver transplantation (SBL) in this model. Orthotopic liver transplantation and heterotopic small intestinal transplantation were performed simultaneously and compared with isolated small bowel allografts (SBA) and isolated small bowel isografts (SBI). All rats were sacrificed on postoperative day (POD) 7 or 14 for immunological and histological studies. The mean time to rejection of the SBA was 6.6 +/- 0.3 days. In contrast, there was no clinical or histological evidence of intestinal rejection in SBL recipients during the 14 days of follow-up. The SBL recipients showed clinical and histological evidence of graft-versus-host disease (GVHD). Lymphocyte proliferation and IL-2 production in response to donor antigens were suppressed after SBL transplantation compared with the SBA or the SBI controls (P < 0.05). Cell-mediated cytotoxicity and lymphocytotoxic antibody production against donor cells were also significantly inhibited in the SBL recipients compared with the SBA control group (P < 0.05). We conclude that SBL transplantation in the Lewis-to DA rat strain combination: (1) suppresses host alloimmune responses, (2) prevents early intestinal rejection, and (3) favors the development of GVHD.

Host immune suppression after small bowel/liver transplantation in rats

Simultaneous liver grafting in the Lewis (RT1)-to-DA (RT1) rat strain combination protects small intestinal grafts from rejection. The present study examined host immune responses after combined small bowel/liver transplantation (SBL) in this model. Orthotopic liver transplantation and heterotopic small intestinal transplantation were performed simultaneously and compared with isolated small bowel allografts (SBA) and isolated small bowel isografts (SBI). All rats were sacrificed on postoperative day (POD) 7 or 14 for immunological and histological studies. The mean time to rejection of the SBA was 6.6 +/- 0.3 days. In contrast, there was no clinical or histological evidence of intestinal rejection in SBL recipients during the 14 days of follow-up. The SBL recipients showed clinical and histological evidence of graft-versus-host disease (GVHD). Lymphocyte proliferation and IL-2 production in response to donor antigens were suppressed after SBL transplantation compared with the SBA or the SBI controls (P < 0.05). Cell-mediated cytotoxicity and lymphocytotoxic antibody production against donor cells were also significantly inhibited in the SBL recipients compared with the SBA control group (P < 0.05). We conclude that SBL transplantation in the Lewis-to DA rat strain combination: (1) suppresses host alloimmune responses, (2) prevents early intestinal rejection, and (3) favors the development of GVHD.

Continuous rat intravenous infusion

Hypovolemic shock and ischemic injury to the graft commonly cause death in small animals after organ transplantation. A venous line must be readily available to replace fluids before fatal complications occur. To establish a venous line, researchers expose a vein by preliminary surgery. This time-consuming procedure adds unnecessary trauma to the recipient and worsens the results. The possibility of long-term fluid transfusion in small animals by serial injections at close intervals is quite limited. We describe a simple technique of continuous i.v. infusion by catheterization of the rat dorsal penile vein with a 24-gauge, 3/4-inch catheter. This easy-to-learn technique has permitted us to establish a venous line quickly without trauma in 148 rats while doing donor and recipient procedures for small bowel and ileocecal segment transplantation. The technique we describe has eliminated one of the most frequent causes of postoperative mortality after organ transplantation-hypovolemic shock. We would like to emphasize that other measures, including avoiding massive bleeding and reducing operative and warm ischemic time, are also very important in preventing this complication. The massive i.v. infusion alone may not totally eliminate hypovolemic shock if other factors are neglected. The use of this technique has allowed us to perform small bowel transplantation with 90% success.