Combined orthotopic liver-small bowel transplantation or small bowel transplantation in pigs: Relations between survival, rejection, and mucosal morphometry

Abstract

THE ADVENT of more powerful immunosuppressive drugs such as cyclosporine (CyA) and tacrolimus (FK 506) renewed interest in the transplant of the bowel alone or combined with other organs. The transplant of the bowel alone (OSBTx) or with the liver (OLSBTx) or as a multivisceral graft of all abdominal organs (MVTx) should be considered in different clinical conditions as the theoretical treatment of choice. Poor results in patients and short graft survival limited the indications, and the transplant should be considered only as a life-saving procedure. 1,2 In these conditions, experimental transplantation has an important role in improving results of clinical transplantation. Most experimental studies are performed on small animals, generally rats. Studies on big animals such as dogs or pigs are rare, and the number of animals transplanted is sometimes small and results are contradictory . 3−8 Graft rejection is frequent after OLSBTx or OSBTx, postoperative survival (POS) is often short, and nutritional conditions are poor, even in animals without rejection. There is evidence from both human and experimental sources that nutritional disturbances, such as reduced food intake or malabsorption, can produce morphologic changes in the intestinal mucosa 9,10 mainly a reduction in villous and crypt height. Therefore, the measurement of the total mucosal height (TMH) seems to be a good parameter of the nutritional state. For these reasons, we planned an experimental study of OSBTx or OLSBTx in pigs that were also submitted to different types of immunosuppressive regimens. Survival and rejection were compared to the results of mucosal morphometry measurements, both of the graft and of the recipient small bowel.