Progress in experimental porcine small-bowel transplantation.

Studies in large animals are needed to overcome technical complications, allograft rejection, and graft-vs-host disease, which are major problems that prevent clinical application of small-bowel transplantation. The small bowel was allografted heterotopically or orthotopically into 30 pigs with the use of cyclosporine, prednisone, and azathioprine. When cyclosporine was given orally to heterotopically transplantation recipients, rejection was frequent, and graft-vs-host disease caused one death. After 30 days of intravenous cyclosporine followed by oral administration, no rejection occurred. Graft-vs-host disease was mild or absent, and there were some long-term survivors. Technical failures were relatively infrequent, but death from sepsis, eg, intra-abdominal abscess, occurred in 17% (5/30). Anastomoses of donor superior mesenteric vein to recipient portal vein offered no advantages over systemic venous drainage. Although the high cyclosporine levels used would be intolerable in humans, these results indicate that successful small-bowel transplantation can be achieved with adequate immunosuppression in a large animal.