Current status of small-bowel transplantation.

Patients who have lost such a large portion of their small bowel that they permanently require total parenteral nutrition for survival would greatly benefit by receiving a small-intestinal transplant. Over the past two decades, many experimental studies have delineated the specific problems surrounding small-bowel transplantation and provided strategies for their control. Control of rejection, the most difficult problem, may be achieved with a combination of cyclosporine, azathioprine, prednisone, antithymocyte globulin, and monoclonal antibodies. The threat of graft-versus-host disease originating from the allogeneic lymphatic tissues in the allograft is abolished by in vitro x-irradiation of the cold, nonperfused graft with 1000 rads. Monitoring of the intestinal allograft is possible with the combination of a function test (maltose absorption, glucose absorption, or any other function test) and repeated graft biopsy. Effective short-term preservation of small-bowel segments for up to 18 h is possible by intravascular flushing with a balanced electrolyte solution containing 3% fructose and by subsequent hypothermic storage. Clinical small-bowel transplantation is certainly not an imminent therapeutic tool. However, clinical trials in highly selected patients could be envisioned on the basis of our present understanding of small-bowel transplantation and of transplantation biology in general, and in view of the clinical successes achieved with duodenal grafts transplanted in conjunction with pancreatic grafts.