Rodrigo M. Vianna, Richard S. Mangus, A. Joseph Tector

Intestinal transplantation has shown exceptional growth over the past 20 years with remarkable progress. As with other solid organ transplants, intestinal transplantation has moved out of the experimental realm to become the stan dard of care for many patients with intestinal failure. Intestinal transplantation may soon be extended routinely to patients who, although not strictly meeting the criteria for intestinal failure, may benefit from intestinal transplantation, such as patients who have nonresectable indolent tumors or diffuse thrombosis of the portomesenteric system. As clinical experience has increased with intestinal transplantation, outcomes have improved. The currently reported 1-year graft and patient survival rate is 80%, which approaches that for other solid abdominal organs. Unfortunately, most of the gains in survival are seen in the first postoperative year, with long-term survival remaining basically unchanged since the early 1990s. With improved outcomes, more centers have entered into the intestinal transplant arena. In the United States alone, 20 centers performed at least one intestinal transplant in 2007. Increase in access to intestinal transplantation and more widespread awareness of this option likely will result in a consistent increase in the number of yearly transplants for the foreseeable future. Immunosuppressive regimens continue to evolve, with induction therapy being the major change in the past 5 years. Although rejection rates in the first year after transplant have been reduced by induction therapy, long-term side effects of heavy immunosuppression continue to weigh negatively on transplant outcomes. The future for immunosuppression lies in two areas: (1) individual monitoring of the immunosuppression level for each individual patient and (2) development of serum and tissue markers for the early identification of rejection. It is likely that a combination of technologies will allow immunosuppression to be tailored to each recipient. Development of these approaches to immunosuppression is necessary to predict graft dysfunction ahead of irreversible graft injury and allows adjustments in immunosuppression before the onset of rejection. Intestinal transplantation continues to be performed only in situations in which all other therapeutic modalities have failed. No randomized trials compare intestinal transplantation to long-term PN to establish guidelines for a timely referral for this treatment option. Late referral remains a crippling problem in the field of intestinal transplantation, with a great number of patients in need of simultaneous liver transplantation at the time of listing for intestinal transplantation. Early referral for isolated intestinal transplant will reduce the need for simultaneous multiorgan transplants and increase the residual organs available for patients in need of (primarily) liver transplantation.