Future Directions

Intestinal transplantation provides unique and difficult challenges. Because of the delicate balance that must be maintained to provide adequate immunosuppression without over immunosuppression, it is imperative that a simple marker be developed which will alert clinicians that an early rejection is brewing. Another goal is to develop strategies, which eliminate or minimize the risk of rejection. To this end many researchers are attempting to develop strategies for inducing tolerance. Several groups have attempted to induce a state of microchimerism and tolerance by transplanting bone marrow along with the intestinal allograft.32 To date, this approach has not been shown to be effective. Other groups have administered donor specific transfusions simultaneous with implantation of the intestinal graft.33 While there are some preliminary animal studies suggesting that this approach might be effective, its benefit has not yet been proven in humans. Another approach, which has been effective in kidney transplantation, is HLA matching. Although due to time constraints this may not always be practical in the realm of cadaveric intestinal transplantation, it is possible with living related donors. While the experience with living related donor intestinal transplantation has been very limited to date, some of the longest surviving intestinal grafts from the pre cyclosporine era were achieved when living related donors were utilized. More recent experiences with modern immunosuppression have shown that graft survival with living donors is at least comparable to that achieved with cadaveric donors.10,14 The potential advantages of using living donors are: (a) opportunity for better HLA matching; and (b) better control over ischemia times. The potential disadvantages are that: (a) the donor, who does not need a surgical procedure, is put at risk; (b) the allograft will consist of a shorter segment of bowel with smaller blood vessels.

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