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Donors should have no previous history of significant intestinal pathology. As with all organs donors there should be no significant hemodynamic instability, sepsis, history of malignancy or chronic infection, severe hypoxia, severe acidosis, and they must have negative serology for HIV, hepatitis B and hepatitis C. A cross match should be performed either using a standard cytotoxicity assay or flow cytometry. In certain circumstances, if the cross match results are not available, but the patient has had no evidence of presensitization based on pre- transplant serologic surveillance, it may be reasonable to proceed without the cross match results. Because of the need to minimize the intestinal cold ischemia time (<6 hours),15,16 it may not always be possible to obtain the cross match results in time. Although HLA matching has not been studied extensively in small bowel transplantation it is also useful to know the HLA status of both donor and recipient, particularly if the recipient in known to be sensitized to certain HLA antigens.

Two other important considerations are the CMV and EBV serologic status of the donors and recipients. Transplantation of a serologically positive donor into a serologically negative recipient for either of these viruses can have serious consequences.17 In addition to the risk of a systemic CMV infection, a CMV enteritis can occur which can lead to graft loss. A new EBV infection combined with posttransplant immunosuppression puts the patient at high risk for developing a post transplant lymphoproliferative disorder (PTLD).18

If a donor is considered suitable, an NG tube should be placed and oral antibiotics administered to try and decrease bacterial counts in the donor gut. Ampho-tericin B, Neomycin, and Erythromycin base are typically administered immediately after the decision is made to go ahead with the procurement and then again at initiation of the multi organ procurement. A formal bowel prep should not be performed in most circumstances because, with the time constraints involved, the bowel will end up severely distended making it difficult to transplant. In the rare circumstance that there will be 12 to 24 hours between the identification of a donor and the donor procurement, a formal bowel prep may be considered. Some programs also consider administering OKT3 to the donor to decrease the numbers of lymphocytes in the allograft prior to transplantation,19 although the merit of this has not yet been determined.

Because the optimal cold ischemia time for intestinal grafts is less than 6 hours, careful attention must be given to the timing of the donor and recipient procedures to prevent prolonged cold ischemia. Consideration should also be given to what other organs are going to be procured, as this may influence the length of the donor procedure and the approach used by the small bowel procurement team.

Living Donors

If a living donor is being evaluated, it is important that the potential donor be evaluated by a multidisciplinary team that includes transplantation surgery, GI medicine, psychiatry, nutritional services, and social work. To avoid a conflict of interest, it is imperative that the physician who is in charge of working up the donor not be an active part of the transplant team. As with any living donor procedure, the potential complications should be explained in great detail to the pro spective donor on multiple occasions. It should also be made quite clear to the patient that other options besides using a living donor are available. Time must also be taken to fully understand the nature of the relationship between the donor and the recipient. Living donation should not be pursued if coercion or financial incentive appear to be the primary motivation for donation.

If a number of potential living donors are available, particularly among family members, then careful consideration should be given to the best available HLA match. The donor-recipient size discrepancy must also be considered but since, in a living donor, only a segment of the intestine is transplanted, size limits are less restrictive. As with cadaver donors, the donor and recipient should be ABO identical, although in some circumstances ABO compatible combinations can be considered.

As with cadaveric donors, living donors must be free of significant pathology involving the GI tract. Any potential living donor must be in good health with no previous significant medical problems, including diabetes, malignancy, or chronic infection. There should be no history of substance abuse or other high-risk activities in the donor, and no significant psychiatric history. Serology in the living donor must also be negative for HIV, Hep C and Hep B. Obese donors should be avoided. As with cadaveric donors, the CMV and EBV status of the donor and recipient must be carefully considered and the combination of positive donors to negative recipients should be avoided. The living donor should be worked up completely including CBC, electrolytes, liver function tests, EKG, chest x-ray. The GI tract should be evaluated endoscopically and if any concerns exist, GI contrast studies should be performed. A mesenteric angiogram with selective study of the SMA and its venous phase should be performed to ensure that the terminal SMA and SMV are adequate.

One day prior to surgery the potential donor should be kept on clear fluids and administered neomycin 1 gram and erthyomycin base 1 gram PO at 1300 and 1400 and 2300 hours. The potential living donor should also undergo a formal bowel preparation using GoLYTELY (4L) the day prior to surgery.

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