[Experimental small intestine transplantation]

Transplantation of the small intestine is a standard treatment method in patients with small intestinal failures. The aim of this study was to master the surgical technique, optimalize immunosuppression regimes, diagnose acute cellular graft rejection based on cellular and humoral indicators.

The authors performed a total of 43 transplantation procedures in pigs. The first, surgical part of the experiment was aimed at mastering two principal methods of vascular anastomosis- firstly, connecting the graft with mesenteric vessels (Group n1 = 18) and secondly, connecting the graft with the aorta and the inferior vena cava (Group n2 = 25). The second part of the experiment included assessment of rejection changes in various immunosuppression regimes. Only animals who did not die because of a technical failure of the procedure or due to internal reasons (n = 24) were assessed. The study animals were assigned to four groups (A (n = 3)--autotransplantation, without immunosuppresion; B (n = 7) and C (n = 8)--allotransplantation with immunosuppression using tacrolimus, resp. in a combination with sirolimus; D (n = 6)--allotransplantation without immunosuppression. Rejection was diagnosed based on histological examination of the grafts@ biopsy samples. Plasmatic citruline was used as a non-invasive humoral indicator of the graft impairment.

Procedural complications were observed in 12 (67%) study animals from the first group, and in 3 (12%) animals from the second group. In the assessment of rejection changes, the longest survival was observed with autotransplantations, the shortest survival period was shown with allotransplantations without immunosuppression. No significant survival differences were demonstrated between the both treated groups. (p < 0.05). Group C showed lower rates of cellular rejections, compared to Group B and D.

During the experiment, the authors managed to master the graft collection, as well as the transplantation technique. Lower rates of surgical complications were observed when the graft was supplied by the central vascular system. No significant differencies were observed between the tacrolimus monoterapy regimen and the combination therapy with sirolimus. Histological examination is the golden standard for the cellular rejection diagnostics. Plasmatic citruline has no signifiance in the rejection assessment.