Surgical Technique of Small Bowel Transplantation in a Large Animal Model

Abstract

An experiment was carried out on pigs during preparation of a clinical project of intestinal transplantation. The objective of this study was to find the best surgical technique of vascular and intestinal anastomosis in different experimental settings (animals with and without immunosuppression) which could have a major impact on everyday veterinary practice. Transplantation was performed in 43 pigs. In the surgical part of the experiment we examined the most suitable surgical technique of vascular anastomosis. A running continuous single-layer seromuscular suture was used for all types of intestinal anastomoses. With regard to vascular anastomosis, the animals were divided into two groups. In group 1 (n = 18) one animal was both donor and recipient of the intestinal graft. Anastomoses were constructed to the mesenteric vessel bed. In group 2 (n = 25), one animal was the graft donor and another was the graft recipient, with revascularization to the central vessel bed. In the second part of the study, we examined the impact of immunosuppressive drug administration on acute cellular rejection and animal survival. Animals that died due to technical failure and reasons unrelated to transplantation were excluded from the evaluation (19 pigs). A total of 24 pigs were included in the second part of the study. The animals were divided into four experimental groups. Group A - autotransplantation (n = 3), group B - allotransplantation on tacrolimus monotherapy (n = 7), group C on combined immunosuppression with tacrolimus and sirolimus (n = 8), and control group D - without immunosuppression (n = 6). Results: A high rate of vascular complications occurred in the first group; 67% (12 out of 18). In the second group, the rate of complications was reduced to 12% (3 out of 25). In the second part of the study the shortest survival was found in group D and the longest in group A. In neither of the immunosuppressed groups (B + C) did we find any significant difference in survival. No complication with the healing of intestinal anastomosis was found in any group. In conclusion we can state the single-layer continuous running suture was safe for all kinds of intestinal anastomoses. Vascular reconstruction to the central vessels was safer for graft survival.