[Small intestine transplantation. Experimental microsurgical model in rats].

Small bowel transplantation may eventually become the definitive solution for those patients who suffer from irreversible intestinal failure and that currently depend on parenteral nutrition for survival. Microsurgical transplantation models in rats are widely used for the application of a great variety of immunological and physiological tests. Herein we report our experience after 30 intestinal harvestings and 12 intestinal transplantations in rats. The following criteria were established to assess the surgical procedures: operative time (harvesting and back table, cold ischemic time and warm ischemic time), vascular and intestinal complications and gut histology before and after transplantation. Average time for the donor surgery (harvesting and back table) was 97.19 min. Average warm ischemic time (includes vascular anastomoses) was 115 min. Histological assessment after 3, 4 and 5 hours of cold ischemia (lactated Ringer's solution with 2.4% mannitol at 4 degrees C) showed only mild ischemic changes. Two thrombotic complications were observed: one at the site of the portalcava anastomosis and one at the aortic suture. Hypovolemic shock was the most common cause of death (9/12) and there was no survival beyond 48 hours. Post-transplantation gut histology showed moderate ischemic injury. We conclude that the harvesting technique, as well as the preservation method used are adequate to obtain grafts in a fast and reliable fashion. However, the number of rats transplanted in this experience do not permit statistical analysis of morbidity and mortality at the present time.