Orthotopic small intestine transplantation in dogs with systemic graft drainage.

Background: Small intestine transplantation has been accepted worldwide to treat complex cases of intestinal failure. Canine intestinal transplantation model is important in training the surgical technique and to study the complications of this procedure. Systemic graft venous drainage is frequently performed in clinic, although the consequences of this partial meso-caval shunt have not been studied in detail.

Aim: To describe the surgical technique and clinical outcome of a canine intestinal transplantation model using mesenteric-caval graft drainage.

Method: Adult mongrel dogs from University of São Paulo Animal Facility, São Paulo, SP, Brazil, were used as donors and recipients in ten consecutives orthotopic intestinal transplantation with mesenteric-caval venous drainage. Clinical examination and body weight measurement were performed daily in all animals. Necropsy was performed in animals presenting moribund state (lethargic posture, diarrhea and loss of over 35% of body weight) to determine cause of death and histological changes.

Results: Three recipients died before day 2 from technical complications and were excluded from the experiment. The remaining seven animals developed signs of graft rejection with onset on days 3-4 and died or were sacrificed presenting severe graft rejection between days 7-9. Necropsy and histology of the graft confirmed the diagnosis of severe acute cellular rejection.

Conclusion: Small intestine transplantation with systemic drainage in dogs courses with analogous and lethal outcome between postoperative day 7 to 9 due to strong graft rejection. This model serves as an excellent pre-clinical model to study the main complications related to this transplantation.