Portal Flow Diversion Is Essential for Graft Survival in Canine Auxiliary Partial Orthotopic Liver Transplantation

Abstract

After auxiliary partial orthotopic liver transplantation for inborn errors of metabolism, finding a balance in portal blood flow distribution between native liver and graft is complicated. We investigated the correction of hypoallantoinuria in the Dalmatian dog with a reduced-size Beagle orthotopic auxiliary liver graft, depending on intra-operative intervention in the portal flow. There were three groups: a ligation group, where the host portal vein was tied off, a free-flow group with random flow to both livers and a banding group, where the host portal vein was banded with an adjustable strapband. Metabolic correction was initially seen in all groups, but ligation led to portal hypertension and early mortality. In the free-flow group, correction was lost after 7 days, while banding preserved correction until 6 weeks. We conclude that acute ligation can lead to portal hypertension and free-flow leads to hypoperfusion and early loss of metabolic correction. Banding divided the portal blood flow between host liver and graft and prolonged metabolic correction.