Heterotopic Auxiliary Liver Transplantation with Portal Flow

摘要

One of the causes of auxiliary liver transplantation failure is the inter-liver competition between the hostliver and the graft for the hepatotrophic factors of the portal blood. We have developed an experimentalmodel of heterotopic partial (30%) liver isotransplant using Wistar rats so as to study this competition.Splenoportography and dissection demonstrate the existence of collateral circulation. The collateralsat 90 days post-transplant (PT) consisted of veins from the portal vein to the host liver (PR),paraesophageal veins (PE) and splenorenal veins (SR). At 60 days P.T., PR and SR veins but not PEones appeared, and at 30 days P.T., there were only PR veins. Graft atrophy at 90 days P.T. wasassociated with a severe degree of bile duct proliferation.The gradual development of portal hypertension causes porto-systemic collateral circulation and thegraft loses the portal hepatotrophic factors. The late development of the portal hypertension and thebiliary proliferation could be caused by the hepatic arterial ischemia in this experimental model. Thus,as has been described in the orthotopic liver tansplantation, the heterotopic one might require a doublevascularization, both portal and arterial.