Cavo-portal transposition in rat: a new simple model

Spontaneous porto-systemic shunts are induced by subcutaneous transposition of the spleen. The presence of porto-caval shunts through the spleen permits the interruption of the main portal vein without splanchnic hemodynamic consequences. Cavo-portal transposition is achieved by anastomosing the inferior vena cava and the main portal vein after division of the pancreatic-duodenal vein.Selective angiography revealed total splanchnic blood diversion to the systemic venous circulation through the neoformed collaterals; macroscopical examination showed the absence of any signs of acute portal hypertension with normal liver and gut appearance.This model of cavoportal transposition is simple, effective and it simulates the clinical hemodynamic condition since the porto-systemic shunts induced by splenic subcutaneous transposition correspond to the physiological inframesocolic collaterals during chronic portal thrombosis in man.Thrombosis of the portal vein has been a formidable challenge in liver transplantation and it was historically considered an absolute contraindication [1]. Refinements in surgical techniques in the last decades allow surgeons to overcome portal thrombosis with progressive extensions, by using phlebothrombectomy, venous jump grafts or portal vein arterialization [2,3]. Moreover, the use of caval blood as unique portal inflow has been used recently to performed liver transplantation in patients with diffuse splanchnic thrombosis: in this setting graft portal flow has been obtained by end-to-end or end-to-side porto-caval anastomosis or by reno-portal anastomosis [4-6].Patients with chronic thrombosis without portal hypertension are the best candidates due to the presence of wide spontaneous porto-systemic shunts that completely supply the splancnic vein drainage [7].The results of these techniques are still heterogeneous and further experimental and clinical studies are needed to clarify the role of spontaneous porto-systemic shunt on liver function a