[Pathomorphology of the transjugular portosystemic shunt]

An interventional radiological procedure TIPS (transjugular portosystemic shunt) assists in the decrease of portal hypertension. Portal blood is conducted via the hepatic vein into the lower vena cava. Blood drainage is performed via non-vascular formation, i.e. by the channel created within the liver parenchyma (shunt). Histological changes (maturation) within the wall of an artificially formed blood conducting channel were studied on the base of examination of the set of 38 autopsy cases with the placed TIPS (25 males and 13 females, ages ranging from 22-81 years). Maturation course can be divided into three periods. The first stage is characterised by the presence of alternative changes mainly within the liver parenchyma surrounding the shunt. Reparative changes pass through the second stage with the predominance of liver cell debris removal and organisation of fibrin remnants. Consolidation changes dominate the third stage with the development of so-called neointima and giant-cell reaction around the stent struts. In three cases of the acute period of stent placement a new, so far not described specific phenomenon of compressive fusiform hepatocellular remodellation was found within the nodules of hepatocytes exposed to the pressure of resilient stent struts. Neointima is a non-thrombogenous structure participating on the shunt patency. It is possible to judge approximately the time of stent placement according to the histologically estimated level of shunt wall maturation. TIPS is a long-lasting supplement conduit between the portal and systemic blood circulation. Contrary to the easily reconstructable formal pathogenesis of histological changes, the problems of causal pathogenesis of the neointima challenge mainly the interest of laboratories involved in basic science.