Changes in liver function and structure due to experimental passive congestion under controlled hepatic vein pressures

Abstract

The effect of various hepatic vein pressures on hepatic hemodynamics, on fluid shifts within the liver, and on certain indices of liver function were studied in the isolated rat liver preparation. In general, venous pressures are scarcely perceived by the hepatic parenchyma unless they exceed the hydrostatic pressures acting at the liver surface, more particularly at the hilum of the liver. Venous pressures exceeding this value appear to distend the liver vasculature so that it acts like a system of rigid conduits; there is great expansion of the sodium space and of the colloid distribution spaces, and some evidence of partial sequestration of blood in the congested liver. All these changes impair oxygen supply to the tissue. To a lesser extent they interfere with the transfer of other substances from blood to parenchyma, and place considerable stress upon the mechanical framework of the liver. The resulting strain in turn tends to limit the extent of intrahepatic changes in passive congestion, and possibly the rate of fluid leakage from blood via parenchyma to transudate at the liver surface.