HEPATIC VENOUS outflow obstruction has proved to be an important factor in the pathogenesis of ascites formation. Experimental procedures1,2 which involve ligation of the hepatic veins in the dog produce a consistent controllable method for the production of ascites. A comprehensive study of the hepatic circulation by corrosion casts in cirrhotic patients3 led to the conclusion that the primary factor in the pathogenesis of ascites formation in these patients was hepatic outflow block.
It was observed during ex-vivo perfusion of the pig liver in this laboratory that clear fluid was produced on the liver surface and that during outflow obstruction this fluid production increased in quantity. This led to the design of this series of experiments to study the quantitative effect of increasing outflow tract pressures on the rate and composition of ascites formation. A further observation during these experiments, namely the improvement in the gross appearance of