THE USE of shunts between the portal venous system and the vena cava or its branches has become a well-established method of combating the complications of portal hypertension.1 The impetus of a reasonable surgical treatment has resulted in an improved understanding of the modes of production of portal hypertension. The frequent disproportion between the level of the portal pressure in intrahepatic disease and the degree of hepatic damage has been studied by Kelty and others.2 These workers find that the regeneration of liver cells which improves hepatocellular function adds to the interference with portal blood flow.
In cases of extrahepatic portal obstruction, the causes are narrowing down to those of congenital nature and those resulting from inflammation and thrombosis of the portal vein with subsequent organization along various lines. This organization may take the form of a single, extremely thick-walled vessel with small lumen, met with in one