Cholangio-venous reflux as a cause of recurrent hyperamylasemia in choledochal dilatation with anomalous pancreaticobiliary ductal union: an experimental study.

Cylindrical choledochal dilatation, associated with anomalous pancreaticobiliary ductal union, causes recurrent episodes of right hypochondrial pain, vomiting, and fever. The symptoms are very often accompanied by hyperamylasemia, which is generally considered to be due to acute pancreatitis. However, our clinical experience and experimental studies have led us to the conclusion that pancreatitis is not the sole cause of hyperamylasemia. In this paper we report our further investigations of the cause of the hyperamylasemia. In 22 mongrel adult dogs, intracholedochal infusion was performed under a continuous hydrostatic pressure of 20 cm H2O for 2 hours. Solutions of amylase from three different sources and a lipase were used in the range of concentrations found clinically in the bile within a cylindrical choledochal dilatation. In the 3 groups, hyperamylasemia was proven by quantitative estimation of serum amylase level and/or by the changes in specific amylase isozymes. Lipase was also shown to transfer into the blood stream. In an additional experiment on 5 dogs, only the extrahepatic biliary tree, including the gallbladder, was infused with a solution of amylase from Bacillus subtilis. This produced no increase in the serum amylase. Our experiments suggest that amylase passes from the hepatocholedochal system into the blood stream. This phenomenon has long been known as cholangiovenous reflux.