The pathogenesis of acute biliary pancreatitis: a controversial issue. Part I. The concept of biliopancreatic reflux.

The pathophysiologic mechanism by which gallstone migration through the sphincter of Oddi may produce acute pancreatitis is a controversial issue. According to one concept, biliopancreatic reflux following concrement obstruction of the common biliopancreatic channel results in contact of bile with pancreatic parenchyma which is known to produce acute pancreatitis. However, the entrance of bile into pancreatic tissue is usually prevented by the pancreatic duct sphincter, by the pancreatic exocrine secretion pressure and by the pancreatic duct mucosal barrier. A breakdown of these protective mechanisms is an essential prerequisite for the validity of this concept. Relevant clinical and experimental data concerning this possibility are reviewed.