Pathogenesis of acute pancreatitis: pancreatic ductal-interstitial-vascular and lymphatic pathways.

The generally accepted theory explaining the pathogenesis of pancreatic autodigestion (acute pancreatitis) is analysed. The pathways are discussed through which the content of the pancreatic duct system, the digestive enzymes, may escape to enter the acinar cells and the pancreatic interstices, together with the effect of the enzymes on the pancreatic vessels and thus on pancreatic blood flow. The potential consequences of vascular damage are described as well as the importance of pancreatic lymphatics in the transport of the escaped enzymes from the interstices. Although no definite answer can be given to the basic problem whether acute autodigestion of the pancreas is a result of some intra- or extra-acinar process, it is suggested that the intra- and extra-acinar processes are linked and are decisive in launching the pathological process.