Vascular Lesions in Hemorrhagic Pancreatitis

Abstract

The cause of the extensive hemorrhage which occurs in hemorrhagic pancreatitis has long been a matter of speculation. Diapedesis of red cells from capillaries has been said to occur as a result of the action of trypsin, but no one has demonstrated that trypsin has the power to destroy the walls of previously intact arteries and veins, and in the only histological study of the question which we have been able to find it is stated that the ferment does not attack vessels larger than capillaries. 1 Our microscopical studies of the pancreas in cases of hemorrhagic pancreatitis have revealed the constant and, as far as we can determine, hitherto unrecognized presence of a specific form of necrosis of the walls of arteries and veins, leading to the rupture of the vessels with consequent hemorrhage. We have found the same vascular lesions in experimental hemorrhagic pancreatitis produced by the injection of irritants into the pancreatic ducts of dogs, following the procedure of Opie 2 and Flexner³; and we have determined experimentally that this vascular necrosis is the direct result of the action of pancreatic juice upon the walls of the vessels, and that the agent in the juice responsible for the necrosis is trypsin. Pancreatic juice, or pancreatic trypsin freed from lipase, when injected subcutaneously produces in the vessels at the site precisely the same vascular necrosis with hemorrhage as that which occurs regularly in hemorrhagic pancreatitis, and when trypsin is injected into the pancreas hemorrhagic pancreatitis results. The activation of trypsinogen by enterokinase is not necessary for the production of the vascular necrosis, for pancreatic juice obtained by cannulating the pancreatic duct outside the duodenum produces local vascular necrosis and hemorrhage when injected into the subcutaneous tissue. We have not yet determined precisely what it is that serves to activate trypsinogen when it is injected into the tissue. It is, however, clear from our experiments that if pancreatic juice escapes about blood-vessels in the substance of the pancreas, necrosis of the vessels with hemorrhage (hemorrhagic pancreatitis) can occur.