In suppurative pancreatitis a single abscess or multiple abscesses may form, or there may be diffuse purulent infiltra tion of the surrounding tissues. Perfo ration into the stomach or duodenum may occur. Fat-necrosis is rare in these cases.
Septic thrombus of the splenic vein may form and lead to infection of the portal vein and multiple abscesses in the liver. The spleen is not usually much enlarged. The pleura and pericardium may become infected by extension of the inflammatory process through the dia phragm. Various bacteria, especially the colon bacillus, are found in the af fected tissues.
The constancy of the presence of fat necrosis in litemorrhagic and necrotic pancreatitis is a striking feature of dis ease of the pancreas. The condition is rarely met with apart from affections of the pancreas. It has been produced ex perimentally by inserting pieces of pan creas beneath the skin or into the sub peritoneal fat, and by experiments on the pancreas itself. The areas vary greatly in size, some being as small as a pin's head, others as large as a hen's egg. They are soft in consistence. Flex ner has found a fat-splitting ferment in them; it disappears within a few days.
Pancreas examined in 75 cases. In 11 total necrosis of connective tissue was found, the protoplasm of the cells being homogeneous and the nuclei staining poorly or not at all; in 29 cases there was disseminated necrosis of the acini and connective tissues; in the remain ing cases there was no necrosis. The necrosis is evidently one of autointoxica tion. Chiari (Zeit. f. Heilk., B. 16, p. 70, '96).
The best results of obtaining fat necrosis were obtained after ligating the veins and lacerating the pancreas on cats and dogs. The necrosis varied in extent and size from that of a pin's head to that of a pea. Although it cannot be confirmed that steapsin was the direct cause of necrosis of the tissue, such an assumption is rendered highly probable by its constant occurrence in diseased areas and its absence from healthy fat and the nature of the pathological changes. The escape of the pancreatic secretions into the peripanereatic and parapancreatie tissues is the origin of the necrosis. This escape is chiefly the outcome of lesions of the pancreas, but also of disturbances in its circulation.
The pancreas in case of fat-necrosis suf fers in two ways: it undergoes necrosis in the same way as the adipose tissue, or it is invaded by new growth of con nective tissue, not limited strictly to the field of necrosis. In this way small nodules characteristic of interstitial pan ereatitis, with a loss of parenchyma, may be formed. Flexner (Jour. Exper. Med., July 1, '97).
Fat-necrosis appears in the fat on the surface of the pancreas and vicinity; similar nodules may be present in the fat of the peritoneum at points more re mote, denominated disseminated or mul tiple fat-necrosis. Peritonitis is not usually present. Pancreas studied in SO dead subjects, and fat-necrosis found in only 2. Pancreas of 100 hogs examined, and fat-necrosis found in the interlobular fat in 2. In some instances the fat nodules were found sterile. The bacillus coil communis was oftenest present. H. U. Williams (Med. Record, July 10, '97).
Experimental work upon pancreatitis leads to the conviction that (1) }hemor rhage per se is a common condition in all forms of pancreatitis; (2) when it is excessive, it dominates the process; (3) it is usually more pronounced than the inflammatory legions, and the two con ditions may be separate and distinct in the same organ or parts of the organ; (4) fat-necrosis is due to perversion of the pancreatic secretion and the direct result of the action of the fat-splitting ferment. to the severity of the means used to provoke pancreatitis in experimental eases, it is not to be sup posed that lhemorrhage would commonly occur independently of inflammation of the gland; and this is found to be the ease. The distintegration of the pan creatic tissue is one of the results of free haemorrhage. lf, now, tendency of the pancreatic secretion to act the pan ereas, as has been pointed out by Blume and by Chiari, is recalled. it follows that these injured foci might easily become the starting-points of another form of degeneration which would lead to necro sis of the gland and to reactive inflam mation: that this dead tissue might then in turn form a favorable point for the location and multiplication of micro organisms, whose presence would still further complicate the process. Simon Flexner (Univ. Med. Mag., Jan., 1901).