Small intestinal necrobiosis and its relationship to the pathogenesis of extraintestinal lesions in haemorrhagic shock and sublethal superior mesenteric occlusion

We have demonstrated that following sublethal clamping of the superior mesenteric artery and haemorrhagic shock a highly characteristic pattern of parenchymal degenerative changes occurs in the heart, liver, kidney, lung and brain of surviving animals. The extraintestinal lesions are strikingly similar in nature, distribution and time of appearance in both shock groups. Necrobiosis of the entire epithelial surface of the small bowel appears to be the common denominator between these two preparations. Two major conditions were identified, therefore both of which must prevail before organic lesions will result. The all important one was an ischaemic injury to the small bowel such as was produced by a period of severe hypotension or temporary occlusion of the superior mesenteric artery. The second condition was related to the nature of the intestinal content. The intestinal chyme should consist of the derivatives of normal food. If both these conditions were met we demonstrated that re-establishment of the circulation after retransfusion or removal of the occlusion, did not prevent the gradual deterioration towards intestinal necrobiosis. We feel that pancreatic proteolytic enzymes function merely as an adjunct to intestinal necrosis