[Pathogenetic concepts of neonatal necrotizing enterocolitis].

The pathogenesis of neonatal necrotizing enterocolitis is still unknown today. Only prematurity has been confirmed as a primary risk factor. Previous studies demonstrated the special pathophysiological conditions in prematurity. Differences in intestinal permeability, blood flow in anemia and hypoxemia, the uptake, transport, delivery and consumption of oxygen, the digestion of carbohydrates and proteins and in intestinal motility between premature and term infants exist. The diving-reflex too is important for intestinal pathophysiology in these patients. The central key of the pathogenesis is the evident vascular damage. Infectious agents, inflammatory mediators, circulatory insufficiency, feeding excess is followed by the initial mucosal damage. This results in an increased intestinal permeability also for inflammatory mediators, endotoxins, bacteria and gas. Ileus, stasis and gas production cause endotoxinemia and abdominal distension. Increased intraluminal pressure with or without activation of inflammatory mediators leads to an important vascular dysregulation. Consecutively these multiple facts cause the "ischemic looking" hemorrhagic necrosis, we call necrotizing enterocolitis.