The role of gastrointestinal microflora in the pathogenesis of complications of mesenteric ischemia
| Autor: | Samuel E. Wilson, Arnold I. Serota, Robert S. Bennion, Russell A. Williams |
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| Rok vydání: | 1984 |
| Předmět: |
Microbiology (medical)
Pathology medicine.medical_specialty Colon Ischemia Sepsis Bacteria Anaerobic Dogs Embolus Enterobacteriaceae Mesenteric Vascular Occlusion medicine Animals Ascitic Fluid Bacteroides Thrombus Aorta Clostridium business.industry Portal Vein Streptococcus medicine.disease Collateral circulation Infectious Diseases Mesenteric ischemia Shock (circulatory) Anaerobic bacteria medicine.symptom business |
| Zdroj: | Reviews of infectious diseases. 6 |
| ISSN: | 0162-0886 |
| Popis: | Mesenteric ischemia is a catastrophic event, which has a mortality due to florid sepsis that approaches 100%. The demography of the bacterial changes has not been documented. After 72 hr of colonic ischemia in the dog, the total number of anaerobic organisms increased while the number of aerobic organisms decreased. After 24 hr of ischemia, anaerobic bacteria appeared only in the portal vein and persisted. Cultures of peritoneal fluid and aortic blood became positive for the same anaerobic organisms after 48 hr. Acute colonic ischemia promotes a relative overgrowth of intraluminal anaerobic bacteria, which progressively invade the portal vein and later the systemic circulation. Blood flow to the bowel may be reduced by occlusion of the mesenteric vessels with an embolus or thrombus or by shunting of blood away from the gut (as occurs reflexly in shock) to meet the needs of the more vital organs-the heart and brain. Shunting leads to "nonocclusive or low flow" ischemia, where the vessels are mechanically patent but functionally occluded. The severity of the ischemic damage is modified by atherosclerosis, duration of ischemia, small-vessel disease, bowel distension, obstruction, peristalsis, collateral circulation, drugs (such as digitalis), and the bacterial content of the gut. The initial ischemic lesion of hemorrhagic necrosis is limited to the mucosa of the bowel. With timely correction of the reduced mesenteric blood flow, the mucosa of the bowel may be the only region of the gut wall to sustain ischemic damage. Persistence of the disturbed blood flow, however, leads to ischemic necrosis of the submucosa and seromuscular layers. The gut wall is then gangrenous-an irreversible lesion treatable only by surgical extirpation. The traditional explanation given for the fact that the mucosa is the region most sensitive to ischemia is that metabolic activities are concen |
| Databáze: | OpenAIRE |
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