Bacterial translocation and mortality on rat model of intestinal ischemia and obstruction

Abstract

Purpose: To develop an experimental model of intestinal ischemia and obstruction followed by surgical resection of the damaged segment and reestablishment of intestinal transit, looking at bacterial translocation and survival. Methods: After anesthesia, Wistar rats was subject to laparotomy, intestinal ischemia and obstruction through an ileal ligature 1.5cm of ileum cecal valve; and the mesenteric vessels that irrigate upstream of the obstruction site to approximately 7 to 10 cm were ligated. Abdominal wall was closed. Three, six or twenty-four hours after, rats were subject to enterectomy followed by an end to end anastomosis. After 24h, mesenteric lymph nodes, liver, spleen and lung tissues were surgically removed. It was studied survival rate and bacterial translocation. GraphPadPrism statistical program was used. Results: Animals with intestinal ischemia and obstruction for 3 hours survived 24 hours after enterectomy; 6hx24h: survival was 70% at 24 hours; 24hx24h: survival was 70% and 40%, before and after enterectomy, respectively. Culture of tissues showed positivity on the 6hx24h and negativity on the 3hx24h. Conclusion: The model that best approached the clinic was the one of 6x24h of ischemia and intestinal obstruction, in which it was observed bacterial translocation and low mortality rate.

Morphofunctional Changes of Blood Supply and the Glycogen Content in the Liver during Acute Strangulational Small Bowel Obstruction

“…The results of our study coincide with the conclusions presented in cases [3,4] and confirm that the liver is the first target organ on which the main impact of toxemia occurs in the form of a massive supply of biologically active substances and toxic products via the portal vein with blood, formed during ischemia and/or necrosis of tissues of the pathologically altered portion of the small intestine.…”

“…Acute intestinal obstruction incidence is 1.2 -14.2% of cases of all acute surgical diseases of the abdominal cavity [1][2][3][4]. In case of ASBO complicated with peritonitis, the mortality is 25 -70%.…”

“…In the case of ASBO, the liver appears to be the first target organ, which takes the main impact of toxemia in the form of a massive supply of blood with biologically active substances and toxic products resulting from ischemia and/or tissue necrosis of the pathologically altered small intestine through portal vein [4,12]. Toxins exert a direct damaging effect on liver cells, damage the membrane structures of hepatocytes and disrupt the transmembrane transport of hydrogen and other substrates, which in turn leads to discoordination of metabolic processes and subsequently with the progression of the disease to cell death.…”

Effect of N-Acetylserotonin on TLR-4 and MyD88 Expression during Intestinal Ischemia-Reperfusion in a Rat Model

“…Extensive studies in various experimental models have established that the integrity of the gastrointestinal mucosa is a key element in maintaining gut barrier function. 20,21 The mechanisms of impaired gut barrier function in patients following intestinal IR are poorly understood and include decreased intestinal motility leading to bacterial overgrowth, reduction in gut-associated lymphoid tissue following loss of intestinal length, inhibition of mucosal immunity of the small intestine by intravenous TPN, and changes in intestinal permeability to macromolecules. 22 Intestinal epithelial cells express a variety of potential sensing receptors, including TLRs, that may play a role in mucosal responses to microbial components.…”

Efeitos da N-acetilcisteína na resposta inflamatória e na translocação bacteriana em modelo de obstrução e isquemia intestinal em ratos

“…Houve elevação 6 horas após isquemia e obstrução intestinal em relação ao momento inicial, e queda 24 horas após enterectomia e anastomose, variando com a reanimação utilizada ou não, denotando a indução de resposta inflamatória do modelo, e sua diminuição após a terapêutica cirúrgica. Entretanto, não se observa efeito protetor da NAC Antes de estabelecer o intervalo de 6 horas de obstrução e isquemia intestinal, seguida de ressecção do segmento necrosado e coleta de sangue e tecidos 24 horas após, realizamos um estudo para estabelecimento do intervalo de tempo mais adequado para obter translocação bacteriana com sobrevida que permitisse os estudos de resposta inflamatória [50]. O período de 6 horas em regime de obstrução intestinal associada a isquemia pela ligadura dos vasos ileais mostrou-se eficaz em induzir translocação bacteriana e baixa mortalidade.…”