Bacterial Translocation After Mesenteric Ligation in Dogs

Abstract

These experiments were designed to determine the relationship between translocation of Escherichia coli and viability of ischemic small bowel. Twenty beagles were gavaged with ¹⁴C-labeled E. coli at two time intervals (3 and 24 h) prior to ligation of the blood supply to a 40-cm segment of ileum. Mesenteric lymph node (MLN) biopsies and bacterial cultures of the peritoneal fluid, peripheral arterial blood, and splanchnic venous blood were taken immediately prior fo ligation and 24 h later both before and after the ischemic bowel was resected and anastomosed. Biopsies of each resection margin were taken to measure translocation of E. coli into the bowel wall. Several hemodynamic parameters were also measured before and 24 h after ligation. Seven of the 20 dogs died of further bowel necrosis. In survivors A-a DO₂was significantly decreased 24 h after mesenteric ligation vs. preligation, whereas in dogs that died DO₂ was significantly increased after ligation vs. preligation. The incidence of mesenteric venous cultures positive for E. coli was significantly higher 24 h after ligation vs. preligation. However, there was no correlation between survival and the incidence of positive E. coli cultures in the blood or peritoneal fluid. Mean MLN counts were significantly higher in dogs gavaged at 3 h vs. those gavaged 24 h prior to laparotomy. However, there was no correlation between survival and translocation into either the bowel wall or MLN at either time interval. Viability of ischemic small bowel in this canine model was not affected by translocation of E. coli. Hemodynamic parameters that are altered during the course of sepsis also did not correlate with survival.

Key Words:

• bacterial infection
• bioengineering
• intestinal blood flow
• intestinal motility
• radioisotopes
• sepsis
• small intestine