The Effect of Peritoneal Contamination on Wound Strength of Small Bowel and Colonic Anastomoses

Abstract

Primary bowel repair in the face of peritoneal soilage is still a controversial area. Previous studies using the rat model have demonstrated a difference in new collagen synthesis after 24 hours of peritoneal contamination. Currently, the effect of short-term fecal contamination of the peritoneal cavity on anastomotic healing and strength is not known. This study was designed to evaluate anastomotic wound strength in the face of fecal contamination during this time period. Twenty Sprague Dawley rats were randomized into two groups: twelve-hour control (n = 10) and 12-hour cecal ligation and puncture (CLP; n = 10). Both groups underwent laparotomy with either CLP (12-hour) or cecal manipulation (12-hour control). Animals were allowed to recover for 12 hours, according to their assigned groups. A second laparotomy was subsequently performed in which the CLP groups had partial cecectomy to remove the source of contamination, followed by mid-jejunal and colonic division with associated primary anastomosis. Control groups had a similar procedure without partial cecectomy. All abdomens were irrigated, and all animals received immediate postoperative antibiotics and an initial fluid bolus. Animals were recovered and received 3 days of postoperative antibiotics. On postoperative day 4, animals were sacrificed and anastomotic sites were resected. Specimens were then placed in a tensiometer and disrupted under dynamic stress. Peak load was recorded for each, and maximum standard load was calculated. Hydroxyproline content of each segment was also determined after disruption. CLP values were compared with control values using unpaired Student's t test. Statistical significance threshold was P < 0.5. There was no significant difference in maximum anastomotic wound strength or hydroxyproline content between 12-hour CLP and 12-hour control group for both small bowel and colon anastomoses. Short-term peritoneal soilage (12-hour) does not significantly effect the maximum tensile strength or hydroxyproline content of primary small bowel or colonic anastomoses in this model. This study suggests that short-term fecal contamination of the peritoneal cavity may not be a contraindication to primary bowel anastomosis.