Effect of early postoperative feeding on the healing of colonic anastomoses in the presence of intra-abdominal sepsis in rats.

PURPOSE: Intra-abdominal infection is generally considered a major risk factor for dehiscence of primary colon anastomosis. To elucidate the indications for nutritional support during intra-abdominal sepsis, we investigated the healing of anastomoses in an animal model.
METHODS: Twenty male Sprague-Dawley rats (280-320 g) underwent cecal ligation and single puncture. After 24 hours the perforated cecum was removed, and the left colon was transected and anastomosed in a single-layer inverted fashion. Animals were randomly assigned to receive both chow and water (early-fed group; n = 10) or water alone for the first 72 hours and chow thereafter (late-fed group; n = 10). Colon-bursting pressure was measured five days after the anastomosis, at which time the anastomosis was excised.
RESULTS: The survival rate after cecal ligation and single puncture was 100 percent, and blood cultures were positive in 20 percent of animals five days after surgery. All data are expressed as means +/- standard error of the mean. Body weight increased more in the early-fed group than in the late-fed group (15.6+/-3 vs. -6.3+/-2.8 g; P < 0.001). Early feeding resulted in increased anastomotic bursting pressure (200+/-11 vs. 161+/-12 mmHg; P < 0.05) and total collagen concentration at the site of anastomosis (2.36+/-0.09 vs. 2.01+/-0.07 microg/mg wet tissue; P < 0.01) compared with the late-fed group.
CONCLUSION: Early feeding has a positive effect on anastomotic healing in the presence of intraabdominal sepsis. The mechanism by which early feeding enhances the colonic anastomotic healing is unclear, although preservation of colonic collagen seems to play a significant role.