Objective: To study the influence of gentamicin-containing sponges on the healing of colonic anastomoses in a rat model of peritonitis.
Design: Controlled laboratory study.
Setting: University hospital, Belgium.
Materials: 40 male Wistar rats.
Interventions: Peritonitis was caused by implantation of a gelatin capsule containing faeces and barium sulphate. The rats then had a colonic anastomosis. They were divided into 4 groups (n = 10 in each). The control group (no additional treatment); a second group in which a plain collagen sponge was wrapped around the anastomosis; a third group in which a gentamicin-containing collagen sponge was wrapped around the anastomosis; the last group in which the animals were given an intramuscular dose of gentamicin.
Main outcome measures: Operative mortality, weight loss and anastomotic bursting pressure four days after the anastomosis.
Results: Seven rats died before necropsy but none in the last group. Peritonitis developed in all rats Weight loss was significantly higher in the plain collagen group. Bursting pressures were similar in the control and two gentamicin groups. In the plain collagen group all the anastomoses but one had broken down.
Conclusion: There was no difference in bursting pressure between rats treated with gentamicin sponges or systemically, and controls. Healing was severely compromised when a plain collagen sponge was used.