Effect of gentamicin-containing sponges on the healing of colonic anastomoses in a rat model of peritonitis

Objective: To study the influence of gentamicin-containing sponges on the h ealing 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 anastomo sis. They were divided into 4 groups (n = 10 in each). The control group (n o additional treatment); a second group in which a plain collagen sponge wa s wrapped around the anastomosis; a third group in which a gentamicin-conta ining 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 bur sting pressure four days after the anastomosis. Results: Seven rats died before necropsy but none in the last group. Perito nitis developed in all rats Weight loss was significantly higher in the pla in collagen group. Bursting pressures were similar in the control and two g entamicin groups. In the plain collagen group all the anastomoses but one h ad broken down. Conclusion: There was no difference in bursting pressure between rats treat ed with gentamicin sponges or systemically, and controls. Healing was sever ely compromised when a plain collagen sponge was used.