The effect of azathioprine on anastomotic healing: An experimental study in rats

PURPOSE: The cytotoxic and immunosuppressive effects of azathioprine, which mitigate the disease activity in inflammatory bowel disease, may compromise the healing of intestinal anastomoses leading to an increased risk of anastomotic leakage. The effect of azathioprine treatment on intestinal healing was tested. METHODS: In an experimental study, rats were randomly given one oral dose of azathioprine (5 mg or 20 mg/kg body weight per day) or placebo. After 28 days of treatment, a left colonic anastomosis was performed. After three days of healing, the breaking strengths of the anastomoses were tested, along with measurements of azathioprine major metabolite concentrations: 6-thioguanine and 6-methyl-mercaptopurine. RESULTS: There were no significant differences in the anastomotic breaking strength between the three groups. CONCLUSIONS: Daily treatment for four weeks with high or low azathioprine doses has no inhibitory effect on colonic healing in rats.