Microperforation of the colon: animal model in rats to reproduce mucosal thermal damage.

BACKGROUND: The aim of the present study was to develop a rat model of colonic microperforation secondary to thermal injury for future studies to assess new treatments. METHODS: Twenty-four male Sprague-Dawley rats were used in this study. Hot biopsy forceps were used for all treatments. All lesions were created in proximal left colon using the soft coagulation setting. The power setting tested was 40 W, and the durations of monopolar soft coagulation application evaluated were 2, 3, and 4 s. RESULTS: In the acute phase, 48 h after thermal injury, durations of cautery of 2 and 3 s resulted in transmural necrosis, whereas with 4 s microperforation was obtained. In the late phase, 7 d after the damage, only duration of cautery of 4 s showed deep cautery effects, with signs of peritonitis. CONCLUSIONS: We determined optimal power settings and duration of therapy in a rat model for producing electrocautery that involves transmural necrosis with microperforation.