Influence of the surgical manipulation of the colon in colonic induced carcinogenesis in rats.

AIM: to investigate the influence of different experimental manipulations in a model of colonic experimental carcinogenesis with pharmacological induction in the rat. EXPERIMENTAL DESIGN: a total of 90 Sprague-Dawley male rats, divided into three groups, were used: non-surgical (n = 30); surgical with colonic trauma (n = 20), and surgical with colo-colonic anastomosis (n = 40). Carcinogenic induction was carried out with 1-2 dimethylhydrazine dihydrochloride. Colonic adenocarcinomas were identified and the number of tumors, as well as tumoral surface and percentage of tumoral surface was established. One-way ANOVA and Chi-square were employed for the statistical analysis. RESULTS: the number of tumors was greater in the surgical group than in the control group, and tumors preferentially developed around the manipulated colon. Surface and tumoral percentage were greater in the surgical group than in the control group, being also greater in the anastomosis group than in the group with colonic trauma. Within anastomosis groups, a greater tumor surface and percentage was found in the group with titanium than in the group with reabsorbable material. CONCLUSIONS: the experimental manipulation of the colon in rats enhances drug-induced colon carcingenesis. The creation of an anastomosis further increases the carcinogenic process compared with simulated anastomosis. This process is also enhanced by the quantity of suture material included in the anastomosis, and by the non-reabsorbable nature of the materials used in the anastomotic line.