OBJECTIVE: To evaluate, experimentally, the effects of chemical mucosectomy on colon healing in rats. METHODS: We studied 17 male Wistar rats divided into following groups: A (n=12), colonic anastomosis; B (n=13), colonic anastomosis after use of 10% silver nitrate. The mucosectomy in group B was made by means introduction of 10% silver nitrate pencil into anastomotic surfaces during 1 minute in an extension of 0.5 cm. The anastomosis was made in single plane with evertent sutures of polyvicryl 6-0 in separated sutures. The animals were evaluated in the seventh postoperative day (A1, 6 of the group A and B1, 6 of the group B) and fourth postoperative day (A2, 7 of the group A and B2, 6 of the group B). The anastomosis was evaluated in macroscopic aspect (adherence, fistula, stenosis, perianastomotic abscesses, peritonitis), rupture pressure (mmHg) and histology (inflammatory infiltrate). The data were analysed by Chi-square test (qualitative data) and ANOVA (quantitative data), and considered significative values of p<0.05. RESULTS: None animal presented fistula. The incidence of adherence was no different among the groups. (A1=100%, B1=100%, p= NS; A2=75%, B2=50%, p= NS). There were anastomosis partial obstruction in 25% of group A1, 50% in B1, 25% in A2 and 50% in B2, without significant differences among the groups. The rupture pressure was 27,0 ± 4,5 in A1 group, 34,5 ± 2,0 in B1 group, 28,9 ± 4,2 in A2 group and 24,0 ± 3,4 in group. There was an significant increase in pressure rupture in B1 group when compared with A1 group (p=0,03) and B2 group (p=0,02). CONCLUSION: The chemical mucosectomy with silver nitrate was not associated with increase in postoperative cicatricial complications in wound colon healing in rats. There was, however, an increase in anastomosis strength in early period of the cicatricial process, without influence in latter period.
Intestinal Anastomosis; Mucosectomy; Fistula
