The present experiment has as a purpose to study comparatively the effect of absorbable and unabsorbable mesh, as a reinforcement in the closing of the median abdominal incisions in rats, in the situation of the partial approximation of the borders of the aponeurosis. For this, 45 male rats of the Wistar breed were studied, divided into three groups, in which the procedure was in the following manner. "Control group": median abdominal incision reaching the peritoneal cavity followed only by the closing of the skin and subcutaneous celular. "Vicryl group": median abdominal incision reaching the peritoneal cavity followed by a reinforcement with vicryl mesh, overlaid in the form of a bridge over the aponeurosis, maintaining the lips of the aponeurosis distant amid themselves by 1,0 cm. "Marlex group": the procedure is identical to the "vicryl" group, substituting the vicryl mesh by the marlex mesh. After one year the animals were sacrificed and submitted to a microscopic valuation as to the presence of hernias and adherences to the meshes; checking the tension resistance of the surgical scar through the traction by dinamometer and histological study of the following phenomenons of the cicatrization; chronical inflamatory reaction, foreign body type granulomatosis inflamation, granulation tissue, fibroblastic hyperplasia and fibrosis. Only animals of the "control group" developed hernias in the final experiment. There was no significative formation of intestinal adherences in any of the group studied. The tension resistence was significantly greater in the animals in which meshes were applied for reinforcement. The chronical inflamatory reaction and the foreing body type granulomatosis inflamation were much more intense in the group in which marlex was used, than in the other groups. As to the granulation tissue and fibroblastic hyperplasia,they were absent in all the groups. The fibrosis was more intense in the group in which the meshes were employed. Its is concluded that the utilization of meshes in this situation avoids the hernia development in the follow up of one year, because it granted a greater tensile resistance of the abdominal wall the employment of the vicryl mesh, besides offering this resistance, still makes it with less chronical inflamatory reaction and foreign body type granulomatosis inflamation.
Surgery; Laparotomy; Hernia; Surgical mesh
