Peritoniostomia com polipropileno revestido por látex : estudo experimental em ratos

Abstract

Correction of large abdominal wall defects leads to the use of synthesis material. There is no ideal prosthesis and, polypropylene is the most used material, although it causes a lot of adhesions formation. Many prosthetic materials have been tested, but until now none have been found to be totally satisfactory. In 1994 a latex based material was developed and used in humans as a biologic dressing for chronic phlebopathic cutaneous ulcer and for pterygium surgery. Objective: To determinate if the biologic activities for adhesions formation in the abdominal wall reconstruction using a polypropylene latex coated mesh is more adequate than polypropylene mesh alone. Methodology: 90 male Wistar rats were distributed in 3 equal groups. Group I (control) - The animals were submitted to a 4 cm medial laparotomy with peritoneal cavity exposition and posterior closure (synthesis); Group II (polypropylene) - The animals were submitted to the resection of a 2.0 cm x 3.0 cm of abdominal wall, and the defect was corrected with a polypropylene mesh; Group III - The animals were submitted to the same procedure, but using the new material (polypropylene latex coated). After 45 days the euthanasia procedure was done and the adhesions were evaluated in 2 ways: 1) classification in a grading system from 0 to 5 according to the number, resistance and structures evolved; 2) Evaluation of the adhesion area that was calculated by dying with India ink the abdominal wall segment that had adhesions, though producing a clear area in contrast with the rest of the dyed areas. Results: The group I animals did not have any complications, whereas in Group II eight animals died, nevertheless one occurred in the immediate post operative period because of bleeding. In Group III nine animals died, one because of the anesthetic procedure, and 8 because of complications related to the surgical procedure (fistula, evisceration and obstruction). The classification in a grading system showed that Group III animals had lesser adhesions formation (P<0.05), but the evaluation of the adhesions area did not show the same result (P>0.05). The severe complications (fistula, evisceration and obstruction) that caused the death were not reduced by the latex coated material. Conclusion: The polypropylene latex coated material causes lesser adhesions formation than polypropylene alone, nevertheless does not diminish the severe early complications.