Avaliação do efeito da membrana de látex de Hevea brasiliensis no reparo de defeito da parede abdominal de rato

Abstract

The incisional hernia (IH) formation is one complication after abdominal surgery, affecting up to 20% of the reoperated patients. The use of prosthesis increased the repair of IH, however there is not yet an ideal treatment to repair or prevent the IH. The latex membrane from rubber tree has demonstrated to be cicatrizing and angiogenic, both in in vitro and in vivo studies. The aim of this work was to evaluate the effect of the latex membrane on the repair of the injuried abdominal wall of rats. Male Wistar rats with 340 ± 20 g were used and it was induced an abdominal wall defect with 1 x 2 cm and the alba line at the centre. The animals were divided into two experimental groups: Control (without repair) and Latex (with membrane repair) and were euthanized at 3, 5, 7 e 28 days after the defect induction. The abdominal wall fragments were removed, divided into two parts and used for histological and biochemical analysis. The histological analysis revealed that the latex membrane induced blood vessels proliferation, new muscle fiber formation and tissue regeneration. It was also observed a fibroblast density and collagen deposition increasing that is important to increase the resistance to tension forces and prevent the incision dehisce and IH formation. There was also a gradual increasing on the deposition and organization of collagen fibers during the experiment. The latex membrane induced the expression of cellular growth factors, FGF-2 and TGFb; decreased the expression of IGF and PDGF and did not alter the TGFa expression. Tissue regeneration requires the influence of growth factors in a sequence of cellular events that results on the cell regulation, proliferation, surviving and differentiation. The modulation of growth factor by the latex membrane may have contributed positively to the abdominal wall defect regeneration. It can be concluded that the latex membrane from rubber tree, when used to reconstruct the rat abdominal wall, allows tissue regeneration, fiber connective tissue formation and may be used effectively in hernioplasty.