Enxerto omental livre sem anastomose vascular na cicatrização cutânea de ratos

Abstract

The healing process in mammals is intimately connected to the maintenance of the internal environment and to the survival of the animal, being influenced by several factors, such as local vascularization, nutritional status, healthiness, presence of infection and concomitant diseases, among others. Biological materials have been recommended in the cicatricial process due to its analgesic and antibacterial attributes, accelerate the formation of granulation tissue and epithelization, provide a barrier to bacterial invasion. The omentum has been used in human and veterinary medicine related to the healing of wounds, through pedicled or free grafts, since before 1900, however, the mechanism by which there is assistance in the resolution of injuries is not fully comprehended. The presence of wide vascularization and innate and specific defense cells, called “milky spots” and mesenchymal pluripotential cells has been determined as preponderant to promote healing and regeneration in injured tissues. The objective of this study was to evaluate the viability and influence of the free omentum graft without vascular anastomosis on the healing process of cutaneous wounds in male Wistar rats, which were divided into four groups of seven animals, two control groups (CT7 and CT14) and two treated (OM7 and OM14), and the following evaluations were performed: macroscopy and morphometry of the wounds, histopathological analysis, quantification of type I and III collagen fibers, and research of cytokines and growth factors, such as Vascular Endothelial Growth Factor (VEGF), Fibroblast Growth Factor (FGF) and Transforming Growth Factor-β (TGF-β), through immunohistochemistry and gene expression made by polymerase chain reaction technique. In the macroscopic results, the graft remained viable in the wound in in all treated animals, without major complications. Compared to the CT14 group, in the OM14 group there was a significant increase in mononuclear infiltrate and a decrease in TGF β at 14 days, with no statistical difference in the other parameters and moments of evaluation. These findings in the mononuclear infiltrate and the quantification of TGF-β at 14 days postoperative, are possibly due to the immunomodulatory capacities of the omentum. It can be concluded that the use of autologous free omentum without vascular anastomosis in cutaneous healing is effective and viable, with no rejection, loss of graft or absence of healing in acute wounds in healthy rats.