gms | German Medical Science

Introduction: Polytrauma patients usually have severe wounds, which require prolonged and costly treatment. Deep skin lesions are characterized by destruction of epithelial tissue and exposure of structures such as fascia, muscles, tendons, and nerves. The healing process occurs through contraction of the wound edges and has three phases: inflammation, epithelization and remodeling, until tissue integrity is achieved.

At the closure of these lesions, the simplest form should be used, seeking the best method to achieve the normal function of the limb affected by the lesion.

Dermal substitutes are widely used in the areas of reconstructive and plastic surgery, and one of the most widely used is the Single Layer Integra®. Nevertheless, no previous study has evaluated the evolution of skin healing through histological analysis in induced wounds.

Objective: This study aimed to investigate the healing process in induced wounds covered with Integra® and rayon bandage in rats.

Methods: We used adult male Wistar rats (~ 420 g, N=9). All procedures were approved by the Animal Ethics Committee. Each rat was anesthetized with 2% isoflurane in 100% O2 and two lesions with 2 X 2 cm separated by 1 cm of distance were carried out in the skin of the rat's back. The lesions were covered with Integra® or rayon bandage (control) and the edges of both coverings were sutured in the rat skin with 3.0 mm nylon suture. Veterinary Pentabiotic (2000 U/mL, i.m., single dose) was used as prophylactic measure and tramadol (10 mg/kg i.m., every 12 h) was injected for 2 days after surgery for analgesia. At 7, 14 or 21 days after performing the surgery, rats (N=3/group) were euthanized with sodium thiopental (100 mg/kg, i.p.) and the lesion sites were sampled and stored in 10% formalin solution for histological preparation. The tissues were embedded in paraffin and sliced in microtome (20 m thickness/slice). Histological sections of the wound were stained using Hematoxylin-Eosin or PicroSirius red and analysed in microscope (Nikon®).

Results and Conclusions: The tissue samples covered with Integra® presented as good cicatrization as rayon bandage at 7 and 14 days, with migration of fibroblasts and collagen type 1 and 3 formation. The great migration of fibroblasts was observed at 21 days, in which the healing was completed.

The data suggest that Integra® act as a great dermal substitute helping for fast skin healing.