gms | German Medical Science

Objectives/Interrogation: 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. No previous study has investigated if sterile plastic covering a skin lesion would be useful on healing process.

The aim of this study was to evaluate the healing process on induced wounds covered with sterile plastic or 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 sterile plastic (obtained from the sterile urine collector) 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 3 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 thickness/slice). Histological sections of the wound were stained using Hematoxylin-Eosin or PicroSirius red and analysed in microscope (Nikon®)

Results: The plastic group shows a slower healing compared to rayon bandage in a period of 14 days and presented a considerable increase of eosinophils at this time point. At the end of 21 days, collagen fibers type 1 and 3 and fibroblasts were found in the healing tissue in samples covered either with sterile plastic or rayon bandage.

Conclusion: The sterile plastic could be used as a possible low-cost dermal substitute.