Existe efeito protetor da oxigenação hiperbárica em retalhos cutâneos randômicos?: um estudo imuno-histoquímico de apoptose celular e fator de crescimento vascular endotelial

Abstract

Rev Bras Cir Plást. 2013;28(2):183-90 183 Does hyperbaric oxygenation have a protective effect on random skin flaps?Does hyperbaric oxygenation have a protective effect on random skin flaps? An immunohistochemical study of cellular apoptosis and vascular endothelial growth factor Existe efeito protetor da oxigenação hiperbárica em retalhos cutâneos randômicos? Um estudo imuno-histoquímico de apoptose celular e fator de crescimento vascular endotelial ABSTRACT Background: Hyperbaric oxygenation (HBO) therapy aims to increase oxygen tissue pres sure by at least 10 times and decrease the adverse effects of ischemia. The aim of this study was to investigate the effect of HBO on the immunohistochemical expressions of caspase 3 and vascular endothelial growth factor (VEGF) in random flaps in rats. Methods: Thir tytwo male Wistar rats were randomly divided into 4 groups: the sham group (GS), the Nacetylcysteine group (GNAC), the HBO group, and the HBO + Nacetylcysteine group. A rectangular skin flap (2 × 8 cm) was dissected from the dorsal muscle layer, and a cranial pedicle was preserved. A polyethylene film was placed on the muscle layer, and the flap was fixed in the original site. On the eighth day, biopsy samples (2 × 1 cm) of the entire thickness of the proximal, medial, and cranial areas as well as of the site outside the flap, which was used as a control, were collected. Results: VEGF expression in the skin layers and vessels was not significantly different between the groups. The number of apoptotic cells was significantly increased in the area of the flap in all groups. The highest increase was noted in the GS and GNAC groups. HBO significantly reduced the number of caspase 3positive cells in the skin layers and vessels of the 3 areas. Conclusions: HBO was asso ciated with decreased apoptosis. VEGF expression in the skin layers and vessels did not differ significantly. The results suggest that oxygen diffusion through the interstitial space was the determining factor for the positive effect of HBO on the decrease in apoptosis.

Morphological study of rat skin flaps treated with subcutaneous dimethyl sulfoxide combined with hyperbaric oxygen therapy

“…Kranke et al (2004) in an immunohistochemical study of cell apoptosis performed in random skin flaps, while evaluating apoptosis with various extracts, noticed the protective effects of HBOT in the mid and distal portions of the flap, representing a possible reduction in expression of caspase 3 in the outer skin of the mouse. This suggested that hyperoxygenation in healthy tissues is similar to that occurring during the surgical stimulus (Rocha, et al, 2013). These facts corroborated our findings, which showed that treatment with oxygen therapy was efficient in reducing cell genotoxicity and cytotoxicity.…”

“…The use of random skin flaps has been tested in several experimental animal models of disease (Rocha et al, 2013). These studies have shown its protective efficacy in reducing ischemia and tissue necrosis.…”

Use of derived adipose stem cells to reduce complications of cutaneous scarring in smokers. An experimental model in rats

“…In a random skin flap in 10 x 4cm rats with subcutaneous nicotine injection (2.5: 1 length / base ratio) a mean necrosis of 40% of the total cutaneous flap area is expected 11 . However, in the flaps with 8cm of length by 2cm of base the proportion length / base is greater 4: 1, then a higher percentage of necrosis is expected; in the literature they are described in average 40% without addition of nicotine 13-15 . A description of an experimental model of a rare cutaneous flap in 8x2cm rats with nicotine addition was not found in the literature, which explains the percentage of necrosis in the total area of this study being higher than the others reported in the literature, 69.4%.…”

“…This experimental model was chosen after a pilot project where 10x4cm and 8x2cm flaps were tested and the nicotine concentrations of 2 mg/kg/day and 1.2 mg/kg/day were tested. As it was not possible to handle the analgesia in the group with 10x4cm flaps and as there were frequent seizures in the 2 mg/kg/day group of nicotine, it was chosen to use the 8x2cm experimental model and the nicotine dose of 1.2 mg/kg/day, which simulates the concentrations of a heavy smoker 9,11-15 .…”

“…Next, the flap was sutured with single stitches of 4-0 monofilament nylon thread in the same original position (“donor area”), spaced 1cm apart between stitches 9,11-15 . In the ADSCs treatment group, cells were used in the approximate concentration of 1X106 cells, suspended in 1ml of 0.9% NaCl.…”