Photobiomodulation Increases Viability in Full-Thickness Grafts in Rats Submitted to Nicotine.

BACKGROUND AND OBJECTIVES: Photobiomodulation (PBM) therapy with 830 nm wavelength or 660 wavelength to compare the effects with parameters of 30 mW, 0.028 cm2 , 9.34 seconds, and 3.64 J on the total integration of total skin grafts in rats submitted to nicotine. STUDY DESIGN/MATERIALS AND METHODS: Sixty male Wistar rats were divided in six groups: Sham-skin-grafting surgery; 830 nm-skin-grafting followed by 830 nm irradiation; 660 nm-skin grafting followed by 660 nm irradiation; Nicotine-subjected to subcutaneous nicotine injection (2 mg/kg twice a day for 4 weeks), followed by skin grafting; Group Nicotine/830 nm-similar to Group Nicotine, followed by 830 nm irradiation; Group Nicotine/660 nm-similar to Group Nicotine, followed by 660 nm irradiation. The percentage contraction of the grafting tissue was evaluated through ImageJ®. The thickness of the epidermis, inflammatory infiltrates, and the space between the implanted tissue and receptor bed were determined by histology; and the expression of vascular growth factor and blood vessel density (factor VIII) were evaluated by immunohistochemistry. RESULTS: The PBM at both wavelengths promoted a facilitating effect on the integration of the skin graft under nicotine and had a more significant effect on the thickness of the epidermis and expression of angiogenesis without nicotine at a wavelength of 830 nm. Different wavelengths influence responses related to the viability of cutaneous grafts in rats submitted to nicotine. CONCLUSIONS: The PBM with 830 nm and 660 nm promoted beneficial results in skin grafts submitted to the deleterious action of nicotine. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Photobiomodulation laser and pulsed electrical field increase the viability of the musculocutaneous flap in diabetic rats.

The purpose of this study is to investigate the effect of pulsed electrical field (PEF) and photobiomodulation laser (PBM) on the viability of the TRAM flap in diabetic rats. Fifty Wistar rats were divided into five homogeneous groups: Group 1-control; Group 2-diabetics; Group 3-diabetics + PEF; Group 4-diabetic + laser 660 nm, 10 J/cm2, 0.27 J; Group 5-diabetic + laser 660 nm, 140 J/cm2, 3.9 J. The percentage of necrotic area was evaluated using software Image J®. The peripheral circulation of the flap was evaluated by infrared thermography FLIR T450sc (FLIR® Systems-Oregon USA). The thickness of the epidermis (haematoxylin-eosin), mast cell (toluidine blue), leukocytes, vascular endothelial growth factor, fibroblast and newly formed blood vessels were evaluated. For the statistical analysis, the Kruskal-Wallis test was applied followed by Dunn and ANOVA test followed by Tukey with critical level of 5% (p < 0.05). The PEF reduced the area of necrosis, decreased the leukocytes, increased the mast cells, increased the thickness of epidermis and increased newly formed blood vessels when it was compared to the untreated diabetic group of animals. Laser 660 nm, fluence 140 J/cm2 (3.9 J) showed better results than the 10 J/cm2 (0.27 J) related to reduction of the area of necrosis and the number of leukocytes, increased mast cells, increased thickness of the epidermis, increased vascular endothelial growth factor, increased fibroblast growth factor and increase of newly formed blood vessels in diabetic animals. The laser and pulsed electrical field increase the viability of the musculocutaneous flap in diabetic rats.