Analysis the effects of preemptive treatment with Low Level Laser Therapy (660 nm) in viability skin flaps in rats

• Grant number: 15/13501-3
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): October 01, 2015
• Effective date (End): March 31, 2019
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Nivaldo Antonio Parizotto
• Grantee: Cintia Cristina Santi Martignago
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The skin flap is a plastic surgery technique often used in reconstructive surgeries of tissue loss, whether traumatic or after surgical procedures. This technique presents the main complication of ischemic tissue and can lead to necrosis of the flap. The preemptive treatment has been studied aimed at primary prevention of various complications, among them, the skin flap necrosis. Studies using the preemptive treatment with drugs showed favorable results on the viability of skin flaps. In vitro research has shown that low level laser therapy (LLLT) acts positively fotobiomodulando important events that act on inflammation, angiogenesis and the formation of extracellular matrix, suggesting that irradiation in the preoperative period may interfere in the above processes cited increasing the viability of skin flaps. The objective of this study is to investigate the effects of preemptive treatment with LLLT (660 nm) with different fluency on the viability of skin flaps. For this will be a in vivo experiment using 91 rats Wistar, divided into 8 groups. Group 1 underwent LLLT treatment of simulation with the device turned off starting at the preoperative 72 hours, Group 2 will be submitted to irradiation with LLLT starting 72 hours preoperatively with a fluency of 2 J / cm2, the group 3 will be submitted to irradiation with LLLT starting 72 preoperative hours with a total fluency of 6 J / cm2, Group 4 will be subjected to irradiation with LLLT starting 72 hours preoperatively with a fluency of 12 J / cm2, the group 5 will be submitted to the simulation treatment LLLT with the unit off starting immediately after the operative procedure, the group 6 will start treatment with LLLT immediately after the operation with a total fluence of 2 J / cm2, the group 7 start treatment with LLLT immediately after operation with a total fluence of 6 J / cm2, group 8 start treatment with LLLT immediately after operation with a total fluence of 12 J / cm2. The experimental groups that with the LLLT preemptive will receive 8 laser applications, already groups who will receive LLLT immediately after the operative procedure, will be irradiated for 5 laser applications, respecting the interval of 24 hours between them, being-those applied in two point 2.5 cm from the skull base and 0.75 cm medial to the flap margins and a distance between the points of 1.5 cm. The random skin flap of cranial base will be carried out with dimensions of 10 X 4 cm and a plastic barrier is interposed between it and the donor site. The animals will be sacrificed in two distinct experimental periods; in the time of the flap and on the fifth day after surgery. In these two moments will be evaluated gene expression (VEGF, VEGFR 2; FGF; TNF; TGFb and IL8); protein expression (immunohistochemistry) and histological analysis (blood vessels and mast cell count). Another factor to be considered is the area of necrosis, it being evaluated only on the fifth day after the surgical procedure with the paper template method. For statistical analysis, the Shapiro-Wilk normality test will be conducted and analysis of variance will be ANOVA- Three way. In the presence of significant difference (p <0.05) is applied post-hoc Tukey test.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTI MARTIGNAGO, CINTIA CRISTINA; TIM, C. R.; ASSIS, L.; NEVES, L. M. G.; BOSSINI, P. S.; RENNO, A. C.; AVO, L. R. S.; LIEBANO, R. E.; PARIZOTTO, N. A.. Comparison of two different laser photobiomodulation protocols on the viability of random skin flap in rats. Lasers in Medical Science, v. 34, n. 5, p. 1041-1047, JUL 2019. (15/13501-3)