title: Low-level laser therapy on the viability of skin flap in rats subjected to deleterious effect of nicotine.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of 830-nm laser in blocking the action of nicotine on the viability of skin flap.
  
  
  BACKGROUND
  The authors have analyzed the deleterious effect of cigarette smoke or nicotine on the skin flap alone with evidence of increased skin necrosis in the flap.
  
  
  METHODS
  Twenty-four Wistar-albino rats were divided into three groups of eight animals each: Group 1 (control), subjected to a surgical technique to obtain a flap for cranial base, laser irradiation simulation, and a subcutaneous injection of saline; Group 2, similar to Group 1, with subcutaneous injection of nicotine (2  mg/kg/day) for a period of 1 week before and 1 week after surgery; and Group 3, similar to Group 2, with skin flaps subjected to a λ 830-nm laser irradiation. The laser parameters used were: power 30 mW, beam area 0.07 cm(2), irradiance 429 mW/cm(2), irradiation time 84  sec, total energy 2.52  J, and energy density 36 J/cm(2). The laser was used immediately after surgery and for 4 consecutive days, in one point at 2.5  cm of the flap cranial base. The areas of necrosis were examined by two macroscopic analyses: paper template and Mini-Mop(®). The pervious blood vessels were also counted.
  
  
  RESULTS
  The results were statistically analyzed by ANOVA and post-test contrast orthogonal method (multiple comparisons), showing that the laser decreased the area of necrosis in flaps subjected to nicotine, and consequently, increased the number of blood vessels (p < 0.05).
  
  
  CONCLUSIONS
  The laser proved to be an effective way to decrease the area of necrosis in rats subjected to nicotine, making them similar to the control group.
authors: Department of Biomechanics, Medicine and Rehabilitation of the Locomotor System, University of São Paulo-FMRP/USP, Ribeirão Preto, Brazil. laisneves@usp.br
authors: Lais Mara Siqueira
authors: LM
authors: das Neves
authors: Alexandre Marcio
authors: AM
authors: Marcolino
authors: Rodrigo Paschoal
authors: RP
authors: Prado
authors: Tiago De Souza
authors: Tde S
authors: Ribeiro
authors: Carlos Eduardo
authors: CE
authors: Pinfildi
authors: José Antônio
authors: JA
authors: Thomazini
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy; D008297:Male; D009336:Necrosis; D009538:Nicotine / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D012535:Scalp / Q000098:blood supply; D013524:Surgical Flaps; D014022:Tissue Survival / Q000187:drug effects* / Q000528:radiation effects*
chemical_list: D009538:Nicotine