Low-level laser therapy on the viability of skin flap in rats subjected to deleterious effect of nicotine.

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 Data: 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.

Materials And 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.