Effect of Low-Level Laser Therapy on Mast Cells in Viability of the Transverse Rectus Abdominis Musculocutaneous Flap

摘要

Objective: To assess the effect of low-level laser therapy (LLLT) on viability of mast cells of the transverse rectus abdominis musculocutaneous (TRAM) flap. Background Data: LLLT has been recently used on the TRAM flap to stimulate mast cells. Materials and Methods: Eighty-four Wistar rats were randomly divided into seven groups of 12 rats in each: group 1 (sham laser therapy); group 2 received 3 J/cm2 at one point; group 3 received 3 J/cm2 at 24 points; group 4 received 72 J/cm2 at 1 point; group 5 received 6 J/cm2 at 1 point; group 6 received 6 J/cm2 at 24 points; and group 7 received 144 J/cm2 at 1 point. All experimental groups underwent LLLT immediately after TRAM surgery and on the next two following days, for three sessions in total. The percentage of the area of skin flap necrosis was calculated on the fourth postoperative day and two samples of skin were collected from each rat with a 1-cm2 punch to perform mast cell evaluations with toluidine blue dye. Results: Statistically significant differences were found in the percentage of necrosis, and higher values were seen in group 1 than in all other groups. Among groups 3–7 no statistically significant differences were found (p < 0.292). For mast cells, when group 1 was compared to groups 5 (6 J/cm2 at 1 point) and 7 (144 J/cm2 at 1 point), it had fewer mast cells. Conclusion: LLLT at a wavelength of 670 nm was effective at reducing the necrotic area, and we found that it can stimulate mast cells growth to increase vascular perfusion.