Low-Level Laser Therapy (LLLT) at 830 nm Positively Modulates Healing of Tracheal Incisions in Rats: A Preliminary Histological Investigation

Abstract

The aim of the present study was to evaluate whether LLLT at 830 nm is able to positively modulate trachea incisional wound healing in Sprague-Dawley rats. Tracheotomy may be associated with numerous complications. Development of excess granulation tissue represents a late complication that may lead to airway occlusion. Low-level laser therapy (LLLT) has been shown to have stimulatory effects on wound healing of different tissues. Therefore, it may be suggested that LLLT could be able to positively modulate trachea wound healing as well. Using general anesthesia, a median incision was performed from the second to the fifth tracheal cartilage ring in 24 rats. Animals were then randomly divided into sham-irradiated control and laser-treated groups. LLLT (power density: 450 mW/cm(2); total daily dose: 60 J/cm(2); irradiated area ∼1 cm(2)) treatment was performed daily during the first week after surgery. Samples for histological evaluation were removed 7 and 28 days after surgical procedure. Histological sections were stained with hematoxylin-eosin and van Gieson. Results from our investigation showed that LLLT was able to reduce granulation tissue formation and simultaneously increase new cartilage development at both evaluated time intervals. From this point of view, LLLT at 830 nm may be a valuable tool in trachea wound healing modulation. Nevertheless, further detailed research is needed to find optimal therapeutic parameters and to test these findings on other animal models.