KISSIMMEE, FLA. – Treatment with a 2,940 Er:YAG ablative fractional laser led to a clinically significant reduction of third-degree burn scars in a prospective study of 11 patients.
Clinical and histologic findings from the laser study provide important clues as to the mechanism of action and appropriate treatment intervals, Dr. Jill S. Waibel reported at the meeting. Scars from fire or thermal injury are among the worst that are seen in clinical practice, and although fractional laser therapy is emerging as the preferred treatment for these injuries, a better understanding of the optimal laser wavelengths, clinical response patterns, scar tissue response, and histologic changes will improve outcomes.
Patients in this study underwent three ablative treatments at 4-week intervals, and – based on blinded evaluation by independent investigators – were found to have an overall modified Manchester score of 2.3 out of 3 points, indicating moderate to excellent improvement. The scores for dyschromia, hypertrophy reduction, vascularity, and scar texture improvement were 1.7, 1.9, 2.0, and 2.0, respectively, indicating mild to moderate improvement, said Dr. Waibel, a physician in private practice in Miami.
The patients, who had third-degree burn scars over an average of 80% of their body, were treated with one pass at depths ranging from 400 to 800 microns, depending on scar thickness and density.
Biopsies were performed at baseline and at 3 months after the final treatment. On biopsies taken at baseline, the scars were noted to have thickened, homogenized, dystrophic collagen structures; and on biopsies taken 3 months after the final treatment, a decrease in these dystrophic fibers was seen, she said.
Dr. Waibel hypothesized that scar improvement resulted from the complete replacement of ablated zones by newly synthesized collagen and that the collagen remodeling led to more normal-appearing skin.
She noted that the erbium laser is "very powerful" and caused a great deal of erythema in two patients, leading her to "turn the power down" over the course of the study. Although no worsening of scars was seen, the increased vascularity in the two patients suggested that intervals longer than 4 weeks between treatments – perhaps to between 2 and 3 months - may be warranted.
Although additional study is needed, the findings suggest that the 2,940 Er:YAG laser is effective for clinically improving burn scars through vaporization and by inducing an organized wound-healing response; this histologic healing response may lead to the improvement that is seen clinically, she concluded.
This study was funded by Sciton. Dr. Waibel said she had no other relevant financial disclosures.