Therapeutic Effect of Topical Triamcinolone Acetonide Combined With 10600-nm Ablative Fractional Carbon Dioxide Laser or 1565-nm Non-Ablative Fractional Laser on Hypertrophic Scars in the Rabbit Ear Model.

Abstract

BACKGROUND: Laser-assisted drug delivery has received increasing attention in scar treatment. This study aimed to compare the effects of ablative fractional laser (AFL) and non-ablative fractional laser (NAFL) combined with triamcinolone acetonide (TAC) on hypertrophic scars (HS) in the rabbit model. METHODS: Thermal paper and pig skin models were used to reveal the characteristics of laser beams. The rabbit ear scars were treated with fractional lasers and/or topical TAC every two weeks for a total of three times. Gross and histopathological assessments were performed at the indicated time points. RESULTS: We found that the laser penetration depth increased with the increase in energy. Compared with NAFL, AFL beams left wider micropores on the surface of pigskin and coagulation zones with more stable width in the subcutaneous layer. All laser treatment groups, especially the AFL+TAC group, reduced the MSS scores and scar thicknesses compared to the control group at two weeks after the first treatment. However, there was no significant difference in the improvement of scar appearance between the AFL+TAC group and the NAFL+TAC group at Week 8. Lasers and combined treatments enhanced the immunoreactivity of IL-1β, CD45, CD68 and CD163 to varying degrees on Day 3 after the third treatment, which returned to the baseline level on Day 30. At the latter time point, the fibroblast density and collagen content, as well as the expression of Ki-67, α-SMA, TGF-β1, p-SMAD3 and SMAD3, were simultaneously decreased. CONCLUSION: AFL and NAFL facilitate the efficacy of topical TAC on HS and regulate inflammation and fibroblast activation. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .