FXCO2 laser therapy of existing burn scars does not significantly improve outcomes in a porcine model

Abstract

Introduction: Fractional CO2 lasers have been used to improve scar properties following burn injury; however, the efficacy of laser therapy alone has been difficult to ascertain. The goal of this study was to evaluate the effect of fractional CO2 laser therapy on objectively measured scar outcomes including scar area, pigmentation, erythema, roughness, histology, and biomechanics in a porcine burn model. Methods: Full thickness burn wounds were created on female red Duroc pigs; burn eschar was excised and wounds were grafted with split-thickness autograft. Sites had no additional treatment for 105 days resulting in thick contracted scars. At 105 days post burn, scars were treated with either a single pulse or three stacked pulses of a fractional CO2 laser at 70 mJ. Three treatments were given at four-week intervals. Scar area, pigmentation, erythema, roughness, histology, and mechanics were evaluated before treatment and at days 133, 161 and 189 post-injury. Results: Neither single nor stacked laser treatment resulted in a significant improvement in scar area, appearance, or biomechanics compared to control scars. Scar roughness was, on average, reduced with fractional CO2 treatment; however, this did not reach statistical significance. Conclusion: Although many clinical studies have reported significant benefits when treating burn scars with fractional CO2 laser therapy, this study did not find significant differences following laser therapy. For greatest efficacy, the selection of laser delivery parameters and co-treatments must account for variability in scar properties, including thickness. Keywords: Burn, Scar, Fractional CO2 laser, Quantitative analyses