Ablative 10,600 nm fractional laser for the treatment of scars

Background: Pathologic scars such as hypertrophic or atrophic scars can be highly disfiguring and could have major psychological impact. These scars remain a challenging problem as current available therapies often fail to improve them. Ablative fractional laser therapy (AFLT) is a new treatment modality and is expected to improve scars. The aim of this study is to assess the efficacy and safety of AFLT for the treatment of atrophic and hypertrophic scars. Methods: In a prospective single blinded randomized controlled split lesion trial twenty-one adult patients with hypertrophic or atrophic scars of 1 year or older and Fitzpatrick skin types I-IV were included. AFLT involved three sessions with an interval of 8 weeks. Blinded on-site evaluations were done at every treatment session and 2 months after the final treatment. Primary endpoints were the Physicians Global Assessment (0-3 categorical scale), the Patients Global Assessment (0-3 categorical scale) and the melanin- and erythema index. Secondary endpoints were the Clinical assessment of particular items of the scar (0-3 categorical scale) and adverse events. Results: Because of delay, the study is still running and preliminary results of one laser treatment of 15 patients were available for analysis and are presented in this paper. A significant difference of the PhGA was found between baseline and 8 weeks post treatment (p=0.025). No significant differences were found on the PGA and Clinical Assessment. Both hyperpigmented and hypopigmented scars showed an unfavorable increase of melanin index. In the intervention group the erythema index significantly increased 8 weeks post treatment (p=0.013). Adverse events reported by patients themselves showed 87% erythema, 40% burning, 40% edema, 47% vesicles, 60% crusting, 40% itching and 20% oozing. Five patients reported long lasting eythema, still present 8 weeks post treatment. The physician reported adverse events showed 31% hyperpigmentations and 46% erythema and no hypopigmenations and scar formations. Conclusion: Ablative 10,600 nm fractional laser therapy after one laser treatment is little efficacious and has a considerable risk of erythema and hyperpigmentation. However, no definitive conclusions about the efficacy of AFLT for the treatment of scars can be drawn as preliminary results of one treatment were analysed. The results after the second and third treatment are needed to draw these conclusions. In addition, AFLT is not as safe as expected as more and long term side effects were reported and objectified. Therefore, caution is urged when treating scars with AFLT. Future research of high quality is necessary to strengthen the evidence of the efficacy and safety of AFLT.