A prospective, randomized controlled trial on the efficacy of fractional photothermolysis on scar remodeling

Background Non-ablative fractional resurfacing (NAFR) has been reported in case studies as an effective treatment for surgical and burn scars [Behroozan et al., J Cosmet Laser Ther 2006; 8(1):35–38; Haedersdal et al., Lasers Surg Med 2009; 41(3):189–195; Waibel and Beer, J Drugs Dermatol 2008; 7(1):59–61; Niwa et al., Dermatol Surg 2009; 35(5):773–777; discussion 777–778; and Tierney et al., Dermatol Surg 2009; 35(8):1172–1180]. We have performed a prospective, randomized controlled study with two different treatment arms to better characterize the response of hypertrophic scars to NAFR. Study Design We conducted a prospective, controlled trial on linear, surgical hypertrophic scars 6 months or older in age. Subjects were randomized into two treatment arms of NAFR: (a) high-density treatment arm (HDTA): 40 mJ and percent coverage of 26% and (b) low-density treatment arm (LDTA): 40 mJ and percent coverage of 14%. One-half of the scar was treated every 2 weeks for a total of four treatments, with subsequent follow-up visits at 1 month and 3 months. Scar improvement was judged as compared to the untreated side by the subjects and two blinded observers using a four-point scale (0 = no improvement or worsening, 1 = minor improvement, 2 = moderate improvement, and 3 = marked improvement). Volumetric changes were also measured for a select group (n = 4) by measuring scar casts with optical frequency domain imaging. Patient satisfaction was surveyed at the end of the trial. Side effects in both treatment arms were assessed. Results Twenty patients were enrolled, of which 17 subjects noted improvement in their scars compared to untreated side. Three subjects in the HDTA rated their scars as having a worsened appearance at the end of the study. After treatment was completed, scars continued to improve in appearance at 3 months compared to 1 month. Subjects in the LDTA rated the treated side with higher scores, than subjects in the HDTA (P = 0.001). Scars <2 years old tended to respond better to NAFR as compared to scars >6 years old. The side effects profile was more severe in the HDTA group. Nevertheless, all subjects were satisfied with the procedure at trial completion. Conclusions This study demonstrates the efficacy of NAFR for treating hypertrophic scars. Low-density treatment is at least as effective as the high-density treatment and with fewer side effects. The study also suggests that younger scars respond better to NAFR. Thus, early intervention may be key in the treatment of hypertrophic scars. Lasers Surg. Med. 43:265–272, 2011. © 2011 Wiley-Liss, Inc.PublishedN/