Non-ablative fractional laser provides long-term improvement of mature burn scars--a randomized controlled trial with histological assessment.

Background and Objectives Non-ablative fractional laser-treatment is evolving for burn scars. The objective of this study was to evaluate clinical and histological long-term outcome of 1,540 nm fractional Erbium: Glass laser, targeting superficial, and deep components of mature burn scars. Materials & Methods Side-by-side scar-areas were randomized to untreated control or three monthly non-ablative fractional laser-treatments using superficial and extra-deep handpieces. Patient follow-up were at 1, 3, and 6 months. Primary outcome was improvement in overall scar-appearance on a modified-Patient-and-Observer-Scar-Assessment-Scale (mPOSAS, 1 = “normal skin”, 10 = “worst imaginable scar”). Secondary outcomes included histology, patient satisfaction (0–10), patient-assessed improvement, and safety. Results Study was completed by 17 of 20 randomized patients with normotrophic (n = 11), hypertrophic (n = 5) or atrophic (n = 1) scars. Scar-appearance improved from laser-treatments (P < 0.001 vs. untreated) and histology at 6 months supported collagen-remodeling. Improvement appeared continuously during the post-operative period (mPOSAS baseline: 7 [5–8], 6 months: 4 [3–5] P = < 0.001). At 6 months, patients were satisfied with treatment (6 [3–9]) and 82% reported improved scar-texture. Treatments caused mild to moderate pain (4 [2–7]). Adverse effects decreased during follow-up and at final assessment, discrete erythema, hyperpigmentation or imprints from laser-grid were present in 11 patients. No patients experienced worsening of scar-appearance. Conclusions Combined superficial and deep non-ablative fractional laser-treatments induce long-term clinical and histological improvement of mature burn scars. Lasers Surg. Med. 47:141–147, 2015. © 2014 Wiley Periodicals, Inc.