Pulsed dye laser versus ablative fractional CO laser in treatment of old hypertrophic scars: Clinicopathological study.

There is a continuous need to find out the best treatment for old hypertrophic scars (OHSs). Thirty patients with OHSs were included. Each scar was divided into right half treated with PDL (handpiece with a 7-mm spot, pulse duration of 1.5 ms and fluence of 6 J/cm ) and left half treated with FrCo2 laser (15 W, spacing 800 μm, dwelling time 600 μs and stack 3) once every month for three sessions. Scars were assessed before and after treatment clinically by Vancouver Scar Scale (VSS) and histologically using hematoxylin and eosin (H&E), Masson trichrome and orcein stains. Both halves showed statistically significant improvement after treatment. However, there was no statistically significant difference in VSS between them (P = 0.176). FrCo2 laser showed more significant improvement in pliability and height (P = 0.017, P = 0,011), while, PDL showed more significant improvement in vascularity (P = 0.039) of OHSs. Both PDL and ablative FrCo2 laser were effective in the treatment of OHSs, however, FrCo2 laser was more effective in improving OHSs pliability, and height which are the main concern in OHSs.