Abstract: Objective: To assess the effect of carbon dioxide fractional laser (CO₂FL, 10600nm), combined with pulsed dye laser (PDL, 585nm) on hypertrophic scars. Methods: The hypertrophic scars model was established in 20 New Zealand rabbits. There were 8 hypertrophic scars in every ear of the rabbits, including 2 scars treated as controls，2 treated with CO₂FL, 2 treated with PDL, and 2 treated with PDL combined with CO₂FL, once every 2 weeks for 2 times. The Scar Elevation Index (SEI), collagen I and collagen III, apoptotic fibroblast cells, and the TGF-β1 and Smad3 levels were detected after treated for 14 days and 28 days. Results: The SEI, fibroblast density index, collagen fiber area, and the level of TGF-β1 and Smad3 in the PDL combined with CO₂FL group were lower than those in the control group, PDL group and CO2FL group, with significant differences (Ps<0.05). The cell apoptosis rate was higher in the PDL combined with CO₂FL group than in other groups, with significant differences (Ps<0.01). Conclusion: PDL combined with CO₂FL laser in the treatment of hypertrophic scar is more effective than  PDL or CO₂FL laser alone. 

Key words: CO₂FL')">

CO₂FL, PDL, hypertrophic scar