Application Of Pulsed Dye Laser Combined With Long-pulsed 1064nm Nd:YAG Laser In Treating Fresh Scars

Objective:To evaluate and compare the effectiveness of pulsed dye laser(PDL)and the combination of PDL and long-pulsed Nd:YAG laser in the treatment of fresh scars starting 3 to 4 weeks after wound healing.Methods:Each scar was divided at the midline into two fields,with half receiving treatment using pulsed dye laser(Vbeam,Candela Corp.)with a 7 mm spot size at0.45ms with 6-9 J/cm~2 and a 20 ms spray duration with a 20 ms delay.The other half was treated using a combination of PDL with the same parameter and Nd:YAG(GentleYAG,Candela Corp.)with 3mm spot size at 10 ms with 150-180J/cm~2 and a20ms spray duration with a 20ms delay.Patients received 3 laser treatment sessions at1-month interval.The follow-up time is 3 months after final treatment.The scars were evaluated for height with Doppler ultrasound system(M7,MindRay),vascularity with Laser speckle detector(Perimed PSI)and pliability with Cutometer~?RR MPA580.Immunological histology was used to detect the destruction of capillaries.The infrared thermography(Fotric 228s)was used to monitor the temperature of the epidermis in the treatment process.Results:Twenty-eight patients with average 3.4-week scars were involved.All objective indicators analysis of the combined laser site was significantly better than the PDL site and was significantly improved compared to pre-treatment(p<0.05).The average height of scars was 0.28±0.72cm for PDL and 0.19±0.56cm for combined site,the speckle flow index was 112.72±16.79PU for the combined cite versus144.59±22.97PU for PDL alone.The gross elasticity index was 0.70±0.05 in PDL compared to 0.87±0.09 in combined site.The histological penetration depth of Nd:YAG was about 1mm,which was obviously deeper than that in group PDL.The combined treatment group immediately after the average temperature of 30.1?,no patients developed persistent erythema,edema,permanent pigmentation change or scar formation.Conclusion:The combination of pulsed dye laser and long-pulsed Nd:YAG provides a more effective option compared to use pulsed dye laser alone to improve the cosmetic appearance of fresh scars.