The effect of wavelength, power and treatment pattern on the outcome of laser treatment of port-wine stains.

The argon laser was used to treat 220 patients with port-wine stains with moderate efficacy and few complications although perfect cosmetic results were rarely achieved. Primary failure of the argon laser to produce permanent blanching graded good or excellent was the most important factor limiting the final cosmetic results whilst severe scarring was rare (less than 2%). In order to improve the efficacy of this treatment, a randomized controlled study of different parameters of laser treatment was undertaken in test patches of port-wine stains in 50 patients. A treatment pattern with contiguous or overlapping laser spots was significantly superior to treatment with spots of 1 or 2 mm separation. Increasing the power level to twice the minimum blanching power did not improve efficacy or significantly increase scarring. A randomized study of selective absorption using a neodymium (Nd) YAG laser showed similar efficacy for the different wavelengths although scarring was greater with the Nd-YAG laser. This study has shown that laser treatment can offer a moderately effective treatment for port-wine stains. For best results spot separation needs to be carefully controlled, whilst wavelength and power level appear to be less important than previously reported.