607 Skin vascular response to laser treatments in port-wine stain

Port-wine stain (PWS) is one of the representative cutaneous vascular malformations. Pulse dye laser (PDL) a traditional treatment method to treat PWS. A newly developed potassium-titanyl-phosphate (KTP) laser, DermaV, can be irradiated with single pulse, or pulse divided into several sub-pulses in length 0.3ms 1.5ms. This study aimed investigate skin response KTP and PDL according different durations wavelengths PWS lesions were five 1x1cm2 square territories, randomly treated by 5 methods: 1) no treatment, 2) (532nm) 3) sub-millisecond (1.5ms) 4) sub-microsecond (0.3ms) 5) (595nm). Three sessions done every 4 weeks, last follow-up was weeks after treatment. total 13 patients included, excluding dropouts. In evaluation efficacy, showed non-inferior efficacy profile PWL compared PDL. higher vessel density thicker vessels more likely respond treatments. After 3 treatments, thick decreased but thin increased. Between responders non-responders, responders. The decrement positively correlated response. better treating vessels. summary, treatments well clinical improvement. However, increased they could cause resistance. combination modes may possible alternative for resistant cases.