532‐nm potassium titanyl‐phosphate laser versus 595‐nm pulsed dye laser for port‐wine birthmarks: A prospective, randomized, split‐side study.

Background: Pulsed dye lasers (PDL) are currently the first‐line treatment of port‐wine birthmarks (PWB). Due to high maintenance costs and instable technology, alternative methods are needed. Objectives: To compare clinical outcomes of a variable‐sequenced, long‐pulsed 532‐nm potassium titanyl‐phosphate (KTP) laser and PDL on treating PWB. Methods: A prospective, randomized, split‐side study. Patients were treated with a KTP laser and PDL with 1 to 5 sessions at intervals of 6–8 weeks. A follow‐up visit was scheduled 6 weeks post‐treatment. Efficacy was evaluated through colorimetric analysis, area reduction measurements and clinical evaluations by two blinded investigators based on photo documentation. Subjects provided rating of pain intensity during treatment, post‐treatment reactions and satisfaction. Safety was measured by adverse events. Maintenance issues of the laser systems were documented. Results: A total of 35 patients (mean age 42.1 years) were enrolled. 63% were female. Patients received 2.4 (SD 1.4; 1–5) treatment sessions. Colorimetric analysis indicated a comparable clearance effect in PWB of both KTP laser and PDL. Independent investigators rated clinical appearance to be significantly improved compared to baseline. No significant difference was observed between both laser systems. Regarding post‐treatment reactions, the KTP laser caused less swelling, purpura and crusts. 96% would recommend both treatment modalities. Patients were satisfied with both laser systems. During the study, PDL systems malfunctioned for 6.6 months in total. For the KTP laser, we did not observe any system failures. Conclusion: Our data indicate that the KTP laser of the latest generation with large‐spot sizes, subpulse technology and cryogen cooling has a comparable efficacy to the PDL in treating PWB. In addition, KTP laser is associated with greater tolerability, fewer technical failures and lower repair costs. Further prospective studies are required to determine the true effectiveness of the KTP laser in PWB treatment. This study was preregistered in Clinicaltrials.gov (NCT05771298). [ABSTRACT FROM AUTHOR]