Experimental study of combined photodynamic and photothermal therapy in the treatment of port wine stain.

Laser therapy has become the golden standard of port wine stain (PWS), but complete clearance of resistant PWSs is still difficult. The application of photodynamic therapy (PDT) in the treatment of PWS shows potential in clinical practice, especially for large-area and deep lesions. In this work, in vivo animal experimental investigation on the coupling effect of PDT with multi-pulse laser (MPL) irradiation on the treatment of PWS was conducted by using a dorsal skin window chamber model. Through visualization of the thermal response of blood vessels and damage evaluation, it is found that the combination of PDT with MPL results in 96.2% more vascular injury than PDT alone and 90% more than MPL alone, thus reducing side effects such as purpura after treatment. The combined therapy also has the benefit of large treatment area, uniform fading effect, shortened light duration, and reduced photosensitizer admit.