Is there an optimal laser treatment for port wine stains?

Optimization of laser treatment of port wine stains (PWS) is discussed from the standpoint of heat production. Laser wavelength, irradiation time, heat conduction, and external epidermal cooling are the variables considered in conjunction with absorbing and scattering behavior of a PWS-model consisting of epidermis, dermis, and ectatic blood vessel. Ideal treatment is defined as minimal heating of the epidermis and upper dermis, but with irreversible damage to the capillary wall. The analysis shows that irradiation times of 1-10 ms in conjunction with external epidermal cooling may give optimal results. The wavelength of choice is 577 nm, followed by 540, 415, 560, and 500 nm (argon laser). The ruby and Nd-YAG lasers are predicted to damage the epidermis and dermis at all times when the capillary is coagulated. Concurrent cooling to prevent epidermal-dermal damage is also recommended here. The CO2 laser is predicted to be the worst laser and, according to our analysis, should not be used to treat PWS. Both upper dermal and capillary destruction can only result from heat conduction from the damaged epidermis and external cooling cannot be applied here.