Numerical Modeling of The Dysplastic Vessel Heating in PWS by Yellow 578 nm Copper Vapor Laser Radiation for Different Skin Phototypes

Journal of Lasers in Medical Sciences

article

IGOR Vladimirovich PONOMAREV¹  SergeyB. Topchiy¹  AlexandraE. Pushkareva² 

[1] P.N. Lebedev Physics Institute;Saint Petersburg National Research ITMO University;49

关键词: Copper vapor laser;    Selective vessel heating;    Computer simulation;    PWS treatment;    Dark skin;   

DOI  :  10.34172/jlms.2022.11

学科分类：基础医学

来源: Shahid Beheshti University of Medical Sciences

【 摘 要 】

Introduction: Many clinical studies and protocols have been written about laser treatment for fairskin phototypes. However, for dark-skinned phototypes, information is limited, and the risk of burnsis higher, especially if the same settings are recommended for fair skin. Competitive epidermalmelanin absorption decreases the light energy reaching dysplastic vessels in a port-wine stain (PWS),preventing the vessel from achieving the temperature of the desired clinical result. Therefore, thechoice of safe laser settings for different skin phototypes can be realized using numerical modelingof PWS vessel heating. This study aimed to demonstrate the algorithm for choosing both effectiveand safe photodestruction of dilated dermal vessels in PWS with the copper vapor laser (CVL) at 578nm for different skin phototypes.Methods: We used the multilayered skin model with different melanin content for detecting thesafe laser parameters for PWS treatment. The calculation of the selective heating of the vascularcomponent with CVL radiation at yellow 578-nm wavelengths for different skin phototypes wasperformed via Matlab mathematical programming system and its application Femlab for solvingpartial differential equations using the Finite element method.Results: We determined the location, depth, and size of blood vessels that could be selectivelyheated to coagulation temperature for different skin prototypes. CVL fluence values need to bereduced almost two times for skin phototype IV than for skin phototype II to provide safe CVLtreatment. The maximum depth of the location of the vessels, which can be selectively heated tocoagulation temperature, also decreased for dark skin phototypes. Histological and histochemicalfindings validated the results of our calculations.Conclusion: To our knowledge, the use of numerical simulation to optimize has not yet beenconsidered. According to our calculations, CVL could selectively heat the dilated vessel, whichoccurred in purple and proliferative-type PWS for dark skin at the reduced fluence range and depth.

【 授权许可】

CC BY