Computational investigation on thermal responses of blood vessels during laser treatment of port wine stain
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 7 March 2016
Abstract
Purpose
The purpose of this paper is to present a numerical analysis of the laser surgery of port wine stain (PWS) with cryogen spray cooling to compare the treatment effect between pulse dye laser and Nd:YAG laser, explain the incomplete clear of the lesion and optimize the laser parameter.
Design/methodology/approach
The complex structure of skin and PWS is simplified to a multi-layer skin model that consists of top epidermal layer and underneath dermis layer embedded with discrete blood vessels. The cooling effect of cryogen spray before laser firing is quantified by a general correlation obtained recently from the experimental data. The light distribution is modeled by the Monte Carlo method. The heat transfer in skin tissue is calculated by Pennes bioheat transfer model. The thermal damage of blood vessel is quantified by the Arrhenius damage integral.
Findings
For the vessel size studied (10-120 µm), pulse duration is recommended shorter than 6 ms. Large and deeply buried vessels, which may survive from 595 nm laser irradiation, can be coagulated by 1,064 nm laser due to its deep light penetration depth in skin. Furthermore, a desired uniform heating within the large vessel lumen can be achieved by 1,064 nm laser whereas 595 nm laser produce non-uniform heating.
Originality/value
The possible reason for the poor responding and incomplete clearance lesions is clarified. Laser wavelength and pulse duration are suggested to improve the clinical results.
Keywords
Acknowledgements
The work is supported by Joint Research Fund for National Natural Science Foundation of China (51336006, 51506161), the International Science and Technology Cooperation Plan of Shaanxi Province (No. 2013KW30-05) and the Fundamental Research Funds for the Central University.
Citation
Li, D., Chen, B. and Wang, G.-X. (2016), "Computational investigation on thermal responses of blood vessels during laser treatment of port wine stain", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 26 No. 2, pp. 534-555. https://doi.org/10.1108/HFF-03-2015-0084
Publisher
:Emerald Group Publishing Limited
Copyright © 2016, Emerald Group Publishing Limited