Abstract
Pulsed dye lasers equipped with cryogen spray cooling (CSC) are now widely used to treat vascular malformation such as port wine stains (PWSs). This paper presents a new integrated model that can quantitatively simulate the cooling of the skin and the heating of the targeted blood vessels in PWSs during laser treatment. The new model is based on the classical homogeneous multi-layer skin model that treats PWS-containing dermis as a mixture of dermal tissue and homogeneously distributed blood. Light propagation in skin and PWSs is simulated by a Monte-Carlo method, which provides accurate description of the light scattering and absorption in the skin. Thermal response of a targeted vessel in the new model is then obtained from the thermal analysis of a Krogh-unit that consists of the vessel and the surrounding dermal tissues and is buried in PWSs. The results from the multi-layer skin model provide appropriate laser influence input as well as the initial thermal condition for the micro-model of the Krogh-unit. A general dynamic relation is also introduced on the surface of skin to quantify the convective cooling of CSC. The model is then applied to dye-laser treatment (wavelength of 585 nm) of PWSs with CSC. Numerical results demonstrate that the present model is able to quantify thermal response of a deeply buried blood vessel in PWSs as a discrete blood vessel does, with a more realistically estimate of the sheltering effect of the dermal tissue (scattering) and blood vessels (absorption) in front of the targeted vessel. To understand the poor response of PWSs in clinic, the thermal characteristics of a targeted vessel was simulated under various conditions. The effects of two morphological parameters, the vessel diameter and the burying depth of the vessel, are then systematically investigated under various pulse durations and fluences of laser. A threshold fluence for given vessel diameter and depth is then estimated quantitatively under the condition of the optimal laser pulse duration. The results indicate that significant high threshold fluence is needed for large vessels buried deeply in the dermis, explaining the physics of the difficulty in clinic of complete clearance of PWSs. The results provide guidance to the clinic selection of the laser pulse duration and laser energy fluence for given PWSs.
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References
Barsky S H, Rosen S, Geer D E, et al. The nature and evolution of port wine stains: A computer-assisted study. J Invest Dermatol, 1980, 74: 154–157
Anderson R R, Parrish J A. Microvasculature can be selectively damaged using dye laser: A basic theory and experimental evidence in human skin. Lasers Surg Med, 1981, 1: 263–276
Tunnell J W, Nelson J S, Torres J H, et al. Epidermal protection with cryogen spray cooling during high fluence pulsed dye laser irradiation: An ex vivo study. Lasers Surg Med, 2000, 27: 373–383
Aguilar G, Majaron B, Verkruysse W, et al. Theoretical and experimental analysis of droplet diameter, temperature, and evaporation rate evolution in cryogenic sprays. Int J Heat Mass Transfer, 2001, 44: 3201–3211
Aguilar G, Verkruysse W, Majaron B, et al. Measurement of heat flux and heat transfer coefficient during continuous cryogen spray cooling for laser dermatologic surgery. IEEE J Sel Top Quant, 2001, 7: 1013–1021
Nelson J S, Milner T E, Anvari B, et al. Dynamic epidermal cooling during pulsed laser treatment of port-wine stain: A new methodology with preliminary clinical evaluation. Arch Dermatol, 1995, 6: 695–700
Fiskerstrand E J, Svaasand L O, Kopstad G, et al. Laser treatment of port wine stains: Therapeutic outcome in relation to morphological parameters. Brit J Dermatol, 1996, 134: 1039–1043
Bernstein E F. Treatment of a resistant port-wine stain with a new variable pulse-duration pulsed-dye laser. J Cosmet Dermatol, 2008, 7: 139–142
Fiskerstrand E J, Svaasand L O, Kopstad F, et al. Photothermally induced vessel-wall necrosis after pulsed dye laser treatment: Lack of response in port-wine stains with small size of deeply located vessels. J Invest Dermatol, 1996, 107: 671–675
Li D, He Y L, Wang G X. Thermal Modelling for Laser Treatment of Port Wine Stains. In: Bernardes M A S, ed. Developments in Heat Transfer. Croatia: InTech Publishers, 2011. 537–556
Aguilar G, Diaz S H, Lavernia E J, et al. Cryogen spray cooling efficiency: Improvement of port wine stain laser therapy through multiple-intermittent cryogen spurts and laser pulses. Lasers Surg Med, 2002, 31: 27–35
Pfefer T J, Smithies D J, Milner T E, et al. Bioheat transfer analysis of cryogen spray cooling during laser treatment of Port Wine Stains. Lasers Surg Med, 2000, 26: 145–157
Majaron B, Verkruysse W, Kelly K M, et al. Er:YAG laser skin resurfacing using repetitive long-pulse exposure and cryogen spray cooling: II. Theoretical analysis. Lasers Surg Med, 2001, 28: 131–137
Verkruysse W, Majaron B, Tanenbaum B S, et al. Optimal cryogen spray cooling parameters for pulsed laser treatment of port wine stains. Lasers Surg Med, 2000, 27: 165–170
Aguilar G, Wang G X, Nelson J S. Effect of spurt duration on the heat transfer dynamics during cryogen spray cooling. Phys Med Biol, 2003, 48: 2169–2181
Franco W, Liu J, Wang G X, et al. Radial and temporal variations in surface heat transfer during cryogen spray cooling. Phys Med Biol, 2005, 50: 387–397
Aguilar G, Diaz S H, Lavernia E J, et al. Effect of time-dependent boundary conditions on epidermal tissue damage during Port Wine Stain laser surgery. In: Proceedings of the International Mechanical Engineering Congress and Exposition (IMECE). New York: ASME Press, 2001, 52: 43–48
Jia W C, Choi B, Franco W, et al. Treatment of cutaneous vascular lesions using multiple-intermittent cryogen spurts and two-wave-length laser pulses: Numerical and animal studies. Lasers Surg Med, 2007, 39: 494–503
Li D, He Y L, Liu Y W, et al. Numerical analysis of cryogen spray cooling of skin in dermatologic laser surgery using realistic boundary conditions. In: 22th International Congress Refrigeration Conference. Beijing. 2007
Li D, He Y L, Wang G X, et al. Numerical analysis of cold injury of skin in cryogen spray cooling for dermatologic laser surgery. In: Proceedings of the International Mechanical Engineering Congress and Exposition (IMECE). Seattle: ASME Press, 2007, 8: 673–681
Kerjzer M, Jacques S L, Prahl S A, et al. Light distributions in artery tissue: Monte-Carlo simulations for finite diameter laser beams. Lasers Surg Med, 1989, 9: 148–154
Lucassen G W, Verkruysse W, Keijzer M, et al. Light distribution in a port wine stain model containing multiple cylindrical and curved blood vessels. Lasers Surg Med, 1996, 18: 345–357
Pickering J W, van Gemert M J C. 585 nm for the laser treatment of port-wine stains: A possible mechanism. Lasers Surg Med, 1991, 11: 616–618
Kienle A, Hibst R. A new optical wavelength for treatment of port wine stains? Phys Med Biol, 1995, 40: 1559–1576
Verkruysse W, Pickering J W, Beek J F, et al. Modeling the effect of wavelength on the pulsed dye laser treatment of port wine stains. Appl Opt, 1993, 32: 393–398
Krogh A. The number and distribution of capillaries in muscles with calculations of the oxygen pressure head necessary for supplying the tissue. J Physiol, 1919, 6: 409–415
Barsky S H, Rosen S, Geer D E, et al. The nature and evolution of port wine stains: A computer-assisted study. J Invest Dermatol, 1980, 74: 154–157
Wang L H, Jacques S L, Zheng L Q. MCML-Monte Carlo modeling of light transport in multi-layered tissues. Comput Meth Prog Biol, 1995, 47: 131–146
Welch A J, Wissler E H, Priebe L A. Significance of blood flow in calculation of temperature in laser irradiated tissue. IEEE Trans Biomed Eng, 1980, BME-27: 164–166
Wissler E H. An analysis of chorioretinal thermal response to intense light exposure. IEEE Trans Biomed Eng, 1980, BME-23: 209–215
Zhou Z F, Wang G X, Guo L J, et al. Comparison and evaluation of evaporation models for single moving droplet with a high evaporation rate. Powder Technol, 2012, doi: 10.1016/j.powtec.2012.07.002
Zhou Z F, Chen B, Wang Y S, et al. An experimental study on pulsed spray cooling with refrigerant R-404a in laser surgery. Appl Therm Eng, 2011, 39: 29–36
Li D. Numerical and experimental studies on laser induced selective photothermolysis in biological tissue (in Chinese). Doctoral Dissertation. Xi’an: Xi’an Jiaotong University, 2011
Sun F, Aguilar G, Kelly K M, et al. Thermal analysis for cryosurgery of nodular basal cell carcinoma. In: Proceedings of the International Mechanical Engineering Congress and Exposition (IMECE). Chicago: ASME Press, 2006, 8: 125–131
Lucassen G W, Svaasand L O, Verkruysse W, et al. Laser energy threshold for thermal vascular injury in a port wine stain skin model. Laser Med Sci, 1995, 10: 231–234
Anvari B, Milner T E, Tanenbaum B S, et al. Selective cooling of biological tissues: Application for thermally mediated therapeutic procedures. Phys Med Biol, 1995, 40: 241–252
Li D, He Y L, Wang G X, et al. Numerical simulation of cryogen spray cooling during the laser treatment of the Port Wine Stain (in Chinese). J Eng Thermophys, 2008, 29: 2107–2110
Van Gemert M J C, Welch A J, Pickering J W, et al. Wavelengths for laser treatment of port wine stains and telangiectasia. Lasers Surg Med, 1995, 16: 147–155
Smithies D J, Butler P H, Day W A, et al. The effect of the illumination time when treating port-wine stains. Lasers Surg Med, 1995, 10: 93–104
Vangemert M J C, Henning J P H. A model approach to laser coagulation of dermal vascular lesions. Arch Dermatol Res, 1981, 270: 429–439
Zhou J H, Liu J. Numerical study on 3-D light and heat transport in biological tissues embedded with large blood vessels during laser-induced thermotherapy. Nnmer Heat Tr A-Appl, 2004, 45: 415–449
Babilas P, Shafirstein G, Baumler W, et al. Selective photothermolysis of blood vessels following flashlamp-pumped pulsed dye laser irradiation: In vivo results and mathematical modeling are in agreement. J Invest Dermatol, 2005, 125: 343–352
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Li, D., He, Y., Wang, G. et al. A new model of selective photothermolysis to aid laser treatment of port wine stains. Chin. Sci. Bull. 58, 416–426 (2013). https://doi.org/10.1007/s11434-012-5444-0
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DOI: https://doi.org/10.1007/s11434-012-5444-0