Photothermal coagulation of blood vessels: a comparison of high-speed optical coherence tomography and numerical modelling.

Optical-thermal models that can accurately predict temperature rise and damage in blood vessels and surrounding tissue may be used to improve the treatment of vascular disorders. Verification of these models has been hampered by the lack of time- and depth-resolved experimental data. In this preliminary study, an optical coherence tomography system operating at 4-30 frames per second was used to visualize laser irradiation of cutaneous (hamster dorsal skin flap) blood vessels. An argon laser was utilized with the following parameters: pulse duration 0.1-2.0 s, spot size 0.1-1.0 mm, power 100-400 mW. Video microscopy images were obtained before and after irradiations, and optical-thermal modelling was performed on two irradiation cases. Time-resolved optical coherence tomography and still images were compared with predictions of temperature rise and damage using Monte Carlo and finite difference techniques. In general, predicted damage agreed with the actual blood vessel and surrounding tissue coagulation seen in images. However, limitations of current optical-thermal models were identified, such as the inability to model the dynamic changes in blood vessel diameter that were seen in the optical coherence tomography images.

[1]  A J Welch,et al.  Pulsed laser-induced thermal damage in whole blood. , 2000, Journal of biomechanical engineering.

[2]  A Rollins,et al.  In vivo video rate optical coherence tomography. , 1998, Optics express.

[3]  J Izatt,et al.  Investigating pulsed dye laser-blood vessel interaction with color Doppler optical coherence tomography. , 1998, Optics express.

[4]  Wim Verkruysse,et al.  Optical Absorption of Blood Depends on Temperature during a 0.5 ms Laser Pulse at 586 nm , 1998, Photochemistry and photobiology.

[5]  E. Tanghetti,et al.  Long Pulse 532‐nm Laser Treatment of Facial Telangiectasia , 1998, Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.].

[6]  Thomas E. Milner,et al.  A three-dimensional modular adaptable grid numerical model for light propagation during laser irradiation of skin tissue , 1996 .

[7]  L. Svaasand,et al.  Possible mechanisms for an irregular vessel coagulation when long laser pulses are used in the treatment of port-wine stains. , 1996, Journal of dermatological science.

[8]  Steven L. Jacques,et al.  Role of temperature dependence of optical properties in laser irradiation of biological tissue , 1992, Photonics West - Lasers and Applications in Science and Engineering.

[9]  Anthony E. Siegman,et al.  Choice of clip levels for beam width measurements using knife-edge techniques , 1991 .

[10]  P. Morrison,et al.  585 nm for the treatment of port-wine stains. , 1990, Plastic and reconstructive surgery.

[11]  K R Diller,et al.  Microscopic instrumentation and analysis of laser-tissue interaction in a skin flap model. , 1989, Journal of biomechanical engineering.

[12]  J. Lepock,et al.  Relationship of hyperthermia-induced hemolysis of human erythrocytes to the thermal denaturation of membrane proteins. , 1989, Biochimica et biophysica acta.

[13]  J. Carruth Argon laser therapy for port wine stains. , 1985, Photo-dermatology.

[14]  V. Dave Laser treatment of port wine stains , 1982 .

[15]  A M Stoll,et al.  Mathematical model of skin exposed to thermal radiation. , 1969, Aerospace medicine.

[16]  A. Moritz,et al.  Studies of Thermal Injury: II. The Relative Importance of Time and Surface Temperature in the Causation of Cutaneous Burns. , 1947, The American journal of pathology.

[17]  Siavash Yazdanfar,et al.  Visualization of subsurface blood vessels by color Doppler optical coherence tomography in rats: before and after hemostatic therapy. , 2002, Gastrointestinal endoscopy.

[18]  A. Welch,et al.  Modeling laser treatment of port wine stains with a computer‐reconstructed biopsy , 1999, Lasers in surgery and medicine.

[19]  A. Welch,et al.  Simultaneous irradiation and imaging of blood vessels during pulsed laser delivery , 1999, Lasers in surgery and medicine.

[20]  Sharon Thomsen,et al.  Rate Process Analysis of Thermal Damage , 1995 .

[21]  Ashleyj . Welch,et al.  Optical-Thermal Response of Laser-Irradiated Tissue , 1995 .

[22]  Francis A. Duck,et al.  Thermal Properties of Tissue , 1990 .

[23]  J. Parrish,et al.  Tunable dye laser (577 nm) treatment of port wine stains , 1986, Lasers in surgery and medicine.

[24]  J. Parrish,et al.  Microvasculature Can Be Selectively Damaged Using Dye Lasers: A Basic Theory and Experimental Evidence in Human Skin , 1981, Lasers in surgery and medicine.

[25]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .