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Exogenous chromophores for the argon and Nd:YAG lasers: A potential application to laser‐tissue interactions
Author(s) -
Brooks Stephen G.,
Ashley Simon,
Fisher John,
Davies Gwilym A.,
Griffiths John,
Kester Ralph C.,
Rees Michael R.
Publication year - 1992
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.1900120309
Subject(s) - argon , chromophore , laser , materials science , lasing threshold , dye laser , infrared , absorption (acoustics) , chemistry , analytical chemistry (journal) , wavelength , optics , optoelectronics , photochemistry , physics , organic chemistry , chromatography , composite material
Chromophore dyes can be employed to modify laser‐tissue interaction. A number of dyes have been investigated for their effect on the absorption and transmission of argon and Nd:YAG laser energy by vascular tissue in vitro. Three histological dyes have been assessed as potential chromophores for the argon laser and four infrared dyes for the Nd:YAG. Segments of porcine coronary artery to which dye had been applied were lased (1,064 nm, 2.5 W, 83 W/cm 2 , 60 s and 488/514 nm, 400 mW, 10.5 W/cm 2 , 60s) and the tissue temperature measured remotely using an infrared thermometer. In addition, energy transmission was measured with a photodiode and tissue morphological changes assessed histologically. All three argon dyes significantly increased energy absorption (typically 60°C v. 20°C at 60 s, P < 0.001, 2‐way ANOVA). Three of the four infrared dyes behaved similarly (40–70°C v. 20°C, P < 0.001). All dyes significantly increased the initial rate of rise in tissue temperature during lasing. A reduction in energy transmission was observed for each of the Argon dyes but not for the Nd:YAG dyes. Histological evidence of thermal damage in control tissue first occurred for the argon and Nd:YAG lasers at 800 mW and 7.5 W without chromophore and at 400 mW and 2.5 W with the chromophore, respectively. A number of effective chromophores have therefore been identified at each wavelength. © 1992 Wiley‐Liss, Inc.