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Plaque‐media rewelding with reversible tissue optical property changes during receptive CW Nd:YAG laser exposure
Author(s) -
Spears J. Richard,
James Leslie M.,
Leonard Bradley M.,
Sinclair I. Nigel,
Jenkins Ronald D.,
Motamedi Massoud,
Sinofsky Edward L.
Publication year - 1988
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.1900080506
Subject(s) - laser , materials science , irradiation , optics , integrating sphere , radiation , biomedical engineering , medicine , nuclear physics , physics
Laser dosimetry for thermal fusion of plaque‐wall separations during laser balloon angioplasty (LBA) is dependent upon the optical properties of the atheromatous arterial wall during one or more exposures to cw Nd:YAG laser radiation. An integrating sphere technique was used to measure relative transmission and reflection continuously during irradiation of human postmortem atheromatous aortic sections. Tissue luminal surface temperature was recorded continuously with a thermographic video imager during repetitive 20–30‐sec, 8–15‐watt exposure of a 3‐mm nominal spot. In all specimens, transmission fell progressively during each exposure by 10–70% of baseline values. This effect was reversible with normalization of transmission during the initial phase of each subsequent exposure. Changes in transmission were inversely related to temperature over a 50–170°C range, wherease relative reflection remained constant. Accompanying reversible transmission changes was the observation that the weld strength of plaqueaortic wall separations was unchanged by repetitive laser welding and tissue separation of individual sections. In conclusion, temperaturedependent reversible optical and physical properties of plaque occur during exposure to 1.06 μm cw laser radiation.