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Proceedings Paper

In vitro assessment of fiber sweeping speed during Q-switched 532-nm laser tissue ablation
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Paper Abstract

Photoselective vaporization of the prostate (PVP) is considered a minimally invasive procedure to treat benign prostatic hyperplasia (BPH). During the PVP, the prostate gland is irradiated by the 532-nm laser and the fiber is swept and dragged along the urethra. In this study the speed of sweeping fiber during the PVP is being investigated. In vitro porcine kidney model was used (N=100) throughout the experiment. A Q-switched 532-nm laser, equipped with sidefiring 750-Um fiber, was employed and set to power levels of 120 and 180 W. The speed of fiber sweeping was the only variable in this study and varied at 0 (i.e. no sweeping), 0.5, 1.0, 1.5, and 2.0 sweep/s. Ablation rate, depth, and coagulation thickness were quantified. Based on the current settings, ablation rate decreased as sweeping speed increased and was maximized between 0 to 1.0 sweep/s for 120-W power level and between 0 to 0.5 sweep/s for 180-W power level. Ablation rate at 180 W was higher than that at 120 W, regardless of sweeping speed. Ablation depth at both 120 and 180 W was maximized at 0 sweep/s and decreased 35% at 0.5 sweep/s. The overall coagulation thickness was less than 1.5 mm and comparable from 0 to 1.5 sweep/s (0.8~0.9 mm) and increased at 2.0 sweep/s (~1.1 mm). This study demonstrated that tissue ablation performance was contingent upon sweeping speed and maximized at slow sweeping speed due to longer laser-tissue interaction time and larger area coverage by the 532-nm light.

Paper Details

Date Published: 17 February 2011
PDF: 5 pages
Proc. SPIE 7883, Photonic Therapeutics and Diagnostics VII, 78831K (17 February 2011); doi: 10.1117/12.879275
Show Author Affiliations
Danop Rajabhandharaks, American Medical Systems (United States)
Hyun Wook Kang, American Medical Systems (United States)
Woo Jin Ko, Columbia Univ. Medical Ctr. (United States)
Douglas Stinson, American Medical Systems (United States)
Benjamin Choi, Weill Cornell Univ. Medical Ctr. (United States)

Published in SPIE Proceedings Vol. 7883:
Photonic Therapeutics and Diagnostics VII
Kenton W. Gregory M.D.; Nikiforos Kollias; Andreas Mandelis; Henry Hirschberg M.D.; Hyun Wook Kang; Anita Mahadevan-Jansen; Brian Jet-Fei Wong M.D.; Justus F. R. Ilgner M.D.; Bodo E. Knudsen M.D.; E. Duco Jansen; Steen J. Madsen; Guillermo J. Tearney; Bernard Choi; Haishan Zeng; Laura Marcu, Editor(s)

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