1 March 2010 Femtosecond laser lithotripsy: feasibility and ablation mechanism
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Light emitted from a femtosecond laser is capable of plasma-induced ablation of various materials. We tested the feasibility of utilizing femtosecond-pulsed laser radiation (λ=800 nm, 140 fs, 0.9 mJ/pulse) for ablation of urinary calculi. Ablation craters were observed in human calculi of greater than 90% calcium oxalate monohydrate (COM), cystine (CYST), or magnesium ammonium phosphate hexahydrate (MAPH). Largest crater volumes were achieved on CYST stones, among the most difficult stones to fragment using Holmium:YAG (Ho:YAG) lithotripsy. Diameter of debris was characterized using optical microscopy and found to be less than 20 µm, substantially smaller than that produced by long-pulsed Ho:YAG ablation. Stone retropulsion, monitored by a high-speed camera system with a spatial resolution of 15 µm, was negligible for stones with mass as small as 0.06 g. Peak shock wave pressures were less than 2 bars, measured by a polyvinylidene fluoride (PVDF) needle hydrophone. Ablation dynamics were visualized and characterized with pump-probe imaging and fast flash photography and correlated to shock wave pressures. Because femtosecond-pulsed laser ablates urinary calculi of soft and hard compositions, with micron-sized debris, negligible stone retropulsion, and small shock wave pressures, we conclude that the approach is a promising candidate technique for lithotripsy.
© (2010) Society of Photo-Optical Instrumentation Engineers (SPIE)
Jinze Qiu, Jinze Qiu, Joel M. Teichman, Joel M. Teichman, Tianyi Wang, Tianyi Wang, Joseph Neev, Joseph Neev, Randolph D. Glickman, Randolph D. Glickman, Kin Foong Chan, Kin Foong Chan, Thomas E. Milner, Thomas E. Milner, } "Femtosecond laser lithotripsy: feasibility and ablation mechanism," Journal of Biomedical Optics 15(2), 028001 (1 March 2010). https://doi.org/10.1117/1.3368998 . Submission:

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