TY - JOUR
T1 - Thulium fiber laser ablation of kidney stones using a 50 -μm -core silica optical fiber
AU - Blackmon, Richard L.
AU - Hutchens, Thomas C.
AU - Hardy, Luke A.
AU - Wilson, Christopher R.
AU - Irby, Pierce B.
AU - Fried, Nathaniel M.
PY - 2015
Y1 - 2015
N2 - Our laboratory is currently studying the experimental thulium fiber laser (TFL) as a potential alternative laser lithotripter to the gold standard, clinical Holmium:YAG laser. We have previously demonstrated the efficient coupling of TFL energy into fibers as small as 100-μm-core-diameter without damage to the proximal end. Although smaller fibers have a greater tendency to degrade at the distal tip during lithotripsy, fiber diameters (≤200 μm) have been shown to increase the saline irrigation rates through the working channel of a flexible ureteroscope, to maximize the ureteroscope deflection, and to reduce the stone retropulsion during laser lithotripsy. In this study, a 50-μm-core-diameter, 85-μm-outer-diameter, low-OH silica fiber is characterized for TFL ablation of human calcium oxalate monohydrate urinary stones, ex vivo. The 50-μm-core fiber consumes approximately 30 times less cross-sectional area inside the single working channel of a ureteroscope than the standard 270-μm-core fiber currently used in the clinic. The ureteroscope working channel flow rate, including the 50-μm fiber, decreased by only 10% with no impairment of ureteroscope deflection. The fiber delivered up to 15.4 ± 5.9 Wunder extreme bending (5-mm-radius) conditions. The stone ablation rate measured 70 ± 22 μg/s for 35-mJ-pulse-energy, 500-μs-pulse-duration, and 50-Hz-pulse-rate. Stone retropulsion and fiber burnback averaged 201 ± 336 and 3000 ± 2600 μm, respectively, after 2 min. With further development, thulium fiber laser lithotripsy using ultra-small, 50-μm-core fibers may introduce new integration and miniaturization possibilities and potentially provide an alternative to conventional Holmium:YAG laser lithotripsy using larger fibers.
AB - Our laboratory is currently studying the experimental thulium fiber laser (TFL) as a potential alternative laser lithotripter to the gold standard, clinical Holmium:YAG laser. We have previously demonstrated the efficient coupling of TFL energy into fibers as small as 100-μm-core-diameter without damage to the proximal end. Although smaller fibers have a greater tendency to degrade at the distal tip during lithotripsy, fiber diameters (≤200 μm) have been shown to increase the saline irrigation rates through the working channel of a flexible ureteroscope, to maximize the ureteroscope deflection, and to reduce the stone retropulsion during laser lithotripsy. In this study, a 50-μm-core-diameter, 85-μm-outer-diameter, low-OH silica fiber is characterized for TFL ablation of human calcium oxalate monohydrate urinary stones, ex vivo. The 50-μm-core fiber consumes approximately 30 times less cross-sectional area inside the single working channel of a ureteroscope than the standard 270-μm-core fiber currently used in the clinic. The ureteroscope working channel flow rate, including the 50-μm fiber, decreased by only 10% with no impairment of ureteroscope deflection. The fiber delivered up to 15.4 ± 5.9 Wunder extreme bending (5-mm-radius) conditions. The stone ablation rate measured 70 ± 22 μg/s for 35-mJ-pulse-energy, 500-μs-pulse-duration, and 50-Hz-pulse-rate. Stone retropulsion and fiber burnback averaged 201 ± 336 and 3000 ± 2600 μm, respectively, after 2 min. With further development, thulium fiber laser lithotripsy using ultra-small, 50-μm-core fibers may introduce new integration and miniaturization possibilities and potentially provide an alternative to conventional Holmium:YAG laser lithotripsy using larger fibers.
KW - 50-μm fiber
KW - ablation
KW - burnback
KW - kidney stones
KW - lithotripsy
KW - retropulsion
KW - thulium
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U2 - 10.1117/1.OE.54.1.011004
DO - 10.1117/1.OE.54.1.011004
M3 - Article
AN - SCOPUS:84905845250
SN - 0091-3286
VL - 54
JO - Optical Engineering
JF - Optical Engineering
IS - 1
M1 - 011004
ER -