How to perform the dusting technique for calcium oxalate stone phantoms during Ho:YAG laser lithotripsy

Lee, Jeong Woo; Park, Min Gu; Cho, Sung Yong

doi:10.1186/s12894-018-0417-5

Cited by 8 publications

(6 citation statements)

References 19 publications

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“…The Holmium laser was limited to producing relatively short pulse lengths (200 and 350 µs) at the lower pulse energy settings (0.2 and 0.4 J) relevant for this dusting mode study. These Holmium pulse durations, measured with an external detector, were much shorter than the values (500, 750, and 1,000 µs) recently reported in the clinical literature . The TFL had the opposite limitation, where the laser pulse length had to be stretched longer (500 and 1,000 µs) to reach sufficient energy (0.2 and 0.4 J) for operation in dusting mode.…”

Section: Discussionmentioning

confidence: 64%

High power holmium:YAG versus thulium fiber laser treatment of kidney stones in dusting mode: ablation rate and fragment size studies

2019

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Objectives The experimental Thulium fiber laser (TFL) is currently being studied as a potential alternative to the gold standard Holmium:YAG laser for lithotripsy. Recent advances in both Holmium and TFL technology allow operation at similar laser parameters for direct comparison. The use of a “dusting” mode with low pulse energy (0.2–0.4 J) and high pulse rate (50–80 Hz) settings, is gaining popularity in lithotripsy due to the desire to produce smaller residual stone fragments during ablation, capable of being spontaneously passed through the urinary tract. Methods In this study, Holmium and TFL were directly compared for ‘dusting’ using three laser groups, G1: 0.2 J/50 Hz/10 W; G2: 0.2 J/80 Hz/16 W; and G3: 0.4 J/80 Hz/32 W. Holmium laser pulse durations ranged from 200 to 350 μs, while TFL pulse durations ranged from 500 to 1,000 μs, due to technical limitations for both laser systems. An experimental setup consisting of 1 × 1 cm cuvette with 1 mm sieve was used with continuous laser operation time limited to ≤5 minutes. Calcium oxalate monohydrate stone samples with a sample size of n = 5 were used for each group, with average initial stone mass ranging from 216 to 297 mg among groups. Results Holmium laser ablation rates were lower than for TFL at all three settings (G1: 0.3 ± 0.2 vs. 0.8 ± 0.2; G2: 0.6 ± 0.1 vs. 1.0 ± 0.4; G3: 0.7 ± 0.2 vs. 1.3 ± 0.9 mg/s). The TFL also produced a greater percentage by mass of stone dust (fragments <0.5 mm) than Holmium laser. For all three settings combined, one out of 15 (7%) stones treated with Holmium laser were completely fragmented in ≤5 minutes compared to nine out of 15 (60%) stones treated with TFL. Conclusions These preliminary studies demonstrate that the TFL is a promising alternative laser for lithotripsy when operated in dusting mode, producing higher stone ablation rates and smaller stone fragments than the Holmium laser. Clinical studies are warranted. Lasers Surg. Med. 51:522–530, 2019. © 2019 Wiley Periodicals, Inc.

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Section: Discussionmentioning

confidence: 64%

High power holmium:YAG versus thulium fiber laser treatment of kidney stones in dusting mode: ablation rate and fragment size studies

2019

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“…This limitation has led for lithotripsy techniques to evolve. Particularly, stone dusting techniques were raised by technological improvements to laser generators, which eventually allowed lower pulse energy, longer pulse duration, and higher pulse frequency laser settings to be suited for fine disintegration of urinary stones [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

What is the exact definition of stone dust? An in vitro evaluation

et al. 2020

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Purpose To propose a size-related definition of stone dust produced by lithotripsy of urinary stones. Methods Stone dust was defined as particles small enough to adhere to the following criteria: (1) spontaneous floating under 40 cm H 2 O irrigation pressure; (2) mean sedimentation time of > 2 s through 10 cm saline solution; (3) fully suitable for aspiration through a 3.6 F working channel. Irrigation, sedimentation, and aspiration tests were set up to evaluate each criterion. Primary outcome was particle size limit agreeing with all three criteria. Stone particles with a given size limit (≤ 2 mm, ≤ 1 mm, ≤ 500 µm, ≤ 250 µm, ≤ 125 µm and ≤ 63 µm) were obtained from laser lithotripsy, including samples from prevailing stone types: calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, carbapatite, struvite, brushite, and cystine. Results All particles ≤ 250 µm from all stone types were in agreement with all three criteria defining stone dust, except for struvite where size limit for a positive irrigation and sedimentation test was ≤ 125 µm. Conclusion A size limit of ≤ 250 µm seems to generally adhere to our definition of stone dust, which is based on floating and sedimentation proprieties of stone particles, as well as on the ability to be fully aspirated through the working channel of a flexible ureteroscope.

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“…The study used phantom stones designed to mimic calcium oxalate monohydrate stones, and the results indicated that a pulse energy of 0.5 J, long pulse width, and a frequency of 70 Hz are the optimal laser settings for efficient dusting. This was achieved using the high-power 120 W Ho:YAG laser in combination with a laser 200-μm fiber [ 20 ]. These results are in context with our results which used long pulse mode and high frequency in disintegration of calcium oxalate monohydrate stones, but the maximum total power in our experiment was 30 W.…”

Section: Discussionmentioning

confidence: 99%

The optimal Holmium laser settings for disintegration of cystine and calcium oxalate monohydrate stones: In vitro study

Zeinelabden,

El-Shazly,

Elsheerif

et al. 2024

Arab Journal of Urology

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Objective Disintegrating cystine and calcium oxalate monohydrate stones present a formidable challenge owing to their hardness and distinct composition. This study aimed to establish optimal laser settings for these hard stones lithotripsy. Patients and Methods Cystine and calcium oxalate monohydrate stones were extracted from two patients. Two experiments were conducted in vitro by utilizing a 272 μm laser fiber with variable settings to disintegrate the cystine and calcium oxalate monohydrate stones. In the first experiment, energy was adjustable while frequency was constant, whereas the second experiment involved constant energy with adjustable frequency on each type of stone and each experiment was repeated three times to ensure robustness and reliability. Results Our findings indicated that for cystine stones, use of higher total power with high energy and low frequency proved to be effective. Conversely, for calcium oxalate monohydrate stones, settings involving higher total power with low energy and high frequency demonstrated superior efficacy and safety. Conclusion Holmium (Ho: YAG) laser settings with higher total power, high energy, and low frequency effectively disintegrate cystine stones despite increased heat, which was measured by a thermometer with a thermocouple. For calcium oxalate monohydrate stones, higher total power, high frequency, and low energy settings are recommended and safe.

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How to perform the dusting technique for calcium oxalate stone phantoms during Ho:YAG laser lithotripsy

Cited by 8 publications

References 19 publications

High power holmium:YAG versus thulium fiber laser treatment of kidney stones in dusting mode: ablation rate and fragment size studies

High power holmium:YAG versus thulium fiber laser treatment of kidney stones in dusting mode: ablation rate and fragment size studies

What is the exact definition of stone dust? An in vitro evaluation

The optimal Holmium laser settings for disintegration of cystine and calcium oxalate monohydrate stones: In vitro study

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