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Pulse modulation with Moses technology improves popcorn laser lithotripsy

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Abstract

Purpose

Moses™ technology has been developed to improve holmium laser fragmentation at 1–2 mm distance from the stone. Because popcorn lithotripsy is a non-contact technique, we compared short pulse (SP) and Moses distance (MD) modes in an in vitro model.

Methods

BegoStones were fragmented using a 120 W Ho:YAG laser (P120 Moses) and a 230 μm core fiber introduced through a ureteroscope. 20 W (1 J × 20 Hz; 0.5 J × 40 Hz) and 40 W (1 J × 40 Hz; 0.5 J × 80 Hz) settings (total energy 4.8 kJ) were tested using SP and MD modes. We assessed fragment size distribution and mass lost in fluid (initial mass–final dry mass of all sievable fragments). High-speed video analysis of fragmentation strike rate and vapor bubble characteristics was conducted for 1 J × 20 Hz and 0.5 J × 80 Hz. Laser strike rate (number of strikes divided by frequency) was categorized as: (1) direct—a visual plume of dust ejected from stone while in contact with fiber tip; (2) indirect—a visual plume of dust ejected with distance between stone and fiber tip.

Results

For 1 J × 20 Hz (20 W), MD resulted in more mass lost in fluid and a lower distribution of fragments ≥ 2 mm compared to SP (p < 0.05). 0.5 J × 80 Hz (40 W) produced no fragments ≥ 2 mm, and there were no significant differences in fragment distribution between MD and SP (p = 0.34). When using MD at 1 J × 20 Hz, 96% of strikes were indirect vs 61% for SP (p = 0.059). In contrast to the single bubble of SP, with MD, there was forward movement of the collapsing second bubble, away from the fiber-tip.

Conclusions

For lower frequency and power popcorn settings, pulse modulation results in more fragmentation through true non-contact laser lithotripsy.

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References

  1. Dauw CA, Simeon L, Alruwaily AF et al (2015) Contemporary practice patterns of flexible ureteroscopy for treating renal stones: results of a worldwide survey. J Endourol 29(11):1221–1230

    Article  Google Scholar 

  2. Humphreys MR, Shah OD, Monga M et al (2018) Dusting versus basketing during ureteroscopy-which technique is more efficacious? A prospective multicenter trial from the EDGE Research Consortium. J Urol 199(5):1272–1276

    Article  Google Scholar 

  3. Klaver P, de Boorder T, Rem AI, Lock T, Noordmans HJ (2017) In vitro comparison of renal stone laser treatment using fragmentation and popcorn technique. Lasers Surg Med 49(7):698–704

    Article  Google Scholar 

  4. Emiliani E, Talso M, Cho SY et al (2017) Optimal settings for the noncontact holmium:YAG stone fragmentation popcorn technique. J Urol 198(3):702–706

    Article  Google Scholar 

  5. Chawla SN, Chang MF, Chang A, Lenoir J, Bagley DH (2008) Effectiveness of high-frequency holmium:YAG laser stone fragmentation: the "popcorn effect". J Endourol 22(4):645–650

    Article  Google Scholar 

  6. Wollin DA, Tom WR, Jiang R, Simmons WN, Preminger GM, Lipkin ME (2018) An in vitro evaluation of laser settings and location in the efficiency of the popcorn effect. Urolithiasis 47:377–382

    Article  Google Scholar 

  7. Aldoukhi AH, Roberts WW, Hall TL, Teichman JMH, Ghani KR (2018) Understanding the popcorn effect during holmium laser lithotripsy for dusting. Urology 122:52–57

    Article  Google Scholar 

  8. Elhilali MM, Badaan S, Ibrahim A, Andonian S (2017) Use of the Moses technology to improve holmium laser lithotripsy outcomes: a preclinical study. J Endourol 31(6):598–604

    Article  Google Scholar 

  9. Aldoukhi AH, Roberts WW, Hall TL, Ghani KR (2018) Watch your distance: The role of laser fiber working distance on fragmentation when altering pulse width or modulation. J Endourol 33:120–126

    Article  Google Scholar 

  10. Brenton W, Daniel W, Evan C et al (2018) Dusting efficiency of the Moses holmium laser: an automated in vitro assessment. J Endourol 32(12):1131–1135

    Article  Google Scholar 

  11. Vassar GJTJM, Glickman RD (1998) Holmium:YAG lithotripsy efficiency varies with energy density. J Urol 160(2):471–476

    Article  CAS  Google Scholar 

  12. Lee H, Ryan RT, Teichman JM et al (2003) Stone retropulsion during holmium:YAG lithotripsy. J Urol 169(3):881–885

    Article  Google Scholar 

  13. Sea J, Jonat LM, Chew BH et al (2012) Optimal power settings for Holmium:YAG lithotripsy. J Urol 187(3):914–919

    Article  Google Scholar 

  14. Chew BH, Brotherhood HL, Sur RL et al (2016) Natural history, complications and re-intervention rates of asymptomatic residual stone fragments after ureteroscopy: a report from the EDGE Research Consortium. J Urol 195(4 Pt 1):982–986

    Article  Google Scholar 

  15. Mues AC, Teichman JMH, Knudsen BE (2009) Quantification of Holmium:Yttrium aluminum garnet optical tip degradation. J Endourol 23(9):1425–1428

    Article  Google Scholar 

  16. Aldoukhi AH, Ghani KR, Hall TL, Roberts WW (2017) Thermal response to high-power holmium laser lithotripsy. J Endourol 31(12):1308–1312

    Article  Google Scholar 

  17. Aldoukhi AH, Hall TL, Ghani KR, Maxwell AD, MacConaghy B, Roberts WW (2018) Caliceal fluid temperature during high-power holmium laser lithotripsy in an in vivo porcine model. J Endourol 32(8):724–729

    Article  Google Scholar 

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Author information

Authors and Affiliations

  1. Medical Sciences Unit I, Division of Endourology, Department of Urology, University of Michigan, 1301 Catherine St, Room 4432, Ann Arbor, MI, 48109, USA

    Kristian M. Black, Ali H. Aldoukhi, Sami E. Majdalany, William W. Roberts & Khurshid R. Ghani

  2. Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada

    Joel M. H. Teichman

  3. Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA

    Timothy L. Hall & William W. Roberts

Authors
  1. Kristian M. Black
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  2. Ali H. Aldoukhi
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  3. Joel M. H. Teichman
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  4. Sami E. Majdalany
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  5. Timothy L. Hall
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  6. William W. Roberts
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  7. Khurshid R. Ghani
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Contributions

KMB: protocol/project development, data collection or management, data analysis, manuscript writing/editing. AHA: protocol/project development, data collection or management, data analysis, manuscript writing/editing. JMT: data analysis, manuscript writing/editing. SEM: data collection or management, data analysis. TLH: data analysis, manuscript writing/editing. WWR: data analysis, manuscript writing/editing.

Corresponding author

Correspondence to Kristian M. Black.

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Conflict of interest

KRG is a consultant for Boston Scientific and Lumenis; WWR is a consultant for Boston Scientific. JMHT has research grants from Boston Scientific, Lumenis, and Cook Urologic. This study was funded by a scientific investigator grant from Boston Scientific.

Research involving human participants and/or animals

This research study did not involve the use of human or animal subjects.

Informed consent

Informed consent was not needed due to the nature of the in vitro study.

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Electronic supplementary material

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Supplementary file1 (DOCX 164 kb)

SP Mode: High-speed (30,000 FPS) video analysis of SP mode at 1Jx20Hz (M4V 164 kb)

MD Mode: High-speed (30,000 FPS) video analysis of MD mode at 1Jx20Hz (M4V 138 kb)

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Black, K.M., Aldoukhi, A.H., Teichman, J.M.H. et al. Pulse modulation with Moses technology improves popcorn laser lithotripsy. World J Urol 39, 1699–1705 (2021). https://doi.org/10.1007/s00345-020-03282-0

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  • DOI: https://doi.org/10.1007/s00345-020-03282-0

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