Presented by: Jia-Lun Kwok MBBS, FRCS(Urol)(Glasg)
Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland ; Department of Urology, Tan Tock Seng Hospital Singapore, Singapore

Introduction

A novel pulsed thulium:yttrium-aluminum-garnet (p-Tm:YAG) laser has recently been introduced for clinical use. Few in vitro evaluations are available in literature, and all based on artificial stone models – not on human urinary stones. The aim of the present study was to evaluate whether stone dust can be obtained from all prevailing stone composition types using the p-Tm:YAG, including analysis of stone particle size after lithotripsy.

Materials

Human urinary stones of 7 different compositions were subjected to in vitro lithotripsy using a p-Tm:YAG laser with 270 µm silica core fibers (Thulio®, Dornier MedTech GmbH®, Wessling, Germany). A cumulative energy of 1000 J was applied to each stone using one of three laser settings: 0.1J x 100Hz, 0.4J x 25Hz, and 2.0J x 5Hz (average power 10W). After lithotripsy, larger remnant fragments were separated from stone dust using a previously described method depending on the floating ability of dust particles. Fragments and dust samples were then passed through laboratory sieves to evaluate stone particle count according to a semi-quantitative analysis relying on a previous definition of stone dust (i.e. stone particles ≤ 250 µm).

Results

,

The p-Tm:YAG laser was able to produce stone dust from lithotripsy up to measured smallest mesh size of 63 µm in all seven urinary stone composition types. Notably, all dust samples from all seven stone types and with all three laser settings had high counts of particles in the size range agreeing with the stone dust definition, i.e. ≤ 250 µm.

Conclusion

To the best of our knowledge, this is the first study in literature proving the p-Tm:YAG laser to be capable of dusting all prevailing human urinary stone compositions, with production of dust particles ≤  250µm. These findings are pivotal for the broader future implementation of the p-Tm:YAG in clinical routine.

Funding

None

Co-Authors

Eugenio Ventimiglia, MD, FEBU
Division of Experimental Oncology/Unit of Urology, Urological Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy ; Young Academic Urologists (YAU), Endourology & Urolithiasis Working Group, Arnhem, The Netherlands; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Vincent De Coninck, MD, FEBU
Department of Urology, AZ Klina, Brasschaat, Belgium ; Young Academic Urologists (YAU), Endourology & Urolithiasis Working Group, Arnhem, The Netherlands ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Mariela Corrales, MD
Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, F-75020 Paris, France ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Alba Sierra, MD
Urology Department, Hospital Clinic de Barcelona, Villarroel 170, 08036 Barcelona, Spain ; Young Academic Urologists (YAU), Endourology & Urolithiasis Working Group, Arnhem, The Netherlands ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Frédéric Panthier, MD
Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, F-75020 Paris, France ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Felipe Pauchard, MD
Urology Department, Hospital Naval Almirante Nef, Viña del Mar 2520000, Chile ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Florian Schmid, MD, FEBU
Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland

Manuela Hunziker, MD, FEBU
Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland

Cédric Poyet, MD, FEBU
Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland

Michel Daudon, MD
Sorbonne Université, Hôpital Tenon, CRISTAL Laboratory, Paris, France

Olivier Traxer, MD
Sorbonne Université, GRC n°20, Groupe de Recherche Clinique sur la Lithiase Urinaire, Hôpital Tenon, F-75020 Paris, France ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)

Daniel Eberli, MD, FEBU
Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland

Etienne Xavier Keller, MD, FEBU
Department of Urology, University Hospital Zurich, University of Zurich, Zurich, Switzerland ; Young Academic Urologists (YAU), Endourology & Urolithiasis Working Group, Arnhem, The Netherlands ; Progressive Endourological Association for Research and Leading Solutions (PEARLS)