Fragments and dust after Holmium laser lithotripsy with or without “Moses technology”: How are they different?

Etienne X. Keller (1, 1, 2) , Vincent de Coninck (1, 1, 3) , Marie Audouin (1, 1) , Steeve Doizi (1, 1) , Dominique Bazin (4, 5) , Michel Daudon (6, 1, 7) , Olivier Traxer (1, 1)

1 CHU Tenon [AP-HP]
2 University hospital of Zurich [Zurich]
3 Department of Urology [Klina]
4 LCMCP-SMiLES - Spectroscopie, Modélisation, Interfaces pour L'Environnement et la Santé
5 LPS - Laboratoire de Physique des Solides
6 CRISTAL - Centre de Recherches et d'Informations Scientifiques et Techniques Appliquées aux Lithiases
7 Des Maladies Rénales Rares aux Maladies Fréquentes, Remodelage et Réparation

Urinary stones can be readily disintegrated by Holmium:YAG laser (Holmium laser lithotripsy), resulting in a mixture of small stone dust particles, which will spontaneously evacuate with urine and larger residual fragments (RF) requiring mechanical retrieval. Differences between fragments and dust have not been well characterized. Also, it remains unknown how the recently introduced “Moses technology” may alter stone disintegration products. Three complementary analytical techniques have been used in this study to offer an in‐depth characterization of disintegration products after in vitro Holmium laser lithotripsy: stereoscopic microscopy, scanning electron microscopy and Fourier‐transform infrared spectroscopy. Dust was separated from fragments based on its floating ability in saline irrigation. Depending on initial crystalline constituents, stone dust either conserved attributes found in larger RFs or showed changes in crystalline organization. These included conversion of calcium oxalate dihydrate towards calcium oxalate monohydrate, changes in carbapatite spectra towards an amorphous phase, changes of magnesium ammonium phosphate towards a differing amorphous and crystalline phase and the appearance of hydroxyapatite on brushite fragments. Comparatively, “Moses technology” produced more pronounced changes. These findings provide new insights suggesting a photothermal effect occurring in Holmium laser lithotripsy. Figure: Appearance of hydroxyapatite hexagons on stone dust collected after Holmium laser lithotripsy of a brushite stone using “Moses technology.”

Mots clés: Fourier‐transform infrared spectroscopy; holmium laser; lithotripsy; Moses effect; residual fragments; scanning electron microscopy; stone dust; urinary stone

Domaines: Chimie analytique; Urologie et Néphrologie

Etienne X. Keller, Vincent de Coninck, Marie Audouin, Steeve Doizi, Dominique Bazin, et al.. Fragments and dust after Holmium laser lithotripsy with or without “Moses technology”: How are they different?. Journal of Biophotonics, 2019, 12 (4), pp.e201800227, 1-9. ⟨10.1002/jbio.201800227⟩. ⟨hal-02160945⟩