Abstract
Ureteroscopy with holmium(Ho):YAG laser lithotripsy (LL) is the primary treatment modality for kidney stone patients. Despite this, the mechanism of stone dusting in LL is unclear. In this work, we treated 6 × 6 mm cylindrical BegoStone phantoms using 0.2–0.4 J and 20 Hz at various fiber-to-stone standoff distances (SD) either in water or air with perpendicular fiber orientation; the latter eliminates the contribution of cavitation. The laser fiber was advanced at different offset distances (OSD) from a flexible ureteroscope tip to alter LL-induced bubble dynamics. Furthermore, stones were treated in parallel fiber orientation to minimize thermal ablation while isolating cavitation damage. Our results demonstrate that stone damage in water is 2.5- to 90-fold of those produced in air. At OSD = 0.25 mm when the bubble collapsed away from the stone surface due to the presence of the scope tip, stone damage was greatly reduced to the level in air. Moreover, the average crater volume produced by parallel fiber orientation after 100 pulses was comparable with those produced by perpendicular fiber within SD = 0.25–1 mm. Altogether, we conclude that cavitation is the primary mechanism over photothermal ablation for stone dusting in Ho:YAG LL.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call