Holmium Laser Lithotripsy in the New Stone Age: Dust or Bust?

Abstract

Modern day holmium laser systems for ureteroscopy (URS) provide users with a range of settings, namely pulse energy (PE), pulse frequency (Fr), and pulse width (PW). These variables allow the surgeon to choose different combinations that have specific effects on stone fragmentation during URS lithotripsy. Contact laser lithotripsy can be performed using fragmentation or dusting settings. Fragmentation employs settings of low Fr and high PE to break stones that are then extracted with retrieval devices. Dusting is the utilization of high Fr and low PE settings to break stones into submillimeter fragments for spontaneous passage without the need for basket retrieval. Use of the long PW mode during lithotripsy can reduce stone retropulsion and is increasingly available in new generation lasers. During non-contact laser lithotripsy, stone fragments are rapidly pulverized in a calyx in laser bursts that result in stones breaking into fine fragments. In this review, we discuss the effect of different holmium laser settings on stone fragmentation, and the clinical implications in a very much evolving field.

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

“…Stone disintegration products from Holmium lithotripsy generally form a mixture of larger residual fragments (RF) and smaller stone dust particles . Growing enthusiasm for laser dusting techniques has emerged over the last years, owing to the observation that dust particles seem to have a propensity for spontaneous evacuation from kidney after ureteroscopic laser lithotripsy, omitting the need for time‐consuming fragment extraction .…”

Therapeutic use of lasers in urology

“…Obecnie najczęściej stosowany jest laser holmowy, który minimalizuje ryzyko urazu moczowodu ze względu na odległość między końcem włókna a ścianą moczowodu wynoszącą > 1 mm. Energia emitowana przez laser powoduje powstawanie pęcherzyków kawitacyjnych, których wielkość jest proporcjonalna do ilości energii i rozmiaru włókna [19]. Bezpośrednio za fragmentację kamieni odpowiada efekt fototermiczny i fotomechaniczny.…”

Updates in endourological management of urolithiasis

“…0.2–0.3J × 40–70 Hz) to break the stones into fine fragments like dust and expecting it will pass spontaneously; fragmentation uses high energy and low frequency (e.g. 0.8–1.4J × 6 Hz) to break the stones into smaller fragments and then retrieve with a basket . Both methods have advantages and disadvantages, and there is little evidence that one is better than the other .…”

“…0.8–1.4J × 6 Hz) to break the stones into smaller fragments and then retrieve with a basket . Both methods have advantages and disadvantages, and there is little evidence that one is better than the other . The EDGE Research Consortium has a comparative study on “dusting” and “basketing”; basketing showed better stone‐free rates in univariable, but not multivariable, analysis with a significantly longer operative time …”

“…156 Both methods have advantages and disadvantages, and there is little evidence that one is better than the other. [156][157][158] The EDGE Research Consortium has a comparative study on "dusting" and "basketing"; basketing showed better stone-free rates in univariable, but not multivariable, analysis with a significantly longer operative time. 158 Different modes of holmium:YAG laser can have a significant impact on the prevention of retropulsion.…”