V6-07: Developments in Ureteroscopic Stone Treatment (DUST): Tips and tricks for lithotripsy of renal stones using multi-cavity high-power holmium lasers
&[prime]Dusting&[prime] is the use of high frequency and low pulse-energy (HiFr-LoPE) laser settings to ablate stones into sub-millimeter fragments. In this video we demonstrate our technique of ureteroscopic stone dusting for renal stones using multi-cavity high-power Holmium:YAG systems.
We present three cases of renal pelvic stones (1.4, 1.5 and 1.4 cm, respectively) and one partial staghorn (3.0 cm) treated with dusting technique via flexible ureteroscopy. We used a 100-Watt (VersaPulse, Lumenis Inc, San Jose, CA) or a 120-Watt holmium laser (Pulse 120H, Lumenis). The 120-Watt system permits dual lithotripsy mode of &[prime]Fragmentation&[prime] and &[prime]Dusting&[prime] as well as change in pulse width. Energy settings were adjusted according to stone composition, location and size, varying from 0.2-0.8 Joules (J) with repetition rates between 30-80 Hertz (Hz).
Effective strategies for dusting renal stones include the technique of &[prime]nudging&[prime] and &[prime]herding&[prime] to displace renal stones into upper pole calyces. Dusting methods include chipping, dancing and pop-corning maneuvers. For chipping, the laser fiber is directed to the periphery of the stone to allow small fragments to break off. For dancing, the tip of the laser fiber is brushed back and forth across the stone surface. We also illustrate the new technique of &[prime]pop-dusting&[prime] using a setting of 0.5J x 80Hz, for rapidly ablating fragments within calyces into powder. With dusting strategy, the utilization of ureteral access sheaths and retrieval devices are minimized.
High-power holmium lasers have opened a new frontier in laser lithotripsy. Strategies that optimize fragmentation and post-procedural drainage when using a dusting technique include nudging and herding stones into upper pole calyces. Pop-dusting is a new technique that can ablate stones rapidly into fine powder. Further clinical evidence is needed to determine if outcomes are similar to conventional laser lithotripsy strategies.