Category: Stones: Ureteroscopy
Introduction & Objective :
Advances in pulse modulation during holmium laser lithotripsy has led to the development of the “Moses technology” in which the laser emits part of the energy to create an initial bubble, and the remaining energy is discharged once the bubble is formed so that it can pass through the already formed vapor channel. A recent preclinical study demonstrated better ablation efficiency when using the Moses mode compared to a regular holmium mode. The aim of this video is to outline the technical capabilities of the Moses technology in treating renal and ureteral stones.
We present two cases of renal stones and one distal ureteral stone treated using a 120 W holmium laser (P120, Lumenis, San Jose, CA) with the Moses technology. Moses has two distinct modes - “Contact” and “Distance” optimized for operation at a distance of around 1 mm, and at 2 to 3 mm from the stone surface, respectively. For the renal stones, we used dusting settings of low pulse energy and high frequency (LoPE-HiFr) at 0.4 to 0.5 J and 70-80 Hz utilizing Moses “Contact” and “Distance” modes, while for the ureteral stone we used fragmentation of 1 J x 8 Hz on “Contact” mode. A 230 um Moses ball-tip laser fiber was used for all cases.
In the first renal stone case, stone dusting with Moses Contact mode followed by noncontact laser lithotripsy (popcorning) in the calyx at a setting of 0.5J x 80Hz resulted in complete stone clearance (post-operative CT showed zero fragments). The second renal stone case required a hybrid technique with predominantly dusting followed by basket retrieval, utilizing a combination of Moses Contact and Distance modes. Activating the Moses Contact mode for fragmenting the ureteral stone demonstrated significant reduction in retropulsion and stone migration.
In our early experience, the Moses technology allows utilization of a Contact mode that facilitates energy ablation, which can be helpful when dusting large renal stones in a single stage. For fragmentation, Moses Contact mode can reduce retropulsion, and is advantageous for treating ureteral stones. Further studies are needed to better understand the safety aspects, especially Distance mode when working in the ureter.
Associate Professor of Urology
University of Michigan
Ann Arbor, Michigan
Khurshid Ghani is an Associate Professor of Urology at the University of Michigan. His research interests include novel techniques of endoscopic and robotic surgery for renal stone disease, health services research and surgical quality improvement. In particular Dr Ghani has been focused on advancing a Dusting technique for endoscopic stone surgery and has extramural funding to study optimal laser settings for holmium laser lithotripsy. He is the Course Director of the Developments in Ureteroscopic Stone Treatment (D.U.S.T.) symposium. In addition, Dr Ghani serves as Co-Director of the Michigan Urological Surgery Improvement Collaborative, which is a consortium of 44 urology practices aiming to improve the quality of urological care in the state of Michigan.