AUA 2018: Double-Blind Prospective Randomized Clinical Trial Comparing Regular and Moses Modes of Holmium Laser Lithotripsy: Preliminary Results

San Francisco, CA USA ( Sero Andonian, MD, a clinical urologist from Montreal, Canada, presented on a randomized double-blind prospective study that compares operative efficiency between Regular and Moses mode of Holmium laser lithotripsy. Currently, about 1 in 11 people are affected by kidney stones in the United States. According to the latest guidelines, Holmium laser lithotripsy is the gold standard for treatment of these stones because it is able to fragment most stone types with high stone free rates while maintaining a safety profile. Despite this, there are still challenges faced by Holmium laser lithotripsy such as energy absorbance by water, stone repulsion, and difficulty reaching certain locations (lower pole).

However, Moses technology provides a possible solution to these problems. With this new technology, the Holmium laser pulse is divided into two peaks. The first peak separates the fluid from the stone while the second peak is precisely delivered to the target, thus decreasing loss of energy compared to the Regular mode resulting in greater energy efficiency and less dependence on distance of stone.

In the study, a total of 66 patients were included and randomly assigned to two groups: Regular or Moses mode of Holmium laser lithotripsy. All patients and physicians were blinded and all procedures were performed by four urologists. Demographic data, stone parameters, peri-operative complications and success rates were compared. The primary objectives were to measure procedure time, fragmentation time, lasing time, total energy and degree of repulsion. Stone repulsion was graded on a Likert scale, which ranged from grade 0 (no repulsion) to grade 3 (migration to the kidney).

In the results, while demographic data and stone parameters were comparable in the two groups, a significant difference was found in fragmentation time and procedure time between the Regular and Moses groups. It was found that there was a 20%-25% reduction in both time measurements despite using the same total energy. Furthermore, there was also a significant reduction is retropulsion grade in the Moses group and stone free rates between the two groups were comparable at one month.

In conclusion, Moses technology was correlated with significantly lower fragmentation and procedural times. This reduction can be explained by the lower repulsion rate of the stone and enhanced energy delivery during laser lithotripsy, therefore improving efficiency. However, Dr. Andonian states that there were limitations to this study due to its preliminary nature, such as small sample size, short-term follow up (only about one month), the use of combined techniques of dusting and fragmentation, and no evaluation of the long pulse of Regular mode.

Presented by: Sero Andonian, MD

Written by: Whitney Zhang, Department of Urology, University of California-Irvine at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA