Presented by: Naren Nimmagadda MD
Johns Hopkins University

Introduction

The clinical impact of Moses pulse-width modulation in decreasing stone retropulsion and increasing lithotripsy efficiency remain debated. We sought to evaluate the potential of Moses 2.0 pulse-width modulation to reduce operative time compared to non-Moses settings for ureteroscopic treatment of nephrolithiasis.

Materials

In this multi-institutional, randomized, double-blind clinical trial, 150 patients were randomized and underwent unilateral ureteroscopy for stones 8-20mm in size at or above the ureteropelvic junction. Patients were randomized to Moses or Non-Moses settings. Stones were treated by attending endourologists with standardized dusting settings to maintain blinding. A validated survey (NASA Task Load Index) was completed afterwards. Stents were maintained for 4-10 days, and CT imaging was obtained 6 weeks postoperatively. The primary outcome was to compare total operative times. Secondary outcomes included blinded measures of stone retropulsion, stone-free rate, and surgeon workload.

Results

,

143 patients were included in the analysis. Demographics and stone characteristics were similar between groups. Moses setting led to shorter ureteroscopy time overall on average, but difference was not statistically significant. Intraoperative outcomes did not reach statistical significance but Moses setting trended towards shorter ureteroscopy time overall (29.5min v 30.7min, p=0.60761). When stratified for stone size, total stone burden between 8-12mm demonstrated shorter operative times (-3.5 min, p=0.41) compared to longer operative times for stone burden 12-16mm (+1.0min, p=0.82583), and 16-20mm (+9.5min, p=0.132). Amongst 112 patients reaching 6 week follow-up, no difference in stone-free status was seen with and without the Moses setting (42.3% v 38.9%). Surgeons correctly perceived the Moses setting in 57.7% of cases compared to 48.6% of cases without Moses. After using Moses, surgeons experienced less mental burden, physical burden, temporal demand, frustration, and less required effort. Perception of operative performance was higher when using the Moses setting. These findings remained significant on multivariable analysis (Table 1).

Conclusion

No significant differences were seen in total operative time, ureteroscopy time nor stone-free rate. However, use of Moses settings remained a significant predictor across NASA task load domains after controlling for factors that increase surgeon workload during ureteroscopy.

Funding

This study was funded by a grant from the Endourology Disease Group for Excellence courtesy of Lumenis. Study data were collected and managed using REDCap electronic data capture tools hosted at Vanderbilt University.

Lead Authors

Nicole Miller, MD
Vanderbilt University Medical Center

Co-Authors

Amy Reed, MD
Vanderbilt University Medical Center

Ryan Hsi, MD
Vanderbilt University Medical Center

Seth Bechis, MD
University of California San Diego

Mitchell Humphreys, MD
Mayo Clinic Arizona

Michael Lipkin, MD
Duke University

Manoj Monga, MD
University of California San Diego

Ojas Shah, MD
Columbia University

Karen Stern, MD
Mayo Clinic Arizona

Roger Sur, MD
University of California San Diego

Sriharan Sivalingam, MD
Cleveland Clinic