Lower Stone Pulverization Time with Moses Mode as Compared to Regular Mode of Holmium Laser Lithotripsy

Table of Content

Introduction

In vitro studies have demonstrated higher stone ablation volumes and lower stone retropulsion with Moses technology as compared to conventional regular mode during Holmium laser lithotripsy. Moses mode has been associated with significantly lower procedural time and better stone fragmentation as compared to the regular mode. However, there is lack of randomized clinical data assessing the efficacy of Moses technology in reducing stone retropulsion, improving procedural, fragmentation and pulverization times.

Aim

This study compares the stone retropulsion, stone fragmentation, pulverization time and procedural time with regular and Moses modes of Holmium laser lithotripsy during retrograde ureteroscopy.

Method

Study Design

  • Prospective, double-blind, randomized clinical trial
  • Patients undergoing Holmium laser lithotripsy during retrograde ureteroscopy were assigned to either regular or Moses modes
  • All procedures were performed by 4 experienced urologists

Endpoints

  • Stone fragmentation/pulverization time measured from starting lasing till end of lasing
  • Procedural time measured as the time from introduction of the ureteroscope till the final removal
  • Degree of stone retropulsion graded on a scale where 0 was equivalent to no retropulsion and 3 represented maximum retropulsion
  • Total energy required to fragment the stone
  • Intraoperative complications
  • Success rate at the end of 3 months defined as no ureteral fragments or presence of non-obstructive renal fragments of <4mm

Results

  • Cohort comprising of 72 patients were randomized into 2 groups of 36 each
  • The pre-operative stone size was similar in both the groups; 1.4 vs 1.7 cm, p>0.05
  • Baseline characteristics between both groups were comparable
  • The comparison of endpoints are shown in figure 1.
Figure 1. Comparison of endpoints

Outcome

Moses

Regular

p value

Fragmentation / Pulverization time

14.2 mins

21.1 mins

0.03

Procedural time

41.1 mins

50.9 mins

0.03

Retropulsion grade

0.5

1

0.01

Lasing time

6.1 mins

7.4 mins

> 0.05

Energy applied to stones

10.8 KJ

11.1 KJ

> 0.05

Intra-operative complications

8.3%

11.1%

> 0.05

Success rate at end of 3 months

88.4%

83.3%

> 0.05

  • Moses mode was associated with significantly lower pulverization time (p=0.03) and lower procedural time (p=0.03)
  • The differences in the lasing time (p>0.05) and total energy applied to the stones were insignificant (p>0.05)
  • The mean retropulsion grade was also significantly lower with the Moses mode (0.5 vs 1.0; p=0.01)
  • The incidence of intra-operative complications was similar across both groups (11.1% vs 8.3%; p>0.05)
  • One patient from Moses group required endo-ureterotomy for stricture
  • Both the groups reported similar success rates at the end of 3 months (83.3% vs 88.4%; p>0.05)  

Conclusion

  • Moses mode of Holmium laser lithotripsy was associated with significantly lower stone fragmentation/pulverization time and lower procedural time as compared to regular mode
  • The lower pulverization time could be related to lower retropulsion of stones with the Moses technology

J Endourol. 2020 Mar 6; doi: 10.1089/end.2019.0695.