Laser ureteroscopic lithotripsy (URSL) is an efficacious treatment for ureteral stones. There have been few previous studies comparing the different energy and frequency settings for URSL in a single center. We compared these two laser modalities, which were simultaneously used in our medical center for the treatment of ureteral stones. Patients who underwent fragmentation or dusting laser URSL between September 2018 and June 2020 were retrospectively reviewed. We compared patients who underwent fragmentation and dusting laser and assessed the enhancing factors for stone free rate. There were a total of 421 patients with ureteral stones who met the study criteria. There was no significant difference between the characteristics of both groups. The fragmentation group had a better stone free rate and a lower retropulsion rate compared with the dusting group. Multivariate analysis revealed that stone basket use, no upper ureteral stone or pyuria significantly improved the stone free rate. Both laser modes were effective and safe for ureteral lithotripsy although the fragmentation system showed slightly higher effectiveness and lower complication rate.

Background Laser ureteroscopic lithotripsy (URSL) is an efficacious treatment for ureteral stones. There have been few previous studies compared the different energy and frequency settings for URSL in a single center. The fragmentation and dusting laser mode were simultaneously used in our medical center. We compared the efficacy and outcomes of these two laser modalities for the treatment of ureteral stones.Methods Patients who underwent fragmentation or dusting laser URSL for ureteral stones were retrospectively reviewed. The demographic data, stone parameters, perioperative data and stone-free rates were analyzed between the two groups.Results There were a total of 421 patients with ureteral stones who met the study criteria. More patients in the dusting group had multiple ureteral stones and pyuria than in the fragmentation group. The fragmentation group had a better stone free rate and a lower push back rate compared with the dusting group. (82% vs. 71%; 10% vs. 20% respectively, both p<0.05). Multivariate analysis revealed that stone basket use (odds ratio [OR] = 3.026; p<0.001) significantly improved the stone free rate, whereas multiple stones (OR=0.322; p <0.001), upper ureteral stone location (OR=0.098; p=0.002) and pyuria (OR=0.428; p=0.001) significantly decreased the stone free rate. The laser mode used was not significantly related to the stone free rate in the multivariate analysis.Conclusions Both laser modes were effective and safe for ureteral lithotripsy. Risk factors associated with a lower stone free rate were multiple stones, pyuria, upper ureteral stone location and an operation without the use of a stone basket.