For dusting kidney stones during retrograde intrarenal surgery, the Holmium:YAG laser and the thulium fiber laser achieve comparable stone-free rates and similar improvements in health-related quality of life, according to a randomized controlled trial published in The Journal of Urology.
Both Lasers Show Similar Success and Low Complications
- Comparable Success: Both the Holmium:YAG and thulium fiber lasers break down kidney stones into dust just as effectively, with matching stone-free rates of roughly 52%.
- Quality of Life: Patients treated with either laser technology experience significant improvements in their overall quality of life following the procedure.
- Minimal Complications: Complications across both groups remain low and minor, primarily involving post-operative pain that occasionally requires an emergency department visit.
Randomized Trial Compares Laser Efficiency in Tertiary Care Centers
Researchers at five tertiary care centers across the United States conducted a randomized controlled trial to evaluate the efficacy of the pulse-modulated Holmium:YAG (Ho:YAG) laser versus the thulium fiber laser (TFL). The study included 178 adult patients presenting with kidney stones ranging from 5 mm to 20 mm between 2023 and 2025. Margaret A. Knoedler of the Department of Urology at the University of Wisconsin School of Medicine and Public Health in Madison, Wisconsin, led the investigation, which was published online on September 24, 2026.
Participants were randomly assigned into two equal cohorts of 89 patients each to receive retrograde intrarenal surgery using either the pulse-modulated Ho:YAG laser or the TFL. During the procedures, operating surgeons utilized a flexible ureteroscope paired with a 200-µm laser fiber. Out of the initial cohort, 133 patients completed confirmatory computed tomography (CT) imaging performed 6 to 12 weeks post-surgery, with 68 patients in the Ho:YAG arm and 65 in the TFL arm.
| Laser Group | Patient Cohort (CT Follow-up) | Stone-Free Rate | Mean Follow-Up Duration |
|---|---|---|---|
| Holmium:YAG (Ho:YAG) | n = 68 | 52.9% | 1.7 months |
| Thulium Fiber Laser (TFL) | n = 65 | 52.3% | 1.5 months |
Outcomes, Efficiency Metrics, and Quality of Life Measures
The primary outcome measure—confirmed stone-free status verified via CT imaging—showed virtually identical results between the two technologies. Specifically, the stone-free rate reached 52.9% in the Ho:YAG group and 52.3% in the TFL group. Secondary intraoperative metrics, including procedure duration, active stone treatment time, total laser energy utilized, and overall laser ablation efficiency, revealed no statistically significant differences between the cohorts.
Safety profiles remained comparable, with overall complication rates showing no significant variance between the two devices. All observed complications were minor, predominantly manifesting as post-operative pain that prompted an emergency department visit. Furthermore, health-related quality of life scores improved significantly across both treatment arms following the intervention (P < .001), with no notable differences detected between the groups.
The authors noted that laser settings were not strictly standardized during the trial, and the investigation evaluated a specific stone size range, which may limit the direct applicability of these findings to larger renal calculi. Approximately 75% of the enrolled patients completed the mandatory post-operative CT imaging protocol. The study received no external funding, and the investigators reported no relevant conflicts of interest.
Findings Offer Clinicians Flexibility in Equipment Selection
These findings offer clinicians flexibility in selecting endoscopic lithotripsy equipment based on availability and hospital resources.
References
- The Journal of Urology – Knoedler et al.
