Pulsed Thulium:Yag, Thulium Fiber, and Holmium:Yag Lasers in Mini-PCNL: A Three-Arm Comparative Cohort Study.

Background &

Objectives

Laser lithotripsy is the standard energy source for mini-percutaneous nephrolithotomy (mini-PCNL). Although Holmium:YAG (Ho:YAG), Thulium Fiber Laser (TFL), and pulsed Thulium:YAG (p-Tm:YAG) are currently available for clinical use, direct comparisons among all three laser technologies are lacking. This study aimed to compare the efficacy, safety, and procedural performance of Ho:YAG, TFL, and p-Tm:YAG during mini-PCNL. The primary endpoint was the stone-free rate (SFR). Secondary outcomes included complications, operative time, lasing time, total energy delivered, and laser-related procedural metrics.

Methods

Consecutive patients treated with p-Tm:YAG during mini-PCNL for renal stones were prospectively enrolled and compared with two cohorts from our institutional database treated with Ho:YAG or TFL. All procedures were performed using the same mini-PCNL technique and predefined laser settings selected to achieve the closest technically feasible match among the three platforms.

Results

Ninety patients were included (30 per group). No significant differences in SFR were observed among Ho:YAG, TFL, and p-Tm:YAG (p = 0.93), or in overall complication rates (p = 0.93). After adjusting for stone volume, density, composition, and location, the laser platform was not independently associated with SFR, whereas stone volume was the only independent predictor of stone-free status. TFL exhibited a significantly longer operative time than Ho:YAG and a longer lasing time than both Ho:YAG and p-Tm:YAG, and was associated with greater total energy delivery, lower ablation efficiency, and lower ablation speed. Conversely, p-Tm:YAG demonstrated a significantly shorter lasing time than TFL and an ablation efficiency similar to that of Ho:YAG, with lasing time and ablation speed values between those observed with Ho:YAG and TFL under the evaluated settings. Laser efficacy did not differ significantly among the three groups.

Conclusions

No significant differences in stone-free or safety outcomes were observed among the three laser platforms in mini-PCNL. Although significant differences were observed in lasing time, ablation speed, and energy utilization, p-Tm:YAG demonstrated an intermediate procedural profile under the operating parameters evaluated in this study. Overall, the present findings suggest that p-Tm:YAG represents a feasible treatment option for mini-PCNL, although larger randomized studies are needed before firm conclusions regarding relative platform performance can be drawn.