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.