Purpose: To present initial clinical comparison between high-power holmium laser with MOSES technology (HPH-M) and thulium fiber laser (TFL) during mini-percutaneous nephrolithotomy (PCNL) for renal calculi with specific emphasis on fragmentation efficiency, fragment size distribution, and stone-free rates (SFRs). Materials and Methods: Between August 2018 and December 2019, we performed mini-PCNL for renal calculi <3 cm using HPH-M (Lumenis, Israel) or TFL (Urolase SP, IPG Photonics). Data were collected prospectively in our institutional stone registry. Propensity score matching (1:1) was performed using stone size and density as predictors resulting in matched cohort of 51 patients in each group. Mini-PCNL with active suction sheath was standard across all patients. Primary end-point was SFR at immediate postprocedure and 1 month using CT/kidney, ureter, and bladder radiograph. Stone fragments were retrieved and segregated to assess proportion of dust (<1 mm), small (1-3 mm), and large (>3 mm) fragments. Result: Both groups were comparable in terms of stone size (p = 0.74), volume (p = 0.17), and density (p = 0.69). SFR at 48 hours was 78.43% in HPH-M group and 68.63% in TFL group. Patients with residual fragments were completely clear at 1 month. Lasing time (678.6 vs 551.95 seconds; p = 0.17), stone fragmentation rate (4.6 vs 5.2 mm3/s; p = 0.23), and total laser energy (21.9 vs 16.3 KJ; p = 0.09) were comparable in both arms. Both groups produced similar dusting (46.8 vs 46.41%; p = 0.93). TFL produced a greater proportion of fragments >3 mm (36% vs 22.68%, p = 0.002). On subset analysis based on stone density, all outcome parameters were comparable except a shorter total operative time with TFL (p ≤ 0.05). Conclusion: HPH-M and TFL showed similar SFR. Within constraints of the laser fiber size and energy settings, both modalities were equivalent in terms of fragmentation efficiency and proportion of dusting across stone densities.
Keywords: MOSES technology; holmium laser; percutaneous nephrolithotomy; suction; thulium fiber laser.