LAUSR

PURPOSE To present initial clinical comparison between high-power Holmium with MOSES technology(HPH-M) and Thulium Fiber laser(TFL) during mini-PCNL for renal calculi with specific emphasis on fragmentation efficiency, fragment size distribution and stone-free rates(SFR). MATERIAL AND METHODS Between Aug2018-Dec2019, we performed mini-PCNL for renal calculi <3cm using HPH-M(Lumenis, Israel) or TFL(Urolase SP, IPG Photonics). Data was 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. MiniPCNL with active suction sheath was standard across all patients. Primary end-point was SFR at immediate post-procedure and 1month using CT/Xray KUB. Stone fragments were retrieved and segregated to assess proportion of dust(<1mm), small(1-3mm) and large(>3mm) 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 1month. Lasing time(678.6v/s551.95 seconds;p=0.17), stone fragmentation rate(4.6v/s5.2 mm3/s;p=0.23) and total laser energy(21.9v/s16.3KJ;p=0.09) were comparable in both arms. Both groups produced similar dusting (46.8v/s46.41%;p=0.93). TFL produced a greater proportion of fragments >3mm(36%v/s22.68%, p=0.002). On sub-set 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.