Introduction
The holmium:yttrium–aluminium-garnet (Ho:YAG) laser used to be the state-of-the-art in lithotripsy. Continuous improvements to this device with pulse modulation and new power possibilities mean that its efficacy has continued to be enhanced year-after-year. Subsequent versions of the laser have incorporated the latest technologies (e.g., pulse modulation). Previous trials were unable to demonstrate any clear advantage over the conventional Ho:YAG [The recently introduced SuperPulsed Thulium-fiber laser (SP TFL) has not only already proved to have 2–4 times higher However, there are still no head-to-head comparison data on Ho:YAG with SP TFL lithotripsy in a clinical trial or different laser fiber diameters for SP TFL. Thus, the aims of the study were: 1) to compare SP TFL and Ho:YAG lasers for RIRS and 2) to compare the efficacy of SP TFL using laser fibers (LF) of different diameters (150 μm and 200 μm) for RIRS.