Comparison of high and low pulse energy dusting protocols using holmium: YAG laser in flexible ureteroscopy for treatment of renal stones.

Objectives: The management of renal stones, particularly those less than 2 cm in diameter, has changed with the development of endourological techniques, among which flexible ureteroscopy (FURS) using laser for lithotripsy has become a cornerstone. This study aims to compare the effectiveness of high pulse energy versus low pulse energy laser settings in renal stone dusting by Holmium YAG laser. Patients and Methods: This prospective randomized study was conducted between September 2021 and November 2023 to compare the efficacy and safety of high energy versus low-energy pulse settings using a Holmium: YAG laser dusting of renal stones less than 2 cm in diameter. A total of 174 adult patients were included, divided equally into high- and low-pulse energy groups, based on the energy settings of the laser high energy (ranged from 1.2-2.5 Joules and frequency of 8 hz) and low energy (less than 0.5 Joules and frequency ≥ 15 hz) using the dusting ‎technique with non-touch non-stop approach. The study sought to evaluate the impact of these settings on stone fragmentation efficiency, operative time, laser energy consumption, and postoperative outcomes, including stone-free rates and complications. Results: The study involved 174 patients who underwent renal stone lithotripsy and showed that using high pulse energy laser dusting settings significantly reduced operative times and more rapid dusting compared to low pulse energy settings, without affecting the stone-free rate. The study observed no significant differences in stone size or location between both groups. Minor postoperative complications were similar between both groups, indicating high pulse energy settings for lithotripsy dusting. Conclusion: The efficacy of high pulse energy dusting in enhancing stone removal during surgery, potentially reducing operative time. Further validation through larger-scale studies is needed to solidify these findings. This technique presents a promising solution, particularly in regions with limited resources where acquiring expensive laser equipment is challenging.