Liang H, Liang L, Yu Y, et al. - This study was intended to assess factors influencing thermal impact of holmium laser during ureteroscopic lithotripsy. Researchers designed in vitro experimental model to simulate the ureteroscopic lithotripsy procedure. They employed different laser power settings (10w (0.5JX20Hz, 1.0 JX10Hz), 20w (1.0 JX20Hz, 2.0 JX10Hz), 30w (1.5JX20Hz, 3.0 JX10Hz)) with various firing time (3 s, 5 s, 10s) and irrigation flow rates(10 ml/min, 15 ml/min, 20 ml/min and 30 ml/min) in the experiment. Via thermometer, the temperature around the laser tip was recorded. The results verify that the thermal impact of holmium laser is related with both laser working parameters and irrigation flow. It was indicated that the proper setting is the key factor to ensure the safety during ureteroscopic holmium laser lithotripsy.