Temperature Increase During Flexible Ureteroscopic Approach with Holmium Laser Lithotripsy: How Much Should We Be Concerned?

<i>Background and Objectives</i>: The aim of our study was to evaluate in an ex vivo setting the impact of the holmium laser lithotripsy over the temperature of the irrigation fluid. <i>Materials and Methods</i>: We recorded temperature changes in an ex vivo porcine model during laser activation using dusting (18 Hz, 0.6 J, 10.8 W) and fragmenting settings (8 Hz, 2 J, 16 W). The temperature was recorded for each of these modes in three settings: without irrigation or access sheath, with irrigation but no access sheath, and with irrigation and a 10/12 F access sheath in place. <i>Results</i>: Using dusting settings, the maximum recorded temperatures were 42.3 degrees Celsius (no irrigation, no sheath), 37.3 degrees Celsius (with irrigation but no access sheath) and 36.2 degrees Celsius (with irrigation and access sheath). In fragmenting mode, the maximum recorded temperatures were 52 degrees Celsius (no irrigation, no sheath), 43.1 degrees Celsius (with irrigation but no access sheath), and 42.9 degrees Celsius (with irrigation and access sheath). <i>Conclusions</i>: In certain conditions (no irrigation, more watts) the temperature may rise to dangerous levels. However, in closer to real-life settings (with irrigation and especially when ureteral access sheaths are employed) the magnitude of this effect is limited, making flexible intrarenal laser lithotripsy a reasonably safe procedure.