The following is a summary of “Factors Affecting the Irrigation Fluid Temperature During Laser Lithotripsy: In Vitro Experimental Study” published in the December 2022 issue of Urology by Peteinaris et al.

For a study, researchers sought to look into how the size of the laser fiber, the size of the pelvis, the presence and kind of the stone, and the temperature increase of the irrigation fluid all affect the results.

The following tools were used: a dual-lumen catheter, a 12/14 ureteral access sheath (UAS), a 20ml syringe, and a thermocouple. The 12/14Fr UAS and the Thermocouple were placed inside the syringe. After closing the syringe, 10 ml/min of fluid might be released from the UAS. They employed the Quanta Ho 150W laser and shot pulses of 10W (2Jx5Hz), 20W (20W(2 × 10 Hz), 40W(2 × 20 Hz), 60W(2 × 30 Hz). Fibers (200µm, 365µm, and 550µm), volumes (5 ml, 10 ml, and 20 ml), and fake stones were used to evaluate the power settings under various situations (soft, hard). As soon as the temperature dropped below 26 °C, the laser was reactivated after being on for 30 seconds.

For all trials, 60W of energy produced a greater increase in temperature. When other fibers were employed, no changes were seen. For 60W, 5ml syringes recorded the highest temperatures (up to 80 °C), whereas 20ml reported the lowest (<45 °C). The output of 60W (1Jx60Hz) resulted in a maximum temperature of >59°C. When power levels >40W were used, the temperature was higher than 43 °C.

The temperature of the irrigation fluid dramatically rose when the total power was increased. The temperature elevation was greater with the smaller pelvic volume. The pattern of temperature rise was unaffected by fiber size. The absorption of laser energy was connected to the existence of synthetic stones.