Effect of Chilled Irrigation on Caliceal Fluid Temperature and Time to Thermal Injury Threshold During Laser Lithotripsy: In Vitro Model

Temperature change during laser upper-tract endourological procedures: current evidence and future perspective

“…The circulation can carry thermal laser energy absorbed by tissues [21]. The operator can use chilled irrigation at one 8C to extend the time until the threshold of thermal damage at an irrigation rate of 8 ml/min to 12 mL/min [15]. Chilled irrigation also lowers the fluid temperature, allowing for excellent energy delivery without crossing the thermal threshold [38].…”

“…Open irrigation systems, chilled irrigation, ureteral access sheaths, and shorter on/off laser activation intervals help to decrease generated temperatures. [15]. They discovered that at an irrigation rate of 8 ml/min, room temperature irrigation reached the time to the threshold of thermal injury (120 min) more quickly than cooled irrigation (28 vs. 33 sec).…”

“…The majority of studies on generated temperatures have been conducted in vitro [6,[11][12][13][14][15] but also in vivo [16], ex vivo [17] and clinical [18,19] settings. The following fibres were used: 200, 242, 272, 365, and 550. studied lasers always operated in pulsed mode with power ratings ranging from 10 to 100 W. Laser activation times ranged from three to 120 s. Surgeons have utilized intelligent pumps [12,15,17], manual/infusion pumps [14,20], and gravity irrigation [6,11,12,16,20]. The applied flow rates ranged from 5 to 100 mL/min.…”

“…The highest temperature recorded during open irrigation experiments was 38.5°C (272 mm, 2 J × 5 Hz, 5 min). Different irrigation fluid temperatures were used by Dau et al , who compared irrigation fluid at room temperature (19°C) and chilled (1°C) [15]. They discovered that at an irrigation rate of 8 ml/min, room temperature irrigation reached the time to the threshold of thermal injury (120 min) more quickly than cooled irrigation (28 vs. 33 sec).…”

A Practical Guide for Intra-Renal Temperature and Pressure Management during Rirs: What Is the Evidence Telling Us

“…Considering the increases in intrarenal pressure that can be obtained by working at high irrigation flow to decrease the temperature using high power in the laser, it has been proposed to perform ureteroscopy with cooled irrigant solution, showing in an in vitro study that the temperature reached in the renal cavities would not be harmful when activating the laser at a 40 W setting and maintaining an irrigation flow of 12 mL/min of fluid at 1 °C [ 33 ]. This seems to be a valid alternative; however, we do not know if performing a ureteroscopy with an irrigation solution cooled to 1 °C at medium flow is safe or not for the patient.…”