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

Introduction: One of the main limitations of Ho:YAG lithotripsy is represented by its advancement speed. The need for faster lithotripsy has led to the introduction of high-power laser equipment. This general trend in increasing Ho:YAG lithotripsy power has certain points that deserve to be considered and analyzed. The objective is to carry out a narrative review on intrarenal temperature and pressure during ureteroscopy. Methods: A literature search using PUBMED database from inception to December 2021 was performed. The analysis involved a narrative synthesis. Results: Using more power in the laser correlates with an increase in temperature that can be harmful to the kidney. This potential risk can be overcome by increasing either the irrigation inflow or outflow. Increasing irrigant flow can lead to high intrarenal temperature (IRP). The factors that allow the reduction of intrarenal pressure are a low irrigation flow, the use of a ureteral access sheath of adequate diameter according to the equipment used, and the occupation of the working channel by the laser or basket. Conclusion: To maintain a safe temperature profile, it has been proposed to use chilled irrigation fluid, intermittent laser activation or to increase irrigation flow. This last recommendation can lead to increased IRP, which can be overcome by using a UAS. Another option is to use low power laser configurations in order to avoid temperature increases and not require high irrigation flows.