Current utility, instruments, and future directions for intra-renal pressure management during ureteroscopy: scoping review by global research in intra-renal pressure collaborative group initiative

Background: Technical advancements and intrarenal pressure are synergistic in improving perioperative outcomes during flexible ureteroscopy (FURS). Mismanaged intra-renal pressure (IRP) has negative consequences and it is associated with an increased risk of sepsis, bleeding, pelvicalyceal fluid extravasation, and even collecting system injuries and acute as well as chronic renal failure. The cornerstone of a safe FURS is the ability to continuously monitor IRP to avoid elevation of IRP above the normal range of 10 mmHg. Objectives: This scoping review aims to report the current state of real-time IRP monitoring in in vivo clinical studies and the various monitoring methods and technology to understand how this may be best used in daily clinical practice. Eligibility criteria: A systematic literature search was conducted. Only in vivo clinical studies published in English documenting IRP measurement methodologies during semirigid or flexible ureteroscopy for urolithiasis management were included. Results: Out of 1326 retrieved papers, 17 studies met the inclusion criteria, comprising 2 randomized controlled trials, 2 retrospective studies, and 13 observational studies. Current noninvasive IRP monitoring devices include ureteric catheters placed retrogradely or via percutaneous tubing and connected to pressure transducers, amplified by cardiology-used pressure sensing systems or urodynamic systems, automated pressure-regulating systems, pressure sensing guidewires, and IRP sensing flexible ureteroscopes. The review revealed significant variations in IRP measurement methods, reporting units, and irrigation techniques. Notably, elevated IRP above 30 mmHg was consistently associated with increased postoperative complications, including sepsis. Conclusion: Current clinical studies have only ascertained that increased IRP above 40 mmHg positively correlates with infectious complications and postoperative pain. No standardized values are available to predefine safe thresholds in practice. With the availability of noninvasive tools for IRP monitoring, future research should focus on multicenter studies to establish reference ranges and best practices for IRP management, ultimately improving patient outcomes in endourological procedures.