Intrarenal Pressure State of the Art: The Past, Present and Future

Background: Kidney stone disease is increasingly prevalent worldwide, resulting in a growing use of ureteroscopy (URS) for stone management. Although URS is generally safe and effective, elevated intrarenal pressure (IRP) during the procedure may contribute to perioperative morbidity, particularly infectious complications. Excessive IRP can promote intrarenal backflow into tubular, venous, lymphatic, and interstitial compartments, potentially resulting in tissue injury, impaired renal perfusion, and systemic exposure to bacteria and endotoxins. Advances in pressure-monitoring technology have enabled continuous intraoperative assessment of IRP and highlighted substantial pressure variability and transient spikes during routine URS. Methods: This narrative review examines the historical understanding and contemporary evidence surrounding IRP during URS, based on a structured search of PubMed/MEDLINE, the Cochrane Library and Europe PMC (January 1980 to October 2026), supplemented by manufacturer and regulatory sources. The review evaluates current approaches to IRP measurement, the pathophysiological and clinical consequences of elevated pressure, patient-specific susceptibility, and strategies aimed at pressure mitigation. Results: Available experimental and clinical evidence indicates that elevated IRP may contribute to acute renal tissue injury, impaired renal perfusion and intrarenal backflow, although most reported pressure thresholds derive from experimental models rather than validated human safety limits. IRP is influenced by irrigation inflow, outflow resistance, and renal compliance, and may vary considerably during URS, with transient pressure spikes occurring even during routine procedures. Multiple strategies can reduce IRP. Novel pressure-guided platforms integrating real-time pressure monitoring with automated irrigation and suction control can regulate IRP in early studies, but evidence that they improve clinical outcomes remains limited. Suction-assisted access sheaths are associated with fewer postoperative infectious complications in comparative studies, although this benefit has not been shown to result specifically from IRP reduction. Conclusions: IRP is an increasingly recognised and potentially modifiable determinant of safety during ureteroscopy. Further clinical research, including standardised reporting of IRP metrics, is required to establish clinically relevant pressure thresholds and determine whether pressure-guided URS improves patient outcomes. The integration of real-time monitoring with automated irrigation and suction control represents a promising direction toward safer, pressure-conscious endourological practice.