Intrarenal pressure during endourologic stone surgery: A systematic review of measurement, clinical impact, and pressure-control strategies

Abstract

BACKGROUND

Intra-renal pressure (IRP) during endoscopic urological procedures, including flexible ureteroscopy (fURS), percutaneous nephrolithotomy (PCNL), and miniaturized PCNL, is increasingly recognized as a critical safety parameter. Elevated IRP may precipitate serious complications such as pyelovenous and pyelotubular backflow, urosepsis, forniceal rupture, and renal parenchymal injury. Although a general knowledge of increased intra renal pressure has been gaining prominence within urology there is no universal or acceptable standard for measuring IRP as well as safe pressure limits.

AIM

To systematically identify all available data on the measurement techniques of IRP, and all clinical outcomes that occur due to various degrees of pressure applied during an endourologic procedure, as well as complications that may arise when IRP reaches excessive levels.

METHODS

Using a systematic search, we searched PubMed/MEDLINE, EMBASE, Cochrane Library, and Scopus using the search terms listed above. Searches were limited to studies published through December 2025. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines were followed. Studies measuring IRP during any endourologic procedure of the upper urinary tract were eligible. Two independent reviewers screened the literature, extracted data and assessed the risk of bias utilizing the Cochrane Risk of Bias tool version 2, Newcastle-Ottawa Scale, Murad Tool, and a customized checklist for in vitro research. A narrative synthesis was performed, grouped by measurement techniques, pressure ranges, and clinical outcomes.

RESULTS

Twenty-nine studies met inclusion criteria. IRP during fURS without a ureteral access sheath (UAS) frequently exceeded 40 cmH₂O, with peak pressures reaching up to 437 cmH₂O in human in vivo studies. UAS placement significantly reduced IRP across all measured parameters. In mini-PCNL, pressures ranged from 2.4 cmH₂O to 39.7 cmH₂O, with optimized sheath designs achieving lower pressures. Pyelovenous backflow was demonstrated at pressures ≥ 90 mmHg and pyelotubular backflow at ≥ 60 mmHg in porcine models. The most feared complication was urosepsis, with clinical studies demonstrating significantly higher IRP in patients who developed postoperative urosepsis (81.7 mmHg vs 38.5 mmHg, P < 0.001). Emerging technologies include ureteroscopes with integrated pressure monitoring (e.g., LithoVue Elite) and novel non-invasive monitoring devices.

CONCLUSION

IRP monitoring during endourologic procedures is emerging as an essential component of patient safety. However, no universally agreed safe pressure threshold exists, and the commonly cited 30 mmHg limit is being challenged by newer evidence. Standardized measurement protocols, large prospective multicenter studies, and integration of real-time IRP monitoring into routine clinical practice are urgently needed.

Keywords: Intrarenal pressure; Endourology; Retrograde intrarenal surgery; Flexible ureteroscopy; Ureteral access sheath; Urolithiasis; Irrigation pressure; Suction ureteral access sheath; Mini-percutaneous nephrolithotomy; Pressure monitoring

Core Tip: Intrarenal pressure has emerged as a critical factor influencing infectious complications, pyelovenous backflow, and procedural safety during endourologic stone surgery. This systematic review summarizes current evidence regarding intrarenal pressure measurement techniques, clinically relevant pressure thresholds, and the impact of modern pressure-control strategies including ureteral access sheaths, suction-assisted systems, and mini-percutaneous nephrolithotomy technologies. The review also highlights emerging monitoring technologies and ongoing controversies regarding safe intrarenal pressure ranges during endourologic procedures.