Presented by: Naeem Bhojani MD, FRCSC
University of Montreal

Introduction

Percutaneous nephrolithotomy and ureteroscopy are common endourological procedures to treat renal stone disease. While highly effective, these procedures carry the risk of complications such as infection, systemic inflammatory response syndrome, and sepsis. Intrarenal pressure (IRP) during these procedures has been thought to play a role in these complications. We performed a contemporary systematic review of experimental studies that reported the associations among IRP, duration of exposure, and complication rates during endourological procedures.

Materials

A systematic review was performed. We identified 12 studies (7 preclinical, 5 clinical) published between January 2000 and December 2022 that reported outcomes of 509 endourological procedures where the relationships of IRP and complication risk were reported or calculable (Table 1).

Results

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Physiological IRP ranged from 6 to 11 mmHg under normal conditions. During endourological surgery, mean IRP was commonly between 20-40 mmHg although pressure spikes >300 mmHg were also reported. No study reported increased complication risk when peak IRP remained below 30 mmHg, or when mean IRP remained below 20 mmHg for procedures lasting over 10 minutes.  However, above these limits, the association of IRP with complication risk was variable. 

Conclusion

IRP is not routinely measured during endourological procedures since specialized equipment is needed. Our findings suggest that IRP monitoring during endourological procedures may be useful in mitigating complication risk. Recent advancements in endourology instruments have led to the development of integrated pressure sensors that enable continuous monitoring of IRP.  Further studies will help determine if the risk of complications is greater in cases where IRP is above 20-30mmHg. Further questions about whether spikes of peak pressure or sustained pressure elevation are more responsible for these complications.

Funding

Boston Scientific

Co-Authors

Helene U. Jung, MD, PHD
University of Souther Denmark

Esteban Emiliani, MD, PHD
Autonomous University of Barcelona

Larry E. Miller, PHD, PStat
Miller Scientific

Anna L. Miller,
Miller Scientific

Ben H Chew, MD, MSc, FRSC
University of British Columbia