Intrarenal Pressure in Retrograde Intrarenal Surgery: A Narrative Review.

Objective: To review the latest evidence on the complications of elevated intrarenal pressures (IRPs) in retrograde intrarenal surgery (RIRS) and the strategies to mitigate the increase of IRP during surgery.

Methods: A literature search of the PubMed, MEDLINE, and Google Scholar databases was conducted from inception to April 2024. The analysis involved a narrative review.

Results: Normal physiological IRP in an unobstructed kidney ranges from 0 to 15 mmHg (0-20cmH2O). During RIRS, dangerous IRPs are often reached, resulting in complications. These include pyelorenal reflux, which predisposes the patient to fever, urosepsis and postoperative pain, and forniceal rupture, which may result in intraoperative bleeding as well as acute kidney injury, postoperative pain, and fluid overload. To maintain safe IRP, outflow should be as close as possible to inflow. Minimizing the irrigation pressure by controlling the flow rate, reducing the pressure of the irrigant fluid, using a ureteral access sheath and maintaining an empty bladder during the procedure and, more recently, using real-time IRP monitoring are appropriate techniques to mitigate unsafe IRPs.

Conclusion: Several complications from RIRS are related to elevated IRPs. Urologists need to understand the concept of IRP in endourology, the dangers associated with an elevated IRP, and the techniques that may be used to mitigate unsafe IRPs.