Pressure matters 2: intrarenal pressure ranges during upper-tract endourological procedures.

PURPOSE: To perform a review on the latest evidence related to intrarenal pressures (IRPs) generated during upper-tract endourology, and present different tools to maintain decreased values, to decrease complication rates.

METHODS: A literature search was performed using PubMed, restricted to original English-written articles, including animal, artificial model and human studies. Different keywords were: percutaneous nephrolithotomy, PCNL, ureteroscopy, URS, RIRS, irrigation flow, irrigation pressure, intrarenal pressure, intrapelvic pressure and renal-pelvic pressure.

RESULTS: IRPs reported during retrograde intrarenal surgery (RIRS), PCNL, miniPCNL, and microPCNL range 40.8-199.35, 3-40.8, 10-45 and 15.37-41.21 cm H2 O, respectively. By utilizing ureteral access sheaths (UASs) IRPs usually remain lower than 30 cm H2 O at an irrigation pressure (IP) of ≤ 100 cm H2 O but could increase to > 40 cm H2 O at an IP of 200 cm H2 O. By utilizing the minimally invasive PCNL system, IRPs remain low at 20 cm H2 O even at high IPs. Utilizing endoluminal isoproterenol during RIRS, could reduce IRP increases with a rate of 27-107%, and maintain low IRPs values, usually below 50 cm H2 O.

CONCLUSIONS: Increased IRP values have been reported during RIRS and UASs constitute the most efficient tool for decreasing them. IRPs during mini-PCNL can be decreased utilizing the vacuum-cleaner and purging effects but might remain uncontrolled during micro- and ultra-mini PCNL. Intraluminal pharmacological treatment could play a role in IRP decrease, with isoproterenol being the most studied agent.