2. UroToday Home
  3. Recent Abstracts
  4. Endourology & Urolithiasis
  5. Minimally Invasive Procedures

EAU 2018: Comparison of Intrarenal Pelvic Pressure Levels During Flexible Ureteroscopy in a Kidney Model

Copenhagen, Denmark (UroToday.com) Dr. Rodriguez-Monsalve Herrero, clinical urologist from the Tenon Hospital in Paris, France, presented his findings on the intensity of intrarenal pressures (IP) during different modes of nephrolithiasis lithotripsy. It is well known in the urologic community that high intrarenal pressures during endoscopic surgery can likely result in potentially harmful adverse effects. In order to limit the amount of injury endured by the patient during these procedures, the relative pressures caused by each of these procedures must be quantified. Dr. Rodriguez-Monsalve Herrero and his team aimed to compare IP between flexible ureteroscopy (fURS), mini-percutaneous nephrolithotomy (mini-PCNL), and conventional PCNL in a kidney model. 

To complete this in vitro analysis, a silicone kidney-ureter-bladder model was used in order to most accurately simulate the human urinary system. The fURS utilized a 3.6 French working channel, mini-PCNL used a 12 French nephroscope with a 6.7 French working channel, and standard PCNL used a 26 French nephroscope. Mini-PCNL was tested with 15, 16.5, and 21 French access sheaths while standard PCNL only used a 30 French sheath. Automated irrigation was used to ensure steady irrigation pressure throughout experimentation. Two flow pressures were tested in each arm of the study: 40 cmH2O versus 193 cmH2O. To monitor pressures within the model kidney, a 0.014” PressureWire was placed into the renal pelvis. Pressure measurements (cmH2O) were reported whenever a plateau was reached, then repeated 5 times. 

Compared to either PNCL method, fURS had significantly higher IP readings throughout experimentation. fURS had the lowest IP whenever a ureteral access sheath was placed in addition to a laser fiber within the lumen of the scope. For mini-PCNL, IP became greater as the access sheath became smaller in diameter and the addition of a laser fiber only had as effect on pressure changes when using 193 cmH2O irrigation pressure. Standard PCNL had a reduced IP when the LithoClast lithotripter was inserted at 193 cmH2O only.   

In conclusion, this study determined that fURS had a consistently higher IP in all circumstances as compared to mini- and standard PCNL. This study was a very important one when analyzing intrarenal pressures for the common stone ablative techniques in today’s clinical practice. Dr. Rodriguez-Monsalve Herrero urged surgeons to be especially mindful with these procedures so that they do not produce excessive intrarenal pressures and potentially injure their patients. 


Presented by: Rodriguez-Monsalve Herrero M. ,MD

Co-Authors: Doizi S.,  Uzan A. , Keller E. , De Coninck V. ,  Traxer O.
Author Information: Tenon Hospital, Pierre et Marie Curie University, Dept. of Urology, Paris, France

Written by: Zachary Valley MD, Department of Urology, University of California-Irvine at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark