Determination of Irrigation Flowrate During Flexible Ureteroscopy: Methods for Calculation Using Renal Pelvis Pressure

Retrograde intra renal surgery and safety: pressure and temperature. A systematic review

“…Seven fully in vitro studies were published in the past two years, three using cadaveric pigs kidney model and two with living animal models (pigs) (Table 1). Various methods of IRP measurement were used: antegradely through percutaneous access [13,17–19], retrogradely aside from the scope [16,20,21,22 ▪▪ ] or through the fURS working channel [23,24] and using a robotic system [25]. Among this studies, IRP is decreased with a reduced inflow (occupied working channel) and an increased outflow (UAS insertion), except in Doizi et al study where a 10–12Fr UAS with 193 cmH 2 O was not associated with an IRP decrease [13,18,22 ▪▪ ,25].…”

“…Among this studies, IRP is decreased with a reduced inflow (occupied working channel) and an increased outflow (UAS insertion), except in Doizi et ]. If a linear correlation between the flowrate on irrigation pressure has been recently suggested, the mechanism of pressure regulation is complex and is still under evaluation [16]. However, the impact of high IRP on renal parenchyma and risk of fornix rupture are defined using living and deceased porcine models [21,23,26]: IRPs at 185 mmHg resulted in forniceal rupture and hematoma but below 150 mmHg, no sign of parenchymal damage was reported [23].…”

“…IRP depends on two parameters: the irrigation inflow and outflow [15]. The irrigation inflow will be determined by the irrigation pressure, the size of the working channel and the resistance index [16]. The irrigation outflow depends on the capacity to exteriorize the inserted fluid and urine, which is related to the space between the endoscope and the ureter on one side, and the space between the endoscope and the ureteral access sheath, on the other side [15].…”