Fluid Dynamic Analysis of Hand-Pump Infuser and UROMAT Endoscopic Automatic System for Irrigation Through a Flexible Ureteroscope

Abstract

The flow rates of irrigation produced by the HP and the E.A.S.I. pump are similar at pressures of 150 and 200 mm Hg irrespective of the occupancy of a ureteroscope's working channel during the first 5-minutes of irrigation. Irrigation pressure at the entry site of the ureteroscope is subject to significant variability with use of the HP compared to the E.A.S.I. pump irrigation system.

Change in irrigation flow through a flexible ureteroscope with various devices in the working channel: Comparison between an automatic irrigation pump and gravity‐based irrigation

“…The irrigation inflow from the tip of the working channel in the fURS depends on the irrigation method used. Although a hand‐ or foot‐activated syringe‐based irrigation system might produce a drastic increase of inflow through the working channel, which influences the intrarenal pressure, and pressurized irrigation bags in which the irrigation pressure gradually decreases cannot maintain constant irrigation flow during the procedure over time, as well as natural gravity‐based irrigation adjusted by the height of the saline bag, the AIP maintains a constant irrigation flow for most of the procedure . In the present study, the efficiency of irrigation flow in gravity‐based irrigation under the same pressure was significantly lower than one of the two AIPs because of the loss of pressure power due to gradually decreasing the height of the saline surface, changing the pipe diameter in the middle of the irrigation tube.…”

“…compared hand‐pump infusers, such as pressurized irrigation bags, versus the UROMAT E.A.S.I. with respect to the irrigation flow rate from the working channel in the fURS . They found that the irrigation flow using a hand‐pump infuser decreased as time passed, whereas the UROMAT E.A.S.I.…”

“…They found that the irrigation flow using a hand‐pump infuser decreased as time passed, whereas the UROMAT E.A.S.I. continuously provided the same irrigation flow over time . Similarly, the irrigation flow rate of natural gravity‐based irrigation also decreased because of decrease in the height of saline surface as time passed.…”

“…A handheld‐activated syringe‐based system is often used to compensate for this problem, thus reproducing optimal renal pelvic distention and good visualization. However, intrarenal pressure of >40 mmHg increases the risk of pyelovenous and pyelolymphatic backflow of irrigated fluid . A handheld syringe‐pump often might be in danger of pyelonephritis and sepsis peri‐operatively.…”

“…recently reported the use of an automatic system for irrigation (UROMAT E.A.S.I. ; Karl Storz, Tuttlingen, Germany) that continues the same irrigation flow over time . In the present study, we evaluated the change in the irrigation flow with various instruments in the working channel at several different irrigation pressure settings of two currently available AIPs (Endoflow II and UROMAT E.A.S.I.)…”