Experimental study on the effect of a constant pressure infusion pump on intrapelvic pressure
XIE Lu-guang
LYU Shi-dong
ZHENG Li
LI Ya-dong
ZHOU Chun-lan
Abstract：Objective To develop a user-friendly and safe constant pressure infusion pump capable of maintai-ning stable irrigation pressure,and to evaluate its efficacy in precisely controlling intraoperative perfusion pressure during ureteroscopic lithotripsy for enhanced surgical safety and effectiveness.Methods The study combined in vitro testing with an ex vivo porcine kidney model(n=12).In the in vitro tests,the experimental group used a constant pressure infu-sion pump(driven by a motorized syringe,with flow rates set at 1.35,2.70,and 5.40 mm/s),while the control group used gravity-based continuous irrigation(500 mL saline hung at 180 cm height).A urodynamic system was used to con-tinuously record irrigation flow rates and pressures over 5 minutes under various operating conditions(open channel,pres-ence of holmium laser fiber,and 2.67F guidewire).In the ex vivo porcine kidney model,a 7.5F ureteroscope was insert-ed 1 cm into the renal pelvis,and intrapelvic pressure was continuously monitored using a BL-420S biological signal ac-quisition system.Key outcomes included intrapelvic pressure levels,flow rate stability,and pressure fluctuation range.Results In vitro testing demonstrated that the constant pressure infusion pump maintained stable pressure under all flow rate settings,with significantly different flow rates between modes(P＜0.001).Average flow rates under open channel conditions were(76.00±0.71),(86.20±0.84),and(96.20±0.84)mL/min for increasing speed levels.Even when the working channel was occupied by a laser fiber or guidewire,the pump ensured steady flow.In the porcine kidney mod-el,the constant pressure infusion pump consistently maintained intrapelvic pressures below 30 mmHg across all settings,with no significant variation between kidneys(P＞0.05).In contrast,gravity and manual infusion groups showed greater pressure fluctuations,with peak pressures exceeding 30 mmHg.Conclusion The constant pressure infusion pump offers significant advantages over traditional gravity-based irrigation by ensuring stable infusion pressure and maintaining in-trapelvic pressure within a safe range,regardless of ureteroscope channel occupancy.
Keywords：ureteroscopyconstant-pressure irrigationintrarenal pelvic pressureupper urinary tract stones
Publication Date：2025-05-15
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 666-671 )