Evaluation of fluid absorption during flexible ureteroscopy in an in vivo porcine model

Abstract

Objective To evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model. Materials and Methods Flexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556‐mm (0.014″) pressure‐sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37–150 mmHg) was maintained for 1 h using a pressure bag and real‐time feedback from the pressure‐sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations. Results A URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001). Conclusion In this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption.

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

“…Manual gravity-based method with a low level of irrigation pressure results in lower IRPs compared to automatic pumps and high irrigation pressure [20]. In vitro studies often required porcine model, but the living or deceased porcine urinary tract elasticity has never been compared to human upper urinary tract [17,18,21,26]. Therefore, exporting the in vitro results to clinical practice appears difficult.…”

“…Considering the fluid absorption risk during fURS, at 50mmHg, 30% of cases presented fluid penetration from calyx to renal capsule, with a significant decrease using UAS [21]. Kottooran et al evaluated the amount of absorbed fluid after 1 h fURS: 7.6, 10.8, 26.0, and 56.8 ml at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively [26]. As a solution to IRP increase during fURS, several devices are under evaluation: new UAS and robotic system [24,25,27].…”

“…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]. Considering the fluid absorption risk during fURS, at 50mmHg, 30% of cases presented fluid penetration from calyx to renal capsule, with a significant decrease using UAS [21].…”

“…75, and 150 mmHg, respectively [26]. As a solution to IRP increase during fURS, several devices are under evaluation: new UAS and robotic system [24,25,27].…”

Comparison of the safety and efficiency of flexible ureteroscopy with the different hanged water heights in a kidney model

“…The data also indicated that elevated renal pelvic pressure during URS demonstrated a positive association with increased uid absorption. 11 These outcomes offer valuable insights into uid dynamics throughout URS procedures, thereby facilitating informed clinical decision-making in managing urinary stone disease.…”