Intrarenal pressure variations during flexible ureteroscopy in a porcine kidney model: impact of ureteral access sheath types and irrigation methods.

PURPOSE

To evaluate intrarenal pressure (IRP) variations during flexible ureteroscopy (f-URS) using flexible and navigable suction (FANS) ureteral access sheath (UAS) and conventional UAS (c-UAS) and irrigation methods.

METHODS

A fresh cadaveric porcine kidney model was used to measure real-time IRP during f-URS via a pressure transducer connected to a ureteral catheter placed in the renal pelvis. FANS and c-UAS were evaluated with three irrigation methods: gravity-based, hand pump-assisted, and machine irrigation (MI) with and without suction.

RESULTS

The combination of MI with suction and FANS resulted in the lowest IRP (1.7 ± 0.6 cm H₂O), significantly outperforming other methods (p < 0.001). The highest IRP was observed with MI in conjunction with c-UAS (39.6 ± 0.8 cm H₂O). Gravity-based and pump-assisted irrigation with c-UAS yielded moderate IRP levels (16.1 ± 0.5 cm H₂O and 22.3 ± 1.9 cm H₂O, respectively). Statistical analysis revealed that both the type of UAS and irrigation method significantly affected IRP (p < 0.001), with a notable interaction effect between the two variables.

CONCLUSION

The combination of FANS and MI with suction provides superior IRP control during f-URS, substantially reducing pressure compared to c-UAS. C-UAS with MI can result in elevated IRP levels. These findings underscore the importance of selecting appropriate irrigation methods and UAS to minimize IRP-related complications during endourological procedures.