Intrarenal pressure and stone fragment retrieval efficiency using foot-controlled irrigation in combination with a...

To evaluate the safety and efficiency of stone fragment retrieval using a flexible and navigable suction ureteral access sheath (FANS) combined with a foot-controlled irrigation device, focusing on intrarenal pressure (IRP) and stone retrieval time in a kidney phantom model.

Phantom kidney models created from self‑healing supramolecular hydrogel were used to simulate the anatomy of the renal pelvis and calyces. Artificial stones were placed in the renal pelvis. Two groups were compared: Group A (control), which used continuous gravity irrigation with the FANS, and Group B (intervention), which used the same setup with additional intermittent flushing via a foot-controlled irrigation device. Outcomes included mean and peak IRP, as well as stone retrieval time.

A total of 44 trials (22 paired comparisons) were conducted using the phantom kidney model. The overall mean IRP was - 3.43 mmHg (95% confidence interval [CI]: -5.04--1.81) in Group A and - 2.24 mmHg (95% CI: -3.64--0.83) in Group B. The mean peak IRP was 6.39 mmHg (95% CI: 4.68-8.10) in Group A and 7.50 mmHg (95% CI: 5.58-9.42) in Group B. No significant differences were observed between the groups for mean IRP (p = 0.30) or peak IRP (p = 0.25). However, Group B demonstrated significantly shorter stone retrieval times compared to Group A (311.73 vs. 235.68 s, p < 0.01).

The combination of FANS with a foot-controlled irrigation device facilitated efficient and safe stone retrieval without increasing IRP, potentially improving procedural performance during retrograde intrarenal surgery.