# Advancing stone treatment: the transformative impact of flexible navigable suction ureteral access sheath (fans) for inferior calyx calculi (<2 cm)

## TL;DR

A new flexible suction sheath improves kidney stone removal success and reduces surgery time for stones in a hard-to-reach kidney area.

## Contribution

The FANS sheath is shown to significantly enhance stone-free rates and reduce operative time in inferior calyx calculi treatment.

## Key findings

- FANS group had a 96.23% stone clearance rate versus 81.03% in the conventional group.
- Operative time was significantly shorter in the FANS group (37.81 min vs. 46.59 min).
- No increase in complications or recovery issues was observed with FANS use.

## Abstract

This study aimed to assess the efficacy, safety, and stone-free rates (SFR) of the application of a flexible navigable suction ureteral access sheath (FANS) in patients undergoing retrograde intrarenal surgery (RIRS) for inferior calyx calculi (<2 cm).

A retrospective analysis of the clinical data of 111 patients who underwent treatment for inferior calyx calculi at Nanchang People’s Hospital between January 2023 and October 2024 was performed. Patients undergoing RIRS with laser lithotripsy were evenly distributed into two groups: FANS with continuous flow lithotripsy in ureterorenolithotripsy procedures (F-Group), a conventional sheath in ureterorenolithotripsy procedures (C-Group).

A significantly greater stone clearance rate (96.23% vs. 81.03%, p=0.017) and shorter operative time (37.81 ± 6.07 min vs. 46.59 ± 6.36 min, p<0.001) were observed with the F-Group. Basic attributes, including demographics of patients and stone properties, the infundibulo-pelvic angle (IPA), length of hospital stay, and complications, were compared between the groups and found to be approximately the same.

Conclusions

FANS significantly improves SFR without increasing postoperative complications or negatively affecting recovery, offering a promising alternative to conventional sheaths in ureterorenolithotripsy procedures for inferior calyx calculi. FANS improves kidney stone surgery outcomes, is feasible and safe for inferior calyx calculi (<2 cm).