# Efficacy and Safety of Flexible and Navigable Suction Ureteral Access Sheath Versus Conventional Ureteral Access Sheath in Retrograde Intrarenal Surgery: An Updated Systematic Review and Meta-Analysis

## TL;DR

Flexible and navigable suction ureteral access sheaths improve stone removal and reduce complications in kidney stone surgery compared to conventional sheaths.

## Contribution

A systematic review and meta-analysis comparing flexible/navigable suction UAS with conventional UAS in RIRS for stone clearance and safety.

## Key findings

- FANS-UAS showed significantly higher stone-free rates compared to conventional UAS.
- FANS-UAS reduced perioperative complications without increasing operative time or hospital stay.
- For stones larger than 2 cm, FANS-UAS tended to yield better outcomes, though evidence was limited.

## Abstract

Background and Objectives: Ureteral access sheaths (UASs) are widely used in retrograde intrarenal surgery (RIRS) to facilitate irrigation and instrument access. Recently, flexible and navigable suction UASs (FANS-UASs) have been developed to enhance visibility and stone fragment evacuation; however, their comparative effectiveness remains uncertain. This study aimed to evaluate the clinical outcomes of FANS-UAS versus conventional UAS during RIRS for renal stones. Materials and Methods: A systematic review and meta-analysis were performed following PRISMA guidelines. PubMed, Embase, and the Cochrane Library were searched through May 2025 for comparative studies of FANS-UAS and conventional UAS. Study quality was assessed using the Scottish Intercollegiate Guidelines Network checklist. Primary outcomes included stone-free rate (SFR), operative time, complications, and hospital stay. Subgroup analyses were conducted according to stone size (≤2 cm vs. >2 cm). Results: Nine studies involving 1791 patients were included. FANS-UAS demonstrated a significantly higher SFR (OR = 5.99, 95% CI: 2.86–12.51; I2 = 86.7%) and fewer complications (OR = 0.33, 95% CI: 0.23–0.45; I2 = 0%). Operative time and hospital stay did not differ significantly between groups. Subgroup analysis showed no significant SFR difference for stones ≤2 cm, whereas for stones >2 cm, FANS-UAS tended to yield higher SFR—though based on limited evidence. Conclusions: FANS-UASs appear to improve stone clearance and reduce perioperative complications in RIRS without increasing operative burden. While further high-quality randomized trials are needed, current evidence supports the growing adoption of FANS-UAS in endourological practice.