Comparison of flexible and navigable suction ureteral access sheath (FANS) versus traditional ureteric access sheath in RIRS: A systematic review and meta analysis

Retrograde intrarenal surgery (RIRS) is a cornerstone in the treatment of nephrolithiasis. The flexible and navigable suction ureteral access sheath (FANS-UAS) is a recent innovation designed to improve upon the traditional ureteral access sheath (T-UAS) by offering enhanced maneuverability and active stone fragment removal. This systematic review and meta-analysis aims to compare the efficacy and safety of FANS-UAS versus T-UAS in patients undergoing RIRS.
Following PRISMA guidelines, a systematic literature search was conducted across multiple databases, including PubMed and Scopus, for studies published up to May 2025. The review included studies comparing FANS-UAS and T-UAS in adult patients undergoing flexible ureteroscopy for kidney stone treatment. The primary outcomes analyzed were the stone-free rate (SFR), operative parameters, and postoperative complications. A random-effects model was used to pool data, with relative risk (RR) for dichotomous outcomes and mean difference (MD) for continuous variables.
Sixteen studies involving 3,342 patients were included. The FANS-UAS group demonstrated a significantly higher stone-free rate (SFR) at immediate, one-month, and three-month follow-ups (e.g. immediate SFR: RR = 1.42; p < 0.00001). However, significant publication bias was detected for immediate and 1-month SFR outcomes. There were no significant differences in operative time or length of hospital stay. The use of FANS-UAS was associated with a significantly lower risk of fever (RR = 0.40; p < 0.00001), sepsis (RR = 0.60; p = 0.02), re-intervention (RR = 0.44; p = 0.01), and total complications (RR = 0.47; p < 0.00001).
This meta-analysis suggests that FANS-UAS provides superior stone clearance and is associated with a significantly better safety profile compared to T-UAS. Despite these promising findings, the conclusions are limited by the low quality of the included studies and the presence of significant heterogeneity and publication bias. Therefore, high-quality RCTs are warranted to corroborate these results.