Meta-analysis of 3 RCTs (n=1,020) finds FANS-RIRS matches mini-PCNL for stone clearance but cuts hemorrhage risk by 92% and shortens hospital stay by 1.75 days
Journal: World Journal of Urology | Published: 2026-03-12 | Type: Systematic Review, Meta-Analysis, Comparative Study | PMID: 41817775 Authors: Li Yulong, Yao Zhuoyue, Zhou Zhongbao, Wang Hanchuan, Zhang Yong, Zong Huantao (Department of Urology, Beijing TianTan Hospital, Capital Medical University) Funding/COI: Funding not disclosed. Authors declare no competing interests. PROSPERO registered (CRD420251136058).
For 2–3 cm kidney stones — a size range where the right surgical approach is genuinely contested — this meta-analysis pools three RCTs to compare a newer retrograde technique (FANS-RIRS) against the established mini-percutaneous nephrolithotomy (mPCNL). Stone-free rates were statistically indistinguishable between the two approaches. Where FANS-RIRS separated itself was on the bleeding and recovery side of the ledger: dramatically lower hemorrhage rates, less hemoglobin drop, fewer blood transfusions, shorter hospitalization, and less postoperative pain. The evidence is promising but thin — three trials, moderate-to-low GRADE certainty, and heterogeneity that the authors acknowledge throughout.
This is a competently executed meta-analysis by standard criteria. RCT-only inclusion is the right call for a surgical comparison question — observational data on operative outcomes are heavily confounded by case selection and surgeon experience. The authors used random-effects models (appropriate given the acknowledged heterogeneity), pre-registered on PROSPERO, searched four major databases through August 2025, and applied GRADE — a framework that actually penalizes you for small sample sizes and inconsistency rather than papering over them. The GRADE ratings of moderate-to-low certainty are an honest self-assessment, not a buried caveat.
The core limitation is baked in: three trials is not a lot. The confidence intervals on the primary outcome (SFR OR 0.80, CI 0.51–1.24) are wide enough that a clinically meaningful difference in either direction cannot be ruled out. The hemorrhage findings are striking but driven by the same thin evidence base — an OR of 0.08 is a large effect that deserves scrutiny before it becomes gospel.
Three well-conducted RCTs say FANS-RIRS clears 2–3 cm stones about as well as mini-PCNL and bleeds substantially less. That's a finding worth tracking. But three trials is a thin foundation for strong conclusions, the CI on the primary outcome is wide, and the bleeding advantage — while dramatic on paper — needs replication before it should drive practice at scale. The paper is methodologically honest about these limits, which earns it credit. File this under "promising signal, watch for the next wave of trials" rather than "settled question."