Suction versus traditional ureteral access sheaths in retrograde intrarenal surgery: an updated systematic review and meta-analysis of stone-free rates and complications

PURPOSE: Suction ureteral access sheaths (S-UAS), fixed-tip or flexible and navigable (FANS), are proposed to improve stone clearance and reduce infections in retrograde intrarenal surgery (RIRS); we updated our 2025 meta-analysis and asked whether tip design changes the effect. METHODS: Five databases were searched from inception to March 2026 for comparative studies of S-UAS versus traditional sheaths (T-UAS) in adult RIRS (PROSPERO CRD420251164154). Outcomes were residual fragments at early (up to 3 weeks) and late (4 weeks or later) assessment, fever, sepsis, septic shock, severe complications, operative time and hospital stay, analyzed with random-effects models, subgroups by design and tip design, small-study tests and GRADE. RESULTS: Twenty-nine studies (four randomized; 5,604 patients) were included. S-UAS reduced residual fragments at early (RR 0.49; 95% CI 0.42-0.58; 22 studies) and late assessment (RR 0.53; 0.45-0.63; 23 studies), fever (RR 0.43; 0.34-0.53), sepsis (RR 0.47; 0.31-0.72) and severe complications (RR 0.48; 0.33-0.69). Septic shock was rare (4 versus 12 events; RR 0.41; 0.15-1.15). Operative time did not differ; hospital stay was 0.32 days shorter, but not robustly so. Post hoc, the late benefit was larger with tip-flexible (RR 0.47) than with fixed-tip sheaths (RR 0.72; p = 0.03). Certainty was moderate for stone clearance and fever (low for early clearance in non-randomized studies), otherwise low or very low. CONCLUSION: S-UAS probably improve stone clearance and reduce fever and may reduce sepsis; the evidence on severe complications is very uncertain. The effect on septic shock and a possible advantage of the flexible tip need randomized confirmation.