Small- and large-calibre ureteroscopes: an updated systematic review and meta-analysis
In brief
Small ureteroscopes achieve stone-free rates and safety comparable to larger scopes
A meta-analysis of eight studies-including four randomized trials-found that ureteroscopes up to 6.3 F produced stone-free rates, overall complication rates, and operative times essentially indistinguishable from those of larger 7.5 F or bigger scopes. The evidence is limited by study heterogeneity, so larger, well-designed trials are still needed.
- Journal
- BJU international (Q1)
- Published
- 28 July 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Francesco Di Bello, Paolo Verri, Alejandra Bravo-Balado, Paula Izquierdo, Lucio Fila, Andres K Kanashiro, et al.
- PMID
- 42521215
- DOI
- 10.1111/bju.70394
Why clinicians should know about it
- Picked for Urology (top studies of the week, 2 August 2026): Small vs large ureteroscopes achieve comparable stone‑free rates and safety
Abstract
OBJECTIVE: To systematically review and meta-analyse the available evidence comparing perioperative outcomes between small- (≤6.3/7.5 F) and large-calibre (≥7.5/9.8 F) ureteroscopes. METHODS: A literature search of MEDLINE/PubMed, and Scopus was performed prior to March 2026 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The endpoints of interest were stone-free rates (SFRs), overall complications, and operative time. Study quality and risk of bias were evaluated using the Newcastle-Ottawa Scale and the Revised Cochrane Risk of Bias Tool for Randomised Trials for non-randomised and randomised studies. Sensitivity analyses were completed on studies reporting flexible ureteroscopes only, 7.5- vs >7.5-F ureteroscopes, and on randomised controlled trials (RCTs). RESULTS: Eight studies were included in the meta-analysis. Of those, four were RCTs while four were retrospective. Specifically, three studies compared 6.3- vs 7.5-F ureteroscopes, one 6.3- vs 8.5-F ureteroscopes, one 6- vs 7.5-F ureteroscopes, while three compared 7.5- vs >7.5-F ureteroscopes. Within the meta-analysis comparing 6.3- vs 7.5-F ureteroscopes, the small-calibre ureteroscopes were associated with a risk ratio [RR] for SFR of 0.99 (95% confidence interval [CI] 0.92-1.06), of 1.08 (95% CI 0.77-1.51) for overall complications, and a standardised mean difference in operative time of -14.5 min (95% CI -33.4 to 3.3 min). These results were virtually confirmed by all sensitivity analyses. No differences in the above outcomes were recorded for the comparison between 7.5- vs >7.5-F ureteroscopes. CONCLUSIONS: Within the present meta-analysis, the small-calibre ureteroscopes achieved comparable outcomes to large-calibre ureteroscopes. To overcome the substantial heterogeneity and residual confounding across studies, well-designed and adequately powered RCTs are required.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.