Carlos González González, Pietro Scilipoti, Federico Zorzi, Nicola Nannola, Marie Chicaud, Frédéric Panthier, Olivier Traxer
Across four decades of evidence, ureteroscopic biopsy forceps achieve approximately 85% diagnostic yield, with no single design demonstrably superior. The determinants of a diagnostic, accurately graded biopsy may therefore lie less in the instrument than in factors this review could not test directly, including operator experience and sampling strategy; whether systematic multisite sampling improves diagnostic yield is a hypothesis that requires prospective evaluation. At the same time, frequent undergrading and upstaging, with often inadequate specimens, expose the diagnostic ceiling of current devices and make dedicated device redesign and prospective, device-stratified research a clear priority.
OBJECTIVES: To evaluate the performance of flexible ureteroscopy (fURS) biopsy forceps for tissue acquisition in upper tract urothelial carcinoma (UTUC), stratified by device, and their concordance with surgical pathology.
METHODS: Preregistered systematic review and meta-analysis (PROSPERO CRD420261392641; PRISMA 2020). MEDLINE and Embase were searched to 1 May 2026 for studies of forceps-based fURS biopsy in UTUC. The primary outcome was diagnostic yield; secondary outcomes included specimen adequacy, lamina propria presence, grade concordance, undergrading, and upstaging to muscle-invasive disease. Pooled proportions used the Freeman-Tukey double-arcsine transformation with DerSimonian-Laird random-effects models; heterogeneity was assessed with Cochran's Q.
RESULTS: Nineteen studies (1397 patients; 1,773 biopsies; 1985-2025) were included. Pooled diagnostic yield was 84.6% (95% confidence interval 77.5%-90.6%; Q = 80.90, df = 10, p < 0.001), and specimen adequacy was 82.0% (76.7%-86.8%). Neither was distinguished by device category (subgroup Q = 6.12, df = 3, p = 0.11 and Q = 6.88, df = 3, p = 0.076). Overall grade concordance was 78.8% (69.9%-86.7%), and 28.3% of tumors were undergraded (18.1%-39.7%). Lamina propria was present in only 71.8% of specimens, and 54.6% (35.8%-72.7%) of tumors appearing non-muscle-invasive at biopsy were upstaged to ≥pT2 at nephroureterectomy. Ex vivo, backloaded forceps caused 6.4-fold less deflection loss than the Piranha (12.7° vs 80.7°) without improving yield.
CONCLUSIONS: Across four decades of evidence, ureteroscopic biopsy forceps achieve approximately 85% diagnostic yield, with no single design demonstrably superior. The determinants of a diagnostic, accurately graded biopsy may therefore lie less in the instrument than in factors this review could not test directly, including operator experience and sampling strategy; whether systematic multisite sampling improves diagnostic yield is a hypothesis that requires prospective evaluation. At the same time, frequent undergrading and upstaging, with often inadequate specimens, expose the diagnostic ceiling of current devices and make dedicated device redesign and prospective, device-stratified research a clear priority.