Metallic versus polymeric ureteric stents for chronic malignant ureteric obstruction: a systematic review and meta-analysis.

BACKGROUND: Chronic malignant ureteric obstruction compromises renal function and may disrupt oncological management. Conventional polymeric stents are limited by external compression, encrustation, and frequent exchange requirements. Metallic stents were developed to enhance long-term patency; however, comparative evidence remains heterogeneous. METHODS: A PRISMA-compliant systematic review of PubMed, MEDLINE, Embase, Web of Science, Cochrane CENTRAL, and Scopus (31 May 2025) identified comparative studies of metallic versus polymeric ureteric stents in adults with chronic malignant ureteric obstruction. Random-effects meta-analysis evaluated stent failure, stent-related symptoms, and Clavien-Dindo complications using risk ratios. Functional duration, renal outcomes, quality of life, and cost implications were synthesised narratively. RESULTS: Six retrospective cohort studies encompassing 511 patients and 595 ureteric stents met inclusion criteria. Metallic stents showed a trend toward lower stent failure compared with polymeric stents (RR 0.68, 95% CI 0.44-1.03; I² = 0%, p = 0.07). Stent-related symptoms and complication rates were comparable. Metallic stents demonstrated fewer exchange requirements in narrative synthesis, although renal function, quality-of-life, and cost outcomes could not be pooled because of inconsistent reporting. CONCLUSIONS: Metallic ureteric stents are a feasible long-term alternative to polymeric stents for selected patients with chronic malignant ureteric obstruction, with potential benefits in reducing exchange burden. Current evidence is not practice-changing and remains limited by retrospective designs, clinical heterogeneity, and sparse patient-centred and cost-effectiveness data. TRIAL REGISTRY: Prospero: CRD420251021868.