Therapeutic advances in ureteral stricture: lessons from radiation-induced fibrosis to regenerative strategies-a narrative review.

Radiation-induced ureteral stricture (RIUS) is a rare but refractory late complication of pelvic radiotherapy, driven by severe fibrosis and microvascular injury that undermines the effectiveness of conventional interventions such as balloon dilation, ureteral stenting, and reconstructive surgery. This review summarizes the pathophysiological basis of treatment resistance in RIUS and critically appraises current management strategies. Beyond its clinical relevance, RIUS is discussed as a paradigmatic model of advanced fibrotic ureteral disease, offering broader insights into the limitations of purely mechanical approaches. We further examine emerging biologically oriented strategies, including mesenchymal stem cell-derived extracellular vesicle-based regenerative therapies, next-generation ureteral stents incorporating advanced biomaterials, and drug-eluting stent platforms for localized antifibrotic and antimicrobial delivery. Although largely investigational, these approaches collectively signal a conceptual shift from palliative drainage toward biologically informed, restorative management of RIUS and related refractory ureteral strictures.