Understanding steinstrasse: a systematic review of definitions, clinical management, and emerging perspectives in endourology

To systematically review the definitions, diagnostic modalities, incidence, predictive factors, and management strategies of Steinstrasse (SS), following extracorporeal shock wave lithotripsy (ESWL) and endourological procedures. A comprehensive literature search was conducted in accordance with the PRISMA guidelines across PubMed, Scopus, and Embase, identifying randomized controlled trials, prospective and retrospective observational studies, and case series published between 1986 and May 2025. Forty-two studies met the inclusion criteria. The reported incidence of SS varied ranged from 1% to 23%, depending on initial stone burden, location, and treatment modality. Historical classifications, such as that proposed by Coptcoat et al., remain the most adopted linking SS morphology to clinical management. Diagnostic methods have evolved over time, from plain abdominal radiography (KUB) to non-contrast computed tomography (NCCT). Conservative management achieved spontaneous clearance in nearly half of reported cases, whereas ureterorenoscopy represents the treatment of choice in the remaining persistent cases. Recent technological advances in flexible Ureterorenoscopy (FURS), laser systems, and the use of flexible aspirating navigable ureteral access sheaths (FANS) have drawn attention to the accumulation of fine residual fragments (≤ 4 mm) and dust, potentially leading to SS-like conditions. Although SS has been traditionally associated with ESWL, its occurrence following FURS is an emerging concern. The present review highlights the importance of early recognition, standardized definitions, and individualized management strategies to optimize outcomes in both ESWL- and endoscopy-related SS.