The study is performed to provide a better understanding of the influence of biofilms on ureteral stents on the entire spectrum of stent-associated morbidity.~Moreover, it could provide more detailed knowledge about the correlation of the occurrence of biofilms on ureteral stents and findings in urinary analysis, which could serve as a decision support whether patients with ureteral stents undergoing further interventions (for example ESWL or simple secondary URS) should receive antibiotic prophylaxis.~Correlation of results of urinary bacteriologies (assessed pre- and intraoperatively) and biofilm analysis on stents could provide information if targeted antibiotic treatment based on urinary bacteriology only is possible at all.~Correlation of urinary analysis and conventional urinary bacteriology could provide a valuable contribution regarding the prediction of bacteriuria and the necessity of postponing operations.~Additionally, the study is intended to provide an overview over the recent bacterial species that are involved into biofilms on ureteral stents and their resistance to antibiotics. This could provide valuable information about the choice of antibiotics in cases were treatment has to be performed empirically.
This study is performed to analyze various aspects of biofilms on ureteral stents.