Bacterial Colonization of Ureteral Stents

Abstract

Objectives: The aim of this study was to assess the frequency of bacterial stent colonization and stent-associated bacteriuria, and to evaluate the significance of urinary cultures for identification of colonizing microorganisms. Methods: A total of 93 ureteral stents from 71 patients were examined: 9 patients with permanent ureteral stenting due to malignant ureteral obstruction (27 stents), and 62 patients with temporary ureteral stents (66 stents). Results: Bacteriuria and bacterial stent colonization were found in all patients with permanent stents. In patients with temporary stents, colonized stents were found in 69.3% (43/62), mainly in combination with sterile urine (45.2%, 28/62). Mean indwelling times did not differ between patients with sterile urine and sterile stents (11.8 days) and patients with sterile urine and colonized stents (11.2 days). Prophylactic antibiosis in 42/62 temporarily stented patients did not reduce colonization rates compared to patients without antibiotics (70 vs. 65%). Enterococci were the bacteria most frequently cultured from urine and stents. Conclusions: In the present study, ureteral stent colonization rates were 100% in permanently and 69.3% in temporarily stented patients. Antibiotic prophylaxis did not prevent stent colonization and should not be routinely administered. Since urinary cultures correctly identified all colonizing microorganisms in only 21%, removal/replacement and bacteriologic evaluation of ureteral stents may be necessary in case of urosepsis.