Urinary Tract Infections and Encrustation in Urinary Stents

Abstract

Regardless clinical benefits of urinary stents, these indispensable tools for everyday practice come with substantial hindrances as they can lead to stent-related symptoms, encrustation, hematuria, infection and hence to an overall reduction in the quality of life of patients. Bacterial colonization of foreign bodies has been a significant problem in Medicine in general and Urology in particular for decades. Studies have shown that around 42–100% of all indwelling ureteral stents are colonized by bacteria. Typically, the bacteria continue to form a more mature biofilm as large, structured communities of bacteria adhere onto surfaces and secret polysaccharides, nucleic acids, lipids and proteins that form an eminently protective cast around the bacteria. Due to the complex biology and interactions between foreign body surfaces, the host and microbes, a simple, one-fits-all solution is not very likely to be developed. Nonetheless, our knowledge of the underlying biology has dramatically expanded, and novel technologies are being tested. Probably the easiest solution is to appraise ureteral stenting critically and omit stenting whenever feasible. However, for patients in need of a ureteral stent the future might bring “ideal” stents that are biodegradable, coated to avoid biofilm formation and incrustation and ideally emit sufficient levels of specific drugs that prevent tissue ingrowth or even dissolve urinary calculi.