Prevention of encrustation and biofilm formation on the ureteral stent's surface. Part 2. Alternative materials for ureteral stents. Physical techniques for the prevention of encrustation and biofilm formation on the surface of ureteral stents

Introduction. Stent encrustation and formation of biofilms on its surfaces are serious medical problems, that cannot be solved without removing or replacing of the drain. Various researches are being conducted worldwide, trying to solve this problem, while a universal way of such stent complications prevention is still unreached. Aim. The aim of this study was to evaluate the effectiveness of biodegradable stents and physical methods as alternative ways to prevent drainage complications. Materials and methods. A literature search was performed of the Pubmed, Web of Sience, Science Direct, Scopus, Cyberleninka, E-library, CNMB and other databases for the period of time from 1984 to 2020for the following keywords: ureteral stent, encrustation, biofilm, urolithiasis, bacteriuria, ultrasound. Of more than 100 studies found, 48 scientific papers, most fully correspond to the article topic, were analyzed. Results. The use of biodegradable stents eliminates a need for interventions to remove them, improving the patient's quality of life, as well as reducing the economic burden on the healthcare system. However, the problem of degradation rate control and stent degradation products elimination still exists. Conclusions. The majority of proposed physical methods of impact on a stent need a contact way of implementation, that largely hinders their clinical use. Thus, non-invasive methods seem promising and require further researches.