Introduction. Currently, stents are used in the treatment of various benign and malignant diseases of the upper urinary tract and urethra. Modern stents made of a superelastic alloy, coated with a polymer, regardless of location, are characterized by higher and longer-lasting patency in terms of decompression and relief of obstruction, fewer irritative symptoms of the genitourinary system and no need for frequent replacement, which leads to improved quality of life in addition to cost savings. Despite promising results, there are few studies in the literature regarding their use, and these tend to be peer-to-peer, retrospective, involving small numbers of patients, and based on the surgeon's personal experience.
Materials and methods. In literature review used data about using minimally invasive methods for treatment of ureteral strictures, published in PubMed’s base (https://www.ncbi.nlm.nih.gov/pubmed/), scientific electronic library of RF – Elibrary.ru (https://elibrary.ru/) and also professional endourological association websites. The databases were searched using the following keywords: «ureteral stent», «urethral stent», «allium», «uventa» and «memokath». At the first stage, 93 sources no older than 5 years were found that were relevant to the topic of the review. Conference abstracts, short communications, and duplicate publications were excluded. Then, based on the relevance of the data, the reliability of the sources, the impact factors of the journals and the sequence of presentation of the material in the manuscript, 43 articles in scientific international peer-reviewed journals, practical guidelines and clinical recommendations were selected directly for citation in the review.
Results. The stent is one of the most common urological prostheses used in the treatment of obstructive uropathy. The main causes of obstruction of the ureter and urethra include benign and malignant factors. Active introduction of minimally invasive technologies into everyday urological practice using ureteral or urethral stents are effective and safe methods of urine diversion (especially in comorbid patients), however, unfortunately, side effects from the use of these prosthetic systems continue to reduce the quality of life of patients.
The use of polymer materials in urology has made it possible to introduce a huge number of non-metallic stents used by urologists, however, due to the occurrence of various kinds of complications, an attempt has been made to introduce a new generation of stents – made of a superelastic alloy, coated with polymer.
Stents made of superelastic alloy coated with polymer have been used in the treatment of various pathologies of the ureter and urethra for more than two decades. The need for reliable long-term urinary tract drainage has led to the development of improved urinary tract stent designs such as Memokath, Allium, and Uventa. The main advantages of the latter are a convenient delivery system, a self-expanding mechanism, low adhesive properties, no tissue ingrowth, ease of removal, and no need for frequent replacement. Despite the evolution of ureteral and urethral stent designs, complications continue to arise that limit their use and the search for «ideal» drainage systems continues.
Conclusion. Today it is difficult to overestimate the role of drainage systems in the treatment of obstructive urological and oncological diseases. However, despite significant success in their use, prostheses are constantly subject to constant modifications and developments aimed at increasing their suitability, durability, ease of implantation and functionality, while reducing the complications associated with them. Future developments in the field of urogenital prosthetic surgery and urology in general continue to attract interest, and ongoing research into new biomaterials, stem cells and tissue engineering is expanding the boundaries of possible interventions in the human genitourinary tract.
