The Current Situation and Prospects for Urinary Stents

The aim of this book is to provide a multidisciplinary overview of an area of knowledge

that affects a multitude of patients worldwide on a daily basis and that unfortunately

shows a slow technological development. The main reasons for the lack of

innovation in the development of urinary stents and catheters are, on the one side,

the characteristics of the urinary tract, urine and the particularities of the research

groups involved. The urinary tract shows challenging characteristics for the placement

of urinary stents and catheters, both at the level of the upper and lower urinary

tract. The peristalsis, the urinary microbiome, the ease of biofilm formation on the

surface of urinary medical devices, as well as the changes that occur when placing

a ureteral stent such as invalidation of the anti-reflux system of the ureterovesical

junction, and the high sensitivity of the bladder trigone cause manifest drawbacks in

patients. On the other hand, urine is a fluid supersaturated with mineral salts, which

represents a very hostile environment for biomaterials, both polymeric and metallic,

leading to a series of side effects with stents and catheters that favour encrustation

and bacterial contamination. This leads to the failure of these medical devices in

daily clinical practice. In addition to all these limitations, which make the urinary

tract a complicated area for innovation in indwelling medical devices, the research

groups involved in the improvement of these devices are composed of a small number

of researchers and are groups generally isolated from each other. It is logical to

think that the possibility of improving urinary stents and catheters will come from a

wider and mainly multidisciplinary approach, as many different disciplines are

needed to overcome the current pitfalls. Not only urologists are important, because

although they are the ones who know the limitations of the current urological armamentarium,

technological development is also the responsibility of other areas of

knowledge. These include bioengineering, chemical engineering, microbiology,

experts in coatings, in new polymers, in biomaterials, translational researchers,

experts in new metal alloys, etc. And to this large group of researchers it is also

necessary to include physicists, mathematicians and experts in an area that affects

the urinary tract and the medical devices that are placed inside it, which is fluid

dynamics