Current Trends in Improving Functional Properties of Intravascular Endoprostheses

Cardiovascular diseases, and in particular, coronary heart disease are the most common cause of death worldwide. Finding the most effective method of treatment seems to be an advanced task. Stenting is a minimally invasive effective way to solve this problem. Immediately with the advent of endoprostheses (stents), there was a problem of repeated vasoconstriction (restenosis) due to neointimal hyperplasia (excessive build-up of the inner shell of the vessel), the causes of which are the release of metal ions from the stent material, damage to the artery wall during implantation, allergic reactions. Initially, they tried to find a solution by searching for the optimal design and material of the stent, as evidenced by the release of more than five hundred models of intravascular endoprostheses differing in design, material, geometric shape, profile, overall dimensions and other parameters. Currently, the most effective way to solve the problems of biocompatibility of stent materials is the formation of coatings on the surface of stents. It is possible to distinguish a number of different intravascular endoprostheses with modifiable coatings: secreting medicinal substances, with biodegradable coatings, with bioactive coatings. The paper presents the results of the analysis of the literature sources of the most advanced research in the field of surface modification of intravascular endoprostheses, which allowed to justify the choice of titanium oxynitride coating as recommended for further optimization and application due to high corrosion resistance, biocompatibility with cells, tissues and fluids of the human body, a good level of adhesion. At the same time there are a number of limiting factors associated with obtaining such coatings while maintaining all structural and technological requirements.