Series of implantation of a new domestic self-expanding nitinol stent in vivo: prototype development

Objective. To determine the characteristics of the prototype of a new domestic self-expanding nitinol stent for the treatment of peripheral arterial disease, based on the results of computer mathematical modeling. Material and methods. 3 domestic pigs were selected to carry out a series of implantation of a domestic self-expanding nitinol stent with an oversizing of 5–20% into the common iliac artery. Vital signs were assessed in all pigs throughout the observation period. After 3 months, the animals underwent control angiography and ultrasound examination of the iliofemoral segment, followed by withdrawal from the experiment by euthanasia. The next step was a morphological analysis of the stented areas of the vessels. The design of experimental samples was carried out using the finite element method and software for computer 3D modeling Orobix, v.1.3. Results. Throughout the entire observation period (3 months), vital signs in all animals remained within normal values. Control angiography and ultrasound examination after 3 months demonstrated patency and the absence of significant restenoses in all pigs. Morphological analysis showed no signs of damage to the vessel walls. Using computer mathematical modeling, we determined the optimal oversizing values and a reference sample of the designed device was determined. Conclusion. The samples of the nitinol stent passed preclinical animal tests and showed the safety of their use. A qualitatively new structure of the stent for peripheral arteries with a corrugated ring of variable pitch was designed.