Development of a new Russian-made self-expanding nitinol stent prototype: a preclinical in vivo study

Aim . To substantiate the design characteristics of an innovative Russian-made selfexpanding nitinol stent prototype, as well as to evaluate the outcomes of its implantation in laboratory animals in an experimental study. Material and methods. We selected five domestic pigs for a study of the efficacy and safety of Russian-made self-expanding nitinol stents within the iliac artery. Animal measurements were regularly monitored throughout the experimental period. Three months after stenting, iliac and femoral vessels was assessed using angiography and ultrasound, after the animals were euthanized. Next, a histological analysis of the stented vascular segments followed. We also analyzed stent geometric characteristics and their impact on the external environment, including external pressure, using computer modeling methods. R e sults . During the three-month follow-up period, the health of all study animals remained stable and without abnormalities. Repeated examinations, including angiography and ultrasound, conducted after this period confirmed complete vascular patency and no hyperplasia in the implantation area. Histological revealed the integrity of the stent wall and no signs of damage. By modeling the implanted stent behavior under external pressure, we developed an optimal design for future medical devices. Conclusion . The developed models of all-metal nitinol stents have successfully completed preclinical testing in animal models, confirming their safety and efficacy. Furthermore, innovative bare-metal stent designs for the treatment of peripheral arterial diseases have been created, featuring a unique structure with adjustable spacing between the corrugations.