Implantation of a Prototype Self-Expanding Nitinol Stent for Peripheral Arteries in an Experimental Pig Model

Introduction. Endovascular treatment is currently the main treatment method of patients with peripheral arterial disease. The main disadvantage of this treatment method is the frequent development of restenosis in the long-term postoperative period, which necessitates the development of more advanced devices aimed at preserving the integrity of the inner layer of the artery. Objective. To study the effect of a new self-expanding nitinol stent on changes in the architecture of the vascular wall and cellular components of tissues adjacent to the implantation site by analyzing the vascular condition in laboratory pigs. Material and methods. Two Landrace pigs had stents with 5–20 % oversizing implanted in the common iliac artery. Vital signs were monitored during the follow-up; 3 days before the procedure and thereafter, dual antiplatelet therapy was used. After 3 months, angiography and ultrasound of the iliofemoral segment were performed, then the animals were euthanized. The extracted sections of the arteries with implanted stents were subjected to a thorough macroscopic and histological analysis. Results. For 3 months, the vital signs remained within the normal range. Angiography and ultrasound revealed patency of the stented area without significant restenosis. Morphological examination of the tissues demonstrated the integrity of the internal elastic membrane of the arteries. Conclusion. The implantation of the new domestic self-expanding nitinol stent caused a favorable reaction of the common iliac artery wall with minimal myointimal hyperplasia in the postoperative period. Thus, the new domestic self-expanding nitinol stent developed by us has successfully passed the stage of preclinical animal testing.

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