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Background: Iliofemoral vein stenosis or occlusion is a common cause of severe chronic venous insufficiency. Endovascular venous stenting has become a preferred treatment because it is minimally invasive and has a high safety profile. Despite the wide application of the wallstent, it is not specifically designed for veins. There are currently few studies on braided stents in the field of veins. We designed a novel braided vein stent, which has higher radial resistive force and more optimized looped ends structure compared with the wallstent. The purpose of this study was to evaluate the safety and performance of the stent in animals, providing a reference for further clinical trials. Methods: The Wallstent is used as a control group. The novel stent and the Wallstent were implanted in the iliac vein of sheep. After 30 days and 90 days, vascular injury, thrombus, neointima coverage, and luminal stenosis were evaluated through venous angiography, endoscopic observation of stent specimen and histopathology. Imaging, histology, and integration data were analyzed by t -test for comparisons between the groups. Results: Two groups of stents were successfully implanted. Follow-up observation showed that there was no thrombosis or obstruction >50% occurred in any group and no significant differences in patency, vascular injury, or intimal hyperplasia compared with the Wallstent. Conclusion: The novel stent significantly increases the radial resistive force and does not increase vascular injury, thrombus and stent stenosis during 30-day and 90-day follow-up. The next step is to further validate the effectiveness of the stent through long-term animal observation and human clinical trials. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the safety and efficacy of heparin-coated venous stents in animals. Methods: We used atomic layer deposition technology to obtain a heparin coating with good stability and then prepared a heparin-coated venous stent based on this technology. The experimental stents were prepared according to the diameter of the rabbit inferior vena cava and were divided into Ni-Ti alloy stent group, Ni-Ti-Al2O3 stent group and Ni-Ti-Al2O3-Heparin stent group. 3 days, 7 days and 14 days after stent implantation, the materials were collected, and the three groups of stents were observed by hard tissue section pathology, immunohistochemistry and scanning electron microscope to observe the differences in vascular wall inflammation, thrombosis, lumen stenosis and vascular intima regeneration. Result and Conclusion: The experiment confirmed the safety of the heparin-coated stent in vivo. Compared with the control group, the experimental group showed a high degree of vascular endothelialization and an intact neointimal structure 14 days after implantation. The long-term safety and biological effects of heparin-coated venous stents in animals require further study. [ABSTRACT FROM AUTHOR]