The Preliminary Experiment Study And The Development Of A New Nano Electro-Spining Covered Stent In Intracranial Aneurysms

Objective:To study a new nano electro-spining covered stent in intracranial aneurysms and valuate the mechanical properties and biocompatibility of the nano electro-spining covered stent by animal experience. Methods: The nano electro-spining covered stent was prepared by the weaving methods and high voltage electrostatic spinning techniques. 10 healthy beagle dogs were implanted 20 nano electro-spining covered stents, left subclavian artery implanted 10 pieces of 0.10 mm wire diameter of nano electro-spining covered stents(group A), right subclavian artery are implanted 10 pieces of 0.15 mm diameter of nano electro-spining covered stents(group B). The stent segment blood vessels were examined by angiography, which were performed immediately and 2, 4, and 6 weeks after stents’ implantation. And we evaluated endothelial and endometrial growth status by histopathological experiments. Results: After the stent was implanted immediately, the angiography showed endoleak in seven stents among group A. During follow-up period, the endoleak of two stent was disappear, and the other five stents still remained endoleaks. After the stent was implanted immediately, the angiography showed endoleak in one stents among group B. During follow-up period, the endoleak was disappear, but three stents occurred mild stenosis(stenosis <50%).The stent specimen in group B were detected through the histopathological examinations. The stents embedded in the vessel wall, vessel wall showed chronic inflammation stent, and part of the cells were edema after 2W. The inner surface of the stent was parialt vascular endothelial and some fibers proliferated after 4W. Then the inner surface of the stent was basic vascular endothelial after 6W. Conclusion: The results of this study preliminarily demonstrated the effectiveness and feasibility of nano electro-spining covered stents in intracranial aneurysms treatment. However, the study of nano electro-spining covered stents have been in the initial phase, and the long-term observation and research are needed, such as membrance degradation, metal stents degradation, parent artery stenosis and improvement of stent graft flexibility and so on.