Forming And Properties Of Textile Scaffolds Of Endovascular Prosthesis

Angiocardiopathies such as arteriosclerosis,thrombus and aneurysm are increasingly common with the social and economical developments.With development of blood vessel prosthesis in last 40 years,it is more and more popular to transplant blood vessel prosthesis in conventional surgery to replace blocked artery and recover blood supply to remote organs.Therefore, research works on structures,performance and fabrication methods of endovascular prosthesis are stimulated by increasing demand for various types of endovascular prosthesis.In 1969,idea of interventional therapy was first developed.Later in 1990,the first endovascular repair(EVR)of an abdominal aortic aneurysm(AAA)was carried out by Parodi with aortic endovascular prosthesis(AEP),which became a milestone in Vascular Surgery research. Recently,a new therapy,minimally invasive surgery named endovascular with advantages like minimal wound,small amount of bleeding and quick recovery,has been developed.In this method,a metal stent and graft complex were transplanted into diseased vascular,which will isolate pathological vasculature from blood circulation.However,due to high price and limited supply of imported endovascular prosthesis,it is increasingly important to development our own endovascular prosthesis system.As a key component of endovascular prosthesis,the tubular textile fabric plays a vital role in separating the pathological vasculature from the normal blood circulation.Therefore,it is important to understand the relationship between the design parameters of the textile fabric and the mechanical properties of the endovascular prosthesis.In this study,a series of woven endovascular prototype structures were made by using different weft yarns and three different weave designs.A 30 denier polyester(PET) monofilament yarn was selected as warp yarn.Tubular textile fabrics were woven in 3/1 twill,2/2 twill and plain weave with 20 and 30 denier monofilament and 20/12f and 30d/12f multifilament polyester(PET)weft yarns.The samples were manufactured on a home-made narrow-width prototyping loom.Finishing in order to achieving improved cleanliness, uniformity and dimensional stability was followed.Before and after finishing, the basic dimensional parameters,such as diameter and density,were measured and compared.Based on the 12 samples after cleaning,important physical properties for endovascular prosthesis,such as thickness,water permeability and bursting strength were tested.After measurement,different pressure did not influence the thickness testing result and the best testing time of water permeability of those 12 samples was 10 minutes.The relationships between the woven textile design parameters and the physical properties of endovascular prostheses could be determined.Additionally,it could be found that use of different yarns and weave patterns leads to differences in thickness,bursting strength,and water permeability performance.Meanwhile the result of testing above were analyses and forecasted by theory of quantification,and the result indicated that the yarn type influenced most significantly in physical properties of woven endovascular prosthesis,then fabric construction,yarn size at last.In conclusion,in this study 12 high and equal density and very thin thickness woven tubular endovascular prosthesis were designed and weaved, and important physical properties for endovascular prosthesis,such as thickness,water permeability and bursting strength were tested.The results indicated notable relationships between the textile design parameters and the physical performance of the prototype endovascular device.Meanwhile, theory of quantification was employed to analyze and forecast testing results, providing the theoretical and experimental basis for further optimization of the fabric design.