The Manufacturing And Performance Analysis Of Warp-Knitted Grafts

With the development of society and the improvement of people's living standard in our country, a number of vascular diseases such as arteriosclerosis, thrombus, aneurysm have already seriously affected the health of people. When the human blood vessel can't work due to aging, damage or other reasons, it requires the use of artificial replacement blood vessels, bypass surgery or interventional treatment. The demand for artificial blood vessels increases every year, according to statistics, only in 2000, there were 180,000 cases of artificial vascular graft surgery in the United States alone. As our research and development of blood vessel has not used in clinic successfully, the clinical use of artificial blood vessel mainly depends on foreign imports. However, the high price and limited supply of imported artificial blood vessel affect the patient's treatment. Warp-knitted vascular grafts contain the advantage of weft-knitted vascular grafts and woven vascular grafts, which is widely used in clinical, but the research and development of warp-knitted vascular grafts in our country is still blank. It's important to develop our own warp-knitted vascular grafts.Firstly, warp-knitted vascular grafts of tricot and Iocknit with tubular and branching tubular shape were individually weaved with Double-needle-bar Raschel machine with 30 latch needles per inch and the material of polyester, through designing the parameter and adjustment of technique properly which based on the performance of commercial warp-knitted vascular grafts. Secondly, according to the ISO7198,we tested the performance of the samples including thickness, circumferential tensile strength, bursting strength and water permeability, and we also analyzed the influence on the properties, from which we learned that the yarn structure, fabric structure have great influence on mechanical properties, geometric properties and water permeability. In mechanical properties, our samples reach or even exceed the level of foreign samples, but there were still gap between our samples and foreign samples in water permeability, which maybe has a great relationship with our materials. It can be said that in our present conditions, we can weave warp-knitted vascular grafts which can reach the level of foreign samples through the optimal design parameter. Finally, we used the dimensional analysis method to establish a mathematical model which can predicts the water permeability of warp-knitted vascular grafts, and it can provides some reference value when we design warp-knitted vascular grafts in the future.In general, the successful development of warp-knitted vascular grafts with good mechanical properties proved the feasibility of our experimental program, which can provide some reference value for future research, and will make contribution to the development of our own warp-knitted vascular grafts.