The Research On Braiding Parameters Of Braided Artifical Tracheal Stents

Tracheal resection and reconstruction are required in the clinical cases, such as tracheal tumors, the tumor of thyroid or other parts,severe stenosis of the trachea caused by tracheal congenital or traumatic and so on. Tracheal reconstruction has been a worldwide problem, therefore, the research and development of artificial tracheal and bronchus as a new technology in the treatment of tracheal stenosis and the maintenance of tracheal patency has aroused widespread concern. The radial force of tracheal stent is the critical pressure when buckling failure of the stent occurs which refers to the resistance to the radial pressure. It is related to the ability to securely attached to the tracheal wall after stent deployment and is one of the most important mechanical properties of stent. In addition to the mechanical properties, the gap morphology, pore size, connectivity and porosity of stent also play an important role in the adhesion of cell or tissue and the transportation of cell nutrients and metabolic waste.As textile techniques, woven, knitted and braiding techniques all can be used to weave tubular fabrics as artificial tracheal stents. Compared with the tubular fabrics made in other textile techniques, the braided tubular fabrics have better axial scalability, flexibility and porosity. At present, woven artificial tracheal stents and knitted artificial stents have been studied and developed by some scholars in domestic field of biomedical textiles. However, braided tracheal stents are rarely studied. In light of this, the subject selects synthetic polymeric biomaterials having good biocompatibility to make braided artificial tracheal stents and mainly studies the influence of braiding parameters on the radial mechanical property and pore size of the braided stents.Firstly, polypropylene and polyester monofilaments were chosen to be the simulation experiment materials because of their low cost and good biocompatibility and the artificial trachea stent samples with a variety of specifications were braided by changing the braiding parameters, such as the type of material, gear ratio and braiding height,on the domestic two-dimensional spindle type braiding machine to study their radial mechanical property and pore size.PDS monofilament as a biodegradable material is an ideal artifical tracheal stent material because it has good biocompatibility, high strength retention ratio and its degradation products in body are water and carbon dioxide, having no side effects on the human body. Thus, PDS monofilament were chosen to braid biodegradable artificial tracheal stents under the guidance of the significant parameters derived from the data of the simulation experiment. Then, the radial mechanical performance of the tracheal stent was studied in the degradation process.In a word, the research project studies the the influence of braiding parameters such as the type of synthetic polymeric materials, braiding height and gear ratio of braiding machine, on the radial compressive property and pore size of the braided artificial tracheal stents which provides a valuable reference for later development of braided artificial tracheal stents.