Development Of A Novel Woven Artificial Tracheal Stent

Tracheal stent is a kind of medical devices that used to repair the damaged tracheal stenosis,currently, most of the tracheal stent that used in the clinical was made of non-degradable materials.As the increasing research and development of biodegradable materials, biodegradable trachealstent has got a mount of research. When transplanted into human body, it will expanding to asuitable shape, producing sustainable and consistent support to the airway, and protecting thetrachea. With the tissue attached and grow on it, the stents will gradually degraded and excreted,avoid the second-harm to the human body when it need a operation to remove the non-degradablestents.The selection of the materials of Woven biodegradable artificial tracheal stent is veryimportant for the reason that the materials should match the requirements of the tracheal stentssuch as have sufficient mechanical strength and flexural properties, provide brace for the damagedtrachea and has good biocompatibility in vivo implantation that the degradation products does notrejected by the human body. In contrast to the degradation characteristics and mechanicalproperties of several FDA-approved biodegradable materials, select poly dioxanone (PPDO) as thestent material.On the basis of the ordinary woven tubular fabric and leno tubular fabric, combined with theperformance requirements of tracheal stent, designed a new type of fancy leno weave structureinnovatively. In this structure, warps were twisted in two systems and the wefts were curved,tracheal stents prepared in this structure have a large porosity in order to facilitate attachment andgrowth of cells and tissues and also have greater radial strength and recovery capability.Based on the artificial tracheal stent performance requirements, designing reasonableweaving process parameters, including diameter, warp/weft density and the looming draft,modifying the ordinary rapier weaving machine to meet the requirements of fancy leno tubularstents, treating the prepared samples with heat setting to got the final stents.The basic physical properties of prepared tracheal stent were measured and compared withthe rabbit trachea, including wall thickness, pore size, radial supporting force, elastic restoring rateand resistance of compression during transportation. The experimental results shows that thedeveloped artificial tracheal stent have good performance.Finally, the study of animal experiments has been done, implanting the prepared trachealstent in the rabbit’s trachea, observing the survival of the rabbits. The results shows that aftertracheal stent implanting, the rabbit trachea keeps smooth, no tracheal stenosis and stent collapseoccurred, cells and tissues can attached and grow on the stent porosity, the time of degradation isappropriate.