Objective To review the research of the artificial tracheal prosthesis in the past decade so as to provide theoretical references for the development of the artificial tracheal prosthesis. Methods The l iterature about the artificial tracheal prosthesis was extensively reviewed and analyzed. Results Many new materials are used for the research of artificialtracheal prosthesis which have excellent biocompatibil ity and stabil ity of the structural characteristics. And many compl ications such as migration, obstruction, and infection have been resolved, but so far none of the new materials has been used for cl inical treatment successfully. Conclusion The choice of the materials for artificial tracheal prosthesis is the key to succeed. Biodegradable polymer materials with its unique biological properties become the new direction of the tracheal prosthesis research.
We developed and designed a new type of artificial trachea. The basic structure of the artificial trachea was polytetrafluoroethylene vascular prosthesis linked with titanium rings on both sides. Dualmesh was sutured on titanium rings. This experimentation follows the replacement of trachea in dogs with a combined artificial trachea to investigate the feasibility of this type of prosthesis. Sixteen dogs were implanted with the combined artificial trachea after resection of 5 cm of cervical trachea. The 5 cm-long trachea of dogs on the necks were resected and the reconstruction of the defect of the trachea was performed with trachea prosthesis. According to the method of trachea reconstruction, the models were divided into 2 groups, artificial trachea implantation group (the control group, n=8) and group of artificial trachea implantation with growth factor (the experimental group, n=8). Then computer tomography scan (CT), bronchoscope and pathologic examination were conducted periodically to observe the healing state of the hybrid artificial trachea. None of the dogs died during operation of cervical segmental trachea construction. But four dogs in the control group died of apnea in succession because artificial trachea was displaced and the lumen was obstructed, while 2 dogs died in the experimental group. In the first month there was granulation around anastomosis with slight stenosis. The rest of dogs were well alive until they were sacrificed 14 months later. The mean survival time of the experimental group was longer than that of the control group. The rate of infection, anastomotic dehiscence, severe stenosis and accidental death in the experimental group were lower than the control group (P<0.05).Artificial trachea was encapsulated by fibrous tissue and no mucous membrane was seen in the lumen of the artificial trachea. The artificial trachea can be used to reconstruction of the defect of the trachea with long-term survival of the animals. The unique design of artificial trachea reduces stenosis around anastomosis effectively but infections and split or displacement of the artificial trachea are still major problems affecting long-term survival of the animals. Application of growth factors to a certain extent promotes tissue healing by changing the local environment.
ObjectiveTo observe the morphological and pathological changes after transplantation of polytetrafluoroethylene (PTFE) in vivo. MethodsPTFE microporous polypropylene tube which was encircled by spiral steel wire was used to prepare the artificial trachea.Forty New Zealand white rabbits (weighing,4-5 kg) were selected,and were divided into 2 groups.After the cervical trachea (2 cm in length) was removed,the end-to-end anastomosis between the trachea and PTFE artificial trachea was performed in the experimental group (n=20),and end-to-end anastomosis of the trachea in the control group (n=20).The survival of the rabbits was observed after operation;the X-ray,gross,and histological observations were carried out at 2,4,and 6 months after operation.The longitudinal tensile and radial support biomechanical tests were performed before and after transplantation. ResultsThe survival time was more than 2 months and the artificial airway was patency in 15 rabbits of the experimental group;the tissue outside the artificial trachea was like tracheal tissue,which filled in the defect,but it was more than 4 months.X-ray observation showed that the PTFE artificial trachea had no obvious displacement in the experimental group,and no tracheostenosis was observed in the control group.After 2 months,there was no epithelial tissue on the artificial airway wall;after 4 months,there was some epithelial cells on the artificial airway wall,incomplete endothelialization and trachea layer structure were seen with no tracheal ciliated columnar epithelium;after 6 months,the artificial trachea wall was covered with epithelium basically,and some ciliated columnar epithelium cells were found,which had the physiological function of the trachea.The transplanted PTFE artificial trachea could keep the stability of the biological mechanics performance,and could be used for the rabbit tracheal reconstruction. ConclusionPTFE artificial trachea can induce to form a tracheal tissue in the trachea tissues of recipients,each layer of the trachea is relatively complete and the experiment animals can be short-term survival.