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.
Objective To investigate the effectiveness of various materials in reconstruction of laryngotracheal framework and to analyze the advantages, disadvantage, and indication of each material. Methods The cl inical data were retrospectively analyzed, from 337 laryngotracheal stenosis patients undergoing laryngotracheal framework reconstruction with various materials between October 1986 and October 2006. There were 229 males and 108 females aged from 2 to 54 years (median, 23.5 years). According to Cotton’s grading criteria for laryngotracheal stenosis, there were 94 cases of grade II, 218 cases of grade III, and 25 cases of grade IV, and all accompanied by laryngotracheal framework defect of 1-5 cm. The costal cartilage autograft was performed in 157 cases, thyroid cartilage graft in 27 cases, nasal septal cartilage graft in 8 cases, sternohyoid myocutaneous rotary door flap graft in 104 cases, hyoid bone flap of sternocleidomastoideus graft in 7 cases, musculo-periosteum flap of sternocleidomastoideus with clavicular periosteum in 21 cases, hydroxyapatite artificial tracheal ring graft in 10 cases, and pedicle myocutaneous flap with “C” shape nickel-titanic alloy net graft in 3 cases. Silastic T-tube was used after reconstruction for 6-12 months. Results Infection occurred in 5 cases and the incisions healed by second intention, the others achieved healing of incision by first intention. Intratracheal granulation formation occurred in 23 cases and choke when taking food in 6 cases; they were all cured after symptomatic treatment. After operation, 4 cases failed to be followed up and 12 cases did not recover, including 6 cases of costal cartilage autograft, 1 case of hyoid bone flap of sternocleidomastoideus graft, and 5 cases of sternohyoid myocutaneous rotary door flap graft. A total of 321 patients were followed up for 1-10 years (mean, 3.5 years). The patients had no laryngotracheal restenosis with good swallowing function and respiratory function. Conclusion Different materials of laryngotracheal framework reconstruction have advantages and disadvantage respectively. The appropriate material should be selected according to the special details of pathological change, and the satisfactory curative effect may be obtained.
Objective To review the recent research progress of base and clinical application of tracheal replacement. Methods Literature concerning tracheal prosthesis and the current achievements were extensively and comprehensively reviewed. Results Most tracheal lesions can be resected and achieve primary reconstruction, but the resectable length was limited.Tracheal replacement was an efficient and feasible way to substitutethe defects resulting from extended resection. Conclusion Newtechniques such as tissue engineering, tracheal transplantation, new tracheal prosthesis of biomaterials break fresh ground for the more rapid development of tracheal surgery.
Objective To review the research advances of the tracheal prosthesis. Methods The articles concerned in recent years were extensively reviewed. Results There were still many arguments about the use of tracheal substitutes. Avariety of artificial trachea had been designed and assessed, but so far none of them had been satisfactory for clinical use. The failures were mainly due to their high mortality and incidence of complication such as prosthetic defluvium, granuloma formation, local infection, air leakage, anastomotic stenosis or obstruction. Conclusion The major causes of the poor effectiveness by the use of tracheal prosthesis are closely related to its biological compatibilities. The selected biomaterials and the design of prosthesis hold the key to a breakthrough in research and clinical use of tracheal prosthesis.
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.
ObjectiveTo perfect the surgical process that trachea could be reconstructed by nickel-titanium (Ni-Ti) alloy stent wrapped with autologous pericardium, and to evaluate the effectiveness and observe the complications. MethodsIn the experiment, twelve healthy Bama suckling pigs with weight of 18-25 kg were selected. The pericardium was harvested to cover the Ni-Ti alloy stent. The compound artificial trachea was used to reconstruct long-segmental (6 cm) trachea defect. The effectiveness, complications, the properties, and growth rate of the new mucosa of the artificial trachea lumen were observed. ResultsOf 12 pigs, 2 died soon because of hemorrhage and infection, respectively; 7 died at 2-4 months after operation because of hyperplasia at the middle section and blockage of phlegm plug; 3 survived after 42 weeks postoperatively, but accompanied with dyspnea symptom. At 1, 2, 3, 4, and 5 months after operation, the average crawl length of the new trachea mucosa was 1, 3, 5, 7, and 10 mm, respectively; the occurrence rates of anastomotic stenosis were 0 (0/10), 0 (0/9), 0 (0/4), 33.3% (1/3), and 33.3% (1/3) respectively; and the occurrence rates of scar hyperplasia in the middle of lumen were 20% (2/10), 66.7% (6/9), 75.0% (3/4), 66.7% (2/3), and 100% (3/3), respectively. At 7 months postoperatively, the bronchoscopy examination showed that the scar in central part of artificial trachea had the trends of stagnation, softening, and narrowing, and respiratory symptom had the trend of slight ease. Hyperplasia tissue could be found in central part of artificial trachea by autopsy and was verified to be fiber cells and necrotic tissue by pathology examination. ConclusionNi-Ti alloy stent with autologous pericardium can insure that the reconstructed tracheal lumen is unobstructed, and support the trachea epithelium regeneration; the main factors of the death of the experimental animals are the lumen hyperplasia of the artificial trachea and the blockage of the secondary phlegm plug.