Tracheal stents are often used to maintain the patency of the trachea and bronchia in patients suffering from central airway lesions. Metallic tracheal stents are now widely used in the clinical setting, but these types of stents can cause many intractable material-related complications. Biodegradable tracheal stents are made of biodegradable polymer materials with good mechanical strength for maintaining the patency of the lesion segment during a certain period of time, and then they can be gradually degraded into harmless products in human body. Compared with conventional metallic tracheal stent, biodegradable tracheal stents have a good prospect in clinic. In this article, we review the choice of biodegradable tracheal stent materials, experimental progress in biodegradable tracheal stent as well as the challenges we are facing.
Objective To investigate change of bispectral index(BIS) and hemodynamic index during induction and orotracheal intubation of sevoflurane anesthesia. Methods This study was a prospective before-after study in the same patients. A total of 30 ASA physical status I and II adult patients without airway abnormalities were enrolled to receive inhalation induction of anesthesia with 8% sevoflurane. Mean arterial pressure(MAP),heart rate(HR) and BIS were recorded before anesthesia(T1),when patients loss of consciousness(T2), before intubation (T3),at 1 min(T4) and 3 min(T5) after intubation. Results BIS at T1-T5 were 96.8±1.7,70.4±8.8,39.2±8.4,43.6±12.9 and 41.6±9.3 respectively, the measurements at T2-T5 were all markedly lower than at T1(Plt;0.05). HR at T3-T5 were all markedly higher than at T1(Plt;0.05). MAP at T2 and T3 were markedly lower than at T1, but at T4 was higher than at T1(Plt;0.05), and recovered to the level at T1 at T5(Pgt;0.05).BIS,HR and MAP at T4 were all significantly higher than T3(Plt;0.05). Conclusion Anesthesia induction with sevoflurane and small dose of succinylchoiline we used can provide adequate depth of general anesthesia,but can not prevent cardiovascular adverse reactions to intubation.
Objective To investigate the impacts of cytokines （interleukin-4，IL-4；tumor necrosis factor-α，TNF-α） and medications of bronchial asthma （dexamethasone，aminophylline，salbutamol） on the activity of histamine N-methyltransferase（HMT） in tracheal epithelial cells.Methods BEAS-2B bronchial epithelial cells were cultured and treated with different concentration of TNF-α, IL-4, dexamethasone, salbutamol and aminophylline respectively. The activity of HMT in BEAS-2B cells was determined by high performance liquid chromatography.Results The activity of HMT in tracheal epithelial cells was (50±7) pmol?min-1?mg pro-1.TNF-α and IL-4 lowered the activity of HMT significantly at the concentration equal to or higher than 1 ng/mL and 5 ng/mL respectively，and reached the maximum inhibitory effect at the level of 10 ng/mL.Dexamethasone and aminophylline could ameliorate distinctly the inhibitory effect of TNF-α on the activity of HMT, while salbutamol had no significant inhibitory effect.Conclusions TNF-α and IL-4 exert the lowering effect on the activity of HMT，which would be one important cause of airway hyperreactivity.Glucocorticoids and theophyllines are administered to treat asthma partly due to its relieving mechanism of TNF-α negative effects on HMT.
Objective To evaluate the clinical features and complications of bedside tracheal intubation in intensive care unit ( ICU) , and explore the suitable strategy of intubation. Methods In this retrospective study,42 patients who underwent bedside tracheal intubation in ICU during September 2008 and March 2009 were divided into a schedule group ( n =24) and an emergency group ( n =18) . The time to successful intubation, number of intubation attempts, and complications were recorded. The schedule group was defined as those with indications for intubation and fully prepared, while the emergency group was defined as those undergoing emergency intubations without full preparation due to rapid progression of disease and accidental extubation. Results The success rate for all patients was only 57. 1% on the first attempt ofintubation. The main complications during and after induction were hypotension ( 45. 2% ) and hypoxemia ( 50. 0% ) . Compared with the emergency group, the schedule group had fewer attempts to successful intubation ( 1. 71 ±1. 12 vs. 2. 67 ±1. 75) , higher success rate on the second attempt ( 87. 5% vs.61. 1%) , and lower ypoxemia incidence ( 29. 1% vs. 77. 8%, P lt; 0. 05) . Conclusions The tracheal intubation in ICU is a difficult and high risk procedure with obvious complications. Early recognition ofpatients with indications and well preparation are critical to successful bedside intubation.
Objective To study the application, safety and efficiency of tetracaine sprayed through thyrocricoid puncture before intubation in intensive care unit ( ICU) . Methods Forty-one patients ready to undergo intubation, admitted in ICU from November 2009 to February 2010, were recruited in the study. They were randomly divided into a tetracaine group and a control group. 2% tetracaine was sprayed through thyrocricoid puncture before intubation in the tetracaine group but not in the control group. The hemodynamic variables and SpO2 at baseline ( T0 ) , beginning of intubation ( T1 ) , 1 min after intubation ( T2 ) , and 5 min after intubation ( T3 ) were recorded. The dosage of propofol and vasoactive agents, the incidence of hypotension, the times of intubation, and complications were also recorded. Results The variance rate about heart rate ( HR) , mean arterial pressure ( MAP) and rate pressure production on time of T1 and T2 were significantly lower in the tetracaine group than those in the control group ( P lt; 0. 05) . There was no difference about the incidence of successful intubation and hypoxia ( P gt; 0. 05) . The dosage of propofol during induction and vasoactive agents after intubation in the tetracaine group were less than those in the control group ( P lt;0. 05) . The incidence of hypotension after intubation in the tetracaine group was 35% , which was lower than 61. 9% in the control group ( P lt;0. 05) . There was no any complications and adverse accidents in the tetracaine group. Conclusions It is safe and simple to spray tetracaine through thyrocricoid puncture before intubation in ICU, which can effectively stabilize the hemodynamics, and decrease the dosages of propofol and vasoactive agents.
Objective To observe the effects of ambroxol injection on mucosal surface structure of trachea injured by intratracheal instillation of amikacin. Methods 280 Wistar rats were randomly divided into four groups( n = 70 in each group) , ie. a normal control group, a normal saline group( intratracheally instilled normal saline) , an amikacin group ( intratracheally instilled amikacin) , and an ambroxol group ( intratracheally instilled amikacin and ambroxol simultaneously) . At the time points of 2, 12, 24, 48, 72 hours six animals in each group were killed and the samples of 1/3 lower segment of trachea were collected and observed by scanning electron microscope. Endotracheal intubation were made on other 6 animals to collecte broncho-alveolar lavage fluid ( BALF) for leucocyte count. Results Compared with the normal control group, elevated leucocyte count was observed in all other groups, various grades of swelling of the cilia were revealed, followed by more or less cilia laid flat with adjacent cilia conglutinated. Then partial cell membrane on top of some cilia bulged out. In terms of injury, the normal saline group was the most mild, and the amikacin group was most serious with the highest leucocyte count. All the parameters were relieved in ambroxol group. Conclusions Intratracheal instillation of amikacin causes acute injury of the ultrastructure of mucosal surface cilia. Ambroxol can promote the recovery process and alleviate inflammation of airway.
Patients with pathological tracheal loss more than a certain length may need tracheal transplantation.Traditional natural tissue and autologous tissue have failed to produce satisfactory clinical outcomes to replace the trachea because of local infection，tracheal stenosis，tracheomalacia，immune rejection et al. In recent years，the emergence oftissue engineering trachea provides a new idea for tracheal transplantation. But scientists have not yet reached a consensus about how to choose ideal extracellular matrix to construct tissue engineering trachea. At present research and applicationof tissue engineering trachea，extracellular matrices mainly include allogenic trachea，allogenic aorta and biologicalcomposite materials. Each allogenic matrix or biological composite material has its own advantages and disadvantages. Therefore，this article mainly summarizes recent application and research progress of extracellular matrix in long segmental tracheal defect and its future perspective.
Abstract： Objective To investigate the methods of diagnosis and treatment for early and late cheobronchial rupture, in order to improve the understanding of this disease. Methods We retrospectively analyzed the records of 19 patients treated for traumatic tracheobronchial rupture in our hospital between October 1988 and August 2010. There were 9 males and 10 females with a median age of 28 years (ranged from 8 to 48 years). We analyzed the clinical characteristics of the disease, including clinical presentation, and the results of chest Xrays, computed tomography（CT）, and fibrobronchoscopy. There were 2 cases of tracheal repair, 1 case of tracheostomy, 8 cases of bronchial reconstruction, 7 cases of bronchial repair, and 1 case of pneumonectomy. Results Seventeen patients were cured by operation and 2 patients died of multiple organ failure. Blood oxygen saturation resumed normal in most patients after operation (9680%±159% vs. 8840%±390%，Plt;0.01). Postoperative followup time was ranged from 3 to 24 months, and no tracheobronchial stenosis was observed and no patients needed stent or dilatation for treatment. Conclusion The diagnosis of tracheobronchial rupture depends on history of trauma, chest Xray, CT and fibrobronchoscopy results. Surgical treatments should be based on the tracheobronchial reconstruction or repair, and the clinical outcome is satisfying.
Objective To summarize the clinical experiences in treating primary tracheal tumors by surgery, so as to improve the results of surgical treatment. Methods The clinical data concerning 22 surgically treated patients were retrospectively analyzed. Four patients tumor were benign and eighteen cases’s tumor was malignant. Tracheal resections and end to end anastomosis were performed in 14 cases, carinal resection was performed in 4 cases, lateral tracheal wall resection was performed in 1 case, local scrape were performed in 2 cases, tumor was resected transfiberoptic bronchoscopy in 1 case. Tracheal resectable length was from 2.0cm to 5.2cm，and the average resectable length was 3.8cm in operation. Results 17 cases had been misdiagnosised ( 77.3%) in outpatient department. It was easy to be misdiagnosised as asthma. One case died of respiratory failure after operation in 30 days. The complication rate was 31.8%, complications consist of pneumonia in 4 cases, anastomosis leakage in 1 case and chylothorax in 2 cases. Anastomosis stenosis was found in 3 cases, the syndromes were improved after treatment.Twenty cases were followed up from 1 month to 8 years. Four cases with benign tumors were still alive. Among 16 cases with malignant tumors, 6 cases had survived more than 5 years， 3 cases died of brain, liver, bone metastasis of malignant tumors. Conclusion Surgical resection is the most effective treatment of tracheal tumors. Tracheal resection and reconstruction is the main choice of primary tracheal tumors treatment. Benign tumors can be resected conservatively. The reductions of operative complications are the key points of good surgical results. To know the characteristic of primary tracheal tumors well can reduce the misdiagnosis rate.
Tissue engineering trachea is an artificial trachea with biological activity, which is constructed in vitro by using tissue engineered principle and technology, and is a tracheal prosthesis for replacing large circumferential defect of the trachea. The course of its construction is as follows. First, seeding cells are cultured and expanded in vitro. Then they are collected, counted and seeded onto the biomaterial scaffold of tissue consistent and biodegradation. Finally, the biomaterial-cells construction is implanted into bio-reaction device or one’s subcutaneous layer. The tissue engineering trachea could be constructed after cultured certain times. Compared with other artificial trachea, the tissue engineering trachea has more advantages, such as nonimmunogenicity, no side-effects related to foreign graft materials, and biologic activity. This will bring some hope to look for an appropriate graft material. However, the study about it is still faced with some difficult problems, such as vascularized trachea, culturing in vitro, and prevention of infection in trachea prosthesia. So there will be long time for tissue engineering trachea to apply clinical tracheal transplantation successfully. This assay has reviewed the study about tissue engineering trachea from three sides——the source of seeding cells, the research about biomaterial scaffold, and the construction of tissue engineering trachea.