Prosthetic reconstruction of the trachea:A historical perspective

This review discusses the history of tracheal reconstruction; from early work to future challenges. The focus is primarily on prosthetic tracheal reconstruction in the form of intraluminal stents, patch repairs, circumferential repairs and replacement of the trachea. A historical perspective of materials used such as foreign materials, autografts, allografts, xenografts and techniques, along with their advantages and disadvantages, is provided.

Tracheal Stenosis Caused by Thoracic Malignancy: Correlation between CT-Based Tracheal Measurement and Spirometric Values before and after Tracheal Stenting

Background: The correlation between computed tomography (CT)-based tracheal size and spirometry values is unknown in patients with tracheal stenosis by thoracic malignancy, which is often treated by tracheal stenting. Objectives: To evaluate the correlation between the tracheal cross-sectional area (CSA) and spirometric values before and after tracheal stenting, and to confirm that greater improvement in tracheal CSA leads to a larger improvement in spirometry values. Methods: A total of 32 patients with malignant tracheal stenosis underwent tracheal stenting. Before (n = 32) and after (n = 27) treatment, patients underwent chest CT, measuring mean and minimum tracheal CSA values, and spirometry. The correlation between tracheal CSA and each spirometric value was evaluated using Spearman rank correlation analysis. Differences in the pre- and posttreatment tracheal CSA and spirometric values were evaluated using the Wilcoxon matched-pairs test. Results: Significant improvement in the minimum tracheal CSA and in spirometric values was observed after stenting (P P P Conclusions: The tracheal size measured on chest CT correlates with patients’ spirometric values, particularly at the prestenting examination, in patients with malignant tracheal stenosis. The increase in the minimum tracheal CSA after stenting on CT is a predictor for improved spirometric values, which is first demonstrated by this study.

Carcinoma ex pleomorphic adenoma of the trachea: A case report

BACKGROUND Carcinoma ex pleomorphic adenoma (CXPA) is defined as a malignant salivary gland tumor arising from a primary or recurrent pleomorphic adenoma.Only three cases of CXPA of the trachea have been reported in the literature.CASE SUMMARY We report a case of tracheal CXPA in a 55-year-old woman,who presented with a more than 3-mo history of progressive dyspnea.Computed tomography of the neck and thorax revealed an inhomogeneous,broad-based lesion arising from the tracheal wall on the right side.Endoscopy revealed a subglottic neoplasm causing up to 90% luminal stenosis.The tumor was resected using a highfrequency electrosurgical snare combined with argon plasma coagulation.Histopathology and immunohistochemistry revealed that the tumor was a CXPA of the trachea.CONCLUSION We report the fourth case of tracheal CXPA,and present the first instance of resection of CXPA using high-frequency electrosurgical snare and laser ablation.We also discuss the pathogenesis,diagnosis,histopathology,and systemic therapy of this rare disease.

A Laminar Flow Model for Mucous Gel Transport in a Cough Machine Simulating Trachea: Effect of Surfactant as a Sol Phase Layer

In this paper, a planar three layer quasisteady laminar flow model is proposed in a cough machine which simulates mucous gel transport in model trachea due to mild forced expiration. The flow is governed by the time dependent pressure gradient generated in trachea due to mild forced expiration. Mucous gel is represented by a viscoelastic Voigt element whereas sol phase fluid and air are considered as Newtonian fluids. For fixed airflow rate, it is shown that when the viscosity of mucous gel is small, mucous gel transport decreases as the elastic modulus increases. However, elastic modulus has negligible effect on large gel viscosity. It is also shown that for fixed airflow rate and fixed airway dimension, mucous gel transport increases with the thickness of sol phase fluid and this increase is further enhanced as the viscosity of sol phase fluid decreases. The effect of surfactant is studied by considering sol phase as surfactant layer which causes slip at the wall and interface of sol phase and mucous gel. It is found that in the presence of surfactant mucous gel transport is enhanced.

Tracheal relaxation of five medicinal plants used in Mexico for the treatment of several diseases

Objective:To assess the relaxant effect of several organic extracts obtained from Agastache mexicana(A.mexicana),Cochlospermum vitifolium(C.vitifolium),Cordia morelosana(C.morelosana),Lepechinia caulescens(L.caulescens)and Talauma mexicana(71 mexicana)used in Mexican traditional medicine for the treatment of several diseases.Methods:Extracts were obtained by maceration at room temperature using hexane,dicliloromethane and methanol for each plant material.The organic extracts were evaluated ex vivo to determine their relaxant activity on the contractions induced by carbaehol(cholinergic receptor agonist,1μmol/L in isolated rat tracheal rings.Results:A total of 15 extracts were evaluated(three for each species).All test samples showed significant relaxant effect,in a concentration-dependent manner,on the contractions induced by 1μmol/L carbachol,with exception of extracts from C.morelosana.Active extracts were less potent than theophylline[phosphodiesterase inhibitor,EC_(50):(28.79±0.82)μg/mL]that was used as positive control.Concentration-response curves revealed that the extracts with more significant effects were dichloromethanic extracts of T.mexhxma[E_(max):(103.03±3.32)%and EC_(50):(159.39±3.72)μg/mL)and C.vitifolium[Emax:(106.58±2.42)%and EC_(50):(219.54±7.61)μg/mL].Finally,hexanic and dichloromethanic extracts from A.mexicana were fully effective but less potent than T.mexicana,and C.vitifolium.Conclusions:Less polar extracts obtained from A.mexicana,71 mexicana and C.vitifolium exhibited greater relaxant effect on tracheal rat rings,which allows us to suggest them as sources for the isolation of bioactive molecules with potential therapeutic value in the treatment of asthma.

Synchronous primary cancers of trachea and esophagus and ventricular tachycardia

The incidence of multiple primary cancers involving trachea is rare. We present a case of synchronous double primary cancer of trachea and esophagus in a 70-year-old woman, with a special symptom of ventricular tachycardia and no/a/story of smoking and alcohol drinking. Biopsies （tom multiple loci demonstrated the patient had primary small cell cancer of trachea and squamous cell carcinoma in situ of esophagus. The patient was successfully treated with four cycles of chemotherapy consisting of etoposide and earboplatin （EC） followed by thoracic radiotherapy （60 Gy in 30 fractions, in 6 weeks）, and was evaluated to have complete response of tumor. To our knowledge, there is no synchronous cancer of trachea and esophagus has been reported in English literature, and our experience showed sequential EC chemotherapy and radiotherapy provided an effective treatment to control both cancers.

Regeneration and Differentiation of Hamster Tracheal Epithelium Used Anti--Brdu Monoclonal Antibody After Mechanical Injury

The ventral quadrant of the tracheal epithelium of the hamster,about one fourth of tracheal mucosa, was denuded by a venous needle reformed.The stains were made with HE, PAS, and PAS-anti Brdu immunohis-tochemic technique. At the 0 h circumference cell number (CCN) was 927. 25.From 6 h post injured the viable cells changed in shapes and migrated from themargin to wound site. By 24 h the wound area was completely covered by a sin-gle layer of non-ciliated flattened cells, then an expotential increassing in cellregeneration occured in wound site by 48 h. The CCN had been restored to thelevel of control (1373), and the proliferative cell, composed of polygonal epi-dermoid metaplasia, 3～4 layers and reached a peak (338.8). The secretoryand ciliated cells appeared gradually from 72 h post injury, the epithelium re-stored to the normal epithelial architecture by one week post injury. In our pre-sent study either in control and non-injured epithelium or in all stages of woundsite about 70% of the Brdu positive cells contained small or confluent PAS posi-tive granules were observed. This fact indicated that secretory cells play a im-portant role in proliferation after mechanical injury and maintaining the normaltracheal pseudostratified epithelium.

Pleomorphic adenoma of the trachea:A case report and review of the literature

BACKGROUND Pleomorphic adenoma(PA)is the most common benign tumor that occurs in the salivary glands;however,tracheobronchial PA is rarely observed.To the best of our knowledge,fewer than 50 cases have been reported in the literature.We report a 49-year-old woman who had been treated for asthma for 2 years before being diagnosed with PA of the trachea.CASE SUMMARY A 49-year-old woman was referred to our hospital due to dyspnea upon exertion and chronic cough with wheezing for 2 years.Laboratory tests showed an elevated white blood cell count,absolute neutrophil count,and percentage of neutrophils.A chest computerized tomography scan showed a well-defined,softtissue density lesion measuring 2.4 cm×2.1 cm in the lower trachea.Flexible bronchoscopy revealed that nearly 90%of the tracheal lumen was obstructed.The histopathological and immunohistochemistry features suggested PA of the trachea.Furthermore,we review the characteristics of 29 patients with tracheobronchial PA over the last 30 years.CONCLUSION Tracheobronchial PA occurs without gender predominance,mostly in the lower or upper trachea,and has a low recurrence rate.The median age at diagnosis is 48 years.The most common symptoms are cough,stridor,dyspnea,and wheezing.

Primary intratracheal neurilemmoma in a 10-year-old girl:A case report

BACKGROUND Tracheal tumors are relatively rare in adults and uncommon in children.Tracheal neurilemmoma is a rare condition in adults that usually affects middle-aged people,but it can also occur in children.Because the clinical presentation is nonspecific and insidious,diagnosis is often delayed.The most common symptoms in these patients are stridor or wheezing(especially positional)and cough.A few patients are misdiagnosed and mistakenly treated for asthma.CASE SUMMARY A 10-year-old girl was admitted to our unit with a 2-mo history of recurrent cough,dyspnea,and tachypnea.Her condition was more severe after exercise.Her symptoms progressed despite treatment with inhaled fluticasone/salmeterol.Flexible electronic laryngoscopy showed a red,smooth,and round mushroomshaped mass in the trachea,about 1 cm below the vocal cords.The surface of the mass was covered with several small and discontinuous blood vessels.About 90%of the tracheal lumen was occupied by the mass.A multidisciplinary operation was performed.The surgically resected mass was diagnosed as benign neurilemmoma by immunohistochemical analysis.CONCLUSION Intratracheal neurilemmoma is fairly rare in children.The main symptoms include coughing,wheezing,and dyspnea.The tumor’s size,location,and degree of intratracheal and extratracheal invasion can be measured by chest computed tomography.The main treatment strategies used for tracheal neurilemmoma are surgical resection and endoscopic excision.Long-term follow-up is warranted for the evaluation of outcomes and complications.

Construction and Identification of Mammary Gland-specific Expression Vector of Bovine Tracheal Antimicrobial Peptide (TAP)

[ Objective] This study aimed to construct nmnmm_ry gland-specific expression vector of bovine tracheal antimicrobial peptide （TAP） gene. [ Method] TAP gene of dairy cattle was amplified from the mammary gland tissue by RT-PCR using a pair of primers which were designed according to bovine TAP cDNA se- quence （NM_174776） in GenBank, and then cloned into pMD19-T Simple vector for sequencing. The recombinant plasmid was digested using EcoRI and KpnI, the target gene fragment was recovered and inserted into general mammary gland-specific expression vector pBLG-EGFP harboring enhanced green fluorescent protein （ EGFP）, and transfected into bovine mammary epithelial cells （bMEC）, COS-7 cells and lactating rabbit mmmnary gland tissue by lipofectin transfection. The ex- pression of green fluorescent protein in transfected cells was detected under fluorescence microscopy, and the expression of TAP mRNA in rabbit mammary gland tis- sue was detected by semi-quantity RT-PCR. [ Result] The constructed mammary gland-specific expression vector pBLG-EGFP-TAP specifically expressed EGFP in transfected bMECs. In addition, semi-quantitative RT-PCR result showed that the expression level of TAP mRNA in rabbit mammary gland tissue was significantly enhanced after transfeeted with pBLG-EGFP-TAP. [ Conclusion] The mammary gland-specific expression vector pBLG-EGFP-TAP was successfully constructed, which provided important materials for further investigation of expression characteristics of TAP gene and prevention of bovine mastitis by using genetic engineering technology.

Cryopreservation of the Trachea Can Reduce Its Antigenicity in Various Species

Background: Cryopreserved tracheal allograft has been used successfully for esophageal replacement in the canine model. The working hypothesis was cryopreservation decreases antigenicity but epithelial desquamation remains. However, cryopreservation of human tracheal samples collected at tracheostomy, resulted in no significant desquamation. The aim of this study was to examine the extent of desquamation of the epithelial layer of cryopreserved animal tracheas and find a reason for decreased antigenicity of cryopreserved canine and pig’s trachea. Methods: 5 cm long tracheal segments were removed from 6 dogs and 125 pigs and stored in liquid nitrogen for 21 days. Cross section samples were taken from the end of the segment, 1 cm from the end and at the middle of the segment. Histological examination was performed using haematoxyllineosin and MHC-II antigen specific antibody staining. Changes in histological structure were analyzed. Results: General histological morphology of samples changed after cryopreservation. The percentage of intact epithelium and the overall intensity of immune-staining increased significantly from the ends to the middle of the segments, but the intensity of immune-staining showed no difference in the remaining epithelial cells. Conclusion: Cryopreservation damages the epithelial cells, but does not influence the cell’s antigenicity or cause desepithelisation. The main effect is a retraction of the epithelial layer from the ends to the midpart and this effect may be protection against organ rejection. Based on our canine and pig results a 5 cm, long tracheal segment seems to be a promising organ for human esophageal replacement.

Immunohistochemical characterization of the rabbit tracheal cartilages

The objective of this study was to immunohistochemically elucidate the major extracellular matrix constituents of rabbit tracheal cartilage. The impetus for this project is the need for crucial design and validation criteria for tissue engineering juxtaposed with the conspicuous lack of trachea extracellular matrix data in the literature. Tracheal tissue specimens were harvested from New Zealand White rabbits, and were immunostained for collagen I, collagen II, aggrecan and decorin;and a Verhoeff-Van Gieson stain was performed to visualize elastin. The most striking result was the highly organized relationship between distinct fibrous (containing collagen I, decorin and elastin) and hyaline-like (containing collagen II and aggrecan) regions of the tracheal wall. The tracheal cartilage stained strongly with collagen II throughout, with periodic bands of aggrecan in the tracheal arches, meaning that there were areas void of aggrecan immunostaining alternating with areas with strong aggrecan immunostaining. In contrast, the periphery of the cartilage and the perichondrium itself exhibited strong collagen I staining and no collagen II staining. Elastin fibers and decorin were also detected along the periphery of the cartilage in the perichondrium and corresponded highly with the distribution of collagen I staining. The body of the rabbit trachea is therefore composed of a hyaline-cartilage structure primarily made of collagen II and bands of aggrecan, surrounded by a fibrous region composed of elastin and collagen I, indicative of a flexible tissue with distinct regions of compressive integrity. This information will be a valuable reference to future tissue engineering efforts in the creation of a biosynthetic substitute for laryngotracheal reconstruction.

Integrating Biodegradable 3-Dimensional-Printing into Tracheal Reconstruction

Background: Currently, there is no set standard treatment for long-segment tracheomalacia and stenosis. In this study we set out to explore the potential to create a tissue engineered, biodegradable and three-dimensionally (3D) printed tracheal ring as a first step towards bioengineering a long segment tracheal replacement. Method of Approach: A 3D-Computer aided design (CAD) model was produced with multiple channels to allow for cellular growth while mimicking the native anatomy. The design was optimized to allow for printability, cellular expansion, and integration and 3D printed using a modified commercial 3D printer. Results: The cells grown in the scaffold demonstrated a similar proliferation trend compared to control. Chondrocytes within the 3D printed ring retained their phenotypic properties and did not infer any significant change in flexibility, contour and strength to the scaffold. Conclusion: The combination of living cells and a 3D modeled patient specific graft may address some of the unmet clinical needs in the field of tracheal reconstruction. This proof of concept study represents a first step towards producing a 3D printed and tissue engineered long segment tracheal replacement graft for airway surgery.

Locally Advanced Anaplastic Thyroid Carcinoma with Long-Term Survival of More Than 7 Years after Combined Surgery Including Tracheal Resection and Radiotherapy: Case Report

Background: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive human malignancies with a mean survival time of 6 months regardless of treatment. Aim: To present a case of locally advanced anaplastic thyroid carcinoma with long-term survival. A 10-year literature review of locally advanced ATC with long-term survival (more than 2 years) is also presented. Case presentation: We present a case of locally advanced anaplastic thyroid carcinoma (ATC) with tracheal invasion in a 67-year-old elderly Chinese man who was treated with radical surgery encompassing total thyroidectomy, neck dissection and tracheal resection followed by adjuvant radiotherapy. Long-term disease-free survival is more than 7 years to date. Conclusion: The prognosis of ATC remains poor as it is characterized by aggressive and extensive disease at presentation, the inability in most patients to perform radical enough surgery in order to achieve clear margins, high morbidity of complete extirpation and limited response to radiotherapy or chemotherapy. However, if complete surgical resection is possible, patients should be treated aggressively with a combination of surgery and adjuvant radiotherapy.

Tracheal Leiomyoma: A Rare Entity &Role of Diode Laser in Its Management

Primary leiomyoma of the trachea is a rare disease which is of smooth muscle in origin. Presenting symptoms depend on the location and size of the tumor. Here we are presenting a 45-year-old female, who was misdiagnosed and being treated for bronchial asthma presented to our institution with stridor. Her x-ray and Computed Tomography of neck showed tracheal mass & biopsy reported leiomyoma. Objective of this presentation is to report tracheal leiomyoma which is a rare clinical entity and how endoscopic resection of the tumor with diode laser helped us in attaining complete resection of tumor with minimal intra-operative and post-operative complications.

The Artificial Trachea Closest to the Real Thing

THREE months after the operation that gave her an artificial trachea, Mi Aiyun was able to breathe normally, and fit enough to work in the fields for three to four hours. On July 26, 2002, Zhao Fengrui, designer of the artificial trachea and main operating surgeon, announced that his was the world’s first tracheal prosthesis capable of integrating completely with the human trachea.Six years ago, Mi Aiyun, a 48-year-old

An Active Endoscopy Robotic System for Direct Tracheal Inspection

The development of active endoscopy techniques is one important area of medical robot.This paper designed a new flexible and active endoscopy robotic system for direct tracheal inspection.The mobile mechanism of the robot is based on the inchworm movement actuated by pneumatic rubber actuator.There are five air chambers controlled independently,by adjusting pressures in air chambers,the robot can move in a straight mode or in a bending mode.The inspection sensors and some therapy surgery tools can be equipped in the front of the robot.The prototype was made and its mechanical characteristics were analyzed.The robot could move smoothly in a small plastic tube,and the robot is respectable to be used for inspection in human trachea directly.

Reconstruction of trachea-esophagus vocalization by tunnel method in 12 cases

Objective To study the therapeutic effect of re construction in improving trachea-esophagus vocalization after total laryngecto-my.Method We reviewed the reconstruction of vo calization with trachea-esophagus tunnel in 12cases patients of total l aryngectomy,i.e.a triangular mucous valve was made by i ncision of the posterior wall of the t rachea with the correlative anterio r wall of the esophagus made into a tunnel and the mucous valve would vocalize.Result11of the 12cases obtained successfu l vocalization,counting for 91%of t he total.Atresia of the vocalizing valve occurred in o ne case.Conclusion Trachea-esophagus tunnel vocaliza tion reconstruction has better therapeutic effect with good vocalization effect and fewer c omplications and easily performed.It avoided the shortcomings of necro sis and atresia of the vocalization v alve and pharyngeal fistula formation,a nd the complexity of exchange of artificial vocalization tube again and a gain.

Surgery in tracheal tumors:thoracic surgeon’s point of view

The trachea is an anatomical structure of 10–12 cm of length in adults,which could appear just a simple conduit that brings the air to the lungs,but it is a very complex organ with a lot of functions and is supplied by many arterial branches arising from inferior thyroid artery,bronchial,intercostal arteries or direct branches from descending aorta,that create a vascular reticulum entering inside and feeding the ciliated pseudostratified columnar epithelium.The literature search has been made by using keywords“Tracheal tumors”,“Trachea surgery”,“Carina surgery”,“Engineered trachea”.We selected 74 articles from 15,191 papers.According to the literature search,we can say that,because of its own structure,it’s not simple to resect and reconstruct the trachea by direct end-to-end anastomosis,especially for more than 50%of its length and it cannot be easily replaced or transplanted.Although surgery is not the only possible therapy,the radiotherapy and the endoscopic treatments are so far from guarantee an adequate survival,and they are usually employed as adjuvant therapies after surgery or they are reserved to non-surgical patients for medical problems or oncological criteria.To overcome the surgical limits in direct reconstruction,have been developed different autogenic or allogenic grafts and nowadays there are different vascularized biocompatible scaffolds till the tissue engineered neotrachea,but more studies are still needed to standardize a valid reconstructive system for tracheal major resections or transplantation.

薄层CT多征象联合多平面重组诊断气管支气管结核

目的 观察薄层CT多征象联合多平面重组(MPR)诊断气管支气管结核(TBTB)的价值。方法 回顾性分析234例接受胸部薄层CT扫描的TBTB患者并行MPR,观察病变直接与间接表现;比较轴位平扫CT(直接观察法)与其联合MPR(联合观察法)的诊断效能。结果 直接观察法诊断TBTB的敏感度、特异度、阳性预测值、阴性预测值及准确率分别为38.88%(201/517)、98.13%(1 789/1 823)、85.53%(201/235)、84.99%(1 789/2 105)及85.04%(1 990/2 340),联合观察法上述各项分别为91.10%(471/517)、98.85%(1 802/1 823)、95.54%(471/493)、97.51%(1 802/1 848)及97.14%(2 273/2 340);2种方法间敏感度、阳性预测值、阴性预测值及准确率差异均有统计学意义(P均<0.001),而特异度差异无统计学意义(P>0.05)。结论 根据薄层CT多征象联合MPR可有效诊断TBTB。