A case of tracheobronchial amyloidosis with emphasis on differential diagnosis.

Tracheobronchial amyloidosis is a manifestation of amyloidosis of the respiratory tract characterized by focal or diffuse deposition of amyloid in the submucosa of the trachea and proximal bronchi. Tracheobronchial amyloidosis is not associated with systemic amyloidosis or pulmonary parenchymal involvement. It affects predominantly men aged over fifty. Depending on the part of the tracheobronchial tree that is affected, stenosis of the airways causes a variety of unspecific symptoms. Diagnosis is reached by means of typical presentation in CT scan followed by bronchoscopy and histopathological confirmation. Tracheobronchial amyloidosis should be borne in mind in the differential diagnosis of patients with chronic cough and/or dyspnea or recurrent respiratory infections.

[Risk factors for pulmonary atelectasis in adults with tracheobronchial tuberculosis].

Objective: To investigate the risk factors for pulmonary atelectasis in adults with tracheobronchial tuberculosis(TBTB). Methods: Clinical data of adult patients (≥18 years old) with TBTB from February 2018 to December 2021 in Public Health Clinical Center of Chengdu were retrospectively analyzed. A total of 258 patients were included, with a male to female ratio of 1∶1.43. The median age was 31(24, 48) years. Clinical data including clinical characteristics, previous misdiagnoses/missed diagnoses before admission, pulmonary atelectasis, the time from symptom onset to atelectasis and bronchoscopy, bronchoscopy and interventional treatment were collected according to the inclusion and exclusion criteria. Patients were divided into two groups according to whether they had pulmonary atelectasis. Differences between the two groups were compared. Binary logistic regression was used to analyze the risk factors for pulmonary atelectasis. Results: The prevalence of pulmonary atelectasis was 14.7%, which was most common in the left upper lobe (26.3%). The median time from symptom onset to atelectasis was 130.50(29.75,358.50)d, and the median time from atelectasis to bronchoscopy was 5(3,7)d. The median age, the proportion of misdiagnosis of TBTB before admission, and the time from symptom onset to bronchoscopy in the atelectasis group were higher than those without atelectasis, and the proportion of receiving bronchoscopy examination and interventional therapy previously, and the proportion of pulmonary cavities were lower than those without atelectasis (all P<0.05). The proportions of cicatrices stricture type and lumen occlusion type in the atelectasis group were higher than those without atelectasis, while the proportions of inflammatory infiltration type and ulceration necrosis type were lower than those without atelectasis (all P<0.05). Older age (OR=1.036, 95%CI: 1.012-1.061), previous misdiagnosis(OR=2.759, 95%CI: 1.100-6.922), longer time from symptom onset to bronchoscopy examination (OR=1.002, 95%CI: 1.000-1.005) and cicatrices stricture type (OR=2.989, 95%CI: 1.279-6.985) were independent risk factors for pulmonary atelectasis in adults with TBTB (all P<0.05). Of the patients with atelectasis who underwent bronchoscopy interventional therapy, 86.7% had lung reexpansion or partial reexpansion. Conclusions: The prevalence of pulmonary atelectasis is 14.7% in adult patients with TBTB. The most common site of atelectasis is left upper lobe. The TBTB type of lumen occlusion is complicated by pulmonary atelectasis in 100% of cases. Being older, misdiagnosed as other diseases, longer time from onset of symptoms to bronchoscopy examination, and being the cicatrices stricture type are factors for developing pulmonary atelectasis. Early diagnosis and treatment are needed to reduce the incidence of pulmonary atelectasis and increase the rate of pulmonary reexpansion.

Notch signaling in the mammalian respiratory system, specifically the trachea and lungs, in development, homeostasis, regeneration, and disease.

The respiratory system has ideal tissue structure and cell types for efficient gas exchange to intake oxygen and release carbon dioxide. This complex system develops through orchestrated intercellular signaling among various cell types, such as club, ciliated, basal, neuroendocrine, AT1, AT2, endothelial, and smooth muscle cells. Notch signaling is a highly conserved cell-cell signaling pathway ideally suited for very short-range cellular communication because Notch signals are transmitted by direct contact with an adjacent cell. Enthusiastic efforts by Notch researchers over the last two decades have led to the identification of critical roles of this signaling pathway during development, homeostasis, and regeneration of the respiratory system. The dysregulation of Notch signaling results in a wide range of respiratory diseases such as pulmonary artery hypertension (PAH), chronic obstructive pulmonary disease (COPD), interstitial pulmonary fibrosis (IPF), and lung cancer. Thus, a deep understanding of the biological functions of Notch signaling will help identify novel treatment targets in various respiratory diseases.

Does Adenovirus and Coxsackie B Virus Infection Play a Role in Tracheobronchopathia Osteochondroplastica (TO).

Background: Tracheobronchopathia osteochondroplastica (TO) is a rare benign disease. We report a case of TO. Methods: Chest CT scan and bronchoscope with biopsy was performed for diagnosis and blood tests explored for the latent etiology. Results: Chest CT scan and bronchoscopic images showed multiple nodular protrusions in the trachea and main bronchi. Histopathology demonstrated sub-mucosal ossification and inflammatory cell infiltration. Laboratory inspection showed adenovirus and coxsackie B virus IgM antibodies were positive. Conclusions: The patient recently had a virus infection and inflammation was observed in histopathology, which indicated adenovirus and coxsackie B virus may play a role in the occurrence or exacerbation of TO.

Feasibility of Bioengineered Tracheal and Bronchial Reconstruction Using Stented Aortic Matrices.

Importance: Airway transplantation could be an option for patients with proximal lung tumor or with end-stage tracheobronchial disease. New methods for airway transplantation remain highly controversial. Objective: To establish the feasibility of airway bioengineering using a technique based on the implantation of stented aortic matrices. Design, Setting, and Participants: Uncontrolled single-center cohort study including 20 patients with end-stage tracheal lesions or with proximal lung tumors requiring a pneumonectomy. The study was conducted in Paris, France, from October 2009 through February 2017; final follow-up for all patients occurred on November 2, 2017. Exposures: Radical resection of the lesions was performed using standard surgical techniques. After resection, airway reconstruction was performed using a human cryopreserved (-80°C) aortic allograft, which was not matched by the ABO and leukocyte antigen systems. To prevent airway collapse, a custom-made stent was inserted into the allograft. In patients with proximal lung tumors, the lung-sparing intervention of bronchial transplantation was used. Main Outcomes and Measures: The primary outcome was 90-day mortality. The secondary outcome was 90-day morbidity. Results: Twenty patients were included in the study (mean age, 54.9 years; age range, 24-79 years; 13 men [65%]). Thirteen patients underwent tracheal (n = 5), bronchial (n = 7), or carinal (n = 1) transplantation. Airway transplantation was not performed in 7 patients for the following reasons: medical contraindication (n = 1), unavoidable pneumonectomy (n = 1), exploratory thoracotomy only (n = 2), and a lobectomy or bilobectomy was possible (n = 3). Among the 20 patients initially included, the overall 90-day mortality rate was 5% (1 patient underwent a carinal transplantation and died). No mortality at 90 days was observed among patients who underwent tracheal or bronchial reconstruction. Among the 13 patients who underwent airway transplantation, major 90-day morbidity events occurred in 4 (30.8%) and included laryngeal edema, acute lung edema, acute respiratory distress syndrome, and atrial fibrillation. There was no adverse event directly related to the surgical technique. Stent removal was performed at a postoperative mean of 18.2 months. At a median follow-up of 3 years 11 months, 10 of the 13 patients (76.9%) were alive. Of these 10 patients, 8 (80%) breathed normally through newly formed airways after stent removal. Regeneration of epithelium and de novo generation of cartilage were observed within aortic matrices from recipient cells. Conclusions and Relevance: In this uncontrolled study, airway bioengineering using stented aortic matrices demonstrated feasibility for complex tracheal and bronchial reconstruction. Further research is needed to assess efficacy and safety. Trial Registration: clinicaltrials.gov Identifier: NCT01331863.

Patterns of Tracheal Compression in the Thorax of the Ground Beetle, Platynus decentis.

Insects breathe using a system of tracheal tubes that ramify throughout the body. Rhythmic tracheal compression (RTC), the periodic collapse and reinflation of parts of the system, has been identified in multiple taxa, but little is known about the precise dynamics of tube deformation cycles. It has been hypothesized that during RTC, compression occurs synchronously throughout the body, but specific kinematic patterns along the length of individual tracheae may vary. Tube collapse or reinflation that proceeds unidirectionally along the length of a tube may function as a pump to transport air, augmenting gas exchange. This study aims to characterize patterns of tracheal compression in one species of carabid beetle, Platynus decentis, to test the hypothesis of directional compression. The internal tracheae of living beetles were visualized using synchrotron x-ray phase contrast imaging at the Advanced Photon Source, Argonne National Laboratory. X-ray video results show that tracheal compression is characterized by the formation of discrete, buckled regions in the tube wall, giving the appearance of "dimpling." Dimple formation in the main dorsal tracheal trunks of the prothorax occurred as two semi-circular fronts that spread symmetrically or directionally along the longitudinal tube axis. In the transverse axis, the main ventral trunks collapsed in the lateral direction, whereas the dorsal trunks collapsed dorsoventrally. Along the length of the ventral thoracic tracheal trunks, collapse and reinflation occurred synchronously in the majority of cycles (75 percent), not sequentially. Synchronous longitudinal compression and consistent dimple formation kinematics within an animal suggest that Platynus decentis employs a stereotyped mechanism to produce cycles of tracheal collapse and reinflation, but such compression does not function as a unidirectional pump, at least along the length of the local trachea. Further data on spiracle opening and closing patterns and internal pressures within the tracheal system are required to determine actual airflow patterns within the body.

[IgG(4)-related disease involving the trachea and paratracheal soft tissue: a case report and literature review].

Objective: To investigate the clinical data of a patient with IgG(4)-related disease involving the trachea and paratracheal soft tissue and review the literature so as to improve the understanding level of the disorder. Methods: To analyze the clinical manifestation, laboratory examination, imaging, histopathology, treatment and prognosis of a patient with IgG(4)-related disease trachea and paratracheal soft tissue involved, who was admitted to the Department of Respiratory and Critical Care Medicine at Beijing Chaoyang Hospital. The relevant literatures were reviewed. Results: A 18-year-old female was admitted with chief complaint of cough, dyspnea, and neck mass. Neck CT suggested that tracheal stenosis was caused by surrounded soft tissue. Paratracheal mass biopsy showed dense collagen fibers with infiltration of many lymphocytes and plasma cells. Immunohistochemical stain found that IgG(4)-positive plasma cells were >50/high power field (HPF) and a ratio of IgG(4)/IgG positive cells was over 40% .The level of serum IgG(4) was significantly increased (2 930 mg/L). She was diagnosed as IgG(4)-related disease. The patient was treated with 80 mg intravenous methylprednisolone per day for three days, then prednisone 40 mg daily oral. Her dyspnea was significantly relieved.One month later, CT scan showed that the cervical tracheal stenosis was significantly improved. We identified 20 cases of IgG(4)-related disease involving the trachea and paratracheal soft tissue from databases, in which only 1 case was similar as this patient. The other 19 cases were of extratracheal involvement. Elevated serum IgG(4) was detected in 11/12 patients. Most patients were treated with glucocorticoid, some combined with immunosuppressive agents and rituximab. The clinical outcome was good. Conclusion: IgG(4)-related disease involving the trachea and paratracheal soft tissue is a rare condition. Serum IgG(4) level and histopathology should be considered for diagnosis. Glucocorticoid is effective.

[Tracheal Surgery]. / Chirurgie der Trachea.

Surgery of the trachea is a specialised field in which many disciplines work jointly due to the variety of indications and the extended topography. Not only because of its particular functional importance, but also because of its complex morphology, anatomy and physiology, this organ represents a special therapeutic challenge. A variety of diseases require surgical procedures of the trachea; the therapeutic strategy is influenced both by the disease itself as well as patient-dependent parameters. Regardless of the nature of the underlying disorder, good results require a high level of expertise in airway management, a careful diagnosis and interventional planning as well as an experienced surgical team that masters extended operative techniques. An optimal treatment decision always requires a multidisciplinary assessment of the patient's individual situation by interventional pulmonologists, thoracic surgeons, visceral surgeons, ENT (ear, nose and throat) surgeons and anaesthesiologists.

Histological Benefits of Sealants in Tracheal Lesions in Wistar Rats.

INTRODUCTION: The purpose of our study was to compare the effect, on the inflammatory response and fibrosis formation, of four commercially available sealant products applied on an injured trachea in a Wistar rat population. MATERIALS AND METHODS: We compared four different sealants: cyanoacrylate, fibrin/thrombin, albumin/glutaraldehyde, and polyethylene glycol-based hydrogel (PEG). Rats were organized into six groups of similar size. Four of them were experimental, one was a baseline control group (BCG), and the sixth one was a reference control group (RCG). The RCG and experimental groups underwent the same surgical intervention with tracheal puncture, but no sealant was applied in the RCG. The BCG underwent the same cervical and peritracheal dissection without tracheal puncture. Rats were euthanized after eight weeks. RESULTS: The operation was performed on 54 rats, of which 12 died, leaving a final sample of 42 rats. Macroscopic analysis revealed no superficial tracheal or vascular fistulas, nor signs of local abscess. Although the groups treated with cyanoacrylate, fibrin/thrombin, and albumin/glutaraldehyde showed some degree of fibrosis, the treated area of the PEG group showed neither inflammatory nor scar signs. Microscopic assessment of the BCG and RCG showed no remarkable findings. With the exception of the PEG group, which had a light fibrosis and poor inflammatory response as did the BCG and RCG groups, the other groups showed varying degrees of fibrosis and cicatrization. CONCLUSION: Our study showed that the group treated with PEG had a mild inflammatory and fibrotic response, which is useful in tracheal or tracheobronchial surgical procedures. However, groups treated with cyanoacrylate, fibrin/thrombin, and albumin/glutaraldehyde showed fibrosis and cicatrization.

Malignant Melanoma of the Syrinx and Liver in an African Grey Parrot ( Psittacus erithacus erithacus).

A 20-year-old, female African grey parrot ( Psittacus erithacus erithacus) was examined because of ataxia and weakness. Radiographs were unremarkable, and results of a complete blood cell count revealed leukocytosis and heterophilia. Because of poor response to therapy with meloxicam, doxycycline, and enrofloxacin; deteriorating condition; and poor prognosis, the parrot was euthanatized. Postmortem examination revealed 2 dark red nodules in the liver. No grossly visible mass was observed in the syrinx. Histologic examination of the liver and syrinx revealed similar foci of round, oval, and polygonal cells exhibiting severe pleomorphism, with poorly demarcated cytoplasmic borders and moderate amounts of eosinophilic cytoplasm containing brown to black granules (melanin). The mitotic index was 15. The presence of melanin pigment is consistent with a diagnosis of melanoma at both sites. The multifocal distribution and intravascular invasion indicate metastasis; however, the site of origin was unknown. To our knowledge, this is the first recorded case of melanoma in an avian syrinx.

Imaging of Large Airways Disorders.

OBJECTIVE: Recent technical advances, including the routine use of CT thin sections and techniques such as 2D minimum-intensity-projection and 3D volume images, have increased our ability to detect large airways diseases. Furthermore, dedicated CT protocols allow the evaluation of dynamic airway dysfunction. CONCLUSION: With diseases of the large airways more commonly seen in daily practice, it is important that radiologists be familiar with the appearances, differential diagnosis, and clinical implications of these entities.

Fatal tracheal aspergillosis during rituximab combined chemotherapy for diffuse large B-cell lymphoma that developed after lung transplantation.

Invasive tracheal aspergillosis (ITA) is an infection that is unique to patients who have undergone lung transplantation (LT). Although the activity of this disease often appears on imaging, we encountered a case of ITA that became exacerbated, despite few computed tomography (CT) findings, during rituximab combined chemotherapy for diffuse large B-cell lymphoma. ITA developed during immunosuppressive therapy after LT. Because CT findings may show false-negative results, bronchoscopy is recommended for such cases.

Computed tomography virtual bronchoscopy: normal variants, pitfalls, and spectrum of common and rare pathology.

A broad spectrum of pathologies that involve the laryngotracheobronchial airway and imaging plays a crucial role in evaluating these abnormalities. Computed tomography with virtual bronchoscopy has been found to be very helpful in defining the location, extent, and nature of these lesions, and is increasingly being used even in patients with contraindications for fiberoptic bronchoscopy and laryngoscopy. Ionizing radiation, associated with virtual bronchoscopy, can be minimized by using low-dose multidetector computed tomography and hybrid iterative reconstruction techniques. Furthermore, retrospectively generated virtual bronchoscopy from a routinely acquired computed tomography data set eliminates additional cost and radiation. In the future, virtual bronchoscopy assisted with advanced navigational techniques will broaden the diagnostic and therapeutic landscape. This article presents the characteristic features of common and rare laryngotracheobronchial pathologies seen with virtual bronchoscopy.

[In vitro Cultivation of Functioning Passaged Ciliated Epithelium for Trachea Tissue Engineering].

BACKGROUND: Currently all tissue engineered trachea transplants had no ciliated epithelium until transplantation, and long-term temporary lack of mucociliary clearance leads to patients' condition decline and reduced life quality in postoperative period. So, the need for a better cultivation method and studying ciliated epithelium growth characteristics in cell culture increased rapidly. OBJECTIVE: The aim of our study was to investigate cultivation offunctionally complete passaged ciliated epitheliumfor trachea tissue engineering. METHODS: Human ciliated epithelium isolated from intraoperative bioptate was used for culturing in the special complex medium with morphological and functional characteristics evaluation. RESULTS: Ciliated epithelial cell-groups were obtained by culturing in the special complex medium. Generated cell-groups had ciliary activity and showed well-coordinated movement with functional characteristics similar to native epithelial tissue. The basic parameters of cell-activity were studied. CONCLUSION: Thus our study provides a new insight for the problem of ciliated epithelium in vitro culturing as well as developing the optimal laboratory method.

A rare case of rapidly enlarging tracheal lobular capillary hemangioma presenting as difficult to ventilate acute asthma during pregnancy.

BACKGROUND: Lobular Capillary Hemangioma (LCH) is a benign tumour that is known to be hormone responsive and have a relatively high incidence during pregnancy, the most common site being the gingival surfaces. A tracheal origin for this tumour is extremely rare, with no case reported so far in this patient population, and the only reported clinical presentation of tracheal LCH in the literature is with haemoptysis. CASE PRESENTATION: We describe a case of a 23-year-old known asthmatic who presented at 32 weeks gestation with life-threatening respiratory failure resembling acute severe asthma, requiring invasive ventilation which was extremely difficult. This was subsequently found to be due to a large tracheal LCH producing a ball-valve phenomenon and predominantly expiratory airflow limitation similar to acute asthma. The endotracheal tube was advanced past the lesion under bronchoscopic guidance, and urgent Caesarean section performed due to foetal distress. The tumour was subsequently debulked and the trachea stented, facilitated by bi-femoral veno-venous extra-corporeal membrane oxygenation with relatively low dose of heparin. CONCLUSION: To our knowledge, this is the first report of a unique presentation and management of largest tracheal LCH so far occurring during pregnancy. Pulmonary and critical care physicians should be aware of this unique differential of refractory asthma, the aggressive nature of this benign tumour due to hormonal influences during pregnancy, and feasibility of using bi-femoral veno-venous extra-corporeal membrane oxygenation with low dose heparin as a rescue, given the high risk of bleeding.

Prefabrication and prelamination strategies for the reconstruction of complex defects of trachea and larynx.

Complex tracheal and laryngeal defects can be reconstructed using prelamination and prefabrication techniques. Three clinical situations are described in detail in the article. In short segment restenosis defects within scarred surroundings, we restore the fibrocartilaginous defect with a radial forearm fascia flap prelaminated with buccal mucosa or cartilage. This provides a newly vascularized inner lining to the tracheal defect and restores the tubular convexity. For long segment defects we need a technique that can withstand respiratory forces. We use a heterotopic prefabrication strategy to vascularize a tracheal allograft wrapped in forearm fascia. Chimerism is created by replacing donor respiratory epithelium with buccal mucosa of the recipient. After orthotopic transfer, this chimerism allows immunosuppression to be tapered and stopped when bronchoscopy shows mucosal integrity of the new trachea, since the recipient epithelium replaces the allogeneic inner tracheal lining by means of a chronic rejection process. A distinct situation occurs after resection of a unilateral larynx tumor, which usually results in a total laryngectomy with loss of both vocal cords, since reconstruction of the hemilarynx is considered too complex. First, we prefabricate a nearby four-ring autologous tracheal segment using radial forearm fascia. In a second stage, this orthotopically vascularized trachea restores the laryngeal structure with the aim to conserve one vocal cord and thus speech. Orthotopic and heterotopic prelamination and prefabrication strategies offer efficient and reproducible solutions for the restoration of challenging short and long segment tracheal defects, as well as unilateral laryngeal defects. The series in this review article are based on previous studies and case reports. The level of evidence is III-"Study of nonconsecutive patients, without a universally applied gold standard: case-control study".

Reconstruction of the trachea.

This article reviews established methods of autologous tracheal reconstruction, the various synthetic prostheses that have been used in clinical practice, and briefly describes the latest developments in stem cell tracheal bioengineering and allogeneic tracheal transplantation. Reconstruction of the trachea is challenging due to its part cervical part thoracic location, proximity to major vessels, variable blood supply, and its constant colonization with bacteria. In cases of limited resection, primary anastomosis, autologous patch grafts, local advancement rotation flaps, and locoregional cutaneous and muscle flaps will often suffice. In more extensive resections, complex composite microsurgical reconstruction with a radial forearm free flap with cartilage grafts for skeletal support has proven to be viable and reliable. Synthetic tracheal prostheses, solid as well as porous, have been trialed with disappointing results. Infection, dislodgement, migration, and obstruction are not uncommon. Reconstruction with the cadaveric tracheal allografts and aortic allografts continue to be fraught with complications, specifically graft infections. Tracheal bioengineering and tracheal allotransplantation have emerged relatively recently. Despite early promising results, long-term outcome data on these new techniques are still lacking.