Hyperelastic modeling of swelling in fibrous soft tissue with application to tracheal angioedema.

Angioedema, the rapid swelling of under-skin tissue, is typically triggered by complex biochemical processes that disrupt an original steady state filtration of liquid through the tissue. Swelling stabilizes once a new steady state is achieved in which the tissue has significantly increased liquid content. These processes are controlled by events at the molecular to the cellular length scale. For describing consequences at organ level length scales it is useful to invoke consolidated continuum mechanics treatments within a generalized hyperelastic framework. We describe the challenges associated with such modeling and demonstrate their use in the context of tracheal angioedema. The trachea is modeled as a two layered cylindrical tube. The inner layer and outer layer represent the soft mucosal tissue and the stiffer cartilaginous tissue respectively. Axially oriented fibers contribute anisotropy to the inner layer, and the swelling is largely confined to this layer. A boundary value problem is formulated; existence and uniqueness is verified. Numerical solutions track airway constriction as a function of mucosal swelling.

Association Between Expiratory Central Airway Collapse and Respiratory Outcomes Among Smokers.

IMPORTANCE: Central airway collapse greater than 50% of luminal area during exhalation (expiratory central airway collapse [ECAC]) is associated with cigarette smoking and chronic obstructive pulmonary disease (COPD). However, its prevalence and clinical significance are unknown. OBJECTIVE: To determine whether ECAC is associated with respiratory morbidity in smokers independent of underlying lung disease. DESIGN, SETTING, AND PARTICIPANTS: Analysis of paired inspiratory-expiratory computed tomography images from a large multicenter study (COPDGene) of current and former smokers from 21 clinical centers across the United States. Participants were enrolled from January 2008 to June 2011 and followed up longitudinally until October 2014. Images were initially screened using a quantitative method to detect at least a 30% reduction in minor axis tracheal diameter from inspiration to end-expiration. From this sample of screen-positive scans, cross-sectional area of the trachea was measured manually at 3 predetermined levels (aortic arch, carina, and bronchus intermedius) to confirm ECAC (>50% reduction in cross-sectional area). EXPOSURES: Expiratory central airway collapse. MAIN OUTCOMES AND MEASURES: The primary outcome was baseline respiratory quality of life (St George's Respiratory Questionnaire [SGRQ] scale 0 to 100; 100 represents worst health status; minimum clinically important difference [MCID], 4 units). Secondary outcomes were baseline measures of dyspnea (modified Medical Research Council [mMRC] scale 0 to 4; 4 represents worse dyspnea; MCID, 0.7 units), baseline 6-minute walk distance (MCID, 30 m), and exacerbation frequency (events per 100 person-years) on longitudinal follow-up. RESULTS: The study included 8820 participants with and without COPD (mean age, 59.7 [SD, 6.9] years; 4667 [56.7%] men; 4559 [51.7%] active smokers). The prevalence of ECAC was 5% (443 cases). Patients with ECAC compared with those without ECAC had worse SGRQ scores (30.9 vs 26.5 units; P < .001; absolute difference, 4.4 [95% CI, 2.2-6.6]) and mMRC scale scores (median, 2 [interquartile range [IQR], 0-3]) vs 1 [IQR, 0-3]; P < .001]), but no significant difference in 6-minute walk distance (399 vs 417 m; absolute difference, 18 m [95% CI, 6-30]; P = .30), after adjustment for age, sex, race, body mass index, forced expiratory volume in the first second, pack-years of smoking, and emphysema. On follow-up (median, 4.3 [IQR, 3.2-4.9] years), participants with ECAC had increased frequency of total exacerbations (58 vs 35 events per 100 person-years; incidence rate ratio [IRR], 1.49 [95% CI, 1.29-1.72]; P < .001) and severe exacerbations requiring hospitalization (17 vs 10 events per 100 person-years; IRR, 1.83 [95% CI, 1.51-2.21]; P < .001). CONCLUSIONS AND RELEVANCE: In a cross-sectional analysis of current and former smokers, the presence of ECAC was associated with worse respiratory quality of life. Further studies are needed to assess long-term associations with clinical outcomes.

Dyspnea, Dysphonia, and Cough: Varied Presentations of Tracheobronchopathia Osteochondroplastica.

OBJECTIVES: Tracheobronchopathia osteochondroplastica (TPO) is an uncommon, benign disease consisting of submucosal, osteocartilaginous nodules that project into the tracheal lumen. Far less commonly, these nodules can occur outside the tracheal cartilage. This case series discusses the wide range of symptoms and treatments of the disease. METHODS: Three patients presented to the laryngology clinic with 3 varied presentations of TPO, including dyspnea, dysphonia, and cough. These patients were evaluated, subsequently diagnosed with TPO, and treated accordingly. RESULTS: Two of the 3 patients presented with extratracheal lesions presenting in the cricoid and thyroid cartilages. The patient presenting with symptoms of dysphonia was found to have bilateral TPO exclusively within the thyroid cartilage, which has never been reported previously. After undergoing a partial thyroid cartilage resection removing the bulk of the lesion, the patient's symptoms drastically improved. CONCLUSION: While TPO may be a rare diagnosis in the general otolaryngologist practice, symptoms frequently bring patients into the otolaryngologist's clinic, and an awareness of the disease can help minimize unnecessary interventions and allow the surgeon to appropriately counsel patients.

Operative technique for tracheo-innominate artery fistula repair.

Tracheo-innominate artery fistula is fatal unless treated surgically. We describe our surgical approach and results in seven patients. The average patient age was 15.7 years; all patients had prior severe neurological deficits. Three of seven patients were in hemorrhagic shock; control of preoperative bleeding was achieved with tracheostomy tube cuff overinflation. The innominate artery and the trachea were exposed through a collar incision and partial upper sternotomy. The innominate artery was divided at the aortic arch and at the bifurcation, with one exception. Cerebral blood flow was monitored by the blood pressure difference in the bilateral upper extremities and by near-infrared spectroscopy. The tracheal fistula was left adherent to the innominate artery in all but one patient. All patients were discharged without new neurologic deficits or severe morbidity. Overall survival was 84% at 37 months, without any vascular, tracheal, or neurological events.

What's in a name? Expiratory tracheal narrowing in adults explained.

Tracheomalacia, tracheobronchomalacia, and excessive dynamic airway collapse are all terms used to describe tracheal narrowing in expiration. The first two describe luminal reduction from cartilage softening and the latter refers to luminal reduction from exaggerated posterior membrane movement. Expiratory tracheal narrowing is a frequent occurrence that can cause symptoms of airway obstruction, such as dyspnoea, wheeze, and exercise intolerance. The accurate diagnosis and quantification of expiratory tracheal narrowing has important aetiological, therapeutic, and prognostic implications. The reference standard for diagnosis has traditionally been bronchoscopy; however, this method has significant limitations. Expiratory tracheal disorders are readily detected by four-dimensional dynamic volume multidetector computed tomography (4D-CT), an emerging, non-invasive method that will potentially enable detection and quantification of these conditions. This review discusses the morphological forms of expiratory tracheal narrowing and demonstrates the utility of 4D-CT in the diagnosis, quantification, and treatment of these important conditions.

An unusual cause for globus sensation: infected tracheal diverticulum with abscess formation.

CASE REPORT: A 43-year-old woman presented with a 3-week history of globus sensation and malaise. A computed tomography scan of her neck showed a large right paratracheal abscess secondary to an infected tracheal diverticulum. The patient was admitted under the ENT surgical team, and underwent incision and drainage of the abscess. There were no post-operative complications and she was discharged home after 2 days, on oral antibiotics. CONCLUSION: This case demonstrates that a tracheal diverticulum may become infected and present as a cervical abscess. To our knowledge, this is the fourth reported case in the international literature of abscess formation related to an infected tracheal diverticulum.

Conservative management of canine tracheal collapse with stanozolol: a double blinded, placebo control clinical trial.

The objective of this study is to determine the efficacy of stanozolol in the treatment of tracheal collapse (TC) in dogs, which is the analogous disease to tracheomalacia (TM) in humans. Twenty-two dogs with endoscopically confirmed and graded TC were enrolled into five groups. Groups S1 (n=5), S2 (n=5) and S3 (n=4) with grade 1, 2 and 3 TC, respectively, received stanozolol orally for 75 days, while groups P1 (n=4) and P2 (n=4) with grade 1 and 2 TC, respectively, received placebo. The clinical score was evaluated every 15 days, whereas TC grade was reassessed at the end of the experiment. Clinical improvement was detected from the 30th day in S2 and S3 group dogs and from the 45th day in S1 group dogs and continued until the end of the experiment. Also, statistically significant differences were seen between S2 and P2 dogs from the 30th day, and between S1 and P1 dogs from the 60th day, and continued until the end of the study. Amelioration of the TC grade was seen in 13 of 14 (92.9%) dogs, which received stanozolol. Of the 14 dogs, 57.1% were cured and 35.8% demonstrated a less severe TC grade, while only one dog (7.1%) did not improve at all. Stanozolol seems to be an effective drug in the management of canine TC and it may have potential for use in humans with TM.

Translating tissue-engineered tracheal replacement from bench to bedside.

There are a variety of airway diseases with different clinical settings, which may extend from a surgical approach to total organ replacement. Tissue engineering involves modifying cells or tissues in order to repair, regenerate, or replace tissue in the body and seems to be a promising approach for airway replacement. The successful implantation of stem-cell-based tissue-engineered trachea in a young woman with end-stage post-tuberculosis left main bronchus collapse serves as a prototype for the airway tissue-engineered-based approach. The trachea indeed could represent a perfect model system to investigate the translational aspects of tissue engineering, largely due to its low-oxygen needs. This review highlights the anatomy of the airways, the various disease conditions that cause damage to the airways, elaborates on the essential components of the tissue-engineering approach, and discusses the success of the revolutionary trachea transplantation approach.

Excessive dynamic airway collapse for the internist: new nomenclature or different entity?

Excessive dynamic airway collapse (EDAC) refers to abnormal and exaggerated bulging of the posterior wall within the airway lumen during exhalation. This condition is pathological if the reduced airway lumen is <50% of the normal. It is a relatively new disease entity that is recognised more easily now with the increased use of multi-detector row CT. EDAC is often asymptomatic and diagnosed incidentally. Although the term excessive dynamic airway collapse is often used interchangeably with tracheobronchomalacia, both entities represent morphologically and physiologically distinct processes. Considering the confusion between the two entities, the prevalence of stand-alone EDAC remains unclear. The prevalence of tracheobronchomalacia and EDAC depends upon the patient population, associated comorbidities and underlying aetiologies, diagnostic tools used and criteria used to define the airway collapse. This review defines EDAC and describes its pathophysiology, precipitating factors, associated symptoms and potential treatments.

A 57-Year-Old Man With Stridor and Critical Tracheal Narrowing.

CASE PRESENTATION: A 57-year-old man with a history of polysubstance use presented with shortness of breath, wheezing, productive cough, subjective fever, and chills of 3-day duration. Additionally, he reported worsening shortness of breath for the last 3 months. Of note, the patient was reported to have had, in the previous 6 months, two episodes of pneumonia that was treated with antibiotics and steroids. He was also diagnosed several years prior with adult-onset asthma due to intermittent wheezing and was prescribed an albuterol inhaler. The albuterol did not help relieve his wheezing, and he stopped refilling it.

Localised laryngotracheal amyloidosis: a differential diagnosis not to forget.

We present a case of multifocal laryngotracheal amyloidosis (LTA) in a 43-year-old man with persistent and progressive dysphonia and dyspnoea, and a first inconclusive histology. Although laryngeal amyloidosis accounts for fewer than 1% of all benign laryngeal tumours, it is in fact the most common site of amyloid deposition in the head, neck and respiratory tract. The clinical scenario is non-specific and diagnosis depends on a high degree of suspicion and on histology. Imaging is useful in mapping lesions, which are often more extensive than they appear during laryngoscopy. Despite being a benign entity, the prognosis is variable with a high-rate and long-latency recurrences, requiring long-term follow-up.

[Estimation of the main indices of external respiration in patients with mediastinal compression syndrome, caused by mediastinal tumors].

The results of estimation of the external respiration function (ERF) in 334 patients, treated in 1992-2007 in the clinic for mediastinal compression syndrome, caused by mediastinal tumors (MT), are adduced. There were delineated the main trends of investigation of the pulmonary ventilation capacity in patients with tracheobronchial obstruction, caused by MT. The concept of optimal estimation of ERF in such patients was formulated. The ERF indices estimation permits to determine the ways of operation security enhancement as well as prognosis conduction and prophylaxis of intra- and postoperative complications occurrence.

APEC infection affects cytokine-cytokine receptor interaction and cell cycle pathways in chicken trachea.

Avian pathogenic Escherichia coli (APEC) can lead to extraintestinal disease in avian species via respiratory tract infection. However, the regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium remains unknown. In this study, we examined pathological changes in chicken trachea at different infection times (4, 8, 12 and 24 h). The RNA sequencing of APEC infection group and the PBS group (negative control) of chicken trachea epithelium were analysed. Our studies revealed that the oedema, heterophil infiltration and hyperaemia appeared at 8 and 12 h post APEC infection. And the hyperaemia phenomenon and heterophilic granulocyte infiltration disappeared at 24 h post infection. Then RNA sequencing showed many genes were dynamically expressed in the APEC infection group. At 4, 8 and 12 h post infection, the mRNA of differentially expressed genes were enriched by cytokine-cytokine receptor interaction and the toll-like receptor signalling pathway. The cell cycle pathway was enriched at 24 h post infection. Altogether, these findings suggest that APEC infection induces pathological change in the chicken trachea, the mRNA of differentially expressed genes participating in inflammation and hyperplasia signalling pathways. Which not only provide more evidence for regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium, but also facilitate the effective management of APEC infections in poultry through trachea.

Clinical Characteristics of Six Cases of Tracheobronchopathia Osteochondroplastica.

Objective: To investigate the clinical characteristics of tracheobronchopathia osteochondroplastica (TO). Methods: The clinical data of six patients with TO from November 2016 to November 2018 were retrospectively analyzed. The etiology, clinical manifestations, diagnosis, and treatment of TO were summarized. Result: All six patients with TO were middle-aged males, confirmed by histopathological examination. The main clinical symptoms were cough, sputum, hemoptysis, chest pain, and repeated pulmonary infection. Some patients could make a preliminary diagnosis by chest CT, and bronchoscopy showed that TO mainly occurred in the trachea and the main bronchus and was more likely to invade the right bronchus. The treatment mainly includes anti-infection, phlegm-resolving, and other symptomatic treatment. Conclusion: TO is a benign disease predisposing to adults, and males are more likely to be affected. Its clinical manifestations are lack of specificity, and the cause may be related to chronic infection. Bronchoscopy combined with histopathological examination is the primary approach for the diagnosis of TO. There is no well-recognized treatment standard for TO, and the judgment of therapeutic effect is inconsistent. It is necessary to improve the understanding of this disease from a clinical perspective.

Prevalence of pharyngeal, laryngeal and tracheal disorders in thoroughbred racehorses, and effect on performance.

Endoscopic examinations were performed on 1005 thoroughbred racehorses in South Africa a mean (sd) 24 (12.3) minutes after racing, to determine the prevalence of pharyngeal, laryngeal and tracheal disorders, and to determine the relationship of these disorders with performance (number of wins and placed finishes). Overall, there was a low prevalence of grade 2 and 3 laryngeal function (LF) (2.2 per cent), grade 4 LF (0.6 per cent), epiglottic entrapment (1.3 per cent), subepiglottic cyst (0.2 per cent) and epiglottic deformity (0.6 per cent), while a higher prevalence of grade 2 to 4 pharyngeal lymphoid hyperplasia (PLH) (63 per cent), laryngeal debris (43.5 per cent), tracheal debris (21.9 per cent), tracheal mucus (99.5 per cent) and tracheal cartilaginous nodules (TCNs) (6.8 per cent) was observed. Performance was not affected by the presence of epiglottic deformity, grade 2 and 3 LF, grade 4 LF, debris within the trachea or larynx, or epiglottic entrapment. Grade 3 PLH occurred in younger racehorses; performance was impaired in horses with grade 2 and 3 PLH. Furthermore, TCNs were more prevalent in male racehorses and were associated with better performance.

Cough syncope and tracheal compression secondary to a retrosternal goitre: looking for a pulmonary embolism.

A 51-year-old man presented acutely with recurrent bouts of coughing associated with transient and brief loss of consciousness consistent with cough syncope, mild stridor and a recent history of a respiratory tract infection. A chest X-ray demonstrated tracheal narrowing. His D-dimer was negative. A non-contrast CT scan of the chest demonstrated a large retrosternal goitre causing tracheal compression, and further investigation with a contrast-enhanced CT scan of the neck and chest demonstrated an incidental finding of a large pulmonary embolus (PE). The full extent of the PE was determined through performing a CT pulmonary angiography. Doppler ultrasound demonstrated a left leg deep vein thrombosis as the primary cause of the PE. His cough syncope improved in response to anticoagulation treatment, to the point where he could be safely discharged home. He had a further significant improvement in symptoms following an elective hemithyroidectomy for retrosternal goitre.