The "forgotten zone": acquired disorders of the trachea in adults

Acute myeloid leukemia: An unusual manifestation of the trachea

Objectives

Hematologic malignancy involving the trachea is rare. It is even less common for tracheal involvement to be the initial manifestation of this disease. We present a case report highlighting an unusual diagnosis of acute myeloid leukemia (AML) that first presented with prominent tracheal manifestations. There have been only three other published case reports of extramedullary AML with involvement of the trachea.

Methods

We discuss direct laryngoscopy and bronchoscopy findings, including pinkish-white irregular lesions, which were similar to findings described in the available literature for tracheal AML.

Results

Laboratory findings from our case are reported, including peripheral smear demonstrating 57% blasts and bone marrow biopsy confirming the diagnosis of AML, and the relevance of these findings is discussed.

Conclusion

In patients with unusual airway lesions, laboratory testing and a comprehensive airway evaluation including biopsy are necessary to narrow the differential diagnosis.

Level of Evidence

5.

Current diagnosis and treatment of salivary gland-type tumors of the lung

Salivary gland-type tumors of the lung are thought to originate from the submucosal exocrine glands of the large airways. Due to their rare occurrence, reports of their study are limited to small-scale or case reports. Therefore, daily clinical practices often require a search for previous reports. In the last 20 years, several genetic rearrangements have been identified, such as MYB::NF1B rearrangements in adenoid cystic carcinoma, CRTC1::MAML2 rearrangements in mucoepidermoid carcinoma, EWSR1::ATF1 rearrangements in hyalinizing clear cell carcinoma and rearrangements of the EWSR1 locus or FUS (TLS) locus in myoepithelioma and myoepithelial carcinoma. These molecular alterations have been useful in diagnosing these tumors, although they have not yet been linked to molecularly targeted therapies. The morphologic, immunophenotypic, and molecular characteristics of these tumors are similar to those of their counterparts of extrapulmonary origin, so clinical and radiologic differential diagnosis is required to distinguish between primary and metastatic disease of other primary sites. However, these molecular alterations can be useful in differentiating them from other primary lung cancer histologic types. The management of these tumors requires broad knowledge of the latest diagnostics, surgery, radiotherapy, bronchoscopic interventions, chemotherapy, immunotherapy as well as therapeutic agents in development, including molecularly targeted agents. This review provides a comprehensive overview of the current diagnosis and treatment of pulmonary salivary gland tumors, with a focus on adenoid cystic carcinoma and mucoepidermoid carcinoma, which are the two most common subtypes.

Challenges in diagnosis and management of central airway obstruction: Case series

Central airway obstruction often presents with respiratory symptoms identical to those of common respiratory diseases. Diagnosis of central airway obstruction is challenging in clinical practice, especially misdiagnosed as asthma or chronic obstructive pulmonary disease in case of "normal" chest X-ray. Here, we reported five central airway obstruction cases: the first and fourth cases misdiagnosed as asthma, the second masquerading as chronic obstructive pulmonary disease exacerbation, the third diagnosed incorrectly with non-resolving pneumonia, and the fifth misdiagnosed as chronic obstructive pulmonary disease. We then analyzed diagnostic clues potentially useful to differentiate central airway obstruction from asthma/chronic obstructive pulmonary disease. A multidisciplinary approach to manage central airway obstruction is essential, particularly selecting judiciously the method of respiratory support due to the high risk of completed airway collapse or obstruction during interventional period.

Tracheal resection in post COVID-19 patients is associated with high reintervention rate and early restenosis

Objectives

A remarkable increase in the number of patients presenting with tracheal complications after prolonged endotracheal intubation and mechanical ventilation for the management of the severe COVID-19 - associated respiratory failure has been observed. In this study, we assessed the postoperative outcomes of tracheal resection in COVID-19 patients.

Methods

We conducted a retrospective study in which all patients with a history of prolonged invasive mechanical ventilation due to COVID-19 infection, who were treated with tracheal resection and reconstruction, were included. The primary objective was in-hospital mortality and postoperative reintervention rate. The secondary objective was the time to tracheal restenosis.

Results

During the 16-month study period, 11 COVID-19 patients with tracheal complications underwent tracheal resection with end-to-end anastomosis. Mean patient age was 51.5 ± 9 years, and the majority were male (9 patients). Eight patients were referred for management of post-intubation tracheal stenosis and 3 for tracheoesophageal fistula. Eight patients had a history of tracheostomy during the COVID-19 infection hospitalization. There was one in-hospital death (9.1%) due to septicemia in the Intensive Care Unit, approximately two months after the operation. Postoperatively, 32 reinterventions were required for tracheal restenosis due to granulation tissue formation. The risk for reintervention was higher during the first 3 months after the index operation. Four patients developed tracheal restenosis (36.4%) and two of them required endotracheal stent placement during the follow up period.

Conclusions

Tracheal resection and reconstruction after COVID-19 infection is associated with a high reintervention rate postoperatively. Such patients require close follow up in expert interventional pulmonology units and physicians should be on high alert for the early diagnosis and optimal management of tracheal restenosis.

Necrotizing Tracheitis Complicated by Tracheal Wall Perforation

Necrotizing tracheitis is a rare condition, mainly seen in immunocompromised patients, that may lead to pseudomembrane formation, airway obstruction and in severe cases, tracheal perforation. We present a case of a 32-year-old male with poorly controlled diabetes who presented with productive cough, dysphagia, and respiratory distress. Bronchoscopy revealed extensive tracheal necrosis along a 4-5 cm segment of cartilaginous trachea and was complicated by tracheal perforation with false passage into the anterior mediastinum. Once the airway was re-established, a multidisciplinary team discussed options for definitive airway management, including tracheal reconstruction, pulmonary stent, or tracheostomy. Ultimately, a distal XLT tracheostomy was placed. Microbiology specimens of the tracheal tissue were positive for Actinomyces. The patient was started on long-term antibiotics and diabetes management. At three-month follow-up, the trachea was patent with near complete mucosalization of the previously necrotic segment. An area of proximal tracheal stenosis was successfully managed with a customized tracheal T-tube. In conclusion, this is a case of necrotizing tracheitis complicated by tracheal perforation. Successful treatment required a multidisciplinary team for airway management as well as medical treatment of immunocompromising risk factors and antimicrobial therapy. This enabled timely healing of the trachea and a durable airway.

Glycosaminoglycan, Antimicrobial Defence Molecule and Cytokine Appearance in Tracheal Hyaline Cartilage of Healthy Humans

Hyaline cartilage is an important tracheal structure, yet little is known about its molecular composition, complicating investigation of pathologies and replacement options. Our aim was to research tracheal hyaline cartilage structure, protective tissue factors and variations in healthy humans. The tissue material was obtained from 10 cadavers obtained from the Riga Stradins University Institute of Anatomy and Anthropology archive. Tissues were stained with Bismarck brown and PAS for glycosaminoglycans, and immunohistochemistry was performed for HBD-2, HBD-3, HBD-4, IL-10 and LL-37. The slides were inspected by light microscopy and Spearman's rank correlation coefficient was calculated. The extracellular matrix was positive across hyaline cartilage for PAS, yet Bismarck brown marked positive proliferation and growth zones. Numerous positive cells for both factors were found in all zones. All of the antimicrobial defence molecules and cytokines were found in a moderate number of cells, except in the mature cell zone with few positive cells. Spearman's rank correlation coefficient revealed strong and moderate correlations between studied factors. Hyaline cartilage is a tracheal defence structure with a moderate number of antimicrobial defence protein and cytokine immunoreactive cells as well as numerous glycosaminoglycan positive cells. The extracellular matrix glycosaminoglycans provide structural scaffolding and intercellular signalling. The correlations between the studied factors confirm the synergistic activity of them.

Tracheobronchomalacia and Excessive Dynamic Airway Collapse: Current Concepts and Future Directions

Tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC) are airway abnormalities that share a common feature of expiratory narrowing but are distinct pathophysiologic entities. Both entities are collectively referred to as expiratory central airway collapse (ECAC). The malacia or weakness of cartilage that supports the tracheobronchial tree may occur only in the trachea (ie, tracheomalacia), in both the trachea and bronchi (TBM), or only in the bronchi (bronchomalacia). On the other hand, EDAC refers to excessive anterior bowing of the posterior membrane into the airway lumen with intact cartilage. Clinical diagnosis is often confounded by comorbidities including asthma, chronic obstructive pulmonary disease, obesity, hypoventilation syndrome, and gastroesophageal reflux disease. Additional challenges include the underrecognition of ECAC at imaging; the interchangeable use of the terms TBM and EDAC in the literature, which leads to confusion; and the lack of clear guidelines for diagnosis and treatment. The use of CT is growing for evaluation of the morphology of the airway, tracheobronchial collapsibility, and extrinsic disease processes that can narrow the trachea. MRI is an alternative tool, although it is not as widely available and is not used as frequently for this indication as is CT. Together, these tools not only enable diagnosis, but also provide a road map to clinicians and surgeons for planning treatment. In addition, CT datasets can be used for 3D printing of personalized medical devices such as stents and splints. An invited commentary by Brixey is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Regenerating airway epithelium using fibrous biomimetic basement membranes

There are reciprocal interactions between epithelial cells and underlying basement membrane. The resemblance of biomaterials to native basement membrane is thus critical for their success when used to regenerate epithelium-containing organs. Particularly, the use of nanofibers and the incorporation of basement membrane proteins may mimic both biophysical and biochemical properties of basement membrane, respectively. Herein we tested how electrospun polycaprolactone/heparin fibers with and without adsorbed laminin and collagen IV proteins affect epithelial cell functions. We found that airway epithelial cells attached, migrated, and proliferated on all scaffolds but protein-functionalized fibers promoted higher attachment, quicker migration, and increased proliferation. Fibers were then integrated on polyethylene scaffolds and cultured at an air-liquid interface. The detection of secretory and ciliated cell markers was higher in cells on polyethylene with fibers. These findings demonstrate that electrospun fibers incite beneficial epithelial cell responses and can be used in the fabrication of bioengineered functional epithelia.

Isolation of multipotent progenitor cells from pleura and pericardium for tracheal tissue engineering purposes

Tissue engineering (TE) of long tracheal segments is conceptually appealing for patients with inoperable tracheal pathology. In tracheal TE, stem cells isolated from bone marrow or adipose tissue have been employed, but the ideal cell source has yet to be determined. When considering the origin of stem cells, cells isolated from a source embryonically related to the trachea may be more similar. In this study, we investigated the feasibility of isolating progenitor cells from pleura and pericard as an alternative cells source for tracheal tissue engineering. Porcine progenitor cells were isolated from pleura, pericard, trachea and adipose tissue and expanded in culture. Isolated cells were characterized by PCR, RNA sequencing, differentiation assays and cell survival assays and were compared to trachea and adipose‐derived progenitor cells. Progenitor‐like cells were successfully isolated and expanded from pericard and pleura as indicated by gene expression and functional analyses. Gene expression analysis and RNA sequencing showed a stem cell signature indicating multipotency, albeit that subtle differences between different cell sources were visible. Functional analysis revealed that these cells were able to differentiate towards chondrogenic, osteogenic and adipogenic lineages. Isolation of progenitor cells from pericard and pleura with stem cell features is feasible. Although functional differences with adipose‐derived stem cells were limited, based on their gene expression, pericard‐ and pleura‐derived stem cells may represent a superior autologous cell source for cell seeding in tracheal tissue engineering.

Tracheitis Caused by Coinfection with Cytomegalovirus and Herpes Simplex Virus

Clinically significant isolated viral tracheitis is scarce in adults, and upper airway obstruction caused by viral tracheitis is even more infrequent. A 74-year-old woman, who was administered low-dose steroids for two months for chronic obstructive pulmonary disease (COPD), developed dyspnea with stridor and required mechanical ventilation for respiratory failure. Chest computed tomography showed a diffuse tracheal wall thickening with luminal narrowing and peribronchial consolidation in the right upper lobe. Bronchoscopy revealed a proximal tracheal narrowing with multiple ulcerations of the tracheal mucosa surrounded by an erythematous margin. Pathologic examinations of the tracheal mucosal tissue, including immunohistochemistry, revealed a cytomegalovirus (CMV) and herpes simplex virus (HSV) infection. Furthermore, the bronchial alveolar lavage fluid was positive on the CMV real-time polymerase chain reaction. The patient was treated with intravenous ganciclovir for 44 days. The follow-up bronchoscopy 49 days after the initiation of ganciclovir revealed improved multiple ulcerations with scars. We report a rare case of tracheitis caused by coinfection with CMV and HSV in a patient with COPD who had been taking low-dose steroids for months. The case showed that CMV and HSV are potential causes of serious tracheitis and respiratory failure.

CT Findings of Central Airway Lesions Causing Airway Stenosis-Visualization and Quantification: A Pictorial Essay

The tracheobronchial tree is a system of airways that allows the passage of air to aerate the lungs and entire body. Several pathological conditions can affect this anatomical region. Multidetector CT (MDCT) helps identify and characterize various large airway diseases. Post-processing tools, such as virtual bronchoscopy and automatic lung analysis, can help enhance the performance of imaging studies. In this pictorial essay review, we provide imaging findings of various bronchial lesions manifested as wall thickening and endoluminal nodules on conventional MDCT and advanced image visualization and analysis.

Longstanding tracheobronchomalacia: A forgotten cause of severe cough and its response to roflumilast

This case report describes a patient with moderately severe tracheobronchomalacia following mycoplasma pneumonia. The patient was considered to have obstructive lung disease despite no prior smoking or lung disease and failure to respond to standard treatment. The possibility of tracheal pathology causing cough and sputum was not considered in 23yrs confirming this to be a “forgotten zone”. The patient was treated with Roflumilast to reduce airway secretions with great success and the Immunology of Roflumilast is discussed.

Flock health survey of Irish Texel society breeders and larynx examination in Texel sheep

Background

Laryngeal chondritis is a disease of undetermined aetiology, characterised by oedema, ulceration, abscessation and necrosis of the laryngeal mucosa and cartilage. The initial aim of the study was to document flock health issues identified by Irish pedigree Texel breeders using a questionnaire survey. Additionally, given the reports of breed predisposition for laryngeal chondritis in Texels, a further aim was to identify if laryngeal problems were perceived as an issue. Work was then conducted to identify if pre-clinical laryngeal mucosal pathology was identifiable in Texel sheep showing no overt clinical signs of respiratory disease and if associations existed between laryngeal measurements and laryngeal pathology.

Thirty one larynges were collected from a Texel flock that previously had laryngeal chondritis diagnosed in fallen stock. Gross visual inspection was performed to identify and grade (0–5) laryngeal pathology. A series of measurements were then performed on larynges that had been formalin fixed. Associations between independent variables (larynx measurements) and the dependent variable (laryngeal pathology score) were examined.

Results

Respiratory disease was the most frequently identified health issue. Farmer-diagnosed ‘throat problems’ were reported by over 80% of respondents.

Laryngeal pathology was noted in Texels showing no overt clinical signs of respiratory disease. Associations between laryngeal measurements and laryngeal pathology were identified relating to the angle between the cranial point of the cricoid cartilage and the vocal process of the arytenoid cartilage.

Conclusions

Mild laryngeal pathology was noted in animals with no overt clinical signs of respiratory disease. Future research should examine whether significant associations between laryngeal measurements and laryngeal pathology identified in the current study can be measured ante mortem, and whether such ante mortem measurements will allow early identification of sheep at risk of developing laryngeal chondritis.

Transplantation of a 3D-printed tracheal graft combined with iPS cell-derived MSCs and chondrocytes

For successful tracheal reconstruction, tissue-engineered artificial trachea should meet several requirements, such as biocompatible constructs comparable to natural trachea, coverage with ciliated respiratory mucosa, and adequate cartilage remodeling to support a cylindrical structure. Here, we designed an artificial trachea with mechanical properties similar to the native trachea that can enhance the regeneration of tracheal mucosa and cartilage through the optimal combination of a two-layered tubular scaffold and human induced pluripotent stem cell (iPSC)-derived cells. The framework of the artificial trachea was fabricated with electrospun polycaprolactone (PCL) nanofibers (inner) and 3D-printed PCL microfibers (outer). Also, human bronchial epithelial cells (hBECs), iPSC-derived mesenchymal stem cells (iPSC-MSCs), and iPSC-derived chondrocytes (iPSC-Chds) were used to maximize the regeneration of tracheal mucosa and cartilage in vivo. After 2 days of cultivation using a bioreactor system, tissue-engineered artificial tracheas were transplanted into a segmental trachea defect (1.5-cm length) rabbit model. Endoscopy did not reveal granulation ingrowth into tracheal lumen. Alcian blue staining clearly showed the formation of ciliated columnar epithelium in iPSC-MSC groups. In addition, micro-CT analysis showed that iPSC-Chd groups were effective in forming neocartilage at defect sites. Therefore, this study describes a promising approach for long-term functional reconstruction of a segmental tracheal defect.

A 62-Year-Old Woman With Refractory Wheezing

CASE PRESENTATION

A 62-year-old Hispanic woman, a resident of Puerto Rico, presented with symptoms of chronic cough and shortness of breath for the past 2 years that were slowly and progressively getting worse. She received a diagnosis of asthma on the basis of her history of symptomatic "wheezing" and had been on treatment with inhaled bronchodilators and corticosteroids with minimal symptomatic improvement. The peculiarity of her symptoms was that her dyspnea was worse when she was reclining in bed and she would often hear a "whistling" noise in her throat during those times. Additionally, she reported difficulty swallowing and would often drink water to aid in swallowing food. There was no prior history of endotracheal intubations or surgeries. She denied any history of joint pain, skin rashes, eye pain, hair loss, mouth ulcers, photosensitivity, diarrhea, blood-mixed stool, or blood in the urine.

Intranasal Acetaminophen Abuse and Nasal, Pharyngeal, and Laryngotracheal Damage

A young adult female originally presented with necrosis of the nasal cavity mucosa and septum after sniffing crushed acetaminophen. She underwent endoscopic sinus surgery and debridement but continued to use acetaminophen intranasally. Four months later, the destruction had extended to include the posterior pharyngeal wall and subglottis. The diagnosis was confirmed by polarizable talc found on biopsy of the subglottis. While nasal insufflation of cocaine and hydrocodone-acetaminophen has been well-documented, intranasal abuse of exclusively acetaminophen is not well understood. This case demonstrates the destructive potential of intranasal acetaminophen use and may help physicians recognize unusual signs and symptoms of intranasal drug abuse.

Flow-Volume Curve Analysis for Predicting Recurrence After Endoscopic Dilation of Airway Stenosis

BACKGROUND

The flow-volume curve is a simple test for diagnosing upper airway obstruction. We evaluated its use to predict recurrence in patients undergoing endoscopic dilation for treatment of benign upper airway stenosis.

METHODS

The data of 89 consecutive patients undergoing endoscopic dilation of simple upper airway stenosis were retrospectively reviewed. Morphologic distortion of flow-volume loop (visual analysis) and quantitative criteria, including maximal expiratory flow rate at 50% of the vital capacity (MEF_50%)/maximal inspiratory flow rate at 50% of the vital capacity (MIF_50%) of less than 0.3 or more than 1.0, forced expiratory volume in 1 second/MEF exceeding 10, and forced expiratory volume in 1 second/forced expiratory volume in .05 second exceeding 1.5, were considered predictive of recurrence. In all cases, the recurrence was confirmed by radiologic or bronchoscopic findings, or both. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of visual, quantitative, and aggregate criteria for detecting recurrence were computed and compared.

RESULTS

Of 89 patients treated, 27 (30%) had a recurrence. Visual analysis presented a sensitivity, specificity, PPV, NPV, and accuracy of 63%, 83.9%, 63%, 83.9%, and 77.5%, respectively. Among the quantitative criterion, the MEF_50%/MIF_50% was the most accurate, having a sensitivity, specificity, PPV, NPV, and accuracy of 77.8%, 79%, 61.8%, and 89.1%, and 78.7%, respectively. Aggregate criterion presented the best yield compared with other criteria in sensitivity (81.5%), specificity (91.9%), PPV (81.5%), NPV (91.9%), and accuracy (88.8%).

CONCLUSIONS

The flow-volume curve is a simple and noninvasive method to monitor patients undergoing endoscopic dilation of upper airway stenosis. Morphologic changes in the flow-volume loop and in the MEF_50%/MIF_50% ratio are suggestive of recurrence and guide the physician to implement the follow-up with further diagnostic (non)invasive examinations.

Radiological evaluation of airway - What an anaesthesiologist needs to know!

Airway management forms the foundation of any anaesthetic management. However, unanticipated difficult airway (DA) and its sequelae continue to dread any anaesthesiologist. In spite of development of various clinical parameters to judge DA, no single parameter has proved to be accurate in predicting it. Radiological evaluation may help assess the aspects of patient's airway not visualised through the naked eye. Starting from traditional roentgenogram to ultramodern three-dimensional printing, imaging may assist the anaesthesiologists in predicting DA and formulate plan for its management. Right from predicting DA, it has been used for estimating endotracheal tube sizes, assessing airway pathologies in paediatric patients and planning extubation strategies. This article attempts to provide exhaustive overview on radiological parameters which can be utilised by anaesthesiologists for prediction of DA.

[Trans-vocal cord prostheses - preliminary experience treating benign laryngotracheal stenosis in adults]

INTRODUCTION

Benign laryngotracheal stenosis is a rare pathology with multiple etiologies, the management of which is complex. This is because of the configuration and proximity of the larynx and the difficulty with surgical approaches, which are potentially mutilating, especially for the management of a benign disease. When surgery is challenging, iterative dilatations of the stricture or the fashioning of a definitive tracheotomy are therapeutic alternatives. Advances in rigid bronchoscopy and the evolution of prosthetic silicone material allow a new approach in the management of benign laryngotracheal stenosis, by placing flexible silicone prostheses which cover all the stenosis from the arytenoids to the trachea. This preliminary work aims to evaluate the feasibility, effectiveness, tolerance and complications of the implementation of this type of prosthesis.

PATIENTS AND METHODS

This is a retrospective single-centre study which analyzed the records of patients with symptomatic benign laryngotracheal stenosis who underwent placement of a transcordial prosthesis over a period of three years. The prosthesis used, inserted under general anesthesia during a rigid tube interventional bronchoscopy, was either a straight silicone prosthesis or a Montgomery T-tube for those with a pre-existing tracheotomy.

RESULTS

Six patients were included. Five are still alive, one patient died from a cause unrelated to the placement of the prosthesis. Four have no tracheostomy and two now have no transcordal prosthesis. The data collected on tolerance found, for three patients, two cases of minor aspiration and one case of transient cough. All patients had whispered voice dysphonia. We did not observe prosthesis migration or obstruction.

CONCLUSION

These preliminary results are encouraging. Transcordal prostheses in benign laryngotracheal stenosis have a complementary or alternative role compared to surgery with a palliative or even curative objective.

A case of anti-melanoma differentiation-associated gene 5 antibody-positive interstitial lung disease complicated with tracheobronchial ulcers

We herein report the first case, to our knowledge, of tracheobronchial ulcer with anti-melanoma differentiation-associated gene 5 (anti-MDA 5) antibody-positive interstitial lung disease (ILD). A 53-year-old man complained of shoulder and wrist pain and was suspected of having polymyalgia rheumatica at another hospital. Thereafter, treatment with prednisolone was started. Although his arthralgia improved, he suffered from progressive dyspnea on exertion and an abnormal shadow was noted on chest X-ray, so he was transferred to our hospital. Chest computed tomography scan revealed ground-glass opacities and intralobular septal thickening. We diagnosed him as having clinically amyopathic dermatomyositis associated with ILD based on the specific skin findings and elevated anti-MDA 5 antibody titer. Fiberoptic bronchoscopy showed ulcerations of the trachea and bronchus. Treatment with dose increments of prednisolone combined with other immunosuppressive drugs resulted in improvement of his respiratory condition and tracheobronchial lesions. Clinicians should be aware that tracheobronchial ulcers can be associated with anti-MDA 5 antibody-positive interstitial lung disease.

Pseudomembranous Invasive Tracheobronchial Aspergillosis with Fulminant Hepatitis and Hemophagocytic Syndrome

Invasive tracheobronchial aspergillosis (ITBA), a rare form of invasive pulmonary Aspergillus infection (IPA), is predominantly confined to the tracheobronchial tree. We herein report a case of ITBA with severe necrotic pseudomembrane in a 57-year-old woman with fulminant hepatitis and hemophagocytic syndrome. Bronchoscopic findings revealed a widespread pseudomembranous formation of the trachea and bronchi. Aspergillus fumigatus was cultured from bronchial lavage fluid, and the histological findings of an endobronchial biopsy revealed necrosis and invasive hyphae. Although she responded to antifungal treatment, she ultimately died of a septic shock with Burkholderia cepacia 57 days after admission.

Otolaryngology in Critical Care

Diseases affecting the ear, nose, and throat are prevalent in intensive care settings and often require combined medical and surgical management. Upper airway occlusion can occur as a result of malignant tumor growth, allergic reactions, and bleeding events and may require close monitoring and interventions by intensivists, sometimes necessitating surgical management. With the increased prevalence of immunocompromised patients, aggressive infections of the head and neck likewise require prompt recognition and treatment. In addition, procedure-specific complications of major otolaryngologic procedures can be highly morbid, necessitating vigilant postoperative monitoring. For optimal outcomes, intensivists need a broad understanding of the pathophysiology and management of life-threatening otolaryngologic disease.

Incidence and Risk Factors of Hypoxemia During Interventional Rigid Bronchoscopy Under Spontaneous-assisted Ventilation

BACKGROUND

Interventional rigid bronchoscopy for tracheobronchial stenosis can be performed under total intravenous anesthesia and spontaneous-assisted ventilation. Intraoperative hypoxemia can occur during this procedure, but the incidence and risk factors have not yet been determined.

METHODS

Medical records of patients who underwent rigid bronchoscopy for the treatment of tracheobronchial stenosis under total intravenous anesthesia and spontaneous-assisted ventilation during the study period from January 2011 to December 2012 were retrospectively reviewed.

RESULTS

There were 126 patients who underwent 263 procedures. The 2 main causes of tracheobronchial stenosis were tuberculosis (41.3%) and malignancy (35.7%). The 2 main locations of stenotic area were the trachea (58.6%) and the left main bronchus (46.4%). Tracheobronchial dilatation and stent insertion were performed in 78.7% and 21.3% of patients, respectively. The incidence of intraoperative hypoxemia was 25.5%. Independent risk factors for intraoperative hypoxemia were a degree of tracheal stenosis ≥75% (odds ratio: 2.48; 95% confidence interval, 1.19-5.17) and tumor removal procedure (odds ratio: 2.9; 95% confidence interval, 1.13-7.41).

CONCLUSIONS

Incidence of intraoperative hypoxemia during interventional rigid bronchoscopy for tracheobronchial stenosis under spontaneous-assisted ventilation was 25.5%. Risk factors for hypoxemia were a degree of tracheal stenosis ≥75% and tumor removal procedure.

Flexible bronchoscopy and mechanical ventilation in managing Mounier-Kuhn syndrome: a case report

CONTEXT

Mounier-Kuhn syndrome is a rare congenital condition with distinct dilatation and diverticulation of the tracheal wall. The symptoms may vary and the treatment usually consists of support.

CASE REPORT

The patient was a 60-year-old male with recurrent hospital admission. He was admitted in this case due to dyspnea, cough and sputum production. An arterial blood sample revealed decompensated respiratory acidosis with moderate hypoxemia. A chest computed tomography (CT) scan showed dilatation of the trachea and bronchi, tracheal diverticula and bronchiectasis. Flexible bronchoscopy was performed, which revealed enlarged airways with expiratory collapse. Furthermore, orifices of tracheal diverticulosis were also detected. Non-invasive positive pressure ventilation (NPPV) was added, along with long-term oxygen therapy. At control visits, the patient's clinical and laboratory findings were found to have improved.

CONCLUSION

Flexible bronchoscopy can be advocated for establishing the diagnosis and non-invasive mechanical ventilation can be used with a high success rate, for clinical wellbeing in Mounier-Kuhn syndrome.

Computational fluid dynamics evaluation of excessive dynamic airway collapse

BACKGROUND

Excessive dynamic airway collapse, which is often caused by the collapse of the posterior membrane wall during exhalation, is often misdiagnosed with other diseases; stents can provide support for the collapsing airways. The standard pulmonary function tests do not necessarily show change in functional breathing condition for evaluation of these type of diseases.

METHODS

Flow characteristics through a patient's airways with excessive dynamic airway collapse have been numerically investigated. A stent was placed to support the collapsing airway and to improve breathing conditions. Computed tomography images of the patient's pre- and post-stenting were used for generating 3-Dimensional models of the airways, and were imported into a computational fluid dynamics software for simulation of realistic air flow behavior. Unsteady simulations of the inspiratory phase and expiratory phase were performed with patient-specific boundary conditions for pre- and post-intervention cases to investigate the effect of stent placement on flow characteristic and possible improvements.

FINDINGS

Results of post-stent condition show reduced pressure, velocity magnitude and wall shear stress during expiration. The variation in wall shear stress, velocity magnitude and pressure drop is negligible during inspiration.

INTERPRETATION

Although Spirometry tests do not show significant improvements, computational fluid dynamics results show significant improvements in pre- and post-treatment results, suggesting improvement in breathing condition.

Case report: Unusual cause of difficulty in intubation and ventilation with asthmatic-like presentation of Endobronchial Tuberculosis

Endobronchial Tuberculosis is hazardous in causing circumferential narrowing of tracheobronchial tree despite the eradication of tubercle bacilli in the initial insult from Pulmonary Tuberculosis. They may present as treatment resistant bronchial asthma and pose challenge to airway management in the acute setting. We present a 25 year-old lady who was newly diagnosed bronchial asthma with a past history of Pulmonary Tuberculosis that had completed treatment. She presented with sudden onset of difficulty breathing associated with noisy breathing for 3 days and hoarseness of voice for 6 months. Due to resistant bronchospasm, attempts were made to secure the airway which led to unanticipated difficult intubation and ventilation. Subsequent investigations confirmed the diagnosis of Endobronchial Tuberculosis and patient was managed successfully with anti TB medication, corticosteroids and multiple sessions of tracheal dilatation for tracheal stenosis. This case highlights the unusual cause of difficulty in intubation and ventilation due to Endobronchial Tuberculosis, which required medical and surgical intervention to improve the condition.

Anatomical considerations in bronchoscopy

A thorough understanding of intrathoracic anatomy enables the interventional bronchoscopist to perform procedures efficaciously. The review of the anatomy of the thoracic cavity focuses first on the trachea and the relationship of the airway with surrounding structures, knowledge important for the safe conduct of bronchoscopic procedures. We then describe the anatomy of the pleural cavity relevant to the practitioner performing pleuroscopy.

Case report: Castleman's disease in trachea

Castleman’s disease (CD) in trachea is rarely reported to date. This report introduces a case of CD in trachea with emphasis on its radiological presentation onCT. A female patient was admitted at our emergency department with dyspnoea. Plain and enhanced CT revealed a mass with distinct border and marked enhancement. Tracheotomy was planned and it turned out to be CD of hyaline type on pathological examination. Two similar case reports on intratracheal CD from 1954 to 2015 were reviewed as we searched in PubMed using key words “endotracheal Castleman’s disease” or “Castleman’s disease in trachea” or “Castleman’s disease in tracheal”. This will be the third case report of CD in trachea in English literature. In this case report, the radiological appearance of CD on multiple imaging modes is reviewed. Lesions that should be taken into consideration in differential diagnosis are mentioned. The two main surgical methods for such lesions are briefly described.

Sarcoidosis Presenting with Tracheobronchial Calcification and Nodularity: An Unusual Case Presentation with Treatment Response Assessment by 18F-FDG-PET/CT

Airway involvement, tracheobronchial nodularity, and calcification are rare occurrences and unorthodox phenomena in sarcoidosis. Here, we report such an unusual case manifesting as tracheal calcification and nodules of the central airways. Radiology and bronchoscopy provide useful diagnostic clues when combined with histopathology. This case serves as an aide-memorie for the variegated presentations of sarcoidosis and emphasizes a high index of suspicion for the entity in such unconventional circumstances. An early favorable treatment response assessment to corticosteroid therapy was shown with ¹⁸F-fludeoxyglucose positron emission tomography/computed tomography.

Evaluating the utility of serological testing in laryngotracheal stenosis

OBJECTIVES/HYPOTHESIS

Whereas mechanical (traumatic) causes of laryngotracheal stenosis (LTS) are identified based on history, autoimmune laryngotracheal stenosis (aLTS) and idiopathic laryngotracheal stenosis (iLTS) are often more difficult to differentiate. The objective of this study was to evaluate serologic testing in a large cohort of nonmechanical LTS patients to determine which tests, if any, lead clinicians to the etiology of the LTS.

STUDY DESIGN

Retrospective chart review.

METHODS

This study reviewed nonmechanical LTS patients seen at a tertiary medical center from 2007 to 2014. Data were obtained on patient demographics, associated preexisting autoimmune conditions, comorbidities, intubation history, and serologic testing.

RESULTS

Ninety-two records were reviewed. Twenty-three (25%) patients were found to have autoimmune disease; 69 (75%) met criteria for iLTS. A history of cigarette smoking was more significant in the aLTS group than the iLTS group (P < .001). Antineutrophil cytoplasmic antibody (ANCA) was positive only in patients with known granulomatosis with polyangiitis (GPA). All other serological testing was equivocal between the two cohorts.

CONCLUSIONS

Differentiating iLTS from aLTS has proven difficult. The lack of information about the two entities has resulted in variability in the diagnostic workup to distinguish them. This study's finding of a more significant smoking history in the aLTS group correlates with the literature, which suggests an inflammatory effect of smoking cigarettes and an association with autoimmune disease. The only significant cohort of patients in this study found to have positive serological testing correlated with a diagnosable condition responsible for LTS was GPA patients with positive ANCA.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:1408-1412, 2017.

Mechanical Characterization and Constitutive Modeling of Human Trachea: Age and Gender Dependency

Tracheal disorders can usually reduce the free lumen diameter or wall stiffness, and hence limit airflow. Trachea tissue engineering seems a promising treatment for such disorders. The required mechanical compatibility of the prepared scaffold with native trachea necessitates investigation of the mechanical behavior of the human trachea. This study aimed at mechanical characterization of human tracheas and comparing the results based on age and gender. After isolating 30 human tracheas, samples of tracheal cartilage, smooth muscle, and connective tissue were subjected to uniaxial tension to obtain force-displacement curves and calculate stress-stretch data. Among several models, the Yeoh and Mooney-Rivlin hyperelastic functions were best able to describe hyperelastic behavior of all three tracheal components. The mean value of the elastic modulus of human tracheal cartilage was calculated to be 16.92 ± 8.76 MPa. An overall tracheal stiffening with age was observed, with the most considerable difference in the case of cartilage. Consistently, we noticed some histological alterations in cartilage and connective tissue with aging, which may play a role in age-related tracheal stiffening. No considerable effect of gender on the mechanical behavior of tracheal components was observed. The results of this study can be applied in the design and fabrication of trachea tissue engineering scaffolds.

Functional changes are associated with tracheal structural abnormalities in patients with acromegaly

INTRODUCTION

Although impaired pulmonary function and respiratory sleep disorders are described as responsible for increased mortality in acromegalic patients, little is known about the tracheal abnormalities in this group of patients. Thus, the objectives of this study were to describe the tracheal structural abnormalities and correlate these changes with the respiratory function and clinical data of acromegalic patients.

MATERIAL AND METHODS

This is a cross-sectional study that was carried out at two university hospitals. Twenty acromegalic patients underwent spirometry, forced oscillation technique, and computed tomography (CT) assessments. Dyspnea and daytime sleepiness were assessed using the Modified Medical Research Council (MMRC) scale and the Epworth Sleepiness Scale (ESS), respectively. Forty matched subjects served as controls.

RESULTS

The acromegalic patients exhibited larger median ratios between forced expiratory flow and forced inspiratory flow at 50% of the forced vital capacity (FEF50%/FIF50%) (2.05 vs. 1.06, p = 0.0001) compared with healthy volunteers. In the CT analysis, acromegalic patients exhibited larger median differences between their cervical and thoracic tracheal diameters (Δ tracheal diameters) (3 vs. 1 mm; p = 0.003). An association was found between FEF50%/FIF50% and the following variables: mean resistance (Rm), cervical tracheal diameter, and Δ tracheal diameters. Rm also exhibited a negative correlation with cervical tracheal diameter. Neither the MMRC scale nor the ESS exhibited any significant correlation with large airway obstruction (LAO) indices or with the measured tracheal diameters.

CONCLUSIONS

Acromegalic patients have tracheal structural abnormalities which are associated with functional indicators of LAO but not with clinical data.

Subglottic stenosis in granulomatosis with polyangiitis (Wegener's granulomatosis): Report of 4 cases

INTRODUCTION

Subglottic stenosis (SGS) in granulomatosis with polyangiitis (GPA) may result from active disease or from chronic recurrent inflammation. The objective of the study was to describe the clinical features and treatment of patients with subglottic stenosis.

METHODS

We retrospectively reviewed the medical records of all patients with SGS due to GPA diagnosed at Rheumatology deparment between January 2000 and June 2015.

RESULTS

We present 4 cases of SGS at our department during a period of 15 years. The interval between the presentation of the GPA and SGS varied between 2 and 144 months. The leading symptoms of SGS were dyspnoea on exertion and stridor. Three patients presented SGS without evidence of systemic activity. Two patients presented SGS grade i and received tracheal dilatation; two recurred and three needed a tracheostomy due to severe airway-limiting stenosis.

CONCLUSION

SGS presents high morbidity. Even though subglottic dilatation provides symptomatic relief, recurrences may present. Severe airway-limiting stenosis often requires tracheostomy.

Focal tracheal stenosis due to intramural hematoma following endobronchial ultrasound-guided transbronchial needle aspiration

Tracheal obstruction can present insidiously or be acute and life threatening. This condition can occur acutely, as in cases of infection or foreign body aspiration, whereas posttraumatic tracheal stenosis or obstruction due to intraluminal tumor growth typically evolves more gradually. Tracheal stenosis secondary to intramural hematoma is exceedingly rare. We report a case of intramural tracheal hematoma causing obstruction following endobronchial ultrasound-guided transbronchial needle aspiration in a 69-year-old woman.