Airway stenting and tracheobronchoplasty improve respiratory symptoms in Mounier-Kuhn syndrome

A rare cause of dyspnea: Mounier Kuhn syndrome

Mounier-Kuhn syndrome, also known as tracheobronchomegaly, is a rare clinical and radiological condition characterized by tracheobronchial dilatation and recurrent respiratory infections. Patients may be asymptomatic or present with severe respiratory illnesses. A CT scan is sufficient to confirm the diagnosis. Treatment is symptomatic, and surgery is rarely indicated. We present the case of a 55-year-old patient with a 30-year history of chronic dyspnea, who presented with worsening shortness of breath, a productive cough, and episodes of bronchial superinfection. A chest CT scan, performed before and after contrast injection during both inspiratory and expiratory phases, confirmed the diagnosis of Mounier-Kuhn syndrome. This case aims to raise awareness of this rare condition and highlights a presentation where dyspnea is the primary symptom.

State-of-the-art narrative review: Mounier-Kuhn syndrome and tracheobronchomegaly

Mounier-Kuhn syndrome (MKS) or tracheobronchomegaly is an uncommon disease of the central airways. It is characterized by pathological dilatation of the trachea and main bronchi and inevitably leads to recurrent respiratory infections, bronchiectasis, hospitalizations, and results in considerable morbidity and mortality. Despite numerous case reports, there is a shortage of evidence on clinical outcomes and limited data on interventions, thus presenting a significant gap in the literature. Fortunately, new strategies and increasing clinical experience have improved the clinical approach, diagnostic workup, classification, and management of MKS. Articles in English, Spanish, and French were searched from databases, including Pubmed, Google Scholar, Medline, and SCOPUS, using the terms "Mounier-Kuhn syndrome," "Tracheomegaly," "Tracheobronchomegaly," and "Bronchomegaly," without date restrictions. A total of 360 articles with the aforementioned syntax were indexed on Pubmed. This state-of-the-art review attempts to fill a void in the current literature by summarizing the current scientific knowledge and highlighting novel interventional strategies in the management of Mounier Kuhn Syndrome.

Tracheobronchial stents: an expanding prospect

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean-Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel-titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug-eluting and three-dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction.

[Interventionnal bronchoscopy for the treatment of tracheobronchomalacia]

Tracheobronchomalacia is usually characterized by more than 50% expiratory narrowing in diameter of the trachea and the bronchi. The expiratory collapse includes two entities: (1) the TBM related to the weakness of the cartilaginous rings, and (2) the Excessive Dynamic Airway Collapse (EDAC) due to the excessive bulging of the posterior membrane. Patients have nonspecific respiratory symptoms like dyspnea and cough. Diagnosis is confirmed by dynamic tests: flexible bronchoscopy and/or computed tomographic scan of the chest. There are different forms of tracheobronchomalacia in adults: primary (genetic, idiopathic) or secondary to trauma, tracheotomy, intubation, surgery, transplantation, emphysema, infection, inflammation, chronic bronchitis, extrinsic compression; or undiagnosed in childhood vascular rings. Some management algorithms have been proposed, but no specific recommendation was established. Only symptomatic patients should be treated. Medical treatments and noninvasive positive pressure ventilation should be the first line therapy, after evaluation of various quality measures (functional status, performance status, dyspnea and quality of life scores). If symptoms persist, therapeutic bronchoscopy permits: (1) patient's selection by stent trial to determine whether patient benefit for surgical airway stabilization; (2) malacic airways stenting in patients who are not surgical candidates, improving QOL despite a high complication rate; (3) the management of stent-related complication (obstruction, plugging, migration granuloma); (4) alternative therapeutics like thermo-ablative solution. Lasty, the development of new types of stents would reduce the complication rates. These different options remained discussed.

Tracheobronchomegaly (Mounier-Kuhn Syndrome) in a 43-Year-Old Male: A Case Report

Mounier-Kuhn syndrome (MKS) or congenital tracheobronchomegaly is a rare disorder characterized by marked dilatation of the trachea and main bronchi, bronchiectasis, and recurrent respiratory tract infections. The etiology of this disorder is uncertain and the clinical presentation is variable. The diagnosis is usually made based on the characteristic computed tomography (CT) scan findings. This report describes a case of a 43-year-old man presenting with persistent cough and recurrent lower respiratory tract infections since childhood associated with copious amounts of purulent sputum, difficulty in breathing, and weight loss. In addition, he reported palpitations, dyspnea, orthopnea, abdominal and lower limb swelling. The chest X-ray showed a dilated trachea (35mm) and bronchi (26mm (right) and 27mm (left)) with cystic bronchiectasis and reticulolinear opacities predominantly involving the middle and lower lung zones. Chest CT scan confirmed the diagnosis of MKS as evidenced by dilated trachea and bronchi complicated by diverticula formation. Electrocardiogram, echocardiography and abdominal ultrasound scan showed features of right-sided heart failure secondary to pulmonary hypertension. MKS, although rare, should be considered as a possible diagnosis in patients presenting with productive chronic cough, recurrent pneumonia, or incomplete response to appropriate antibiotic therapy for pneumonia.

Congenital tracheobronchomegaly (Mounier-Kuhn syndrome) in a 28-year-old Zambian male: a case report

Congenital tracheobronchomegaly, also known as Mounier Kuhn Syndrome (MKS) is a rare respiratory disorder characterized by dilatation of the trachea and bronchi. We report a case of a 28-year-old male of African descent in Zambia, who presented with a history of chronic productive cough and repeated chest infections since childhood. He had been treated numerous times for lower respiratory tract infections, and had received empiric tuberculosis (TB) treatment based on chest radiograph findings, despite negative sputum microscopy and molecular tests for TB. Investigations revealed normal baseline blood results and sputum results. He however, had markedly increased levels of serum immunoglobulin E, and spirometry showed an obstructive pattern with significant post bronchodilator improvement. High-resolution computed tomography scan revealed tracheal dilatation, extensive bilateral bronchiectasis and tracheal and bronchial diverticula. The latter were also seen on bronchoscopy, confirming the diagnosis of Mounier-Kuhn syndrome. The patient was treated with combined inhaled corticosteroids and bronchodilators, as well as chest physiotherapy for mucus clearance, which led to improvement in his symptoms. Our case highlights how in low-resource settings, chronic lung diseases, particularly bronchiectasis, are often clinically and radiologically mistaken for and presumptively treated as TB (or its sequelae). Mounier-Kuhn syndrome, albeit rare, should be considered in the differential diagnosis of patients with recurrent lower respiratory tract infections or bronchiectasis. Multidisciplinary team meetings can help in the diagnosis of rare lung diseases.

An Accidental Discovery of Tracheobronchomegaly: a Case Report

Tracheobronchomegaly is a rare disease with congenital abnormal change in respiratory tract; its image features are also very special. In this case, we described a 57-year-old male with cough, expectoration, chest pain, and dyspnea. In our institution, the result of chest CT scan is highly extraordinary, which showed obvious dilation of the trachea and main bronchi, emphysema, and a number of pulmonary bullae, and there was a big bulla with air-fluid level on the lower lobe of the right lung. Fortunately, after wedge resection for the big bulla on the lower lobe of right lung under video-assisted thoracoscopic surgery, this patient’s symptoms were significantly relieved. The clinical manifestations of tracheobronchomegaly lack specificity; this disease has freakish image features. At present, there are no effective treatments for tracheobronchomegaly, which just was an accidental discovery in this patient; we just mainly take surgical measures to treat the big bulla for relieving symptoms.

Thoracic Computed Tomography Scan and Bronchoscopy Appearance of Mounier-Kuhn Syndrome: A Case Report

Mounier-Kuhn syndrome (MKS) is a rare congenital disease with an autosomal recessive inheritance pattern, characterized by an enlargement of the trachea and bronchi. MKS is secondary to a thinning of the muscular mucosa and atrophy of the longitudinal muscle and elastic fibers of the tracheobronchial tree. As a consequence, tracheal diverticulosis and dilatations in the posterior membranous wall appear, along with bronchiectasis that tend to be cystic in appearance. Overall, there is an impairment of mucocilliary clearance, with an ineffective cough, which predisposes the patient to recurrent lower respiratory tract infections. Clinical manifestations vary from asymptomatic to respiratory failure and death, most patients being diagnosed between the third and fourth decades of life. It is an often undiagnosed disease, with a diagnostic algorithm that includes the use of radiological techniques, alone or in combination with bronchoscopy. Specific diagnostic criteria have been developed, based on patients’ tracheal and main bronchi diameter on chest X-ray and thoracic computed tomography scan. We present the case of a 45-year-old African American man who presented with a history of multiples episodes of pneumonia that required management in the intensive care unit, on whom MKS was diagnosed.

Recurrent Lower Respiratory Tract Infections Due to Mounier-Kuhn Syndrome

Mounier-Kuhn syndrome (MKS) is a rare disorder characterized by recurrent lower respiratory tract infections and bronchiectasis due to dilation of the trachea and bronchi. Diagnosis is made based on clinical suspicion along with radiographic evidence of tracheobronchomegaly. Mucolytic agents and chest physiotherapy have been shown to offer symptomatic improvement, and definitive surgical treatment is reserved for those with persistent symptoms. Herein, we report a case of MKS in a 72-year-old woman with bronchiectasis and recurrent multidrug-resistant lower respiratory tract infections.

Improving Airways Patency and Ventilation Through Optimal Positive Pressure Identified by Noninvasive Mechanical Ventilation Titration in Mounier-Kuhn Syndrome: Protocol for an Interventional, Open-Label, Single-Arm Clinical Trial

BACKGROUND

Mounier-Kuhn syndrome or congenital tracheobronchomegaly is a rare disease characterized by dilation of the trachea and the main bronchi within the thoracic cavity. The predominant signs and symptoms of the disease include coughing, purulent and abundant expectoration, dyspnea, snoring, wheezing, and recurrent respiratory infection. Symptoms of the disease in some patients are believed to be pathological manifestations arising due to resident tracheobronchomalacia. Although treatment options used for the management of this disease include inhaled bronchodilators, corticosteroids, and hypertonic solution, there is no consensus on the treatment. The use of continuous positive airway pressure (CPAP) has been reported as a potential therapeutic option for tracheobronchomalacia, but no prospective studies have demonstrated its efficacy in this condition.

OBJECTIVE

The purpose of this is to identify the presence of tracheobronchomalacia and an optimal CPAP pressure that reduces the tracheobronchial collapse in patients with Mounier-Kuhn syndrome and to analyze the repercussion in pulmonary ventilation. In parallel, we aim to evaluate the prevalence of obstructive sleep apnea/hypopnea syndrome.

METHODS

This interventional, open-label, single-arm clinical trial will enroll patients who are diagnosed Mounier-Kuhn syndrome. Patient evaluation will be conducted in an outpatient clinic and involve 3 visits. Visit 1 will involve the collection and registration of social demographic, clinical, and functional data. Visit 2 will entail polysomnography, bronchoscopy for the evaluation of tracheobronchomalacia, titration of the optimal pressure that reduces the degree of collapse of the airway, and electrical impedance tomography. In visit 3, patients exhibiting a reduction in collapse areas will be requested to undergo chest computed tomography during inspiration and forced expiration with and without positive pressure (titrated to determine optimal CPAP pressure).

RESULTS

This protocol is a doctorate project. The project was submitted to the institutional review board on January 24, 2017, and approval was granted on February 2, 2017 (Brazilian Research database number CAAE 64001317.4.000.0068). Patient evaluations started in April 2018. Planned recruitment is based on volunteers' availability and clinical stability, and interventions will be conducted at least once a month to finish the project at the end of 2020. A preliminary analysis of each case will be performed after each intervention, but detailed results are expected to be reported in the first quarter of 2021.

CONCLUSIONS

There is no consensus on the best treatment options for managing Mounier-Kuhn syndrome. The use of positive pressure could maintain patency of the collapsed airways, functioning as a "pneumatic stent" to reduce the degree of airflow obstruction. This, in turn, could promote mobilization of thoracic secretion and improve pulmonary ventilation.

TRIAL REGISTRATION

ClinicalTrails.gov NCT03101059; https://clinicaltrials.gov/ct2/show/NCT03101059.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/14786.

A curious case of cough: Mounier-Kuhn syndrome in a Namibian female patient

We report a case of a 43-year-old female who presented with a history of recurrent productive cough, since her teenage years. Her associated symptoms included dyspnoea, occasional pleuritic chest pain and rarely, constitutional symptoms. Treated numerous times for lower respiratory tract infections, her symptoms would improve after antimicrobial therapy, but always recurred. She had a background of HIV infection and was virologically suppressed on antiretroviral therapy for nine years. Investigations revealed an active pseudomonas infection and high-resolution computed tomography scan (HRCT) and bronchoscopy confirmed features of Mounier-Kuhn syndrome. The patient was treated accordingly with positive airway pressure, mucolytic agents and chest physiotherapy aimed at aiding mucus clearance and received pneumococcal and influenza vaccines. Mounier-Kuhn syndrome, though rare, should be considered in the differential diagnosis of patients with recurrent lower respiratory tract infections. In Africa, more cases may be identified and treated appropriately with timely investigation and treatment.

Tracheobronchomegaly, cough and recurrent chest infection: Mounier-Kuhn syndrome

A 49-year-old male ex-smoker was referred for recurrent chest infections requiring one course of antibiotics every winter, occurring over the last 20 years. Each episode is characterised by a productive cough with purulent sputum along with difficulty breathing, chest tightness and fatigue, but without haemoptysis. On some occasions, these symptoms were preceded by fever and rhinorrhoea. Each episode lasted ∼10 days and responded well to antibiotics. He had never been hospitalised for these infections, nor received a chest radiograph or sputum microbiology. He had been told that he developed episodes of pneumonia in his first year of life. Apart from these yearly infections, the patient was asymptomatic during the rest of the year.

Mounier-Kuhn Syndrome (MKS) is a rare disease characterised by recurrent chest infections, and dilation of the trachea and main bronchi, most likely to due to atrophy of elastic fibreshttps://bit.ly/3azhDjr

Tracheobronchoplasty after a trial with a silicone Y-stent in a patient with Mounier-Kuhn syndrome

Tracheobronchomegaly or Mounier-Kuhn syndrome is a rare disorder characterized by the widening of the trachea and the main bronchi. It is a form of tracheomalacia called 'cartilaginous malacic' and is characterized by deformation of the tracheal cartilages and intrusion of the redundant membranous wall into the lumen of the airway. We present a patient with Mounier-Kuhn syndrome managed like patients with tracheomalacia of other aetiologies-a tracheobronchoplasty with a reconstructed D-shaped trachea and stabilization of the posterior membranous wall by attaching a polypropylene mesh to the posterior membranous wall of the trachea and the main bronchi after a trial period with a tracheobronchial Y-shaped silicone stent.

Congenital Tracheobronchomegaly (Mounier-Kuhn Syndrome) in a Woman with Human Immunodeficiency Virus: A Case Report

Congenital tracheobronchomegaly (Mounier-Kuhn Syndrome, MKS) is a rare idiopathic disorder characterized by dilation of the central airways, including the trachea and first through fourth order bronchi. MKS disproportionately affects men and results in chronic respiratory tract infections. The diagnosis is made through the synthesis of clinical and radiological data. Here we report a unique case of MKS in a patient with human immunodeficiency virus (HIV) infection. A 45-year-old African American woman with a past medical history of HIV, tobacco and recreational drug abuse, chronic obstructive pulmonary disease, sleep apnea, and a 15-year history of recurrent respiratory infections presented with dyspnea, wheezing, a productive cough, increased yellow-green sputum production, and subjective fevers. Computerized tomography (CT) of the chest revealed striking dilation of the trachea and central bronchi. Fiberoptic bronchoscopy demonstrated a dilated trachea and bronchial tree with complete collapse of the trachea and bilateral mainstem bronchi during expiration. Serial imaging over 14 years allowed the radiologist to confidently diagnose her underlying disorder and recommend appropriate clinical management, which included mucolytics, chest physiotherapy, prophylactic vaccinations, and antibiotics during infectious exacerbations. To the best of our knowledge, there is only one reported case of MKS in the setting of HIV in the English literature. We report the second such case and outline the clinical presentation, diagnostic criteria, and management of MKS with the hope that increased awareness will prevent delayed or misdiagnosis for patients with MKS. This case highlights the common diagnostic delay for MKS and the need to include MKS in the differential diagnosis of recurrent respiratory tract infections.

Mounier-Kuhn syndrome (tracheobronchomegaly): An analysis of eleven cases

BACKGROUND AND AIM

Mounier-Kuhn syndrome (MKS) is a congenital disorder characterized by tracheobronchomegaly resulting from the absence of elastic fibers in the trachea and main bronchi or atrophy and thinning of the smooth muscle layer. In this syndrome, dead space associated with tracheobronchomegaly increases and discharge of secretions decreases because of ineffective coughing. The most common complications are recurrent lower respiratory tract infections and bronchiectasis. We examined the clinical characteristics, radiological features, and related complications of patients with MKS.

METHODS

The cases were obtained between September 2007 and November 2015. Computed tomography scans of the chest were used to diagnose tracheobronchomegaly.

RESULTS

All cases (a total of 11) were males with a mean age of 63 ± 13 (range, 38-80) years. The mean diameter of the trachea was 31.53 ± 2.99 mm; the mean transverse diameter was 31.69 ± 3.10 mm and the mean sagittal diameter was 31.36 ± 3.01 mm. Complaints at the time of presentation included chronic cough, purulent sputum, dyspnea, and hemoptysis. There were recurrent pulmonary infections in seven cases, bronchiectasis in six, and tracheal diverticulum in four at the time of diagnosis.

CONCLUSIONS

In this article, 11 cases with various rarely seen complications are presented and evaluated in the light of current literature. We recommend that if chronic cough, recurrent pulmonary infections, and bronchiectasis seen in a patient, MKS should be kept in mind.

Respiratory Conditions Associated with Tracheobronchomegaly (Mounier-Kuhn Syndrome): A Study of Seventeen Cases

BACKGROUND

Mounier-Kuhn syndrome (MKS) is a rare disorder characterized by enlargement of the trachea and main bronchi and associated with recurrent respiratory tract infections.

OBJECTIVE

This multicenter, retrospective study was carried out to describe respiratory conditions associated with tracheobronchomegaly.

METHODS

Nine institutions involved in the 'Groupe d'Endoscopie de Langue Française' (GELF) participated in this study. A standard form was used to record patient characteristics, treatments and follow-up from medical charts.

RESULTS

Seventeen patients, 53% male, aged 58 ± 18 years at diagnosis were included. Recurrent infections revealed MKS in 88% of cases. Main comorbid conditions were diffuse bronchiectasis in 88% of patients and tracheobronchomalacia in 67% of cases. The exacerbation rate was 1.5 exacerbations/patient/year. The main non-respiratory morbid condition was gastroesophageal reflux disease in 29% of cases. Interventional bronchoscopy was performed in seven patients (41%), consisting of laser (n = 2) and tracheal stenting (n = 5). Complications related to stents were observed in 80% of cases with a mean stent duration of 8 months. Four deaths, including three due to respiratory causes, occurred during follow-up.

CONCLUSIONS

This is the largest series of MKS reported in the literature, showing that bronchiectasis and tracheobronchomalacia are the main associated morbid conditions that constitute a challenge for treatment.

Mounier-Kuhn Syndrome in an Elderly Female with Pulmonary Fibrosis

Mounier-Kuhn syndrome (MKS), or tracheobronchomegaly, is a rare clinical and radiologic condition characterized by pronounced tracheobronchial dilation and recurrent lower respiratory tract infections. Tracheobronchomegaly presents when the defect extends to the central bronchi. MKS can be diagnosed in adult women when the transverse and sagittal diameters of the trachea, right mainstem bronchus, and left mainstem bronchus exceed 21, 23, 19.8, and 17.4 mm, respectively. Its diagnosis is based on chest radiograph and chest computed tomography (CT). Patients, usually middle-aged men, may be asymptomatic or present with clinical manifestations ranging from minimal symptoms with preserved lung function to severe respiratory failure. Pulmonary function tests (PFTs) typically reveal a restrictive pattern. This report presents an elderly woman with previously diagnosed pulmonary fibrosis with symptoms of increased sputum production and haemoptysis. High-resolution chest CT showed tracheal and main stem bronchi dilatation along with bronchial diverticulosis. PFTs indicated a restrictive pattern characteristic of the underlying pulmonary fibrosis. The patient is the oldest, referred to the female gender, at presentation of MKS hitherto reported. This case highlights the need to include MKS in the differential diagnosis of recurrent lower respiratory tract infections, even in older subjects.

Tracheobronchial smooth muscle atrophy and separation

We report a case series involving 4 patients with chronic obstructive pulmonary disease who were on an appropriate medical regimen including a high dose of inhaled corticosteroids (ICS). During bronchoscopy, patients were found to have an excessive dynamic collapse of the posterior wall and its separation from the ends of the adjacent cartilaginous rings. This was causing a near-total occlusion of the tracheal and bronchial lumen during exhalation, thereby presenting with an obstructive pattern on the pulmonary functions. We suspect that this was caused by the atrophy of the smooth muscles of the tracheobronchial wall. We reviewed the literature to explore the mechanisms causing atrophy of the bronchial smooth muscle, focusing on the potential role of long-term ICS use.

Tracheomalacia treatment using a large-diameter, custom-made airway stent in a case with mounier-kuhn syndrome

Mounier-Kuhn Syndrome (MKS) is a rare congenital disease that presents with abnormal enlargement in the central airways. In MKS, tracheomegaly is accompanied by difficulty in expelling recurrent lung infections and bronchiectasia. We presented a patient with MKS where commercially made stents were inadequate for stabilization and a custom-made, self-expandable metallic stent with a diameter of 28 mm and length of 100 mm was used. Chest pain that was thought to develop due to the stent and that disappeared after stent removal may be considered the main complication leading to stent removal. Continuous positive airway pressure therapy (CPAP) therapy was planned for the control of symptoms, which re-emerged after stent removal. This case is presented as an example that complications developing due to the stent as well as patient noncompliance may lead to stent removal, even when useful results are obtained from treatment of MKS.

Mounier-Kuhn syndrome masquerading pulmonary thromboembolism in an elderly male

Mounier-Kuhn syndrome, also referred to as tracheobronchomegaly, is a rare idiopathic clinical and radiologic disorder characterized by significant tracheobronchial dilation. It results in recurrent lower respiratory tract infections and bronchiectasis. In severe cases, patients may present with acute respiratory distress requiring hospital admission and ventilatory support. Clinical examination and chest radiography may be misleading in these patients as tracheobronchomegaly is easily overlooked on radiographs. We present an interesting report of our patient who presented with acute shortness of breath. A diagnosis of acute pulmonary thromboembolism was suggested by initial evaluation. Computed tomography pulmonary angiography was negative for thromboembolism; however, it revealed diagnosis of this rare disorder.

Mounier-Kuhn syndrome or congenital tracheobronchomegaly: a literature review

Mounier-Kuhn syndrome or congenital tracheobronchomegaly is a chronic airway condition which for currently unknown reasons mostly affects males. It is commonly overlooked on conventional chest X-rays, and is considered to be rare, but the prevalence might be higher as commonly assumed. The hallmark of it is a dilatation of the main airways which frequently, but not always, causes marked, mainly respiratory, symptoms, and patients usually present with varying degrees of recurrent infections, breathlessness, haemoptysis, dyspnoea. Although at least 200 case reports have been published, there have been only a few attempts to review them, and none in the last 20 years. Due to the lack of clinical trials and wide variability of case-report format, a systematic review was deemed not feasible, therefore PubMed and Medline databases were searched using terms "Mounier-Kuhn syndrome", "tracheobronchomegaly", "tracheomegaly", and "bronchomegaly", without any time restrictions, to summarize currently known facts about the syndrome. To the authors' best knowledge, the result is currently the most comprehensive review of previously published literature about the congenital tracheobronchomegaly, and summarizes what's known about symptoms, prevalence, disease associations, and treatment options for this syndrome.

Mounier-Kuhn syndrome and bilateral vocal cord paralysis

Mounier-Kuhn syndrome is a rare disorder of unknown cause that is characterized by atrophy of the elastic and smooth muscle of the tracheobronchial tree leading to tracheobronchomegaly and bronchiectasis. The syndrome is likely underdiagnosed, because the patients usually present with common respiratory symptoms such as productive cough and usually labeled as chronic obstructive pulmonary disease. Diagnosis is established on the basis of radiologic findings. Association with bilateral vocal cord paralysis has not been described. Treatment is mainly supportive. Symptomatic patients may require endobronchial stenting if airway collapse is encountered. Here, we described a patient who presented with hoarseness and pneumonia. Further studies confirmed the diagnosis of Mounier-Kuhn syndrome with bilateral vocal cord paralysis.

Respiratory support with venovenous extracorporeal membrane oxygenation during stenting of tracheobronchomalacia

A subset of patients with severe airway disease cannot be adequately supported with conventional mechanical ventilation during complex airway procedures. We report the successful respiratory support of a patient with severe tracheobronchomalacia with venovenous extracorporeal membrane oxygenation during rigid bronchoscopy with stent removal and stent placement.

[Tracheobronchomalacia in adults: breakthroughs and controversies]

Tracheobronchomalacia (TBM) in adults is a disease defined by a reduction of more than 50% of the airway lumen during expiration. It encompasses many etiologies that differ in their morphologic aspects, pathophysiological mechanisms and histopathologies. TBM is encountered with increasing frequency, as it is more easily diagnosed with new imaging techniques and diagnostic bronchoscopy, as well as because of its frequent association with Chronic Obstructive Pulmonary Disease (COPD), which represents the most frequent etiology for acquired TBM in adults. A distinction between TBM in association with failure of the cartilaginous part of the airways and TBM affecting only the posterior membranous part is emerging since their physiopathology and treatment differ. The therapeutic management of TBM should be as conservative as possible. Priority should be given to identification and treatment of associated respiratory diseases, such as asthma or COPD. Surgery addressing extrinsic compression (thyroid goiter or tumor, for example) may be necessary. Noninvasive ventilation can be considered in patients with increasing symptoms. Endoscopic options, such as the placement of stents, should only be used as palliative or temporary solutions, because of the high complication rates. Symptomatic improvement after stenting might be helpful in selecting patients in whom a surgical management with tracheobronchoplasty can be useful.