Tracheobronchomalacia: Evolving role of dynamic multislice helical CT

Le collapsus trachéobronchique expiratoire regroupe la trachéobronchomalacie, maladie des anneaux cartilagineux et le collapsus dynamique excessif des voies aériennes, bombement majeur de la membraneuse au niveau la paroi postérieure. La symptomatologie repose sur des signes respiratoires peu spécifiques comme la dyspnée, la toux ou les difficultés d’expectoration. Le diagnostic est obtenu lors d’épreuves dynamiques, par l’endoscopie bronchique et/ou le scanner. La trachéobronchomalacie peut être primaire (génétique, idiopathique) ou secondaire liée à un traumatisme, une trachéotomie, une intubation, une intervention chirurgicale, une transplantation, un emphysème, une infection, une inflammation, une bronchite chronique, une compression extrinsèque ou à des anneaux vasculaires non diagnostiqués dans l’enfance. Certains algorithmes décisionnels thérapeutiques ont été proposés, mais aucune recommandation précise n’a été établie. Le traitement, d’abord médical (prise en charge de la pathologie sous-jacente, parfois associée à la ventilation non invasive), est réservé aux malades symptomatiques, après évaluation du retentissement de la maladie (statut fonctionnel et perfomance status du malade, évaluation des symptômes et de la qualité de vie par différents scores). Si les symptômes persistent, d’autres traitements sont discutés. Au sein de l’arsenal thérapeutique, la bronchoscopie interventionnelle permet : (1) la sélection des malades pouvant bénéficier du traitement chirurgical de référence, avec la mise en place d’une endoprothèse comme test thérapeutique avant trachéobronchoplastie ; (2) la pose d’endoprothèses dans les voies aériennes chez les malades non chirurgicaux, dans le but d'obtenir une amélioration des symptômes et de la qualité de vie, au prix d’effets secondaires majeurs liés aux endoprothèses ; (3) la prise en charge de la majorité des complications associées aux endoprothèses (obstruction, granulomes, migration fracture) ; (4) des alternatives thérapeutiques avec la possibilité de techniques thermo-ablatives. Enfin, le développement de nouvelles endoprothèses pourrait permettre de diminuer le taux de complications. Ces différentes options restent encore très discutées à l’heure actuelle.

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.

The diagnosis, prognostication, and differentiation of phenotypes of COPD can be facilitated by CT scan imaging of the chest. CT scan imaging of the chest is a prerequisite for lung volume reduction surgery and lung transplantation. Quantitative analysis can be used to evaluate extent of disease progression. Evolving imaging techniques include micro-CT scan, ultra-high-resolution and photon-counting CT scan imaging, and MRI. Potential advantages of these newer techniques include improved resolution, prediction of reversibility, and obviation of radiation exposure. This article discusses important emerging techniques in imaging patients with COPD. The clinical usefulness of these emerging techniques as they stand today are tabulated for the benefit of the practicing pulmonologist.

This study examines the long-term anatomic and clinical effects of tracheobronchoplasty in severe excessive central airway collapse.

Included patients underwent tracheobronchoplasty for excessive central airway collapse (2002-2016). The cross-sectional area of main airways on dynamic airway computed tomography was measured before and after tracheobronchoplasty. Expiratory collapse was calculated as the difference between inspiratory and expiratory cross-sectional area divided by inspiratory cross-sectional area ×100. The primary outcome was improvement in the percentage of expiratory collapse in years 1, 2, and 5 post-tracheobronchoplasty. Secondary outcomes included mean response profile for the 6-minute walk test, Cough-Specific Quality of Life Questionnaire, Karnofsky Performance Status score, and St George Respiratory Questionnaire. Repeated-measures analysis of variance was used for statistical analyses.

The cohort included 61 patients with complete radiological follow-up at years 1, 2, and 5 post-tracheobronchoplasty. A significant linear decrease in the percentage of expiratory collapsibility of the central airways after tracheobronchoplasty was present. Anatomic repair durability was preserved 5 years after tracheobronchoplasty, with decrease in percentage of expiratory airway collapse up to 40% and 30% at years 1 and 2, respectively. The St George Respiratory Questionnaire (74.7 vs 41.8%, P < .001) and Cough-Specific Quality of Life Questionnaire (78 vs 47, P < .001) demonstrated significant improvement at year 5 compared with baseline. Similar results were observed in the 6-minute walk test (1079 vs 1268 ft, P < .001) and Karnofsky score (57 vs 82, P < .001).

Tracheobronchoplasty has durable effects on airway anatomy, functional status, and quality of life in carefully selected patients with severe excessive central airway collapse.

The term tracheobronchomalacia refers to excessively compliant and collapsible central airways leading to symptoms. Although seen as a coexisting condition with various other pulmonary condition, it may cause symptoms by itself. The condition is often misdiagnosed as asthma, bronchitis or just chronic cough due to a lack of specific pathognomonic history and clinical findings. The investigation revolves around different modes of imaging, lung function testing and usually confirmed by flexible bronchoscopy. The treatment widely varies based on the cause, with most cases treated conservatively with non-invasive ventilation. Some may require surgery or stent placement. In this article, we aim to discuss the pathophysiology behind this condition and recognize the common symptoms and causes of tracheobronchomalacia. The article will highlight the diagnostic steps as well as therapeutic interventions based on the specific cause.

Airway complications following lung transplantation result in considerable morbidity and are associated with a mortality of 2% to 4%. The incidence of lethal and nonlethal airway complications has decreased since the early experiences with double- and single-lung transplantation. The most common risk factor associated with post-lung transplantation airway complications is anastomotic ischemia. Airway complications include the development of exophytic granulation tissue, bronchial stenosis, bronchomalacia, airway fistula, endobronchial infection, and anastomotic dehiscence. The broadening array of bronchoscopic therapies has enhanced treatment options for lung transplant recipients with airway complications. This article reviews the risk factors, clinical manifestations, and treatments of airway complications following lung transplantation and provides our expert opinion when evidence is lacking.