Severe refractory asthma? Consider acquired tracheobronchomalacia

Tracheobronchomalacia (TBM) is characterized by weakness of the tracheal and bronchial walls with resultant narrowing and dynamic collapse of the airways, causing shortness of breath, coughing and wheezing, and increased risk of infection. Primary disease in children often resolves with growth. However, acquired TBM can occur in adults secondary to trauma with recurrent intubation, chronic inflammation (relapsing polychondritis), endoluminal cancer, or external compression by goiter, cysts, or aortic aneurysm. TBM is associated with COPD, chronic bronchitis, and asthma, but the disease may be under-recognized or attributed to refractory asthma or COPD in the community setting. We present a patient with common variable immunodeficiency (CVID) and recurrent bronchiectasis/asthma exacerbations who was eventually diagnosed with acquired TBM, illustrating the importance of interdisciplinary collaboration among immunologists, pulmonologists, and ENT specialists to ensure diagnosis and successful treatment. Case: A 56-year-old female was admitted for pneumonia and respiratory failure. She reported monthly outpatient visits for dyspnea, wheezing and cough (attributed to asthma) and numerous hospitalizations for pneumonia over the previous 2 years. Her history included childhood toxoplasmosis and eosinophilic gastritis. Additionally, she received monthly IVIG therapy for confirmed CVID. She was followed by pulmonology, allergy/immunology and ENT for severe refractory asthma, bronchiectasis (diagnosed by HRCT), and recurrent infections. Innumerable antibiotics, mepolizumab, inhalers, and high dose prednisone were prescribed. She failed weaning of steroids, and developed iatrogenic Cushing's syndrome and osteoporosis. Eventually, dynamic phase chest CT and bronchoscopy confirmed severe TBM, showing 50-60% tracheal collapse, 60-80% left main bronchial collapse, and 80-90% right main bronchial collapse. Treatment with BiPAP was unsuccessful, and she was readmitted with pneumonia requiring intubation. During her prolonged hospital course, she failed extubation multiple times, necessitating tracheal Y stent placement. This allowed successful extubation, but she suffered laryngeal and vocal cord injury with stent removal and was reintubated. Subsequent mesh tracheoplasty was performed, with remarkable symptom resolution. Discussion: The overall estimated incidence of TBM is 5-10%, though one study reported TBM in 23% of 200 patients with chronic bronchitis. Disease recognition is important to avoid complications of ineffective therapy (in our case, rotating antibiotics, iatrogenic Cushing's and osteoporosis). Management includes smoking cessation, and treatment of underlying disease and infection. In some cases, continuous positive airway pressure can act as a “pneumatic stent”; however, stents or tracheoplasty may be required for severe TBM. Advances in CT dynamic imaging has improved recognition of this disorder, though bronchoscopy remains the “gold standard” for TBM diagnosis.