Novel Multimodality Imaging and Physiologic Assessments Clarify Choke-Point Physiology and Airway Wall Structure in Expiratory Central Airway Collapse

Choke points and airway wall structure in expiratory central airway collapse are poorly defined. Computed tomography, white light bronchoscopy, endobronchial ultrasound, vibration response imaging, spirometry, impulse oscillometry, negative expiratory pressure, and intraluminal catheter airway pressure measurements were used in a patient with cough, dyspnea, and recurrent pulmonary infections. Computed tomography and white light bronchoscopy identified dynamic collapse of the trachea and mainstem bronchi, consistent with severe crescent tracheobronchomalacia. Spirometry showed severe obstruction. Endobronchial ultrasound revealed collapse of the airway cartilage, and vibration response imaging revealed fluttering at both lung zones. Impulse oscillometry and negative expiratory pressure suggested tidal expiratory flow limitation in the intrathoracic airways. Intraluminal catheter airway pressure measurements identified the choke point in the lower trachea. After Y-stent insertion, the choke point migrated distally. Imaging studies revealed improved airway dynamics, airway patency, and ventilatory function. Novel imaging and physiologic assessments could be used to localize choke points and airway wall structure in tracheobronchomalacia.