Excessive dynamic airway collapse

Excessive dynamic airway collapse (EDAC) refers to a dynamic form of central airway obstruction characterized by a decrease of ≥50% (more recent publications suggest >70%) in the cross-sectional area of the tracheobronchial lumen. Diagnosis is usually confirmed by dynamic cross-sectional imaging studies or bronchoscopy.

Terminology

Some authors consider an overlap with tracheomalacia, however, it is best thought that tracheomalacia describes a pathology whereby the cartilaginous structures of the trachea are weak, while EDAC is a mechanical description of the resultant effect on the airway .

Pathology

It is marked by excessive bulging of the posterior membrane into the airway lumen during exhalation.

Associations

Can co-exist patient with chronic obstructive pulmonary disease.

Classification

Some classification on terms severity with some proposing a collapse of >90% during expiration on dynamic imaging being considered as severe.

Radiographic features

CT

Typically exaggerated bulging of the posterior wall within the airway lumen during exhalation with an excessive flattening in AP diameter.