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 ¹.

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 ¹.

Classification

Some classification on terms severity with some proposing a collapse of >90% during expiration on dynamic imaging being considered as severe ⁴.

Radiographic features

CT

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

See also

• dynamic tracheal collapse