Tracheobronchomalacia and/or Excessive Dynamic Airway Collapse?

Expiratory airway collapse is defined as more than 50% reduction in the horizontal cross-sectional area of the airway at expiration or during coughing; and is due to pure tracheobronchomalacia (TBM) or excessive dynamic airway collapse (EDAC). It is not easy to make a clear differentiation between TBM and EDAC. These two conditions are different entities, yet they may be mistaken for each other and they may also coexist. In this paper we discuss differential diagnosis of EDAC and TBM in the light of fiberoptic and virtual bronchoscopic images according to a newly proposed FEMOS classification.