Correct!
4. Tracheobronchomalacia
Note the near or total collapse of the trachea and major bronchi at end expiration. Severe, diffuse tracheobronchomalacia (TBM) is an underrecognized cause of dyspnea, recurrent respiratory infections, cough, secretion retention, and even respiratory insufficiency (3). The posterior wall of the trachea and airways normally collapse during expiration (Figure 5A, 5B). However, when this is excessive (5C, 5E) or when the anterior wall collapses (5D, 5E) it can lead to symptoms.
Figure 5. Schematic of normal airway collapse, excessive dynamic airway collapse (EDAC) and tracheomalacia (TBM). Panel A: normal trachea at end inspiration. Panel B: normal trachea at end expiration. Panel C: abnormal trachea showing EDAC at end expiration with the tracheal cartilage supporting the anterior trachea but excessive collapse of the posterior trachea. Panel D: TBM at end expiration showing collapse the anterior trachea and to a lesser extent the posterior trachea. Panel E: EDAC and TBM and end expiration showing collapse of both the anterior and posterior trachea forming a crescent.
The prevailing definition of TBM as a 50% reduction in cross-sectional area is nonspecific, with a high proportion of healthy volunteers meeting this threshold (4). The clinically significant threshold is complete or near-complete collapse of the airway. TBM may result from relapsing polychondritis or occur in association with airway diseases such as asthma, chronic obstructive pulmonary disease, or cystic fibrosis. However, most of these patients have an acquired form of TBM in which the etiology in unknown. Diagnosis of TBM is made by airway computed tomography scan or flexible bronchoscopy with forced expiration. The prevailing definition of TBM as a 50% reduction in cross-sectional area is nonspecific, with a high proportion of healthy volunteers meeting this threshold. The clinically significant threshold is complete or near-complete collapse of the airway.
Airway stenting may treat TBM, although complications resulting from indwelling prostheses often limit the durability of stents (4). Surgical central airway stabilization by posterior mesh splinting (tracheobronchoplasty) effectively corrects malacic airways and has been shown to lead to significant improvement in symptoms. A short-term tracheal stent trial facilitates surgical selection.
After hearing the pros and cons of therapy, our patient chose to be followed rather than undergo tracheobronchoplasty.
References