Airway malacia in chronic obstructive pulmonary disease: prevalence, morphology and relationship with emphysema, bronchiectasis and bronchial wall thickening

The aim of this study was to determine the prevalence of airway malacia and its relationship with ancillary morphologic features in patients with chronic obstructive pulmonary disease (COPD). A retrospective review was performed of a consecutive series of patients with COPD who were imaged with inspiratory and dynamic expiratory multidetector computed tomography (MDCT). Airway malacia was defined as ≥50% expiratory reduction of the airway lumen. Both distribution and morphology of airway malacia were assessed. The extent of emphysema, extent of bronchiectasis and severity of bronchial wall thickness were quantified. The final study cohort was comprised of 71 patients. Airway malacia was seen in 38 of 71 patients (53%), and such proportion was roughly maintained in each stage of COPD severity. Almost all tracheomalacia cases (23/25, 92%) were characterised by an expiratory anterior bowing of the posterior membranous wall. Both emphysema and bronchiectasis extent did not differ between patients with and without airway malacia (p > 0.05). Bronchial wall thickness severity was significantly higher in patients with airway malacia and correlated with the degree of maximal bronchial collapse (p < 0.05). In conclusion, we demonstrated a strong association between airway malacia and COPD, disclosing a significant relationship with bronchial wall thickening.