Description of a multidimensional classification system for patients with expiratory central airway collapse

Patients with expiratory central airway collapse present with various symptoms, aetiologies, morphologies, extent and severity of airway collapse. The aim of this study was to delineate a multidimensional classification system and common language for evaluating patients with expiratory central airway collapse.

The classification system was based on the morphology and origin of the airway abnormality as well as stratification parameters such as functional status, extent and severity of airway collapse. Patients with expiratory central airway collapse who underwent clinical and bronchoscopic examination before and after treatment were identified from a bronchoscopy database. The classification was applied to the study patients before and after treatment to assess the utility of this stratification approach.

Eighteen patients were studied. Four had excessive dynamic airway collapse and 14 had tracheobronchomalacia. Post-treatment, functional status improved by one class in 12 patients, by two classes in four patients and remained unchanged in two. Severity of airway collapse improved in 15 and remained unchanged in three patients. The extent of abnormality diminished in 14 patients and did not change in four.

Using this classification, the morphologies and aetiologies of expiratory central airway collapse are identified, and an objective stratification of patients according to degree of functional impairment, extent of disease and severity of airway collapse is possible.