Tracheal and main bronchial diverticula: the role of CT

This paper describes an asymptomatic and rarely diagnosed entity without a clear correlation with respiratory disease identified in 1%-2% of cases at spiral computed tomography (CT).

We retrospectively reviewed the CT features of air collections contiguous to the tracheal or main bronchial wall and communicating with the airway in 16 patients undergoing CT for other reasons. Four patients were also studied by virtual bronchoscopy and three by actual bronchoscopy.

Thirteen of the 16 patients had a single diverticulum, whereas the remaining three had multiple diverticula. Only one patient had a bronchial diverticulum. The most frequent site was the right posterolateral wall of the trachea at the level of the second or third thoracic vertebral body. In 2/3 of patients, chronic obstructive pulmonary disease was not documented.

CT was the most effective method for evaluating the presence and features of diverticula. A correlation between tracheobronchial diverticula and chronic respiratory disease was documented in 5/16 patients, whereas no respiratory disorder was identified in the remaining 11. Although chronic inflammatory tracheobronchial changes and increased endoluminal pressure may be important causes, we hypothesise that other, as yet unknown, aetiopathological factors could exist.