Size and morphology of the trachea before and after lung volume reduction surgery

The purpose of this investigation was to determine the effect of lung volume reduction surgery on measured tracheal features.

Twenty-four male and 19 female patients with emphysema underwent lung volume reduction surgery, pulmonary function testing, and repeated CT. The tracheal air column was segmented from axial images. The sagittal and coronal dimensions of the intrathoracic trachea were determined. Tracheal morphology was quantified using the tracheal (coronal and sagittal dimensions) and circularity indexes. The results were compared with pulmonary function test results.

Morphologic appearance of the intrathoracic trachea was consistent before and 3 months after surgery. The group means of the tracheal length, mean area, and volume were 78.60 mm (+/- 16.88 mm), 283.84 mm(2) (+/- 61.47 mm(2)), and 22.59 cm(3) (+/- 7.69 cm(3)), respectively, before surgery and 67.53 mm (+/- 15.78 mm), 309.12 mm(2) (+/- 79.83 mm(2)), and 20.99 cm(3) (+/- 7.27 cm(3)), respectively, after surgery (p < 0.05). Mean tracheal indexes were 0.85 (+/- 0.11) before surgery and 0.82 (+/- 0.04) after surgery (p < 0.01). Mean circularity indexes were 0.91 (+/- 0.03) before surgery and 0.90 (+/- 0.04) after surgery (p < 0.05). The size of the trachea was significantly correlated with lung volume before and after surgery (p < 0.05). The changes in tracheal features and changes in pulmonary function were not correlated (p > 0.05), except for tracheal area (p < 0.05).

Our data suggest that tracheal dimensions reflect the severity of emphysema as reflected by increased lung volumes. Tracheal features were poor predictors of changes in postsurgical pulmonary function parameters evaluated in this preliminary study.