Tracheal Stenosis Caused by Thoracic Malignancy: Correlation between CT-Based Tracheal Measurement and Spirometric Values before and after Tracheal Stenting

Abstract

Background: The correlation between computed tomography (CT)-based tracheal size and spirometry values is unknown in patients with tracheal stenosis by thoracic malignancy, which is often treated by tracheal stenting. Objectives: To evaluate the correlation between the tracheal cross-sectional area (CSA) and spirometric values before and after tracheal stenting, and to confirm that greater improvement in tracheal CSA leads to a larger improvement in spirometry values. Methods: A total of 32 patients with malignant tracheal stenosis underwent tracheal stenting. Before (n = 32) and after (n = 27) treatment, patients underwent chest CT, measuring mean and minimum tracheal CSA values, and spirometry. The correlation between tracheal CSA and each spirometric value was evaluated using Spearman rank correlation analysis. Differences in the pre-and posttreatment tracheal CSA and spirometric values were evaluated using the Wilcoxon matched-pairs test. Results: Significant improvement in the minimum tracheal CSA and in spirometric values was observed after stenting (P < 0.001). Pretreatment analysis revealed significant correlations between the minimum tracheal CSA and various spirometric values (P < 0.01), but posttreatment analysis showed weak or insignificant correlations. The increase in the minimum tracheal CSA obtained by stenting was significantly correlated with improvement in multiple spirometric values (P < 0.05). Conclusions: The tracheal size measured on chest CT correlates with patients' spirometric values, particularly at the prestenting examination,

3D-measurement of tracheobronchial angles on inspiratory and expiratory chest CT in COPD: respiratory changes and correlation with airflow limitation

“…This can be applied in patients with excessive dynamic airway collapse related to COPD, relapsing polychondritis, and tracheobronchial stenosis due to malignant neoplasms. 27 – 29 Although a previous study precisely analyzed branching angles of the RMB and LMB on chest CT to simulate insertion of double-lumen endotracheal tubes for lung isolation (1-lung ventilation), 30 no attempt has been made to modify the angles of endotracheobronchial stents. Currently, all commercially available endotracheobronchial stents (Y-shaped stents) have fixed angles (trachea–RMB angle=135°, trachea–LMB angle=150°), which are not suitable for certain patients.…”