Table 1 Case characteristics
| Disease | Covered group (n = 36) |
Uncovered group (n = 9) |
|---|---|---|
| Cicatricial tracheal stenosis after tracheotomy | 12 | 3 |
| Granulation tissue hyperplasia after tracheotomy | 3 | 1 |
| Cicatricial stenosis of the trachea after tracheal intubation | 9 | 2 |
| Granulation tissue hyperplasia after tracheal intubation | 1 | 0 |
| Tracheobronchial tuberculosis | 4 | 2 |
| Traumatic injuries | 1 | 0 |
| Polychondritis | 1 | 0 |
| Tracheal invasion by esophageal carcinoma | 2 | 1 |
| Esophageal stent oppression | 1 | 0 |
| Lung cancer | 1 | 0 |
| Neoplasm metastasis or lymphadenectasis | 1 | 0 |