a) Tracheomalacia
b) Tracheal stenosis
i) Congenital
ii) Acquired
c) Endotracheal tumors
i) Papillomatosis
ii) Carcinoid
iii) Hemangioma
iv) Others
d) Tracheoesophageal fistulas
e) Tracheal compression syndromes
i) Right aortic arch
ii) Vascular rings
iii) PA sling
iv) Paratracheal tumor or mass
v) Innominate artery compression
vi) Esophageal foreign bodies or masses
vii) Mediastinal mass lesions
f) Tracheoesophageal clefts (high grade)
g) Trauma