Tracheal malformation is a very big concept. For example, the right lung is divided into ten segments and the left lung is roughly eight segments, each of which is innervated by a trachea. In addition, if the trachea is larger or smaller than normal in a certain place, this is also a developmental abnormality. In other places, it seems that the bronchus is not developed, it is just a bud, this is called bronchial failure, this time it may be a diverticulum, bronchial development abnormalities, mainly including these things.