Tracheal stenosis after tracheostomy (stages of bronchoscopy, annotations)

Pictures taken as the bronchoscope progresses from the larynx (Picture 1) to the stenotic area (Pictures 2 and 3) and the normal post-stenotic trachea (Picture 4).

Black arrows: vocal cords
Cycle: stenotic trachea. The stenosis has a pseudo-glottic aspect
White arrow: closure of the tracheostomy