Laryngotracheal stenosis is a narrowing of the larynx or trachea, usually caused by scarring or congenital abnormalities (e.g. congenital abnormalities of the tracheal cartilages). Mild laryngotracheal stenosis usually causes no symptoms. However, if the narrowing is greater than 50% of the airway circumference, it can lead to serious complications.

Endoscopic surgery for facial paralysis is a difficult surgery that takes a long time to perform. Endotracheal anesthesia is the anesthesia method used to perform endoscopic surgery for facial paralysis.