Unexpected Difficult Intubation Caused by Idiopathic Subglottic Stenosis

A 44-year-old woman was scheduled to undergo an emergency laparoscopic operation for acute appendicitis. Her past medical history included chronic asthma (2 years prior) that was not treated with medication or inhaler. After inducing general anesthesia, a 6.5-mm internal diameter (ID) endotracheal tube (ETT) could not be advanced below the level of the vocal cords because of resistance, and a reattempt with a 6.0-mm ID ETT also failed. Although a laryngeal mask airway was inserted, ventilation was inadequate. The appendectomy was cancelled. Because of the unexpectedly difficult intubation, an otolaryngologist was consulted to examine her larynx, and subglottic stenosis (SGS) of unknown origin was suggested. We present a case of unexpected difficult intubation caused by idiopathic SGS after induction of anesthesia.