Fig. 2

Cervical coronal and corresponding transverse section imaging of CT scanning. Preopeartive imaging showing no obstruction in upper airway in cervical vertebrae 4-6 segement (a, Cervical vertebrae 4-5 and b, Cervical vertebrae 5-6; green asterisk, trachea). On postoperative day 9, no space between tracheal tube and surrounding tissue was noticed from CT scanning images, indicating severe airway edema (c-e, corresponding to Cervical vertebrae segement of 3-5; yellow asterisk, showing swollen Oropharyngeal cavity). On postoperative day 15 (5 days after trecheostomy), airway stenosis still existed with significant edema, corresponding to the level of Cervical vertebrae segement of 4-6, (f-i; corresponding to C4-6 segement; yellow arrow, airway edema and resultant tracheal stenosis)