A Case of Traumatic Closed Cricothyroid Ligament Perforation Causing Severe Mediastinal and Subcutaneous Emphysema

Traumatic laryngeal injuries are classified as either open or closed. In general, open laryngeal injuries require repositioning or reconstructive surgery at an early stage. Closed laryngeal injuries can also be cured with conservative therapy using a steroid. Blunt external trauma to the larynx often causes dyspnea due to damage to the thyroid or cricoid cartilage or dislocation of the arytenoid cartilage. Herein, we report a case of traumatic closed cricothyroid ligament perforation caused by the blunt external force of a wood chip that led to severe mediastinal and subcutaneous emphysema and required emergency reconstructive surgery. The patient was a 75-year-old man carpenter with no significant past medical history. He sustained a throat injury from a wood chip while working and was transported by ambulance to the hospital. He presented with a neck swelling and dysphonia, but no dyspnea. Computed tomography (CT) showed extensive emphysema in the subcutaneous tissue of the neck, mediastinum, right pleura, and right upper back, with no damage to the laryngeal cartilages. The patient was admitted for observation. His emphysema suddenly worsened significantly eight hours after the injury. Therefore, we performed emergency surgery nine hours post-injury under general anesthesia. During intubation, we confirmed a subglottic forward fistula using a video laryngoscope, based on which we made the diagnosis of cricothyroid ligament perforation. We performed closure of the laryngeal perforation through an external incision. The patient was discharged six days after the injury. By four weeks post-injury, the emphysema had resolved completely. We rescued the patient before he developed severe dyspnea.