"Saber-sheath" trachea.

Narrowing of the intrathoracic trachea in the coronal plane with anteroposterior lengthening is characteristic of the "saber-sheath" trachea deformity. This structural disorder is strongly associated with chronic obstructive pulmonary disease and may be related to chronic bronchitis. Although lateral compression suggests weakening and collapse, the supporting tracheal cartilage is usually thickened and densely calcified. We present a patient who was discharged after uneventful total laryngectomy but later complained of increasing airway obstruction from crusted secretions, resulting in visits to the emergency room and admission to the hospital. After the diagnosis was made by computed tomography, tracheal dilation was performed with some improvement. The diagnostic findings of the saber-sheath trachea, differential diagnosis, possible causes, and clinical implications are discussed.