A case of unexpected intraoperative airway obstruction in a patient with an aneurysm of the ascending aorta and aortic arch.

Upper airway compression is one of the clinical manifestations of thoracic aortic aneurysm, which is associated with poor prognosis and high mortality. A 44-year-old patient with ascending aortic and arch aneurysm who was scheduled for Bentall surgery and total arch replacement under cardiopulmonary bypass suffered difficult ventilation after endotracheal intubation. The patient did not exhibit any positional dyspnoea or orthopnoea, did not show any difficulties in the supine position, and had no noteworthy medical history. However, we encountered unexpected hypoventilation after intubation. Isoprenaline infusion was effective while emergency cardiopulmonary bypass was established to deal with this crisis. Fibreoptic bronchoscopy revealed complete obstruction of the carina and confirmed the supracarinal position of the tube. Complete airway obstruction may occur even if there are no symptoms before surgery in patients with thoracic aortic aneurysm. Comprehensive preoperative assessment, a well-developed airway management plan, and responses to possible emergencies are essential to reduce unnecessary events or complications.