Case Report: Emergency management of difficult airway in a thyroid cancer patient with undiagnosed tracheal diverticulum preoperatively and literature review.

Tracheal diverticulum, a rare chronic airway pathology characterized by cystic outpouchings from the trachea or main bronchi, has scant epidemiological documentation. We present a thyroid cancer case with known airway stenosis but an undiagnosed tracheal diverticulum. Perioperatively, repeated displacement of the endotracheal tube into the undiagnosed diverticulum caused critical intubation failure and complicated tracheostomy. Under fiberoptic bronchoscopic guidance, the tracheal tube was successfully advanced past a right subglottic diverticular orifice into the left tracheal lumen, achieving secure placement in the true tracheal cavity. Our retrospective analysis of published cases further characterizes pathological features. For elective surgery patients with suspected tracheal diverticulum, particularly those with prior cervical surgery or pathology, we strongly advise preoperative bronchoscopy to confirm the defect and develop tailored airway management. This case also demonstrates that transnasal fiberoptic bronchoscope-guided intubation effectively rescues unanticipated difficult airways during tracheal diverticulum-related reintubation.