A Computed Tomographic Assessment of Tracheostomy Tube Placement in Patients with Chronic Neurological Disorders: The Prevention of Tracheoarterial Fistula

OBJECTIVE: Tracheoarterial fistula (TAF) is a rare but devastating complication of tracheostomy caused by pressure necrosis from the elbow, tip, or over-inflated cuff of the tracheostomy tube. The incidence of TAF is reportedly higher in patients with neurological disorders than in those without such disorders. To evaluate the incidence of and factors contributing to the misalignment of tracheostomy tubes in bedridden patients with chronic neurological disorders. METHODS: We retrospectively assessed three-dimensionally reconstructed serial computed tomography (CT) images to see if the tip of the tube made contact with the tracheal wall and if the main arteries were running adjacent to the tube's elbow, tip or cuff. RESULTS: The tip of the tube was in contact with the tracheal wall in 14 of the 30 patients assessed. Among them, the tip was adjacent to the innominate artery in eight, the aortic arch in three and an aberrant right subclavian artery in one. In one patient with the tube tip adjacent to the aortic arch and the other four patients, the cuff of the tube was adjacent to the innominate artery across the tracheal wall. Patients with the tube tip in contact with the anterior tracheal wall had a significantly greater cervical lordosis angle than those without contact (p<0.05). CONCLUSION: More than half of tracheostomized patients with chronic neurological disorders had a latent risk of TAF. The variability in the location of the innominate artery, anomalies of the aortic arch, and skeletal deformities may therefore be contributing factors.