A tracheoesophageal (T-E) fistula is an abnormal communication between the trachea and fistula. It is a rare complications that occurs in less than 1% of individuals with tracheostomy (Epstein, 2005). Individuals with tracheostomy may develop a tracheoesophageal fistula due to injury of the posterior tracheal wall. The perforation can occur during percutaneous insertion of the tracheostomy tube, malpositioning of the tube, movement of the tube during suctioning or tracheostomy care, or from excessive tracheostomy tube cuff pressures (>30cmH2O). The presence of a nasogastric tube, especially wide-bore, can aggravate the tissue and contribute to the development of a T-E fistula (Sanwal, M et al, 2012). Predisposing factors include poor nutrition, airway infection, hypotension, hypoxemia, anemia, diabetes, and steroid therapy.
The use of high-volume, low-pressure endotracheal and tracheostomy cuffs has reduced the incidence of this complication. Tracheostomy tube cuff management is important for preventing a tracheoesophageal fistula with emphasis on daily cuff measurements not to exceed 30 cm H2O. Deflating the cuff every few hours has not been shown to decrease the risk of injury (Hameed et al, 2008).
The main symptoms of an acquired tracheoesophageal fistula are copious secretions and recurrent aspiration of secretions, food and/or liquids, which can lead to life threatening pulmonary complications. There should be a high suspicion for a T-E fistula if tube feedings are noted in the tracheostomy tube or around the stoma. For mechanically ventilated patients, additional manifestations may include increasing dyspnea, a persistent cuff leak, or severe gastric distention (due to excess air in the stomach). Usual manifestations in nonventilated patients include uncontrolled coughing after swallowing (Ono’s sign), breathing difficulty, repeated pneumonia, and unexplained weight loss (Santra, G & Pandit, N, 2009).
Chest xrays may show a dialation of the esophagus (distal to the fistula) and dilation of the stomach. It may also show hypertransparency from an overinflated cuff with a diamter greater than 35mm (indirect sign of fistula).
The diagnosis of tracheoesophageal fistula is made by, high resolution CT scan, barium or water soluble esophagography, or endoscopy. The esophagram is especially useful where endoscopic examination is not possible. The patient ingests a small amount of contrast which typically reveals the site of the fistula and any contrast substance that leaks into the tracheobronchial tree. A contrast substance that produces a minimal bronchial inflammation should be used. The Clinical Consensus Guideline indicates that if a T-E fistula is suspected, a bronchoscopy is indicated (Mitchell, 2013).
While smaller T-E fistulas may heal spontaneously, in most cases, the fistula must be surgically repaired. For patients who are not able to tolerate surgery, treatment includes esophageal or double (tracheal and esophageal) stenting using self-expanding metallic stents (Sanwal et al, 2012).