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Tracheoesophageal Fistulas and Tracheal Anomalies


Tracheoesophageal Fistulas and Tracheal Anomalies
Tracheoesophageal fistula (TOF) and esophageal atresia rarely occur as separate entities, but they are often seen in various combinations: esophageal atresia with upper fistula, lower fistula, and double fistulas. Approximately 10% of infants with esophageal atresia do not have a fistula, but there is a long gap between the esophageal segments. An isolated tracheoesophageal fistula (H or N fistula) can occur without an esophageal atresia. The cause of these congenital anomalies is not well understood. Esophageal atresia is usually sporadic and rarely familial.

Maternal polyhydramnios and a small or absent fetal stomach bubble on antenatal ultrasonography suggest the possibility of esophageal atresia antenatally. Postnatally, the diagnosis can be suspected in a newborn infant who has excessive mucus and cannot handle his or her secretions adequately. Suction provides temporary relief, but the secretions continue to accumulate and overflow, resulting in aspiration and respiratory distress. Feeds are also regurgitated and aspirated. The TOF provides a low-resistance pathway for respiratory gases and gastric distension, and subsequent rupture may further compromise ventilation.
Tracheoesophageal Fistulas and Tracheal Anomalies

Formerly, the diagnosis was made by using a contrast study with barium or Gastrografin (meglumine diatrizoate); however, there is the danger of aspirating these materials into the lungs. The diagnosis can readily be made by passing a fairly large radiopaque plastic catheter through the nose or mouth into the pouch. When the catheter cannot be advanced into the stomach, the catheter should then be taped in place and put on constant gentle suction. This keeps the pouch free of saliva and minimizes the chances of aspiration pneumonitis. On the chest radiograph, it will be noted that the tip of the catheter is usually opposite T2-T3. If the surgeon prefers a contrast study, no more than 0.5 mL of contrast material should be introduced through the catheter, with the child in the upright position. Radiography will show the typical esophageal obstruction, and the contrast material should then be immediately aspirated.
Initial management is aimed at keeping the airway free of secretions using a 10-Fr double lumen Replogle tube in the proximal pouch on continuous low pressure suction. The ideal surgical procedure consists of disruption of the fistula and an end-to-end anastomosis of the esophagus. If there is a long gap between the esophageal segments, surgery is delayed to allow the pouches to elongate and hypertrophy over a period of up to 3 months. During this time, the infant is fed through a gastrostomy, and the upper pouch is kept clear of secretions.

Anomalies and Strictures of The Trachea
Tracheal anomalies are very rare. With stricture of the trachea, there is local obstruction of the passage of air. In the absence of cartilage, the trachea can collapse and therefore obstruct on expiration. With deformity of cartilage, there is obstruction on inspiration and expiration. When abnormal bifurcations are present, the right upper or left upper lobe bronchi (or both) arise independently from the trachea.
Clinically, stenosis may be localized or diffuse. The localized form is caused by a web of the respiratory mucosa or by excessive growth of tracheal cartilage. The diffuse form is caused by a congenital absence of elastic fibrous tissue between the cartilage and its rings in the trachea or by an absence of cartilage. Clinically, obstruction of the trachea causes chronic dyspnea; cyanosis, especially on exercise; and repeated attacks of respiratory tract infection. The diagnosis is established by bronchoscopy and by radiography.
For localized obstruction, surgery is advisable, either dilatation or excision with end-to-end anastomosis. Resection and anastomosis of the trachea can be carried out, including up to six tracheal rings. For generalized stenosis, only supportive therapy is available.