esophageal atresia

Esophageal atresia refers to an absence in the continuity of the esophagus due to an inappropriate division of the primitive foregut into the trachea and esophagus. This is the most common congenital anomaly of the esophagus.

Epidemiology

It is thought to occur in ~1:3,000-4,500 live births .

Clinical presentation

Esophageal atresia may be suspected on antenatal ultrasound (see below) or in the neonate due to inability to swallow saliva or milk, aspiration during early feedings, or failure to pass a nasogastric tube into the stomach successfully.

Pathology

It results from a failure of the primitive foregut to divide into the trachea anteriorly and the esophagus posteriorly. This usually occurs at ~ the 4 week of gestation.

General pathogenesis includes teratogenic effects caused by early pregnancy use of antithyroid drugs

Genetics

Most cases have a sporadic occurrence .

Subtypes

It is frequently associated with a tracheo-esophageal fistula. As such, the types of esophageal atresia / tracheo-esophageal fistula can be divided into :

  • proximal atresia with distal fistula: 85%
  • isolated esophageal atresia: 8-9%
  • isolated fistula (H-type): 4-6%
  • double fistula with intervening atresia: 1-2%
  • proximal fistula with distal atresia: 1%

See main article: esophageal atresia classification.

Associations

Esophageal atresias are frequently associated with various other anomalies (50-75% of cases). They include

Radiographic features

Plain radiograph

Chest x-ray:

  • may show a dilated pharyngeal pouch
  • the presence of air in the stomach and bowel in the setting of esophageal atresia implies that there is a distal fistula
  • if an esophagogastric (feeding) tube insertion has been attempted this may show the tube blind looping and turning back at the upper thoracic part of the esophagus or heading into the trachea and/or bronchial tree
Fluoroscopy

Contrast swallow may show contrast blindly ending and pooling in an esophageal stump and/or may show evidence of the tracheo-esophageal fistula. Fluoroscopy is particularly useful in demonstrating H-type fistula. A withdrawal esophagogram is performed for a H-type fistula. The patient is positioned prone and a horizontal beam is used, contrast material is injected through the nasogastric tube into the distal esophagus while the tube is slowly withdrawn under fluoroscopy . If the imaging study fails to locate the fistula while there is high suspicion then combined bronchoscopy and esophagoscopy is used . The gap between esophageal pouches is determined by inserting a Higer dilator through gastronomy into the distal esophagus and Repogle tube into proximal pouch; both tubes are radiopaque .

Antenatal ultrasound

  • non-specific but may not show the expected shape and position of the stomach
  • should be suspected if other VACTERL anomalies are seen
  • polyhydramnios may be present particularly in cases where there is no concurrent fistulation
  • the fetus may appear growth restricted
  • the subtypes without a tracheo-esophageal fistula may be suspected in the context of persistent non-visualization of the fetal stomach
CT
  • has been trialled for 3D detailed visualization of anatomy but not part of routine investigation

Treatment and prognosis

Surgical intervention with a re-anastomosis can be attempted post delivery. The prognosis is variable dependent on other associated anomalies.

Esophageal strictures secondary to surgical correction of esophageal atresia is a known complication of the procedure and usually requires further surgical correction.