1) Esophageal Atresia
In this anomaly the lumen of the esophagus is completely interrupted. Esophageal atresia can occur as an isolated anomaly but in most of the cases it is accompanied by a tracheoesophageal fistula, ie, an abnormal communication between the trachea and esophagus.
Improper reconalization of esophagus during the 7th and 8th weeks of
development results in the production of esophageal atresia as an isolated anomaly. However, much more frequently (in 85% of the cases) the esophageal atresia is accompanied by tra-cheoesophageal fistula. This complex anomaly may take various forms (which are described in more detail under the topic of development of trachea in the next chapter). In the most common variety of this anomaly the esophagus is divided into two segments. The proximal segment of esophagus ends blindly, whereas the distal segment opens into the posterior wall of trachea by a fistulous communication.The developmental reason for esophageal atresia with tracheo-esophageal fistula has been believed to be an anomalous deviation of the tracheo-esophageal septum in a posterior direction. However, more recently, it has been proposed that this anomaly may be caused by an abnormal epithelial connection between the developing trachea and esophagus.
In a fetus with esophageal atresia the amniotic fluid can not enter the intestinal tract for absorption. Consequently, there is accumulation of excess fluid in the amniotic sac, resulting in polyhydramhios.
Newborns with esophageal atresia appear to be normal at birth. However, with the first feed,,the milk returns through the nose and mouth. This regurgitation usually leads to aspiration of fluid into the larynx and trachea, resulting in pneumonia (infection of lungs). In time surgical correction of
the anomaly can save most of the cases of esophageal atresia