Esophageal Atresia

Introduction

An esophageal atresia is a congenital malformation (atresia) of the esophagus, which is known as the esophagus in medical terminology. In this case, an interruption in the continuity of the esophagus occurs. This interruption of continuity can have different lengths.

The length is usually given in centimeters or in the number of vertebral body heights of the affected children. However, the literature does not really agree on the division into a short-distance and a long-distance esophageal atresia. The morphological classification (morphology=science of the construction and organization of living beings and their components).

is according to Vogt and takes into account the length, the type of malformation and a possible fistula formation. (Fistula=artificial channel created by disease or artificial channel that connects an organ with the body surface or another organ. The latter is very common, so that the lower end of the esophagus opens into the trachea to 85%. Typically, esophageal atresia is associated with other congenital malformations.

Causes

The development of esophageal atresia takes place in the embryonic period. To understand how this malformation develops, it is advisable to visualize the natural development of the foetal period. During the physiological development, the esophagus is formed from the fetal forebowel, which extends from the pharynx to the stomach.

From the 20th day of pregnancy onwards, a thickening forms on the front edge of this forebowel, in which parts of the later trachea begin to differentiate. This part is called respiratory epithelium. Until the 26th day of pregnancy, two tubes develop from this structure, namely the oesophagus and the trachea, which are completely separated from each other by the septum oesophagotracheale, a kind of dividing wall. If disturbances occur during this separation process, esophageal atresia may develop.

Classification according to Vogt

The different forms of esophageal atresia are classified according to Vogt’s classification. This classification has existed since 1929 and distinguishes four types of esophageal atresia. The classification takes into account the presence of a fistula formation to the trachea as well as an atresia (malformation) or aplasia (complete absence) of the esophagus.

Vogt type I is an esophageal aplasia. The esophagus is therefore completely absent. This malformation is very rare (about 1%).

The Vogt type II is a long-distance esophageal atresia without esophagotracheal fistula formation and accounts for about 8% of the total. The bailiff type III is divided into a type IIIa, b and c. An esophageal atresia with an upper esophagotracheal fistula is called type III a. The lower end of the esophagus ends here blind.

With a frequency of >1 % this type is very rare. The most frequent manifestation is the Vogt type IIIb, which accounts for about 85% of the total. This is an esophageal atresia with a lower esophagotracheal fistula.

In type Vogt IIIc an esophagotracheal fistula is present in both the upper and lower segment. This characteristic is present with a frequency of about 5%. The Vogt type IV is a so-called H-fistula, an esophagotracheal fistula without atresia. Its frequency is about 2%.