I Oesophageal atresia
Oesophageal atresia is a birth defect in which the oesophagus, which normally connects the mouth with the stomach, is interrupted. The medical definition of ‘atresia’ is the following: absence or closure of a natural passage of the body.
- Different types of malformation
The normal anatomy of the oesophagus and respiratory tract shows a direct connection of the oesophagus to the stomach and the windpipe to the lungs. There is no connection between the two. The figure below shows the different types of oesophageal atresia.
Type A: Oesophageal atresia without tracheoesophageal fistula (8%):
With this type, a large part of the oesophagus, so-called long-gap, is missing and there is no connection to the trachea. This distance has to be bridged: depending on the distance to be bridged, the surgical technique is determined.
Type B: Oesophageal atresia with a proximal tracheoesophageal fistula (1%):
In this case, not only is part of the oesophagus missing, but there is also a connection (fistula) between the upper (proximal) part and the trachea. Saliva or food goes via the fistula to the lungs, instead of to the stomach. The lower part of the oesophagus ends blindly. The atresia is often long-gap.
Type C: Oesophageal atresia with a distal tracheoesophageal fistula (85%):
This is the most common type. There is a connection between the lower (distal) part of the oesophagus and the windpipe, which means a direct connection between the stomach and the airways. The upper half of the oesophagus ends blindly. During breathing the child suffers from the accumulation and overflow of saliva from the closed "pouch". In addition, the lungs can be irritated from gastric fluid flowing through the connection with the windpipe in the lower part of the oesophagus.
Type D: Oesophageal atresia with both a proximal and a distal tracheoesophageal fistula (1%):
Here we find a combination of both types B and C. This type has a double fistula connection: the upper and lower oesophageal stumps both end into the trachea. Through these two connections, both saliva and stomach contents can go to the lungs.
Type E: Tracheoesophageal fistula without atresia (H-fistula) (4%):
With this type, the oesophagus has normally developed but there is a connection between the oesophagus and the windpipe. This type is usually only noticed a few days or even weeks after birth because there is a passage to the stomach. This allows a child to drink normally. However, food and saliva may enter the lungs, causing the child to choke or having trouble breathing.
Type F: Oesophageal stenosis (1%):
There is no connection between the oesophagus and the trachea, but the oesophagus is constricted. The narrowing can be so severe that nutrition and/or saliva cannot pass through to the stomach.
A sphincter, which is a kind of ’valve’, controls the passage of food from the oesophagus to the stomach. It is a bundle of muscle fibres that opens up when food goes from the oesophagus to the stomach. Immediately after that, the sphincter closes to prevent the backward flow of gastric juices into the oesophagus. In the case of achalasia, this lower oesophagus muscle does not work properly: it does not relax sufficiently, so that food remains in the oesophagus after swallowing. This is because the nerves that control this sphincter are affected. Another characteristic of achalasia is the lack of the normal rhythmic contractions of the oesophagus (wave movements) that propel the food from top to bottom into the oesophagus. Probably this is also due to an impairment of the nerves.
Achalasia can occur at any age, but usually starts between 20 and 40 years. It can remain unnoticed for a long time and gradually increase over the years.