Diaphragmatic hernia is a congenital defect in the diaphragm. The diaphragm is a muscle that separates the chest from the abdominal organs.
It is important to distinguish between cases of diaphragmatic hernia and cases caused by diaphragm paralysis. In diaphragm paralysis, the abdominal organs are located in a higher location, but these organs will nor penetrate the chest.
A paralyzed diaphragm can be caused by various phenomena, some are mild and temporary, others are more severe such as myotonic dystrophy, or other muscular disorders.
Types of diaphragmatic hernia
Diaphragmatic hernia is usually divided into two types:
- Bochdalek hernia – or posterolateral hernia, is the most common form of diaphragmatic hernia, with a prevalence of 1 in 7,000 births. It involves the back of the diaphragm, which has an abnormal closure. In healthy people, the posterior of the diaphragm is connected to the peritoneum, but in this condition, this connection is impaired. It is more common on the left side than the right side.
- Morgagni hernia – a rare type of diaphragmatic hernia with a prevalence of 1 in 100,000 births. It affects the anterior (front) of the diaphragm. In this condition, the left side of the diaphragm is not connected to its right side.
What are the symptoms?
In posterolateral hernia, symptoms include small-bowel obstructions, and a penetration of gastrointestinal organs (such as the liver) into the chest which causes them to push the organs in the chest to the right side.
The pressure inflicted by the internal organs on the lungs causes them to develop abnormally. The more organs penetrate the chest, the more severe the symptoms. Severe cases also include an increased amount of amniotic fluid, caused by the damage to the lungs.
After birth, infants suffer from respiratory distress. In milder cases, respiratory distress occurs a day after birth, in more severe cases it will appear shortly after birth along with other severe complications such as lung ruptures, which require immediate surgery.
Surgery is used to drain the air in the area surrounding the lungs. Mortality rate ranges from fifty to ninety percent, depending on the severity of the disorder.
Defects that accompany posterolateral diaphragmatic hernia occur in thirty percent of babies and include heart defects, neural tube defects, gastrointestinal defects, and more.
Anterior diaphragmatic hernia does not usually involve the lungs but may cause bowel obstructions that require surgery. In addition, defects in the central nervous system and the heart may occur.
What is the genetic basis of this disorder?
It is still unclear which gene mutation causes this disorder. therefore, there are currently no genetic tests that can be performed prenatally and allow carrier screening for couples during preconception. Moreover, there are currently no fetal genetic tests that can genetically rule out this condition in the fetus.