Congenital Diaphragmatic Hernia: CDH Causes, Symptoms, Treatments

Introduction

Defining Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a congenital malformation (birth defect) of the diaphragm. The most common type of CDH is a Bochdalek hernia; other types include Morgagni hernia, diaphragm eventration and central tendon defects of the diaphragm. Malformation of the diaphragm allows the abdominal organs to push into the chest cavity, hindering proper lung formation. A diaphragmatic hernia is a rare defect that occurs while the baby is developing in the womb. The abdominal organs, such as the stomach, small intestine, spleen, part of the liver, and the kidney, may take up part of the chest cavity. This prevents the lung from growing normally.

Main Item

Congenital Diaphragmatic Hernia (CDH) involves a hole, or opening in a person's diaphragm, which is the muscle separating the chest cavity from their abdominal cavity. CDH is a birth defect, occurring while the fetus is developing. The opening caused by this defect causes some of the organs that are usually found in the baby's abdomen to move into their chest cavity.

Causes

There are many genetic and environmental factors involved with CDH, and thought is that there are multiple environmental factors, as well as genes from both of the child's parents, contributing to the disorder. Scientists at this time do not understand the exact causes of CDH. What is understood is that in cases where the only health problem a child is experiencing is CDH, the chance that any other children the parents have will also have CDH is ninety-eight percent against.

Nearly one in three babies affected by CDH has another birth defect as well. The most common birth defect in addition to CDH is one which affects the child's heart. Another five to sixteen percent of babies with CDH could have chromosomal defects like Down Syndrome, or Trisomy 21. Approximately one in three-thousand to five-thousand babies is born with CDH.

Concerns

Different organ systems develop and mature as a fetus grows before birth, and their diaphragm usually forms between seven and ten weeks. The tube which leads from their throat to their stomach called the, 'esophagus,' their intestines, as well as the stomach itself develop during this time too. Muscles in babies who have CDH do not form completely, for reasons that are not understood. CDH usually affects the left side of a baby's body, although it may also affect the child's central portion of the diaphragm, or the right side of their body.

Lungs develop at the same time as the digestive system and the diaphragm in the fetal development process. CDH permits organs which should have remained in the abdomen of the fetus to move into the chest cavity as they develop. Due to the lungs, heart and the organs that should be in the abdominal area of the fetus now being in the chest area, the lungs simply don't have the space they need in order to develop properly. The underdevelopment of a fetus' lungs is referred to as, 'Pulmonary Hypoplasia.'

A Congenital Diaphragmatic Hernia is life-threatening because of improper development of the lungs during pregnancy. Lack of proper lung development can make it hard for the baby to breathe once it is born as well. Fully-developed lungs have millions of, 'Alveoli,' or small air sacs, which resemble tiny balloons and fill with air for the body to use. Babies with Pulmonary Hypoplasia have less Alveoli than a baby with fully-developed lungs, or Alveoli which are only partially functional because they do not have a necessary lubricant fluid referred to as, 'Surfactant.' The lack of sufficient numbers of Alveoli, or adequately functional ones, presents the possibility that the baby may not be able to take in enough oxygen to remain healthy.

Diagnosing

Ultrasound imaging testing often identifies CDH before the child is born. Further ultrasound testing, once the fetus has been diagnosed with CDH, can help to determine the severity of the disorder and any additional problems that may be present. Magnetic Resonance Imaging (MRI) testing can assist in these efforts as well. Sometimes CDH does not appear through ultrasound images, and a diagnosis is made after the child has been born. There are a few centers where a Fetal Therapeutic or CDH team might both evaluate a baby prior to birth, and discuss treatment options with the parents of the child.

Symptoms

The symptoms of CDH vary from baby to baby, and are usually seen shortly after the child is born.

The symptoms of CDH include a fast heart rate, difficulty breathing, rapid respiration, a blue color to the skin, an abdomen that appears caved-in and abnormal chest development where one side of the baby's chest appears larger than the other. Some of these symptoms can resemble other medical issues or conditions; it is always wise to discuss your baby's health with a doctor.

Tests

Once the baby is born a doctor will perform a physical examination.

The doctor will take a chest X-ray of the baby to look for anything that may be wrong with their lungs, intestine, or diaphragm. The doctor will also order a blood test called an, 'Arterial Blood Gas,' in order to evaluate the baby's breathing abilities. An Echocardiogram or and ultrasound of the baby's heart may be performed, as well as another form of blood test which looks for chromosomal abnormalities to determine if there is a genetic condition present.

Treatments

Many times, babies who are affected by CDH are transferred to a hospital that has a doctor specializing in newborn babies or, 'Neonatologist,' as well as a Pediatric Surgeon. If surgery is needed, a Pediatric Surgeon specializes in providing surgical care to children. The kind of care a baby with CDH receives depends on their individual needs, and is determined by the baby's physician. A Neonatal Intensive Care Unit is required for babies born with CDH because it is life-threatening, and babies born with it are usually unable to breath effectively on their own; their lungs are underdeveloped. A breathing machine called a, 'Mechanical Ventilator,' is something that babies with CDH are placed on to help them breath.

Some babies with CDH have more severe problems, and require the temporary use of a machine called an, 'ECMO,' machine. The ECMO machine is a heart/lung machine that is available at specialized centers that does the job the lungs and heart usually do. The ECMO machine puts oxygen into the baby's blood stream while pumping blood to the baby's body. The baby uses this machine until their condition both stabilizes and improves. Once the baby's condition has improved, a surgeon will repair the diaphragmatic hernia. The baby needs to be in as stable a condition as they possibly can be prior to this surgery. Making sure that the baby is stable can take anywhere from days to weeks.

When the surgery to repair the diaphragmatic hernia is performed, the surgeon will move the baby's intestine, stomach, and other abdominal organs out of their chest cavity and back to their abdomen. The surgeon then repairs the hole in the baby's diaphragm using stitches, and possibly a piece of mesh or plastic. A number of babies continue to stay in the Neonatal Intensive Care Unit for a period of time after undergoing this surgery to repair their diaphragmatic hernia.

Repair of the diaphragmatic hernia, and placement of the intestine, stomach and abdominal organs back in the abdomen, does not mean that the baby's lungs are unaffected. The baby's lungs still remain underdeveloped, and the baby will probably require breathing support for some time after they have gone through the operation. When the baby no longer requires assistance from a breathing machine, they may still need medications or oxygen to help them with breathing over the coming months or even years.

Congenital Diaphragmatic Hernia and Disability

Children with CDH who have the more serious lung problems are more likely to have difficulty growing because of the illness, requiring more calories to grow and maintain health. Some may need a feeding tube in order to get the amount of nutrition they need to grow.

Many times, babies with CDH will experience Gastroesophageal Reflux, causing things such as heartburn, feeding issues, vomiting, or lung issues.

Medications prescribed by a doctor can help to control Gastroesophageal Reflux, but occasionally babies with CDH who experience it require surgery to treat it.

Other baby's with CDH have developmental disabilities, and may not crawl, sit, stand, or roll over at the same time babies without developmental disabilities do.

Facts and Statistics

• Severe breathing problems almost always develop shortly after the baby is born.
• A diaphragmatic hernia repair is an emergency that requires surgery. Go to the emergency room or call the local emergency number (such as 911). A diaphragmatic hernia is a surgical emergency. Surgery is done to place the abdominal organs into the proper position and repair the opening in the diaphragm.
• Congenital diaphragmatic hernia affects approximately 1 in 2,500 newborns. (Aprox. 1,600 cases per annum in the U.S.)
• Congenital diaphragmatic hernia has a mortality rate of 40-62%, outcomes being more favorable in the absence of other congenital abnormalities. With advances in surgery and care, the survival rate is now upwards of 80%.
• A Bochdalek hernia is a defect in the side or back of the diaphragm. Between 80 and 90 percent of congenital diaphragmatic hernias are of this type.
• Approximately 50 to 60 percent of congenital diaphragmatic hernia cases are isolated, which means that affected individuals have no other major malformations.
• In about 1 percent of cases, congenital diaphragmatic hernia has no symptoms; it may be detected incidentally when medical imaging is done for other reasons.
• In 5 to 10 percent of affected individuals, signs and symptoms of congenital diaphragmatic hernia appear later in life and may include breathing problems or abdominal pain from protrusion of the intestine into the chest cavity.
• In 10 to 15 percent of affected individuals, the condition appears as a feature of a disorder that affects many body systems, called a syndrome such as; Donnai-Barrow syndrome, Fryns syndrome, and Pallister-Killian mosaic syndrome.