Congenital Diaphragmatic Hernia
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Condition: Congenital Diaphragmatic Hernia (CDH)
Overview (“What is it?”)
- Definition: Congenital Diaphragmatic Hernia (CDH) is a condition where baby is born with a hole in the diaphragm. The diaphragm is muscle that separates the chest from the belly. Normally, the heart and lungs are in the chest and the intestines and other organs are in the belly. When there is a hole in the diaphragm, organs from the abdomen can go through the defect into the chest cavity. As the baby grows in the womb, his lungs are compressed by these abdominal organs. The lungs are smaller because they lack the space to grow. In addition, the blood vessels of the lung are thicker, making it sometimes difficult for blood to pickup oxygen in the lungs. CDH occurs more commonly on the left. The cause of this defect is not fully known.
- Epidemiology: CDH occurs in about 1 in every 4,000 babies. The size of the hole can vary. Larger defects are associated with more problems because the lungs are usually smaller. Sometimes the lungs are so small that the babies are not able to breathe adequately after they are born, and they die. Most diaphragmatic hernias occur on the left side (80%) and will often contain stomach, spleen, small and large intestine. Those on the right side will often contain portions of the liver.
Signs and Symptoms (“What symptoms will my child have?”)
- Early signs: Diaphragmatic hernias are mostly discovered during routine prenatal ultrasounds of the mother. An MRI (magnetic resonance imaging radiology test that uses magnetic waves to create images of the inside of the body) of the developing fetus can sometimes be done to predict how big the lungs are and how badly they are being compressed by the intestines and other organs. If a fetus is diagnosed with CDH, his or her birth is planned at a hospital with the capability of caring for babies with this diagnosis. The baby may have severe breathing difficulties, low oxygen levels in the blood and problems with blood pressure. These symptoms can be so serious that they can be life-threatening.
- Later signs/symptoms: Some babies with CDH that do not have symptoms right after birth may later develop problems tolerating their diet or may begin to have difficulty breathing. Some may be discovered after an X-ray is taken for respiratory symptoms such as coughing or wheezing.
Diagnosis (“What tests are done to find out what my child has?”)
- Chest X-ray usually shows intestinal loops in the chest which confirms the diagnosis of CDH.
- Blood will be obtained to check routine labs and to look for oxygen levels in the blood which show how well the lungs are working.
- Echocardiogram (“ECHO”) or ultrasound of the heart will be performed to look for any congenital heart problems and to determine if the heart is being affected by the increased pressure in the lungs from the abnormal growth of lungs. Some babies also have problems with their heart, which may occur in up to 15% of babies with a CDH. This study may also indicate how bad the blood pressure is within the lungs (pulmonary hypertension).
- An ultrasound of the head is usually obtained to make sure that there are no abnormalities or bleeding into/around the brain.
Figure. 2: Chest Xray showing “bubbles” in the left chest indicating intestine pushing into the chest (small arrows) and heart being pushed over to the right (single large arrow).
- Conditions that mimic this condition:
- Diaphragm Eventration: An abnormal elevation of one side of the diaphragm. This may be congenital (baby is born with it) causing the diaphragm muscle to be very thin, or it may occur after an injury to the nerve that controls the diaphragm, which then weakens the muscle.
- Foramen of Morgagni Diaphragmatic Hernia: This is a defect in the center and front part of the diaphragm. These types of hernias account for less than 2% of diaphragmatic hernias and typically presents in older children and adults.
- Hiatal Hernia: When the center opening in the diaphragm enlarges, the stomach can then go through the hole into the middle part of the chest. These types of hernias make be associated with symptoms of reflux such as vomiting and heartburn.
Treatment (“What will be done to make my child better?”)
- It is important to know that in babies with CDH, replacing the intestines into the belly and repairing the hole in the diaphragm will not cure the breathing problems. The breathing problems are a result of (1) smaller lung size and (2) pulmonary hypertension.
- Pulmonary hypertension is increased pressure in the arteries of lungs. Under normal circumstances, blood goes through the vessels in the lungs. Blood picks up oxygen and gets rid of carbon dioxide in the lungs. However, if the pressure is high in these vessels, blood is shunted away from the lungs. Exchange of oxygen and carbon dioxide does not happen effectively between the blood and the lungs. Pulmonary hypertension is a life-threatening problem.
- In most cases, the blood pressure within the lungs goes down within several days after delivery. The main issue after birth is to support breathing (bringing oxygen into the body and getting rid of carbon dioxide) without causing permanent and severe damage to the lungs.
- Medical therapy
- The baby is admitted to the neonatal intensive care unit and a breathing tube is placed to help with breathing. A machine (ventilator) is used to regulate breathing, give oxygen and get rid of carbon dioxide. There are several types of machines that deliver increasing and different types of support. Which of these machines are used depend on your baby’s breathing needs.
- A tube is placed through the mouth into the stomach to drain air or fluid. A full stomach can compress the lung and contribute to more problems breath.
- Medicines are usually given intravenously for sedation and pain. These medicines can calm the baby and decrease the pressures within the lung.
- Catheters will be placed in veins (IV) or arteries to deliver medications and also to draw blood to check oxygen levels.
- ECMO (Extra corporeal membrane oxygenation) is a type of heart-lung bypass.
- A procedure to place cannulas (large catheters) into the blood vessels in the neck is performed at the bedside. Oxygen-poor blood is drained from the baby through the cannula in the neck and put through a machine where oxygen is infused into the blood and carbon dioxide is removed. This oxygen-rich blood is returned back into the baby and goes through the organs. Heparin, a medicine that thins the blood, is put into the blood to keep it from clotting.
- Preoperative preparation: Echocardiogram (heart ultrasound) and head ultrasound are usually required prior to ECMO.
- Benefits and risks: ECMO is used when other treatment options fail. ECMO takes on the job of the heart and lungs while pulmonary hypertension resolves. The heart and lungs are able to rest. A baby only can stay on ECMO for a brief time, up to 21 days. If the baby’s lung function does not get better at that time, then prognosis is poor. Risks of ECMO are bleeding, dislodgment of the cannula, clotting of the circuit. Placement of the cannulas can also be risky.
- If the lung function and pulmonary hypertension gets better, the baby is taken off ECMO and placed back on regular ventilator. Repair can be done either on ECMO or after the baby is taken off.
- Congenital diaphragmatic hernia repair: Timing of surgical repair is typically dependent on the baby’s stability and degree of pulmonary hypertension. Sometimes, surgery may be performed while the baby is still on ECMO. The type of surgery will be up to the surgeon and can often be performed through an incision on the abdomen or through the chest. Minimal access approaches (laparoscopy or thoracoscopy) may also be used. For large defects in the diaphragm, a patch may have to be used to close the hole.
- Postoperative care: Following the surgery, the baby will need the same monitoring and support as before the surgery. Often, the baby will need to remain on the ventilator to support the lung function and may need medications to lower lung blood vessel pressure and other medications to raise overall blood pressure.
- Risks/Benefits: The primary risks of surgery include bleeding, infection, injury to the lung, heart or abdominal organs; respiratory failure and death. Survival rates vary from 60-90%. There is also a risk of recurrence of the hernia; recurrence is greater in those that had a patch. placed at the time of surgery. Benefits of the surgery include the replacement of the abdominal organs in the abdomen, allowing the heart and lungs to reclaim the chest.
- Sometimes, if there are a lot of organs that were originally in the chest, replacing them all back in the belly may make the belly too tight. A tight belly would decrease the blood flow to the organs, creating a dangerous situation. In these cases, the abdomen is left open with the organs contained in a silastic silo or closed with a large temporary patch. The belly is then closed in stages.
Home Care (“What do I need to do once my child goes home?”)
- Diet: Your child will likely be on a typical infant formula or breast milk but may require nutritional supplementation to increase calories and protein. In some cases, if the lungs continue to be weak, feeding by mouth may be too much to coordinate with breathing. The baby may require feeding by tube through the nose or a gastrostomy tube (G tube).
- Activity: Normal activity after the wounds have healed is allowed. Ask the surgeon when “tummy time” is allowed.
- Wound care: Wounds are kept dry for the first three days after surgery, then the wounds may be washed but not soaked for a week. Most of the time, if the baby was born with CDH and repair was performed, he or she should be able to be bathed normally by the time he or she gets home.
- Medicines: The baby may need to continue on some of the medicines for pulmonary hypertension if he/she continues to have difficulty with breathing.
- What to call the doctor for: Call the doctor for fevers, worsening breathing, vomiting, pain or any redness/drainage from the incisions.
- Follow-up care: You will need close follow-up with the pediatric surgeon as well as your pediatrician and possible pediatric pulmonologist.
Long-Term Outcomes (“Are there future conditions to worry about?”)
- Survival rates vary from 60-90%.
- Issues with breathing are the most common long term problem and follow-up with lung specialists may be needed.
- Some children may not have the same exercise tolerance as their peers due to the lung abnormalities.
- There is a higher incidence of developmental delay in children with CDH—motor and language problems may be evident. Hearing problems may also be present.
- A high incidence of gastroesophageal reflux is often seen in babies with CDH, some eventually needing surgery to correct.
- The hernia may come back (recur) in up to 50% in babies requiring a patch and 10% in those that did not need a patch. Therefore, regular follow-up is needed.
- Coran: Pediatric Surgery 2012.
- O’Neill: Pediatric Surgery, 5th Edition.
Author: Patricia Lange, MD
Editor: Marjorie J. Arca, MD