The diaphragm is a curved muscle that separates the contents of the chest from the abdomen (tummy). Diaphragmatic hernias occur when the diaphragm does not form completely, leaving a hole.This page explains about diaphragmatic hernias, how they are treated and what to expect when a child comes to Great Ormond Street Hospital (GOSH) for treatment.
This usually happens early in pregnancy at around six to eight weeks. The hole can be on either side, but in most children it is on the left side. You may hear the term Bochdalek hernia, which is the medical term for this type of diaphragmatic hernia. The hole in the diaphragm allows part of the intestine (gut) to move into the chest, which can squash the lungs and can stop them developing properly before birth.
Other abdominal organs can also move into the chest area, such as the liver, stomach and spleen, squashing the lungs even more.
We do not know exactly what causes diaphragmatic hernias. Doctors think that a number of factors can have an effect on diaphragmatic hernia development. They are very rare, occurring in one in around 2,500 babies. They are more common in boys than girls. Diaphragmatic hernias can be associated with other problems, so the doctors will examine your child closely to check if this is the case.
How is a diaphragmatic hernia diagnosed?
A diaphragmatic hernia can often be diagnosed by a routine ultrasound scan during pregnancy. Otherwise, it is diagnosed soon after birth when a baby shows signs of breathing difficulties. A chest x-ray will show which organs are in the chest area and how much they are squashing the lungs. Blood tests to show how much oxygen is contained in the blood are also commonly used.
How is a diaphragmatic hernia repaired?
Diaphragmatic hernias are repaired in an operation under general anaesthetic. The surgeons will only carry out the operation once a baby’s breathing and heart are stable.
Depending on the child’s size and how stable they are, the operation will either be carried out using keyhole surgery or by traditional open surgery.The surgeon would explain which approach is more likely, but there is a chance that they may need to switch from keyhole to open surgery once the operation has started.
Are there any alternatives?
Not really, no. Diaphragmatic hernias inevitably require treatment, because if they are not repaired the baby’s breathing problems would get worse as they grow. Feeding problems would also get worse with time.
What happens before the operation?
The baby will be admitted to GOSH soon after birth. To begin with, they will be nursed in an incubator and will have a tube passed through their nose into their stomach (naso-gastric tube or NG tube). This will release any excess air that is in the stomach and intestine, which also relieves the pressure on the lungs.
They will also have a ‘drip’ (intravenous infusion) to give fluids and medicines directly into their bloodstream. A machine will be used to help the baby to breathe before the operation. In most cases, this will be a ventilator or an oscillator. If the baby has problems with ventilation, they may be referred for extra-corporeal membrane oxygenation (ECMO) support. The ECMO machine is similar to a heart-lung bypass machine using during open-heart surgery. It gives the child’s body a chance to rest his or her heart and lungs for a short while. The doctors will explain all about ECMO if it is needed. The surgeons will only operate to repair the hernia when the child is stable on ventilation.
The surgeon will explain about the operation in more detail, discuss any worries the family may have and ask them to sign a consent form giving permission for the child to have the operation. An anaesthetist will also visit to explain about the anaesthetic.
What does the operation involve?
During the operation, the surgeon will move the child’s intestine back into the abdomen and repair the hole in their diaphragm. Sometimes, the surgeon may need to use a ‘patch’ of special material to close this hole. If a child’s intestine has become twisted while it is in the chest (which is not uncommon), the surgeon will correct this during the same operation. If the intestine has been damaged by being squashed in the chest, the surgeon may remove a damaged portion. This will not usually cause children any long-term problems unless a large portion has to be removed.
Are there any risks?
All operations carry a small risk of bleeding, during or afterwards. There is a chance that the intestines or other abdominal organs could be damaged when they are moved back into the abdomen but this is very rare. If damage occurs, this can be fixed in the same operation. There is a small risk of infection but this is minimised by giving the child antibiotics before the operation.
After treatment, there is a chance that the hole in the diaphragm could come back, which would require another operation to repair it. This risk is higher if the child has needed a patch repair.
Every anaesthetic carries a risk of complications, but this is very small. The anaesthetist is a very experienced doctor who is trained to deal with any complications.
What happens afterwards?
The baby will come back to the ward to recover, and be able to have visitors as soon as they are settled. For a while after the operation, the baby will need help with breathing so will be connected to a ventilator. All babies are closely monitored after the operation, and so the baby will be connected to monitors to check his or her breathing, heart rate and oxygen levels. They will also be given pain relief through a ‘drip’. Occasionally there may be a tube from the operation site (chest drain) to drain off air and fluid so that the lungs have room to expand. This will be removed as soon as it is no longer needed.
A child’s lungs may not have developed properly by being squashed by the intestines in the chest. The length of time that a baby needs the ventilator depends on the condition of their lungs. If this is likely to cause long term problems, the doctor will explain it.
While the baby’s intestines recover and start to work, they may be fed through a tube into their veins (total parenteral nutrition or TPN). This will gradually be replaced by breast or bottled milk given through the naso-gastric tube when the baby is ready for this. As the baby recovers, they will be able to feed from the breast or bottle. Over time, the drips and monitors will be removed one by one.
The nurses on the ward will encourage families to look after their baby as much as they feel able while they are recovering. This can be daunting, especially while the baby is connected to drips and monitors, but it will become easier with time. Anyone worried about caring for their baby is encouraged to talk to the nurses.
Once your baby is feeding properly and gaining weight, they will be transferred to another ward within GOSH or to a local hospital . We send a letter with details of the outpatient appointment soon after the child leaves the hospital.
People should call your local hospital if their baby:
vomits when feeding
has a swollen stomach
vomits green liquid
is not gaining weight
The doctors there will discuss any concerns with the team at GOSH.
What is the outlook for children with diaphragmatic hernias?
This depends on how quickly the condition is diagnosed and how much the lungs were damaged before birth. The respiratory team at GOSH will continue to see and treat children if their lungs were badly affected, for instance, by pulmonary hypertension, before birth. The outlook is improving all the time, as better treatment is developed. Children who would previously have not survived are now growing up and we will only know the long-term effects of diaphragmatic hernia by studying these children closely.
However, there are a couple of side-effects which families should know about, should they arise in the future.
Sometimes it takes a while for the baby’s intestine to work properly, so the child may need extra nutrition. This will enable the child to gain weight to reach the right size and weight for their age. Dieticians can be spoken to about this.
Some children who have had a diaphragmatic hernia develop a problem with gastro-oesophageal reflux when they are older. This is where the contents of the stomach flow back up the oesophagus (gullet) causing pain and irritation.
A small number of children continue to have lung problems so need to have oxygen or medications to help them breathe. Children may also seem to be ‘behind’ in their developmental milestones, which means that they sit, walk and talk later than other children their own age. Many children catch up in the end and have few long term problems.