The ductus arteriosus is a blood vessel that allows blood to bypass a babies’ lungs while they are in the womb.
This is because their lungs are underdeveloped until they start breathing. The ductus arteriosus therefore acts as a ‘safety feature’ and is biologically programmed to shut when babies are born at full-term.
The closure usually happens in the first few days or weeks after birth. If it remains open, it is known as patent ductus arteriosus (PDA).
PDA means a baby has an additional (and abnormal) source of blood flow to the lungs. As a result, there is extra strain on the left-hand side of the heart, which has to collect and deal with the extra blood.
What causes patent ductus arteriosus?
Patent ductus arteriosus is a congenital heart defect (present when your child was born). The exact cause of congenital heart defects isn’t often clear. Most heart problems in children are present from birth due to an anomaly in the way the heart forms during the very early stages of pregnancy.
The reasons for this may be due to a number of factors, such as genetics, environmental factors or infection. The likelihood that a heart problem will have been caused directly by anything you have done during pregnancy or early life is very rare.
What are the signs and symptoms of patent ductus arterious (PDA)?
The signs and symptoms will vary depending on the size of the PDA, the age of your child and whether they have any other heart problems.
- Small ducts (PDA) Your child may not have any symptoms and the PDA may only be picked up at a routine health check where a heart murmur is also detected.
- Moderate ducts (PDA) Your child may have symptoms of heart failure, such as breathlessness, poor feeding or impaired growth. They may also be more susceptible to chest infections.
- Large ducts (PDA) Your child may have signs of severe heart failure, such as breathlessness at rest, failure to thrive and multiple respiratory infections.
How is patent ductus arteriosus (PDA) diagnosed?
Your child will have an echocardiogram
, a non-invasive, high frequency ultrasound scan of the heart. It allows doctors to see the PDA, the aorta and pulmonary blood vessels, how blood is moving through the heart and the impact the blood flow is having on other components of the heart.
They will also have an electrocardiogram (ECG). This measures electrical activity in the heart to see how well it is working. Doctors will look to see whether the left ventricle (one of the lower pumping chambers) is dilated, a sign that it is working harder than it should be.
How is patent ductus arterious (PDA) treated?
The treatment your child will need will depend on the size of the PDA and any other heart problems they might have.
If the PDA is not affecting blood flow to the heart (and is not audible via stethoscope), it is unlikely to cause your child any health problems in the future. Your child may be discharged without needing further treatment.
The first line of treatment is usually with medication to try to close the PDA. If this is not appropriate or does not work, your child will need surgical treatment.
If the PDA is affecting blood flow to the heart (and is audible via stethoscope), your child may need a keyhole procedure (known as cardiac catheterisation with PDA device occlusion). This procedure avoids the need for more invasive surgery. Your child will be given an anaesthetic before a cannula (a thin tube) is inserted into a blood vessel in their groin. A catheter (a thin, flexible tube) is fed through their veins using special X-rays until it reaches the heart. A special plug is then inserted across the PDA to block blood flow to the heart. The plug will remain in position within the ductus. The procedure lasts approximately two hours and your child will be able to go home the same day.
In some instances, when the PDA is very large (or your baby is very small), cardiac catherisation may not be appropriate. Your child may need surgery to ligate (tie-off) the duct and remove the abnormal source of blood flow. This type of operation is usually very straightforward and does not require the use of cardio-pulmonary bypass. Commonly, the operation can be performed by performing a small incision at the side of the chest (under the armpit) avoiding a scar on the front of the chest. At GOSH, this operation is often carried out in the Neonatal Intensive Care Unit.
What happens next?
The long-term outlook for PDAs is very good irrespective of the strategy used to close the hole (catheter device closure or cardiac surgery). Further surgical or catheter procedures are not usually required and children lead normal healthy lives.
Last reviewed: 10 August 2012