Patent ductus arteriosus (PDA)
The ductus arteriosus is a blood vessel that connects the pulmonary artery (main vessel supplying the blood to the lungs) to the aorta (main vessel supplying the blood to the body).
This connection is present in all babies in the womb, but should close shortly after birth.
In some babies, especially in those born prematurely, this vessel may remain open. This is called a patent or persistent ductus arteriosus.
What causes a baby to have a ductus arteriosus?
In the womb, the mother’s placenta provides oxygen for the baby and the ductus arteriosus allows blood to bypass the lungs. After birth, the baby must use their lungs to take in oxygen and get rid of carbon dioxide. To achieve this, the blood flows to the lungs and the ductus arteriosus closes. The ductus arteriosus normally closes shortly after birth. However in some babies, especially premature babies, it can remain open or even reopen.
How will it be detected?
A heart murmur will be heard by the doctor examining the baby.
The team looking after the baby may have suspected a PDA as the baby had difficulty coming off the ventilator or CPAP machine. The baby will then have had an echocardiogram to confirm the diagnosis.
What happens if this blood vessel stays open?
A patent ductus arteriosus increases the blood flow to the lungs. This can make it harder for the baby to breathe and come off the ventilator.
The heart also has to work harder to pump blood around the body, which can lead to heart failure (which is completely reversible). Many babies with a PDA will have been kept on reduced fluid intake and given diuretic medicines to try to treat fluid overload caused by heart failure.
To try to close the connection, the baby may have been given medication (often a non-steroidal antiinflammatory drug such as ibuprofen). Sometimes medication is unsuccessful or not appropriate and a surgical closure might be needed.
What happens before the procedure?
The baby will be moved to the Neonatal Intensive Care Unit (NICU) at GOSH by a neonatal transport team. Accommodation can be provided for parents during their baby’s stay on the NICU. The baby will continue to receive the care they need in NICU.
To assess a child, various tests will be performed:
- Chest x-ray
- Blood tests
The surgeon will explain about the operation in more detail, discuss any questions parents may have and ask them to sign a consent form giving permission for their child to have the operation.
We will ask that all parents leave the unit when the operation is in progress.
What does the procedure involve?
The procedure involves a full team of doctors, nurses and technicians. Your baby will be asleep and so will not feel any discomfort. A small tube (catheter) is inserted into the vein at the top of the leg. The catheter is moved up the blood vessel into the heart and into the PDA. An X-ray picture is then taken of the PDA. A device is then threaded through the catheter and placed into the PDA.
The device is made of a fine wire mesh, which plugs the flow of blood flow through the PDA. The position of the device is checked by echocardiography (heart ultrasound) and by X-ray pictures. Once a good position is confirmed the device is released, the catheter is removed and the small cut at the top of the leg is covered with a dressing.
An anaesthetist and the cardiologists performing the procedure will visit your baby before the operation to find out about your baby’s general health, previous experiences of anaesthesia, any medicines he/she is on and any allergies he/she might have. This is a good time to talk about any particular concerns you have.
Are there any risks?
No medical procedure is entirely without risk. In general, the main risks include bleeding, infection, damage to the vessels leading to, or around the heart, damage to the valves inside the heart, protrusion and dislodgment of the device. As with any procedure, there is a very rare risk of death.
What happens afterwards?
- Your baby’s heart rate, blood pressure and oxygen levels will be monitored.
- Echocardiograms and sometimes X-rays will be done the same day and/or the next day to confirm good position of the device and closure of the PDA.
- Your baby should be able to go back to the neonatal unit from which your child was referred within 48 hours of the procedure.
- Your baby will then be followed up in the neonatal unit and later in outpatient clinic at regular intervals thereafter.