Restoring correct blood flow

Expert treatment for neonates

At Royal Brompton Hospital, the large team of consultants and clinical specialists have many years of experience of paediatric care and treating children with heart conditions.

Children, infants and neonates are brought to Royal Brompton Hospital from across the UK – and around the world – to access expert treatment for complex conditions that may not be treated in their local hospital but are only available at a specialist tertiary centre.

Indeed, Royal Brompton Hospital is the only hospital the UK to conduct PDA closure through the transcatheter route. This results in a shorter hospital stay and recovery time, with no chest scar.

Professor Alain Fraissé introduced the technique after joining the hospital in 2014.

During the procedure, under general anaesthetic, a catheter is inserted into the femoral vein and guided towards the heart using echocardiography imaging. A very small occluder device – called Amplatzer Duct Occluder II Additional Sizes (ADOIIAS) – is released at exactly the right location to block the PDA.

“The device is a mix of titanium and nickel and it has a memory shape. It loads into a 1.3mm catheter,” explains Professor Fraissé.

After the duct is closed, the baby’s breathing, feeding and growth soon improves. Over time, heart tissue grows over the wire mesh occluder. The device is designed to not set off metal detector alarms at airports and it is compatible with MRI (magnetic resonance imaging).

Ligature or occlusion?

At hospitals around the UK, PDAs are routinely fixed by attaching a clip or suture around the vessel to close it. While ligation is a proven surgical technique, it is more invasive as the heart is accessed via a thoracotomy – a surgical incision into the chest wall. Recovery can be longer, and it has higher risks particularly for very small babies.

Instead, Professor Fraissé has researched the benefits of treating PDA in premature babies with a transcatheter occluder. “Preliminary results regarding comparison between surgery and transcatheter intervention look favourable for transcatheter intervention.” His recent findings suggest that “postoperative ventilation after transcatheter closure of the PDA is significantly less, statistically, than after surgical ligation.”

This is especially evident when treating very small premature babies – born at just 23 or 24 weeks gestation and weighing as little as 800g at the time of treatment, like baby Carl.

“The problem is that when babies have immature lungs, they have a lot of respiratory complications. If you do a thoracotomy to an 800g baby, it’s more concerning than if you insert an occluding device via a keyhole transcatheter, in the femoral vein,” Professor Fraissé explains.

Nadia would recommend transcatheter PDA closure to other parents and referrers: “It’s a delicate procedure, but it is quite fast. It’s successful, it fixes the problem, and the recovery time is better than surgery.”

“My son is now a healthy, happy two-year-old lad. He is a little bit smaller than his peers, but he is catching up,” Nadia observes.

At the time, Carl was the smallest baby with a PDA closure that Professor Fraissé and his team had ever treated using the transcatheter approach. Since then, more than 80 babies weighing under 1kg (2lb 3oz) have undergone successful PDA closure at Royal Brompton Hospital.


At a glance

Procedure

Transcatheter occlusion of patent ductus arteriosus (PDA) in premature babies.

Carried out by

Professor Alain Fraissé

What problem does it solve?

By closing the PDA, correct blood flow is restored to the body.
This improves symptoms of heart failure such as fatigue, difficult or rapid breathing, or failure to grow normally. It is a less invasive intervention than surgical ligation, avoiding damage to the lungs, and is therefore associated with better recovery.

How does it work?

Under general anaesthesia, the duct is close by inserting a wire mesh transcatheter occlusion device into the PDA. Following treatment, the baby’s breathing feeding and growth soon improves.


 

Patient case study


Patent ductus arteriosus (PDA) is an extra blood vessel found in newborn babies. If it doesn’t close as normal, then intervention might be required. Royal Brompton Hospital offers a unique and less invasive way to close the vessel and correct the blood flow.

Carl was born in London at 23 weeks premature, weighing just 685g (1 lb 8 oz). “He was a tiny baby,” his mum Nadia recalls, “He was ventilated and had difficulty breathing.”
A duct in Carl’s heart, between his pulmonary artery and the aorta, had not closed shortly after birth.

Professor Alain Fraissé, director of paediatric cardiology at Royal Brompton Hospital, explains: “When a baby is premature, they often keep their fetal circulation after birth. 50 per cent of premature babies who are born at less than 30 weeks, have PDA.”
“Premature babies can be very sick because of a big PDA. Sometimes the PDA is larger than the aorta.”

In full-term infants, the PDA typically shrinks and closes on its own in the first few days of life. If it stays open longer, it may cause extra blood to flow to the lungs, and lead to heart failure as the heart needs to work harder to pump blood around the body.

The neonatologist will monitor the baby and determine how to manage the condition. The vessel can close naturally, and sometimes drug therapy will help with this. But if those options are unsuccessful and the baby is continuing to experience negative symptoms like fatigue, difficult or rapid breathing, or failure to grow normally, then surgery can be considered to close the PDA.

Despite treatment with ibuprofen, Carl’s PDA remained open. When he weighed around 800g, Nadia firstly was told that the next step was surgical ligation via thoracotomy to tie the PDA closed.

However, Nadia was then offered a new treatment which could suit her son better: “A transcatheter route to close the PDA was then recommended to me, as they can access the heart without cutting through respiratory muscles,” Nadia says. “I decided to go for this – as I didn’t want my son to be hindered by further damage to his lungs and the surrounding muscles.”

The neonatal unit overseeing Carl’s care and treatment found a short-notice opening at Royal Brompton Hospital and Carl was quickly transferred across for treatment by Professor Alain Fraissé.

A small device was implanted in Carl’s heart to successfully close the PDA, by occluding the duct. After two days, he was stable enough to be returned to the neonatal unit