Stem cell plasters to stop children needing repeated heart surgeries

Researchers at the University of Bristol, partly funded by the Bristol Biomedical Research Centre (Bristol BRC) and the British Heart Foundation (BHF), have developed ‘stem cell plasters’ to revolutionise the way surgeons treat children living with congenital heart disease, so they don’t need as many open-heart operations.

Heart defects are the most common type of anomaly that develop before a baby is born, with around 13 babies diagnosed with a congenital heart condition every day in the UK. These include defects to the baby’s heart valves, the major blood vessels in and around the heart, and the development of holes in the heart.

Currently, for many of these children, surgeons can perform open-heart surgery to temporarily repair the problem, but the materials used for the patches or replacement heart valves are not completely biological and cannot grow with the baby. This means they can be rejected by the patient’s immune system which causes the surgical materials to gradually break down and fail in a few months or years.

A child might therefore have to go through the same heart operation multiple times throughout its childhood, which keeps them in hospital for weeks at a time, hugely impacts their quality of life and causes a lot of stress for the family.

BHF Professor Massimo Caputo, workstream lead for Bristol BRC’s cardiovascular theme between 2017 and 2022, developed the first type of stem cell patch to repair abnormalities to the valve in the large blood vessel that controls blood flow from the heart to the lungs, and to mend holes between the two main pumping chambers of the heart.

The stem cell plasters are designed to be sewn into the area of the child’s heart that needs repairing during surgery. The stem cells could then boost the repair of heart tissue without being rejected by the child’s body.

These patches have the potential to adapt and grow with the child’s heart as they get older, removing the need for repetitive heart surgeries and the many days at hospital recovering after each one.

There are around 200 repeat operations for people living with congenital heart disease every year in the UK. The technology could save the NHS an estimated £30,000 for every operation no longer needed, saving millions of pounds each year.

Professor Caputo now intends to continue his work with the help of nearly £750,000 of funding from the BHF. His aim is to get these patches ready for testing in patients so clinical trials can start in the next two years, enabling more children and babies to benefit from the life-altering technology. The materials have already proven to work safely in animals.

The team is also in the early stages of developing other stem cell technologies using 3D bioprinting and gene therapy to one day be able to mend more complex congenital heart defects.

Massimo Caputo, BHF Professor of Congenital Heart Surgery at the Bristol Heart Institute, University of Bristol, said:

“For years families have come to us asking why their child needs to have heart surgery time and time again. Although each operation can be lifesaving, the experience can put an unbelievable amount of stress on the child and their parents. We believe that our stem cell patches will be the answer to solve these problems.

“Our ultimate vision in the next decade is to create a paradigm shift in the way doctors treat congenital heart disease, by developing personalised stem cell and genetically-engineered treatments for the most complex of heart defects.”

Melissa Hudd, mother to Finlay – the first baby to receive this treatment, said:

“We can’t thank Massimo enough. I believe, if it wasn’t for the stem cell treatment, then Finley wouldn’t be here with us today. Finley is very feisty and very funny – he’s a real heart warrior and I tell him that all the time.

“We don’t know what the future brings, but we are so grateful for Finley’s life to be turned around after the stem cell treatment as he now has a chance at life he might not have had otherwise. The stem cell plasters Massimo is now developing sound incredible. If they could give the gift of life and save other families from the emotional turmoil of their children having repeated open-heart surgeries, then that would be life-changing.”