Fears over the future of paediatric heart surgery services in Belfast escalated after a 2012 UK wide review.
Led by Professor Sir Ian Kennedy, it concluded that although the service at the Royal Belfast Hospital for Sick Children is safe, due to the small number of operations being carried out it is not sustainable.
It said that centres must perform a minimum of 450 children's surgical procedures each year.
Congenital heart disease is the most common birth defect in children born in Northern Ireland with on average 250 children per year born with one or more conditions. Roughly one-third of these children will require open heart surgery or other interventional procedures.
About 90 heart surgery operations are carried out each year by the Belfast Health Trust with a further 40 taking place in either England or Dublin.
As a direct result of the conclusions of the UK-wide review, Stormont Health Minister Edwin Poots said he was re-examining the future of local paediatric heart surgery provision.
Among the proposals he said he was considering was stopping all children's heart surgery in Northern Ireland.
This would mean seriously ill children from across Northern Ireland and their families having to travel to England or Dublin for life-saving treatments.
A public consultation on the future of children's heart surgery was launched in September 2012 and ended last December.
A campaign was launched by the Children's Heartbeat Trust charity to keep services open at the Royal.
The charity wants an all-Ireland network to help ensure the viability of undertaking specialised surgery locally.
Almost 10,000 people signed an online petition calling for the retention of the surgery in Belfast.
Restrictions -- introduced last year -- are being placed on paediatric heart surgery leading to an increasing number of families having to travel for their child's treatment.
Heart operations are still taking place in the Royal Victoria Hospital.
However, children with complex diagnoses have been transferred mainly to Birmingham Children's Hospital in England.
In April 2013, the Health and Social Care Board (HSCB) recommended a transfer from the Children's Hospital in Belfast to Our Lady's Hospital in Dublin.
The HSCB recommended the setting up of a Children's Cardiology Centre in Belfast.
However, it will not be a round- the-clock service for children suffering from heart problems.
The report was subject to ministerial approval.
But in the same month Mr Poots publicly stated that there were weaknesses with a Dublin-only solution and that his preferred option would be a surgical network between Belfast and Dublin. A decision had been expected within "weeks".
But seven months later families of children with congenital heart defects are still awaiting a decision.
There is still no indication of where children will receive critical treatment in the future -- Belfast, Dublin or England.
The surgical service for congenital heart disease in Belfast is currently provided by two surgeons, with support where needed from two further surgeons based at Our Lady's Hospital for Sick Children in Dublin.
But following the retirement of Professor Fred Wood in December this will drop to one.