A review into children's heart services in Belfast has suffered a further delay.
Health officials have said the report, which was expected at the start of July, is now expected "in the near future".
In the past week more children than ever before have had to travel to England for heart treatment, according to the Children's Heartbeat Trust.
A total of 96 children in Northern Ireland had paediatric cardiac surgery in England between July 1, 2013 and June 30, 2014.
In the same period, seven children had cardiac surgery in Dublin, while between January 1 and June 30, 2014, the paediatric cardiac surgeons from Dublin carried out 14 procedures in Belfast.
A mother whose daughter has to travel to Birmingham for heart surgery and had her operation cancelled last week, has told of her frustration.
As Joanne Black and daughter Myra (6) from Co Down were leaving they received a call to say the operation had been cancelled.
Joanne said: "The day we were to travel we just found out at nine o'clock in the morning that there was no bed available and surgery would be cancelled for the next day.
"We were then given a new date which is next Wednesday, but unfortunately the same can happen again," she added.
Sarah Quinlan from the Children's Heartbeat Trust said: "So many more families have been travelling to England than ever before. We have been supporting in the region of 10 families a week who have to travel to England for surgery. The system in place between Belfast and Dublin seems very sporadic."
The Department of Health said: "The ministers of health in Northern Ireland and the Republic of Ireland have asked an international expert group to carry out an assessment of the potential for an all-island paediatric cardiac surgery model which would meet the respective needs of the population of Northern Ireland and the Republic of Ireland.
"We had expected to receive the expert group's report by July 1 2014, but this has been delayed and the report is expected in the near future."