John Radcliffe Hospital has suspended paediatric cardiac surgery while it investigates the deaths of four children who underwent heart operations there in recent months.
The deaths have all occurred in the past four months.
In a statement, the hospital said, “The families of children awaiting cardiac surgery are being contacted and we will be placing those patients who need to be seen urgently with other hospitals. We are reviewing each of these patients to ensure that they are not put at risk by any delay in their treatment.”
They further stated that the children had been “very sick”.
An external review will be carried out to see if there are any common factors linking the deaths.
Those requiring urgent treatment have been transferred to other hospitals.
The John Radcliffe Hospital carries out about 100 heart operations on children every year.
