Their parents were told that from their birth, the boys were unlikely to survive. Twin boys from Turkey, joined at the head.
The only place in the world that was able to operate to separate Derman and Yigit was London’s Great Ormond Street Hospital.
Channel 4 News has had exclusive access to the painstaking operations, as the hospital’s team used new technologies to navigate their way through separating the boys’ brains.
And a warning, there are scenes of surgery throughout this special report by our Health and Social Care Editor Victoria Macdonald.