Dr Hilary Jones explained on Daybreak how Mark Cahill's hand transplant was a world first.
He said hand transplants have been done since the 1960s, however this is the first time that the hand has been removed and the donor organ has been transplanted on at the same time.
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A fine start to Sunday but rain moves in from the southwest later on.
A second police officer has died after he and a colleague were shot as they scuffled with a suspect in Florida.
Thousands of demonstrators have marched through Boston in opposition to a right-wing rally in the city which was eventually cut short.