In an astonishing seven-hour operation, London doctors successfully rebuilt a toddler's heart with tissue taken from a cow.
Jamie Goodier was diagnosed with life-threatening abnormality called atrioventricular septal defect.
His heart had only two valves instead of four so it struggled to pump blood around his body.
"When they said what they were going to do we were totally shocked," the New of the World quoted mother Rebecca as saying.
"But we just wanted to save him - and if it took part of a cow to do it then fine, whatever helped Jamie survive," she added.
Jamie was put under five months of tender care until he was strong enough for the surgery.he doctors performed tripe-le bypass, where they used tissue from around a cow's heart to repair the missing main wall in Jamie's before splitting his two valves into the four he needed.
"This was a very unusual case. We used a plastic band on one of Jamie's main arteries to restrict blood flow to the lungs," said Cardiac surgeon Nelson Alphonso.
"That allowed his condition to improve until he was strong enough for the operation.
Now 21 months old, Jamie has gone from strength to strength. "He's a lovely healthy colour and he's full of energy," said Rebecca.