'Hero': Man's lifesaving Christmas gift of a new kidney for his best mate

The life-changing surgery has substantially improved James' quality of life. Photo / 7 News

For Adelaide man James, 38, a new kidney from his best friend Callum, 31, was the ultimate Christmas gift.

The lifesaving surgery between mates has drastically improved James' quality of life, after he had suffered from chronic kidney disease for the past 10 years.

Speaking to 7 News, Callum said he was inspired to commit to the altruistic act after another friend died from kidney disease. He and James now have matching scars along the base of their torsos.

"If I was to find out that Jamie had passed away, it would be something that if I never put my hand up, I would regret not doing," he said.

The friends now have matching scars. Photo / 7 News

James said the operation had left him feeling better and full of gratitude.

"Just to feel better and to feel different, no one can see that, but just to feel the way I'm feeling, it means everything," he said.

"I'm full of gratitude. I continually questioned him, I said, 'Are you sure about this?' Because it's just such a massive gesture.

"I call him a hero, even though he hates that, but I don't care."

The most common transplant surgery in Australia, the operation carries a high success rate: more than 94 per cent of transplants work one year later.

According to Kidney Health Australia, patient survival is at 91 per cent for five years and 46 per cent for 20 years for first transplants from deceased donors, and subsequent transplants carrying a similar survival rate.

Currently 1800 Australians are waitlisted for a transplant. A further 13,000 are on dialysis who may need the operation, according to Donate Life.