What is a three-way kidney exchange?

he process takes three incompatible donor and recipient pairings and matches them with each other to allow a transplant to take place.

Pairing one would receive a kidney from paring two and give one to pairing three. Pairing two would get a kidney from pairing three and so on.

The logistically challenging set of operations starts with the kidney removals in the morning, organ transit around midday and the transplants into the recipients’ bodies by evening.

The 12 hours of operations were preceded by months of paper work, testing and liaising with families.

Ian Dittmer, the physician who supervised the three-way transplant, said it was very hard to find a donor that matched Christa, due to her extremely high antibody count meaning that only 10 per cent of the population could potentially donate to her.

‘‘One of the biggest hurdles to finding compatibility is having to make sure the person who is getting the kidney doesn’t have any antibodies to the donor. . . otherwise the recipient’s body will start to attack the new organ.

‘‘Antibodies are proteins that your body makes, normally to fight infection. These antibodies attach to the kidney cells or the liver cells and attack it and try and get rid of it.’’

Christa has an extraordinarily high amount of antibodies that came from her previous kidney transplant and subsequent blood transfusions, Dittmer explained.

Even though the odds were stacked against her they were able to find a match.

"It’s quite exciting when you can ring those people up and say ‘we’ve got a kidney for you’,’’ says Dittmer.

While New Zealand had done ‘‘quite a few’’ two-way kidney swaps since the introduction of the procedure in 2012, this was the first three-way exchange, he says.

‘‘Three-way swaps are definitely the way of the future for people who are hard to find kidneys for.’’

Much better than, say, giving a kidney to someone who isn’t a complete match and loading them full of anti-rejection medicine."It’s the treatment of choice for end-stage renal disease. In most patients it provides superior quality and quantity of life compared to dialysis and in addition is more cost effective for society.’’

Dittmer, who is also the director of the New Zealand kidney exchange, hopes to be able to join with Australia to set up a trans-Tasman exchange. "This would help generate more exchange opportunities, to help more people with renal failure from both countries who are hard to find donors for.’’

With more people in the transplant pool, it would open the door to more sophisticated exchanges – for example a seven-way exchange including 14 people at a time, says Dittmer.