Former New Zealand all-rounder Chris Cairns remains in a serious condition after undergoing a second heart operation in a Sydney hospital.

The 51-year-old was transferred to St Vincent's on Tuesday having initially had surgery in Canberra last week for a reported aortic dissection – a tear in the lining of the body's main artery.

"Chris suffered a major medical event in Canberra late last week," said a statement from his wife Melanie.

"He initially underwent surgery in Canberra, but the seriousness of his condition is such that he has now been transferred to St Vincent's Hospital in Sydney, where he has undergone further cardiovascular surgery.

"Chris' family and friends are heartened by the respectful and warm manner in which this terrible news has been reported, and received by the public, both in New Zealand and around the world, and thanks everyone for their warm wishes, prayers, and kind words.

"For now, no further statements will be made regarding Chris' situation, and the Cairns family asks that people continue to respect their privacy as they deal with this difficult, upsetting and concerning situation."

Cairns played 62 Tests, 215 one-day internationals and two Twenty20 matches for his country between 1989 and 2006 and support has poured in from his homeland and throughout the cricketing world.

"We're deeply concerned to hear of Chris Cairns' medical emergency," said New Zealand Cricket chief executive David White.

"Our thoughts are with his family in Australia and here in New Zealand. Chris is a much-loved husband, father, and son – and remains one of our finest all-rounders. We hope he's able to make a full recovery."

The New Zealand Cricket Players' Association added: "The NZCPA and our members are all deeply saddened by the news about Chris Cairns and our thoughts and prayers are with him and his family at this difficult time."