Two months ago housewife Lee Kim Mui was in dire straits.
Because her liver was failing, her heart, kidneys and other organs were shutting down one by one. Her only hope was a new liver, but her husband and three adult children had been ruled out as donors.
As she lay jaundiced, swollen and barely alive in intensive care at the National University Hospital, her only son Wilson Wong, 29, pleaded with doctors to reconsider him as a donor even though earlier tests had shown that giving to his mum would leave him with too little of his own liver.
After intense discussion and planning, the transplant team decided to go ahead, modifying the operating technique to salvage enough of the organ for both mother and son.
Madam Lee, who turns 64 on Tuesday, will sit down today to a birthday and Mother's Day celebration with her husband, son, two daughters and two grandchildren.
"I'm very happy," she told The Sunday Times in Mandarin.
The only reminders of those grim days are the twin scars branded from chest to abdomen on mother and son.
She needed a transplant because the liver disease she had been diagnosed with had caused cirrhosis - the hardening and shrinkage of her liver.
Her husband, retiree Willy Wong, 70, gave up his job as an estate manager early last year to take care of her full-time.
"Last year was a stressful year," he said, relating how, at her worst, his wife was stricken by the effects of poisons her liver could no longer process.
He said she was a walking zombie who sometimes could not recognise family members, and was so drained by her illness that she sometimes fell asleep while chewing her dinner.
By March this year, doctors felt that without a transplant, she would not see her next birthday.
The operation on March 11 changed everything.
"She's improved tremendously," said Mr Wong. "She's thinking of the future now and interested in the newspapers and in Facebook, and going out."
Everyone in the family had volunteered to be donors, but were struck out one by one: Mr Wong, because of his age; daughter Sue Lynne, 38, a training manager, had a fatty liver; daughter Sue Anne, 30, an advertising executive, had a higher body mass index, which made the procedure too risky.
That left Wilson, an ex-commando who is single.
The traditional - and easiest - way of taking a portion of liver from a living donor is by dividing the liver through a straight plane, following the middle vein of the liver.
However, scans had shown that this would leave the younger Mr Wong with only a quarter of his liver, less than the 30 per cent recommended globally.
But he was determined to donate because he knew it was his mother's only chance.
"Of course I had to do it," he said.
Checking again, Dr Stephen Chang, an associate professor and senior consultant at NUH's National University Centre for Organ Transplantation, decided that cutting the liver at a slant would retain 29.8 per cent of Mr Wong's liver, just shy of the international standard.
The trade-off: It would be riskier for the donor. He told Mr Wong that his risk of dying would jump 10-fold, to 5 per cent, given that such an operation had not been done before.
The surgical strategy took another twist during the operation itself.
Said Dr Chang: "At the time of surgery, an idea suddenly came to me which helped me further reduce Mr Wong's risk. Instead of cutting along a plane, I decided to cut the liver according to exactly where his remaining blood vessels would supply his remaining liver. It was then, on the fly, that I redrew the cutting plane and did a zig-zag line instead."
This technique was unheard of.
"It was scary, it gave me too much white hair. This was the last resort and I wouldn't have attempted it if there was an alternative," said the surgeon.
The hospital has done more than 100 living donor liver transplants since 1990, and all the donors have survived.
"There are people dying who could be saved with living donor liver transplants," said Dr Chang. "Doing so is a true, meaningful act of love, and one which is extremely safe in Singapore."
Two teams comprising at least eight surgeons, four anaesthetists and eight nurses were involved in the 12-hour procedure for Madam Lee and her son. Another team of liver and intensive care specialists cared for them in the days after the operation.
When Mr Wong woke up from his operation, his first thought was of his mother. He was wheeled over to see her a few days later, when he had recovered sufficiently.
"I asked her if she was okay and she could reply, so that was good," he recalled.
He and his mother had always been close, Mr Wong said, relating an incident when he was a toddler with her on a bus, and she broke her wrist shielding him from a fall.
He added with a laugh: "I had full confidence in the doctors and was never really worried. My so-called sacrifice was nothing much, although it does make a good Mother's Day gift.
"While I was still recovering with all those tubes in me, I thought of my mum who had even more tubes in her, and said if she can do it, why not me?"
He is back at work as a product marketing specialist. And the fitness enthusiast who enjoys running, cycling and swimming has started cycling again.
His mother, though still a bit weak, has also started exercising in her Jurong West flat.
"I'd like to thank the doctors and nurses, they took such good care of me. They have become my friends," she said.
"My son, I was afraid for him, not myself. He rescued me."