David Lange, 63 today, not only had his right lower leg amputated on Tuesday without a general anaesthetic - halfway through the risky operation, as the limb was nearly off, he drowsily asked the surgeon: "Have you got the right leg?"
"My heart stopped for a moment," surgeon Peter Vann, Middlemore's head of vascular surgery, told the Herald. "And then I just smiled to myself."
The other seven members of the theatre team laughed.
Mr Vann said Mr Lange's poor health precluded general anaesthesia. Amputations without it were "very, very rare" and this was only the second he had done.
Mr Lange's operation was "extremely high-risk", said his renal physician, Mark Marshall. "There was significant debate about whether it could be done. We were all swayed by David Lange, who made it quite clear he would rather lose his leg than his life."
In theatre, Mr Lange was sedated and given nerve blockers so he would feel no pain when his lower leg, the foot gangrenous as a result of diabetes, was removed below the knee.
Mr Lange declined music during the 40-minute procedure, said Mr Vann. "He was laughing and joking with us.
He was a bit drowsy."
Although an electric saw was used to detach the leg, Mr Lange would have heard little more than "a buzzing", said Mr Vann.
His relieved wife, Margaret Pope, described the operation as "a heroic feat of the surgeon and anaesthetist". Mr Lange "felt great after the operation because he had no pain at all", she said. On the second day, however, "he became much more uncomfortable". The hospital yesterday described his condition as fair.
Mr Lange's younger brother Peter spent the night at the hospital after the operation, and reported that the former PM wasn't upset to see the leg go. "I think it was a huge relief, because it was so sore."
Mr Lange, who has described his prognosis as "rather dismal", has been in hospital for 21 days. He was admitted for treatment of the gangrene, a complication of diabetes which causes tissue death.
Mr Lange was also being treated for end-stage kidney failure requiring nightly peritoneal dialysis; he was not a candidate for kidney transplantation, said Ms Pope. The incurable plasma disorder amyloidosis, which affects organs such as the heart and kidneys, was further compromising his health.
However, there were no plans as yet for his British-based children, Byron and Emily, to fly home, said Peter Lange.
David Lange has now become one of the 500 New Zealanders who annually undergo lower-limb amputations as a result of diabetes - the condition is responsible for half of all such removals, according to Diabetes New Zealand president Murray Dear.
"The upside is that amputation corrects the medical problem, and that improves the patient's overall condition."