Brian Coker, who had both legs amputated in the Christchurch earthquake, in bed with his wife Helen with their children.

Brian Coker, who had both legs amputated in the Christchurch earthquake, in bed with his wife Helen with their children. Photo: Waikato District Heath Board

Pinned under a concrete wall and in agonising pain, a Christchurch quake survivor wanted to die before a penknife-wielding surgeons - including an Australian doctor - hacked his legs off in a remarkable rescue.

"I just wanted there to be a decent aftershock to finish it," Brian Coker said of his ordeal trapped in the rubble of a Christchurch office block after the devastating tremor that has killed at least 148 people.

Quick-thinking surgeons, who were in Christchurch for a medical conference, saved Mr Coker's life by amputating his legs using a pocket knife and a hacksaw so the 52-year-old financial adviser could be pulled from the wreckage.

Mr Coker issued a statement from the Waikato Hospital, where he is recovering, praising the surgeons who put their own lives at risk to operate on him in the still shaking building, using a Leatherman knife and builder's hacksaw.

"I'd like to meet the doctors and rescuers at some time ... I would like to thank them," he said.

Mr Coker said he did not remember the amputation because he was anaesthetised, but he could recall the quake and drifting in and out of consciousness trapped in a stairwell beneath debris for six hours, not knowing if help would arrive.

"I was swept off my feet when a concrete wall fell on me," he said.

"I knew straight away I was pinned and there was no way I could get myself out ... the pain was excruciating. I had blood dripping from my head."

He hesitated to text his wife because "I didn't want to worry her", eventually deciding to make contact for what he thought may be the final time.

"I wanted to tell her I loved her and that I may not survive," he said.

Harried rescuers finally found him in the wreckage of the Pyne Gould building, giving him a drink of water and some morphine to ease the pain.

"They kept reassuring me they would get me out," he said. "I could hear other people screaming in the building."

After seeing Mr Coker's horrendous injuries and realising they could not move the massive chunk of masonry bearing down on his legs, the rescuers enlisted the help of the visiting surgeons to get him out.

"I didn't know they were going to amputate my legs but I should have known," he said. "They cut my trousers and they did that while I was still conscious.

"They had no choice."

Australian doctor Stuart Philip described last week how he and his colleagues turned the ruined building into a makeshift operating theatre and used the basic tools available to perform the amputations.

"I've never been so frightened in my life, but we just kept going," he told ABC radio, saying a female New Zealand medic did most of the surgery because she could fit in the tight space in which Mr Coker was trapped.

Mr Coker said he would remain in hospital for several weeks while his stumps healed before beginning a long program of rehabilitation.

But while acknowledging his life would never be the same, he said his thoughts were focused on the people of Christchurch as the traumatised city is rattled by constant aftershocks, particularly those who had lost loved ones.

"My heart goes out to them," he said. "I have colleagues who are injured and colleagues who are missing and my condolences go out to their families."

AFP