The paralysed Polish man who regained his ability to walk after receiving revolutionary treatment said Wednesday he was a "lucky devil", as his doctors announced they were looking for new candidates for the procedure.

Darek Fidyka, 40, was paralysed from the chest down by a knife attack in 2010 but can now walk using a frame after nerve cells were transplanted into his severed spinal column two years ago.

"I hope to recover further," said Fidyka alongside his doctors at a press conference in the southwestern city of Wroclaw, a day after the research behind the breakthrough treatment was published in the journal Cell Transplantation.

"The attack turned my life upside down. Since the surgical operation, it's been steps in the opposite direction," the former fireman told reporters.

"I'm already able to get myself into bed, to dress and undress without help, to drive," he said, tears welling up in his eyes.

"I'm still having a hard time processing it all. I'm a lucky devil, relatively speaking."

Wlodzimierz Jarmundowicz, who heads neurosurgery at the Polish clinic where the operation was carried out, however cautioned against raising "the hopes of every person with a damaged spine".

The treatment can only be applied to "injuries caused by a sharp instrument, like a machete," he said.

Pawel Tabakow, who led the team of surgeons in the medical procedure, said the injury "is very rare".

They are now looking for two more patients suffering from similar injuries from across the world.

The criteria will be posted, in Polish, on the website of the Akron Neuro-Rehabilitation Centre in Wroclaw where Fidyka was recovering.

An English version will go up on the website of the University College London's Institute of Neurology, whose British research team collaborated on the project.

'No looking back'

The two institutions had worked "in synergy" on the project for years, but it was chance that led to the revolutionary treatment, Tabakow said.

He said that doctors generally take the cells that are supposed to promote nerve regeneration straight from the patient's nose. But that was not possible in Fidyka's case because of sinus inflammation.

Instead, they transplanted cells from his olfactory bulb, which required them to open up his skull—a "risky" procedure according to Tabakow.

The scientists involved had said Tuesday they think that the cells, implanted above and below the injury, enabled damaged fibres to reconnect.

"What we've done is establish a principle—nerve fibres can grow back and restore function, provided we give them a bridge," said Geoff Raisman, chair of neural regeneration at University College London's Institute of Neurology, who led the British research team.

"To me, this is more impressive than a man walking on the Moon. I believe this is the moment when paralysis can be reversed."

But other scientists have responded more carefully, saying it was important to await the results of clinical testing with more cases.

"Whoever decides to follow suit and get involved, he'll have to forge ahead with unflinching determination and no looking back," Fidyka told AFP.

"I told my doctors at the outset: let's do this, do what you can, it can't get any worse than it already is... I had highs and lows, I had a moment of despair, but I managed to overcome it."

Reporters were shown video footage of Fidyka before surgery and several months after. One scene showed the one-time goalkeeper kicking a ball.

"I'm 40, too old to take up football again," Fidyka said, before adding that Colombia goalkeeper Faryd Mondragon was 43 years old during this year's World Cup.

"So I'm not losing hope," he quipped.

Journal information: Cell Transplantation