Claudia Twiby was the second child in the UK to ge given a mechanical "piggy-back" heart while waiting for the vital organ donar.

The operation was a success and within a month a donor was found.

A mechanical heart kept little Claudia Twiby alive for 27 days before a donor organ was found.

The 18-month-old toddler is recovering well at home in Brighton after the pioneering treatment at London's Great Ormond Street Hospital.

Donor organs are in dangerously short supply across the UK and 23 per cent of all paediatric heart transplant candidates die within six months while waiting for an organ.

The miniature pump, called a Berlin Heart, had only been used on one other child in the UK before it saved Claudia's life.

Four weeks after the pump was fitted she received a new donated heart and is now back at home in Westfield Crescent with her parents Jodie Lansdale, 32, and Shaun Twiby, 42, and sisters Pasha, 11, Lara, nine, and Millie, two.

Jodie, a history teacher, said the family had been through "a horrible time" because Claudia was in hospital for three and a half months, but now Claudia is a "happy smiling" child again.

She said: "Claudia first fell ill when she was just over one year old.

First, she was diagnosed as having bronchilitis. But after a few days she still wasn't getting any better and we took her to our local hospital. She was very unwell, lethargic, listless, and her eyes were getting puffy.

"Doctors did lots of tests but no one knew what was wrong with her.

We were referred for an ECHO which showed she had a problem with her heart.

"They said we had to go to Guy's Hospital in London straight away and go into intensive care. They said they didn't even have time to explain anything. It was horrible."

Claudia was kept in intensive care for a few days before being transferred to the cardiac ward. Then doctors discussed giving her a heart transplant.

They had discovered she had dilated cardiomyopathy which meant her heart was bigger than usual and not working efficiently.

Jodie said: "She was just deteriorating. The doctors wanted to transfer her to Great Ormond Street to be put on an ECMO, a mechanical assist device for the heart. They were worried she was going to have a cardiac arrest.

"As we were preparing her to transfer they asked if we wanted to call a chaplain. They were concerned she wouldn't even make the journey. That was the worst time because we thought she was going to die.

"But they ventilated her at Great Ormond Street and she was fine so they put her on the transplant list and she was sent back to Guy's. It was exhausting. Sitting by a hospital bed became our way of life.

"We tried to focus on all the positive things. Friends would come and visit and burst into tears because she looked so bad, but we just focused on the details, we didn't look at the big picture. "So it was quite a surprise when we were visited by a heart surgeon who told us about this new device.

"It was explained to us that, because of Claudia's age, they would find it very difficult to find a donor organ, and it might take a long time before one was available.

"The ECMO device can only be used for a short space of time, so they decided for Claudia it was best to go on this new Berlin Heart, which can be used for much longer."

Carin Van Doorn, an honorary consultant cardiothoracic surgeon at Great Ormond Street, told the family about the Berlin heart procedure. The operation to fit the Berlin heart was carried out by Ms Van Doorn on November 1.

Ms Van Doorn said: "Historically there have been more bridge devices available for adults than for children, so the fact that the Berlin Heart is available in such small sizes is a positive step forward.

"There are, however, complications associated with all such devices and while this provides us with more options in the future, what we really need to do is reduce the waiting time we desperately need more donors in the UK."

Jodie said: "Once Claudia had been put on the Berlin Heart, the transformation was incredible. She went from being very sick, very weak to being like a normal child again.

She was able to come off the ventilator and start breathing by herself.

"She could sit up and play and have physio. We could read books to her. It was a massive relief to see her looking more normal. She looked like a healthy child if you covered up the Berlin Heart."

Jodie told of their relief when they heard a donor heart had been found on November 27.

She said: "I got a call just before 10pm saying there was a heart available. It was awful because we knew there was another child the same age in Newcastle who needed a heart too. It was like we were competing for it.

"It was agonising waiting for the surgeons to say if the operation could go ahead. Shaun was in Brighton and we couldn't get hold of him. My mum came up and we sat with Claudia all night.

"Then they told us at 6am that it was happening and she went straight into surgery. I gave her a kiss and that was it. She was in surgery for six and a half hours.

Shaun arrived and we just waited. It was very surreal, we had been hoping for this to happen for months.

"When she came out we saw her briefly before she was taken into an isolation unit. Her chest was left open for a couple of days to let the new heart settle as it was three times bigger than a heart for someone her size. It was very weird, you could actually see her heart beating.

"It took a while for us to get used to the fact that this was another person's heart. But now it is just Claudia and her new heart.

"After a couple of weeks we were allowed to bring her home.

"We are so pleased to have her home. We were a normal family who went through something horrible and now we are a normal family again.

"She is on 23 lots of medication at the moment but this will whittle down over time to two lots in the morning and three in the evening.

"Doctors say she has a limited life expectancy and will not see old age.

They say she will only live to about 40. But that is 39 years away and I am confident technology will be very different and she will be able to live a normal life.

A Berlin Heart is a mechanical device which serves as a bridge to assist the function of the heart until a donor becomes available.

First introduced in 1992, it comes in a variety of sizes and can be used in very young children.

It is a mechanical pump which can take over the function of either the left or right pumping chamber in the heart. If both chambers are failing, then two pumps can be fitted.

Great Ormond Street Hospital (GOSH) became the first hospital in the UK to successfully use the Berlin Heart in a small child in November 2004, when a two-year-old stayed on the device for 67 days before undergoing successful heart transplantation.

The children chosen for the Berlin Heart had severe heart failure and were chosen largely because it was proving difficult to match them with a donor.

As with all mechanical devices there are significant risks associated with treatment, including infection and blood clots.

It is a relatively small device and is worn outside the chest, connected to the heart by tubes that transverse the skin.

It costs about £41,000 per child and is funded by the National Specialist Commissioning Advisory Group.

The longest time a child has stayed on the Berlin Heart device was for 15 months in Hong Kong.

There are just over 60 hospitals worldwide that use the Berlin Heart. In England, just two other hospitals do the John Radcliffe Hospital in Oxford (adults only) and the Freeman Hospital in Newcastle.

To date, there have been 1,260 implantations worldwide, including 158 in children.

There has been a success rate of between 70 to 75 per cent in young children.