Jordanian cardiologist Dr Ziyad Hijazi takes two or three children every year to his home country for procedures requiring devices that are not approved in the US.

In a typical case, Dr Hijazi went to Jordan to implant a device called an amplatzer muscular VSD into the heart of a child from Massachusetts.

The device can be used to close up congenital 'holes' in the heart and is manufactured by Minneapolis-based AGA Medical.

It was available for 9 years in Jordan before it was finally approved for US use in 2007.

Dr Hijazi believes that children are getting worse treatment in the US, and have even died, because approval for adult medical devices takes priority.

He claims that more than 90 per cent of the medical devices he uses on children are 'off-label', meaning that they are approved for use on adults only.

"We take responsibility as physicians for using unapproved devices on kids," he said.

One medic is sure that children have died as a result of the lack of specialised implants for the young.

"In the nineties, we lost lives in the cath lab," said Dr Thomas Forbes, director of cardiac catheterisation at the Children's Hospital of Michigan.

"Patients have died on the table because we were using stents that were made for adults and weren't flexible enough."

A recent law provides financial incentives for companies to make devices for children -- but it also requires them to track the progress of patients at their own expense.

"It's a paperwork nightmare," Dr Forbes said.

"They have to commit resources and follow these patients forever."

"If I'm a [Johnson & Johnson] stockholder, I'm saying, 'I love kids, I'd love to help them out, but move on.'"

Some believe that the focus on adults is down to the fact that the market for children is much smaller.

"We're all anxious for the dissolvable stent...but do you think Johnson & Johnson is going to be interested in doing this for babies?" said Dr Richard Ringel, a paediatric cardiologist at Johns Hopkins Hospital.

"No, they want to do it for [adult] coronary patients because the numbers are so much larger."

One manufacturer acknowledged the inherent problems with developing devices specifically for children.

"We have not cracked the code on this," said Michael Mussallem, chief executive of Edwards Lifesciences, makers of a a blood-oxygen monitor designed for the young.

"Development is time-consuming, there are regulatory hurdles and how do you recoup your investment?"

"The math generally does not work."

Mussallem also believes that there is a culture of 'getting by' when it comes to treating children.

"There's not a climate for innovation," he said.

"A great percentage of devices are used off-label to accommodate children's needs."

"Physicians are just used to getting by."

An upcoming conference organised by the state-funded National Institutes of Health (NIH) will bring doctors and manufacturers together to discuss the issue.

The trade association representing medical device makers is looking to the government for leadership on the issue.

"First, we need to understand what the needs are and I'm hopeful that NIH will help catalogue the needs," said Tara Federici of AdvaMed.