WASHINGTON - It took a metal plate improperly lodged in a young boy's skull to make Dr. David Staffenberg realize just how dangerous adult-sized devices can be in children.
The plate was implanted to help stabilize the boy's skull but ended up resting on his brain. While Staffenberg was able to safely remove the titanium disc, the fact that he was faced with this added risk speaks to a problem pediatricians face every day: The vast majority of medical devices are made for adults.
Doctors work around the problem by jury-rigging adult-size devices to suit their needs. But they acknowledge that such ingenuity has limits and that the risks to patients are often high. With growing support from lawmakers, doctors are prodding the medical device industry to design a new class of kid-friendly equipment.
A law signed by President Bush in September offers financial incentives to companies that design devices for kids. It also gives regulators more power to scrutinize the use of adult-size devices in children and requires manufacturers to bear the costs of tracking them.
While this added oversight has dampened industry's enthusiasm for the law, there are other more practical reasons device makers remain cautious about jump-starting production.
The profit potential is limited because the law allows experimental kid-size devices to be sold without full federal approval only if they're used to treat rare diseases. Also, compared to adults, kids are healthier, and therefore a much smaller market to begin with.
"The pediatric market is a mere fraction of the market for adults," said Paul Citron, who recently retired as vice president of technology at device maker Medtronic Inc. While the US market for medical devices is estimated at nearly $90 billion, healthcare experts agreed the pediatric portion is minuscule.
And with companies like Medtronic and Natick-based Boston Scientific Corp. already under scrutiny for pacemakers, stents, and other adult devices, they may be reluctant to start testing in kids.
Child-safety proponents and parent groups have largely stayed out of the debate, preferring doctors take the risks of working with less-than-ideal tools rather than do nothing.
But as the use of devices has increased, so have complaints from physicians. Shortcomings include:
Heart valves that quickly deteriorate in growing bodies.
Heart-shocking pacemakers that cause infection, stroke, and death in small patients.
Surgical cameras that damage tissue in children because they are too big.
The Food and Drug Administration, which regulates devices, has almost no data on how widely adult devices are used in children. The only large-scale study of this issue, conducted in 2005 by the Institute of Medicine, yielded no estimate on how many deaths or injuries result from the practice, though doctors say there have likely been some of each.
Problems range from the mundane - oversize oxygen masks - to the complicated - pacemaker batteries that run out because of children's faster heartbeats. And some, like a metal plate placed in a growing skull, could cause seizures or more serious problems.
To be sure, a steady trickle of pediatric devices has made it to market. Device maker Respironics has built an entire subsidiary around respiratory equipment for hospitalized babies, a relatively large market. Last year, German device firm Berlin Heart began US testing of the first heart pump for infants awaiting transplant.
Dr. James Lock, head of cardiology at Children's Hospital Boston, said 98 percent of the devices he has in the operating room are designed for adults. One of the few pediatric devices he uses, a cloth patch to seal tiny holes between heart chambers, is one he invented himself.
Lock finally persuaded NMT Medical to manufacture his Cardioseal after studies suggested an alternate use in adults. The Boston-based company would never have built the seal without discovering a market "potentially 20 times larger than the pediatric market," Lock said.