James Walsh / Minneapolis Star Tribune

MINNEAPOLIS — There is no such thing as a baby pacemaker. Or a defibrillator for kids.

For children with an irregular heartbeat, the only option is an adult device. Pacemakers are wedged into children’s abdomens because there isn’t enough room in their chests. As their bodies grow, they face years of surgeries as the adult devices are replaced or modified.

The wave of medical device innovation that is improving and extending the lives of younger generations is passing over the youngest. While more patients in their 30s, 40s and 50s are benefiting from an extensive range of treatments, products are rarely developed with children in mind. Doctors must routinely alter devices to fit into kids’ bodies or wait until they are older to provide treatment.

“The biggest challenge, by far, is size,” said Dr. Christopher Carter, a pediatric cardiologist at Children’s Hospitals and Clinics of Minnesota. “But there are other issues as they get older: They aren’t going to be able to play contact sports. ... Really, it becomes a lifetime of compromise.”

The scarcity of specialty devices for kids is largely a numbers game: There aren’t enough children with chronic illnesses to justify the cost of developing products just for them.

Since most devices are developed in the private sector, companies such as St. Jude Medical and Medtronic spend their time on products that reach a broader population and ultimately return a profit.

“It can cost $100 million to bring a device to market,” said Dr. Steve Oesterle, Medtronic’s senior vice president for medicine and technology. “The market (for kids) just isn’t big enough.”

Children are noticeably absent from the development of treatments for pain, movement disorders and heart ailments — treatments that are helping tens of thousands in other age groups.

An estimated 1,600 children ages 1 through 17 in the United States had a procedure involving a pacemaker or a defibrillator in 2010, according to data from the U.S. Department of Health and Human Services. That compares with 56,033 patients ages 45 through 64 and 155,446 ages 65 through 84.

Kids also make up just a fraction of those receiving orthopedic treatments. Only 200 children had a procedure involving artificial hips in 2010; 188 received knee replacements.

Yet doctors and advocates say there are several technologies they are trying to develop with children in mind — and a few already are coming to market. Among them are defibrillators that don’t use wires to connect to the heart and tracheal tubes that won’t damage a baby’s esophagus during some procedures.

Such specialty devices also could prove more durable and efficient because they are a better fit. A smaller pacemaker, for instance, could further improve heart function in young children and be better secured in their bodies.

“The need is for a whole variety of low-tech and higher-tech devices that are optimized for kids,” said Donald Lombardi, who runs the Institute for Pediatric Innovation in Massachusetts. “It’s not rocket science to develop these things. But it takes good engineering — and an overall market.”

A group at the University of Michigan is trying to develop products aimed at kids. So are others at the University of California, San Francisco; Stanford University; and Atlanta Children’s Hospital.

All have won grants through the Office of Orphan Products Development, a program through the U.S. Food and Drug Administration that seeks to nurture the development of medical products for patient populations of fewer than 200,000.

But most new devices, if they ever make it to market, are years away.

“It takes a lot of dedicated people and continuing to think outside the box to make things happen,” Lombardi said.

A child’s pacemaker

Asher Thomas was 3 days old when doctors cracked open his chest to run the wires from his pacemaker to the outside of his heart. He was born with a condition called heart block, a problem with the electrical system that controls heartbeats.

His heart rate had plunged to 39 beats per minute. On the morning of his surgery, his anxious parents, Robyn and Aaron, couldn’t see him awake.

“His heart rate dropped so low that they had to sedate him,” Aaron Thomas said. “That was the scariest part.”

Asher went home from the hospital after spending eight days in neonatal intensive care. The pronounced bulge extending from Asher’s abdomen is a reminder of the adult pacemaker that he will need for the rest of his life.

“Once you’re a cardiac patient, you’re always a cardiac patient,” said Robyn Thomas.

Every three months, Robyn and Aaron hook their son’s pacemaker up to a telephone line at their Eden Prairie home so that doctors can see if it’s working properly. That’s the easy part. They know that every few years, Asher’s pacemaker will need to be replaced. They know that the wires that attach the device to his heart — the leads — come with risks.

“Kids are just tougher on leads,” said Dr. Charles Gornick of the Minneapolis Heart Institute.

Leads are known to last 15 to 20 years, but sometimes they wear out sooner, requiring a complicated surgery to replace them. Even if no hiccups occur, Asher eventually will have the leads run through a vein to his heart, which is how they are placed in adults.

There also are long-term effects of needing an implantable device. No one really knows what a lifetime of pacing does to the human heart.

“These things are not developed for children,” said Carter, Asher’s doctor. “We’re still learning.”

Then there are other difficulties. It can be tough to program devices to accurately sense when a child’s heart is dangerously out of rhythm because kids have naturally higher heart rates. Children are also harder on devices because they don’t always rein in their physical activities.

“It’s always an ongoing negotiation with our younger patients,” Carter said.

Fortunately, Asher, now 2, is proving to be as energetic and rambunctious as any little boy. He was walking at 10 months. He clambers up and down the carpeted stairs of his family’s home. He plays with puzzles and the family dog. Visits to the neighborhood playground are frequent and tiring — for his parents.

“He’s into everything,” Robyn Thomas said of her son. “He’s just busy. He’s always been busy.”

The first devices

Several cardiac devices — pacemakers, heart valves and stents — got their start with children.

In the 1950s and ’60s, before FDA oversight, the first devices were used in an effort to save young heart patients before the technology was expanded to a broader population.

“Why is that? Because no one wants to see a kid die. I believe kids are the catalysts for imagination,” Medtronic’s Oesterle said.

But the way devices are developed has changed dramatically since then. In 1976, the FDA was given the responsibility of approving medical devices, which increased oversight. Where doctors once conducted research in backroom labs and tested devices with parents’ consent, the FDA now requires extensive testing and clinical trials for new devices.

Convincing device makers to do that for a costly product that might only help a handful of children is a nearly impossible sell, said Dr. Robert Campbell, a pediatric orthopedic surgeon and director of the Center for Thoracic Insufficiency Syndrome at the Children’s Hospital of Philadelphia.

Campbell has developed products for children, including a spine device that can be adjusted as a child grows, but it took 14 years to get it to market.

“I was very lucky,” he said. “I had a company that was owned privately and an owner that was very sympathetic to children.”

The two main areas of device adaptation for children are cardiovascular and orthopedic, said Brad Slaker, founder of DesignWise Medical, a Minnesota company that facilitates development of pediatric devices. Slaker calls those segments “low-hanging fruit” with moneymaking possibilities.

Otherwise, companies are reluctant to develop lifesaving or life-sustaining pediatric devices because they require expensive human testing. So potential pediatric devices, such as diabetes monitors for children, lack the profit margins that spur commercial research and development.