The U.S. military is testing the use of foam injections as a way to staunch internal bleeding of soldiers wounded on the battlefield. The technology may also eventually save the lives of civilians injured in car or other serious accidents far from a hospital emergency room.
Expanding foam technology has long been a dream of military and civilian emergency medical staff. All previous attempts have failed. Now, working with $22.5 million from thefederal Defense Advanced Research Projects Agency, closely held Arsenal Medical Inc. has developed a powerful injectable foam that pushes past bleeding and molds itself around injured organs in animal tests, DARPA plans to announce today.
The foam is intended for injection through the navel from where it spreads through the chest cavity, applying pressure on internal injuries that may not be visible to medics. Tests suggest it will provide them as much as an additional three hours to get soldiers to care.
“We’re solving what is, for most of the generals, the most-emotional problem they worry about,” said Duke Collier, the executive chairman of Watertown, Massachusetts-based Arsenal, in a telephone interview. “The guys who can be saved but who die from bleeds.”
Arsenal was founded by a partnership of Harvard University chemist George Whitesides, and the biological engineer Robert Langer of the Massachusetts Institute of Technology. Some of its funding is provided by DARPA, the elite Pentagon research unit that developed the Internet and provided early work leading to stealth technology for military aircraft.
The technology holds promise of treating injuries far beyond the battlefield, according to civilian trauma experts.
“War is a terrible thing, but this type of research is the kind of silver lining that can sometimes come out of it,” said Daniel Bonville, the program director for critical care at Albany Medical Center, New York’s busiest trauma center.
Car accidents are a particular problem for his center, Bonville said. With no other major city closer than a several hour drive, injured car passengers are often out of range of help.
“If people bleed uncontrollably for too long, even if they get here alive it can end up being too late,” he said. “The quicker we can get the bleeding controlled in all cases, the better off we are going to be.”
Arsenal’s foam product, so far successfully tested in pigs, could have an immediate impact on the battlefield. More than 20 percent of casualties are in shock when they’re admitted to a military hospital, and about a quarter require a blood transfusion, according to data from the U.S. Army’s Institute of Surgical Research. Shock is serious, occurring when blood loss damages tissues, and eventually leading to organ failure and death.
Field medics don’t know where internal injuries are located and they aren’t sure how complex the wounds are, David King, a surgeon at Massachusetts General Hospital Trauma Center, said in a telephone interview. Because many major arteries run through the trunk, the time for adequate response is measured in minutes, he said.
“I give a lecture to paramedics now called ‘Bleeding Control: Use Diesel Fuel,’” said King, who has been deployed as a military doctor in Afghanistan and Iraq. “I tell them to step on the gas, because there’s nothing else you can do to help patients.”
The time to get to a surgical team is now about an hour in the field, he said. When he was initially in Baghdad, that time was “upward of several hours,” he said.
Lots of people have tackled the bleeding problem for the last 25 years and mostly failed, according to Brian Holloway, DARPA’s manager for the program, in a telephone interview.
“The main problem is complexity,” Holloway said. “The abdominal cavity is a complex environment to work in. You can get a multitude of different injuries from the same event, with limited access.”
If the U.S. Food and Drug Administration green-lights the project, perhaps as early as next year, Arsenal plans to test the foam using a small group of trained special-forces medics.
Foam has been tried before to staunch internal bleeding, and have failed multiple times, said Upma Sharma, Arsenal’s director of material science and engineering.
“The problem is with these injuries, you’re going in blind, with a large pool of blood acting like a moat,” she said in a telephone interview. “Most materials never get to the site of the bleeding.”
The Arsenal group looked at 1,200 foams to find the one they decided to use. While 15 met the criteria for animal testing, only one expanded the way they wanted, had the right viscosity and wasn’t attracted to water, which allowed it to push through pooled blood to an injury site, Sharma said.
The foam was designed with two liquid precursors in a canister, injected through the navel. The force of the reaction propels the mixture through the abdomen, and the foam expands inside, molding around the internal organs.
Finally, it hardens to provide continuing pressure against the source of bleeding. Once a patient gets to a trauma center, the hardened foam is designed to be non-stick, so it can be easily removed by surgeons.
The material was initially tested in pigs because they have similar abdomens to humans. The pigs’ bellies were opened up and fishing line was inserted around the liver. After their bellies were closed again, researchers pulled on the fishing line, creating wounds around the liver.
Untreated patients with liver injuries often bleed to death within a half-hour, Sharma said. That’s because all of the body’s blood goes there to be filtered.
In the company’s studies, one group of injured pigs were given standard battlefield treatment while the other received the injected foam.
After three hours, only one of the 12 pigs in the control group was still alive, compared with 72 percent of the 15 pigs who received the foam. The mean survival times showed that most pigs who received standard treatment lived 43 minutes while the experimental treatment group lived a mean of more than 2.5 hours. The data is under review for publication, Sharma said.
Arsenal has another product in testing: fibers it calls AxioCore, which are meant to relay drugs embedded in their cores, speeding tissue regeneration and repair.
Langer, 64, has been instrumental in the creation of more than two dozen biotechnology startups from his MIT lab in Boston. He is best known for his 1976 discovery of factors in cartilage that limit blood vessel growth, and for creating new ways to deliver them slowly over time. Whitesides, 73, is the author of more than 950 scientific articles, and is listed as an inventor on more than 50 patents. Among the companies he helped found was Genzyme Corp., which was bought by Paris-based Sanofi for $20.1 billion in February 2011.
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