Urethane foam stems abdominal blood loss

Production of polyurethane foam within a human abdomen can cut blood loss six-fold and boost survival rate at three hours post-injury to 72%.

The U.S. military is studying the technology developed by Arsenal Medical (Watertown, MA) as a way to staunch blood loss from severe internal injuries suffered in combat.

"Currently, there are no effective pre-hospital treatments available for intra-abdominal bleeding on the battlefield," says David King, MD, a trauma surgeon at Massachusetts General Hospital with medical combat experience. "Our ultimate goal is to find innovative ways to improve treatment and save lives of those who are serving their country, as well as those who experience serious injury through trauma."

Earlier this month, Arsenal Medical was awarded a Phase II contract from the Defense Advanced Research Projects Agency (DARPA) to support continued development of its foam approach to control intra-abdominal hemorrhage. DARPA has provided $22.5 million for the program to date.

Liquid polyol and isocyanate are injected into the abdominal cavity, triggering two chemical reactions, starting with creation of foam that expands to approximately 30 times its original volume while conforming to the surfaces of injured tissue. Then the foam becomes solid, enabling it to resist intra-abdominal blood loss. According to DARPA, the foam can expand through pooled and clotted blood and withstand the hydrostatic force of an active hemorrhage.

Surgeons can remove the foam in one block in less than one minute. Features appearing in relief indicate partial encapsulation of the small and large bowels, spleen, and liver. There is no blood inside the foam.

"Wound Stasis has been an exciting program because we were able to move unexpectedly from fundamental research to a pre-clinical proof-of-concept based on the strength of our findings," says Brian Holloway, DARPA program manager. "According to the U.S. Army Institute of Surgical Research, internal hemorrhage is the leading cause of potentially survivable deaths on the battlefield, so the Wound Stasis effort should ultimately translate into an increased rate of survival among warfighters. If testing bears out, the foam technology could affect up to 50% of potentially survivable battlefield wounds.

Swine injury model data has been used to test the foam."