Medicine may be advancing by leaps and bounds in certain fields – mind-controlled prosthetics and bioprinting come to mind. But in some respects, we are still very much in the dark ages. Considering gunshot wounds, for example. When it comes to modern warfare, uncontrolled hemorrhaging caused by a bullet is the biggest cause of death. In fact, “bleeding out” is responsible for 80% of deaths caused in battle, more than headshots, chest wounds, or IEDs combined.
This startling statistic doesn’t just apply to soldiers who are wounded in the field, as about the same proportion of those who sustain bullet wounds die after being evacuated to a medical treatment facility as a result of hemorrhaging. In the ongoing conflicts in Iraq and Afghanistan, about 5,000 US troops have been killed, and some 50,000 injured, while combined military and civilian losses are estimated to have been some 500,000 people killed.
The immediate cause of death in most of these cases was bleeding out, which is usually associated with deep arterial wounds that simply cannot be treated using tourniquets. As a result, combat medics pack these wound with a special gauze coated with a material that stimulates the clotting process, then applies strong direct pressure over the wound in the hopes that a clot will seal off the artery. If the bleeding is not controlled, the medic has to remove the gauze and try again.
This process is so painful that, according to John Steinbaugh, a former Special Ops medic, the patient’s gun is first taken away so that he will not try to kill the medic or himself to stop the agony. And in the end, people still die, and all because medical science has yet to find an effective way to plug a hole. Luckily, RevMedX, a small Oregon startup, has developed an alternative approach to treat such potentially survivable injuries.
That’s Revmedx and its new invention, the XStat, comes into play. Contained within this simple plastic syringe are hundreds of small sponges (1 cm, or 0.4 inches, in diameter) made from wood pulp and coated with chitosan, a derivative of crustacean shells that triggers clot formation and has antimicrobial properties. When they are injected into a deep wound, the sponges expand to fill the cavity, and apply enough pressure to stop arterial bleeding.
And since they adhere to wet surfaces, the sponges counter any tendency for the pressure to push them out of the wound. After conducting tests of early prototypes, the final development was carried under a US$5 million U.S. Army contract. In most cases, an arterial wound treated using XStat stops bleeding within about 15 seconds. The sponges are also marked with an x-ray absorbing material so they can be located and removed from the wound once surgical treatment is available.
XStat is currently awaiting FDA approval, bolstered by a request from the US Army for expedited consideration. Combined with a new Wound Stasis Technology (aka. a medical foam) that earned its inventors a $15.5 million from the Defense Advanced Research Projects Agency (DARPA) back in Dec of 2012, army medics will likely be able to save a good many lives which in the past would have been written off as “casualties of war” or the all-too-common “collateral damage”.
Similar to the XStat, the idea for this injectable foam – which consists of two liquids that, when combined, form a solid barrier to stop bleeding – the inspiration for this idea comes from direct experience. As a military doctor in Iraq and Afghanistan, David King – a co-investigator of the foam project and a trauma surgeon at Massachusetts General Hospital – saw a great many deaths that were caused by uncontrolled internal bleeding.
Located in Watertown, Massachusetts, Arsenal Medical designed this substance that consists of two liquids to fill the abdominal cavity and form a solid foam that does not interact with blood. This is key, since the hardened foam needs to remain separate and stop the blood from flowing. Comprised of polyurethane molecules, this foam belongs to a family of materials that is already used in bone cement, vascular grafts, and other medical applications.
The team began by testing the foam in pigs that were subjected to an internal injury that cut the liver and a large vein. With the treatment, nearly three-quarters of the pigs were still alive three hours later. Afterward, the team began monitoring how the pigs fared once the foam was removed. In 2013, the company began working with the U.S. Food and Drug Administration to determine how to test the technology on the battlefield (though no dates as to when that might have been available yet).
As always, developments in the armed forces have a way of trickling down to the civilian world. And given the nature and prevalence of gun violence in the US and other parts of the world, a device that allows EMTs the ability to seal wounds quickly and effectively would be seen as nothing short of a godsend. Between saving young people for gang violence and innocent victims from mass shootings, NGOs and medical organizations could also save countless lives in war-torn regions of the world.
Source: gizmag.com, technologyreview.com, medcrunch.net
One thought on “The Future of Medicine: Injectable Sponges and Foam”
Quite the invention!