Abdominal Aortic Tourniquet – AAT™
The project is focused at the number one priority identified by the Institute of Surgical Research for care on the battlefield: how to address uncompressible hemorrhage that is not treatable by a tourniquet in the leg, groin and inguinal region. This encompasses a significant capability gap related to preventable deaths. The solution to this problem must be stable, easy to apply and completely stop the loss of blood. The AAT™ is capable of this, and animal and human studies have demonstrated its safety and efficacy.
The AAT™ provides a rapid application of pneumatic compression to the aorta at the abdominal-pelvic junction to occlude blood flow in the inguinal arteries. The specific claim of the device is to occlude arterial flow through the inguinal region. The target of the compression is the aortic bifurcation, which has historically been identified in relation to the umbilicus or the superior margin of the iliac crests. Difficult bleeds in the inguinal region continue to be a significant source of morbidity and mortality on the battlefield. Providing solutions for treating these wounds have direct life saving results. Wounds to the pelvis and inguinal region are now preventable causes of death.
The AAT™ is a circumferential device that greatly increases the stability of the compression. The pneumatic wedge shaped bladder provides focused pressure to squeeze the blood vessels passing through the lower abdomen and preventing flow. The research referenced below demonstrates the safety of up to one hour of application and its effectiveness in non-invasively cross-clamping the aorta or fully stopping all blood flow to the pelvis and lower extremities. In essence the AAT™ acts as a valve to figuratively ‘turn the faucet off’ and prevent the further flow of blood out of wounds below its application site.
Blood is the vital component to surviving blunt or penetrating trauma in the golden hour. It allows oxygen to be carried to the heart, brain and kidneys. Every drop of blood lost impacts survival. Why let any of it spill to the ground when we can prevent its loss?
Georgia Health Sciences University (formerly the Medical College of Georgia) has conducted research on the device using a swine model in 2009. Flow was undetectable in the femoral catheter during the tourniquet application. For hemodynamic variables, there were no significant differences in MAP or CVP measurements among animals. However, using one way repeated measures analysis of variance, there was a significant difference in MAP (P = 0.008) between 0 and 55 minutes for each subject. Serum potassium did not reach clinically significant numbers. However, serum lactate was significantly different between times 55 minutes (3.6 mmol/L +/- .95) and after tourniquet release 65 minutes 5.9 mmol/L +/- .87) (p <0.001). Gross and histological examination revealed no signs of significant ischemia or necrosis of the small and large intestine. These data were presented at the Advanced Technology Applications for Combat Casualty Care conference in August 2009 and the American College of Emergency Physicians Scientific Assembly in 2009.
Application of the device was studied on humans in 2011 again at the Georgia Health Sciences University and found to be safe and effective during the protocol. The Common Femoral Artery (CFA) was reduced to a no flow state by applying an average of 191 mm Hg. The device was associated with moderate discomfort that resolved completely with device removal. These data were presented at the Advanced Technology Applications for Combat Casualty Care conference in August 2011.
Compression Works received FDA approval for the AAT™ on October 22, 2011.