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?
Research
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.
FDA Approval
Compression Works received FDA approval for the AAT™ on October 22, 2011.
