Page 32 - JSOM Spring 2021

Conversion of the Abdominal Aortic and Junctional Tourniquet (AAJT)
to Infrarenal Resuscitative Endovascular Balloon Occlusion of the Aorta
(REBOA) Is Practical in a Swine Hemorrhage Model

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Kyle S. Stigall, MD ; Perry E. Blough, BS ; Jason M. Rall, PhD ; David S. Kauvar, MD *
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ABSTRACT
Background: Two methods of controlling pelvic and inguinal has been uniformly successful or gained widespread adoption.
hemorrhage are the Abdominal Aortic and Junctional Tour- Two specific therapies capable of treating pelvic and junc-
niquet (AAJT; Compression Works) and resuscitative endo- tional bleeding are the AAJT and REBOA.
vascular balloon occlusion of the aorta (REBOA). The AAJT
can be applied quickly, but prolonged use may damage the The AAJT consists of a belt with a wedge-shaped inflatable
bowel, inhibit ventilation, and obstruct surgical access. RE- bladder that can be applied to occlude blood flow at junc-
BOA requires technical proficiency but avoids many of the tional sites (i.e., axilla and groin) or occlude the distal aorta
complications associated with the AAJT. Conversion of the and iliac vessels when placed in the lower abdomen. The AAJT
AAJT to REBOA would allow for field hemorrhage control was chosen for this study because of this ability to occlude
with mitigation of the morbidity associated with prolonged blood flow in proximal inguinal and pelvic hemorrhage com-
AAJT use. Methods: Yorkshire male swine (n = 17; 70–90kg) pared with more commonly used junctional tourniquets, such
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underwent controlled 40% hemorrhage. Subsequently, AAJT as the SAM Junctional Tourniquet (SAM Medical). When
was placed on the abdomen, midline, 2cm superior to the il- placed around the abdomen, the AAJT applies pressure at the
ium, and inflated. After 1 hour, the animals were allocated to level of the aortic bifurcation. The product has been shown
an additional 30 minutes of AAJT inflation (continuous AAJT to be effective in limiting femoral artery blood flow in both
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occlusion [CAO]), REBOA placement with the AAJT inflated laboratory and clinical settings. One of the main benefits
(overlapping aortic occlusion [OAO]), or REBOA placement of the AAJT is that it can be applied quickly and accurately
following AAJT removal (sequential aortic occlusion [SAO]). by prehospital personnel with minimal training. 9,10 Complica-
Following removal, animals were observed for 3.5 hours. Re- tions of AAJT application include increased pain, respiratory
sults: No statistically significant differences in survival, blood arrest, obstruction of surgical access sites, and the potential
pressure, or laboratory values were found following interven- for ischemic bowel damage with extended inflation times. 6,11–13
tion. Conversion to REBOA was successful in all animals but The AAJT is currently fielded by Special Operations medi-
one in the OAO group. REBOA placement time was 4.3 ± 2.9 cal personnel for use to prevent exsanguination from severe
minutes for OAO and 4.1 ± 1.8 minutes for SAO (p = .909). pelvic and femoral injuries. As a noninvasive, externally ap-
No animal had observable intestinal injury. Conclusions: Con- plied device, it is suitable for use on the battlefield and during
version of the AAJT to infrarenal REBOA is practical and ef- evacuation.
fective, but access may be difficult while the AAJT is applied.
REBOA uses an inflated intravascular balloon that stops blood
Keywords: hemorrhage; Abdominal Aortic and Junctional flow to achieve hemostasis. The balloon catheter is introduced
Tourniquet; resuscitative endovascular balloon occlusion of via the femoral artery and can be positioned in the descending
the aorta; swine aorta between the subclavian and the celiac arteries (Zone 1)
or inserted between the renal artery and the aortic bifurcation
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(Zone 3), depending on the site of hemorrhage. Current clin-
ical practice guidelines from the American College of Surgeons
Introduction recommend an aortic occlusion time of less than 15 minutes
Hemorrhage is responsible for a quarter of all deaths in com- when positioned in Zone 1 and less than 60 minutes when
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bat and is the leading cause of potentially survivable battle- positioned in Zone 3. Initiation of REBOA requires signif-
field deaths. The liberal use of tourniquets has been successful icant training and technical proficiency. Because of this, and
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in preventing exsanguination from extremity injuries, but in contrast to the AAJT, REBOA has been used in military
noncompressible pelvic hemorrhage is particularly difficult to casualty care no farther forward than Role II facilities with
treat because of the inability to rapidly and safely compress surgical capability on site. 16,17 Several translational studies
the site of injury. Recently, specialized products, including have demonstrated broad equivalence between REBOA and
expandable foams, injectable compressed sponges, and vari- the AAJT for the control of femoral hemorrhage. 18–20 In simple
ous junctional tourniquets, have been developed to manage controlled hemorrhage and polytrauma models, similar hemo-
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hemorrhage from such injuries. Unfortunately, none of these static, hemo dynamic, and metabolic profiles were observed.
*Correspondence to Brooke Army Medical Center, 3551 Roger Brooke Drive, JBSA Fort Sam Houston, TX 78234.
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1 CPT Stigall is affiliated with the San Antonio Uniformed Services Health Education Consortium and Brooke Army Medical Center. Mr Blough
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and Dr Rall are affiliated with the Office of the Chief Scientist, Wilford Hall Ambulatory Surgical Center. LTC Kauvar is affiliated with the San
Antonio Uniformed Services Health Education Consortium, Brooke Army Medical Center, and Uniformed Services University.
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