Page 79 - JSOM Winter 2019

Current and Future Operating Environment for its effectiveness, usefulness, and potential role is still devel-
oping. REBOA is an invasive intervention that requires passing
Dismounted Complex Blast Injury (DCBI) is a challenging and a catheter via the femoral artery and inflating a balloon in the
significant injury pattern. It usually consists of bilateral lower aorta occluding distal flow. REBOA can be used in Zone 1 or 3
limb, often proximal, amputations with associated pelvic inju- of the aorta and thus has a potential capability that the AAJT
ries. Alongside this there is frequently upper limb injury and does not. As REBOA is an invasive procedure, it is technically
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other thoraco-abdominal and neuroaxial injuries. This injury much more challenging than the AAJT with a heavy training
pattern became increasingly common in recent conflicts where burden, maintenance of competency, and a greater governance
asymmetrical warfare resulted in tactical shift and improvised burden. It is also unlikely that those who do not routinely gain
devices and it is reasonable to predict this to be a feature of femoral access in their daily job role would feel confident or be
future conflicts.
able to gain access quickly, effectively, and safely in a periarrest
patient while in a combat zone. Fifty percent of REBOA inser-
Non-state actors driven by ideological ideals are predicted to tions in a hospital setting required femoral cut-down, highlight-
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continue to persist. It is reasonable to assume that they will ing that it is a complex skill requiring a trained clinician.
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continue to use Improvised
The American College of Surgeons Committee on Trauma (ACS
Explosive Devices (IEDs). Equally this group will seek to have COT) in conjunction with the American College of Emergency
continued impact and therefore will wish to successfully carry Physicians recently released a policy statement on REBOA use.
1
out violent and “spectacular” events that mean blast injury They advise the REBOA should only be deployed by an acute
will likely intermittently affect civilian populations with injury care surgeon, vascular surgeon, or interventional radiologist
distal to the aortic bifurcation being a risk and challenging to trained in REBOA. Under certain conditions, a trained emer-
manage if a large-scale civilian mass casualty situation arises.
gency physician with critical care experience can deploy RE-
BOA. One of the key statements is that REBOA should only be
Defense Engagement performed if an acute care surgeon is immediately available; this
Although regular UK military forces are not currently involved is unlikely to be the case in the prehospital environment. Addi-
in active combat operations, those we are supporting in both the tionally, within the military setting, they advise that if an emer-
Middle East and Africa are often involved in asymmetrical war- gency physician is to deploy the device, an acute care surgeon
fare where IEDs are commonplace. We therefore have a respon- must be immediately available. The ACS COT statement does
sibility as mentors and advisors to prepare our allied partners not advocate prehospital use of REBOA and, importantly, from
for complex blast injury patterns such as the DCBI. Preparing a military point of view, does not recommend it being used in
those we train for these injuries benefits the individual but will the transfer of patients, opposing its use as a “bridging” device
in turn contribute to our soft power in such engagements. The between levels of care. There are reports of REBOA being used
AAJT could be a useful salvage device for these partners, espe- in the military setting successfully, but it is important to note
cially as other invasive techniques such as REBOA are unlikely this is by Special Operation Surgical Teams and not in the far
to be pushed forward in these environments—the training and forward prehospital environment without a surgical team. 37,38 A
governance burden are too great. However, prior to taking to recent review article in the New England Journal of Medicine
partner forces, we need to build a larger evidence base and fur- has further classified devices such as the AAJT as prehospital
ther clarify our own institutional stance on the device.
interventions and REBOA as an in-hospital intervention. 39
Limited Resources—The Austere Operating Environment Lendrum et al. recently published a descriptive case series of
Current UK and partner nation deployments are often at reach prehospital Zone 3 REBOA for pelvic hemorrhage. They de-
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with limited resource availability compared with previous scribe a 32% failure rate despite using ultrasound; furthermore,
commitments in mature operating environments such as Op there was a high rate of arterial thrombus alongside other com-
HERRICK (Afghanistan). A single casualty can exhaust medi- plications being described such as superficial femoral artery
cal supplies, especially when it comes to fluid resuscitation. A cannulation requiring patch angioplasty, inadvertent zone 2
team may be limited to the fluids carried in a medical bergan placement causing renal infarcts, and iatrogenic dissection of
or be reliant on an emergency donor panel when operating in the CFA to distal aorta. This further demonstrates that REBOA
very small teams.
use is not without risk and requires a high level of user skill.
It has been suggested when confronted with significant lower Rall et al. compared Zone 3 REBOA and the AAJT in a me-
limb hemorrhage that the AAJT can dramatically reduce fluid chanically ventilated swine model with an application time of
requirements to maintain mean arterial pressure (2900mL no 1 hour. They found that both interventions achieved 100%
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AAJT vs 340mL at 60 minutes and 400mL at 4 hours). This hemorrhage control with the AAJT group having a signifi-
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would also aid surgeons in the Role 2 environment. In the cantly higher MAP (59.9 ± 16.1 vs 44.6 ± 9.8mmHg) but
event of a mass casualty situation, the AAJT would be used raised lactate (4.5 ± 2.0 vs 3.2 ± 1.3mg/dL) compared with
to stabilize patients while the surgical team operates on other REBOA. The AAJT also had increased peak inspiratory pres-
patients and prevent exhaustion of their limited resources of sures compared with REBOA, but this had no effect on oxy-
blood and fluids.
genation or other markers of pulmonary indices. The authors
conclude that despite the difference of the devices, they both
Is the AAJT a Direct Alternative to REBOA? achieve hemostasis with a similar hemostatic, hemodynamic,
and metabolic profile.
A full comparison of REBOA and the AAJT is beyond the scope
of this article; however, it must be acknowledged as a potential A retrospective study performed by Cantle et al. explored the
hemorrhage control device. Much like the AAJT, the evidence
potential benefits of REBOA, intra-abdominal foam and the

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