Page 77 - JSOM Winter 2019

hemorrhage with 19.2% of hemorrhages due to junctional in- the abdomen, thorax, and brain) and more effective compres-
juries. Kragh et al. later reviewed all coalition deaths between sions due to counterpressure on the diaphragm secondary to
2001 and 2010 and concluded that 20% of all potentially sur- the AAJT; in addition, because the AAJT blocks both venous
vivable deaths were secondary to junctional hemorrhage —a and arterial flow, it may increase pressure, resulting in greater
5
consistent figure. coronary and carotid blood flow. 20
A study of the UK Joint Theatre Trauma Registry identified all Placed at the Axilla or Groin
UK combat-related pelvic junctional vascular injuries between In human studies looking at the outcome of arterial occlusion,
2008 and 2011. This study identified 37 casualties who died there are two studies looking at groin application and one
due to pelvic/lower limb junctional injury. An injury at this looking at axillary use. In total, this equated to 31 groin ap-
6
level would be amenable to AAJT use. Morrison et al. per- plications and 13 axillary applications with a 100% occlusion
formed a retrospective 10-year review of our UK casualties in rate; no other axillary or groin devices on the market currently
Afghanistan and Iraq highlighting 165 casualties who survived demonstrate a 100% occlusion rate. This high level of effec-
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beyond point of wounding with injuries amenable to zone 1 tiveness is suggestive that the device is easy to use; however,
or zone 3 aortic occlusion. When these 165 are split into died further work is needed to collect real-use data on time to effect
7
en route, died in hospital, and survivors, those with potential and how easy it is to use. Effectiveness outside of studies on
benefit from zone 3 occlusion amounted to 40.9%, 43.3%, animal models and healthy human volunteers are limited, but
and 41.4%, respectively. A UK civilian retrospective popula- there are case reports of successful axillary and groin use of
tion-based analysis of the 2012–2013 Trauma Audit and Re- the AAJT. 21,22 Both of these case reports were for penetrating
search Network (TARN) data also looked at those who might gunshot wounds in junctional regions.
benefit from aortic occlusion in trauma. The authors found
that 4.9% had an indication for aortic occlusion, of which Usability
40.6% (n = 161) would have required zone 3 occlusion. 8
Practicalities
The AAJT is an external device, so it can be both used in the
Effectiveness
sterile in-hospital environment or deployed in an unsterile,
Placed at the Aortic Bifurcation chaotic environment such as the modern asymmetric battle-
There are four healthy volunteer human studies looking at the field. It can sit in a medical rucksack or webbing, and small
effectiveness of the AAJT placed at the aortic bifurcation. Re- tears in packaging, which will often occur in the deployed aus-
sults were dichotomous with a pooled average of 52%. The tere environment, do not indicate that the product becomes
9
four studies had flow cessation percentages of 94%, 78% (re- unserviceable. The AAJTs stored dimension is 7.5 inches (W) ×
duced flow in 100%), 27%, and 11%. 10–13 This low marker 6.5 inches (D) × 2 inches (H) with a weight of 17 oz (1.06 lb).
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of effectiveness should be taken with caution; it appears the These qualities mean the device could be easily stored in a
reason for failure was not device failure but pain resulting in Role 1 (prehospital) environment and carried during high-risk
the healthy volunteer being unable to tolerate the device. For missions. An even smaller pack has been developed.
example, in the study by Kragh et al. with 11% effectiveness,
89% could not tolerate the AAJT and therefore their appli- Time to Effect
cation was deemed ineffective. This is similar to a separate In human studies, time to effectiveness for abdominal use has
13
study by Kragh et al. with an effectiveness of 27%. Yet, in been quoted as 92 and 171 seconds. The author agrees that
9
10
another study, only one British airborne soldier appeared to be this is a quick device to apply. In contrast, REBOA use by a
unable to tolerate the device with an effectiveness of 94%. 11 Special Operations Surgical Team has been shown to take be-
tween 5 and 9 minutes to achieve aortic occlusion. 24
Overall numbers reported in the literature are small, but when
looking at why the device has failed, it is suggested that the Robustness
underlying reason is pain. It is highly likely that the acutely There are individual reports in human studies of the AAJT
unwell trauma patient, who is hypotensive with significant or breaking during use. One such case had no effect on its effec-
catastrophic bleeding and possibly in a periarrest state, would tiveness, with a side prong breaking off from the male end of
be able to tolerate an abdominal application of the AAJT. the snap-together buckle. In another case, breakage occurred
of the pressure gauge on removal of the device after its use. 25,26
There is only one case report of AAJT use at the aortic bifurca- Real-life case reports of use reveal no evidence of breakage or
tion in real life trauma, and this was in a military patient in Af- malfunction. 14,21,22 Further data are likely to become apparent
ghanistan with bilateral lower limb amputations. There was only once more reports of its use are available.
14
almost immediate effect following application and no evidence
of any complications 48 hours after use. The patient survived. Suitability During Patient Transfer
Much of the current literature for AAJT use comes from an- In the three case reports of real-life use, the AAJT has been
imal models. These models have repeatedly demonstrated an effective in transport. 14,21,22 Patients trying to remove painful
excellent ability for the AAJT to effectively control bleeding stimulus such as the C-A-T is not an uncommon phenomenon,
distal to the aortic bifurcation. 15–19 but in the case of the AAJT, one patient thought it was more
comfortable than a C-A-T when applied at the groin. There
21
One such recent animal study explored AAJT use during trau- has been one report of the AAJT dislodging when placed at the
matic cardiac arrest. The authors found that survival, alongside axilla when the patient sat up but it was reapplied and then
other markers of CPR efficacy, were significantly improved in continued to be effective. Nevertheless, the patient must be
22
the AAJT group. Speculated explanations for this included observed and the AAJT rechecked regularly, especially after
sequestration of resuscitation fluid above the AAJT (i.e., to any movement.

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