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efficacy of XStat relative to Combat Gauze in wounds The limited use of XStat to date is due to the recent
that do not have a well-defined wound cavity. introduction of this hemostatic adjunct into clinical use,
the relatively high cost of first article production, the
Both the Mueller and the Cestero studies state that they decreasing combat operational tempo for US Military
allowed the use of up to eight applicators of XStat. 7,26 At forces at present, its limited availability, and the previ-
a cost of $1,000 per three applicators, combat medical ous battlefield use restriction in the FDA clearance letter.
providers are unlikely to have eight applicators of XStat The recent removal of the “battlefield only” restriction
available for use. Actual casualties, however, may have on XStat will allow for a much greater customer base
wounds with smaller wound cavities than that created by by making XStat available for use in civilian trauma pa-
the surgical dissection used in the Mueller and Cestero tients and potentially will lower the unit cost. Addition-
studies. In this event, one or two applicators of XStat ally, the relatively high pilot production costs of XStat
would be more likely to suffice for hemorrhage control. may be mitigated significantly in the future through on-
going government-funded efforts to modify production
The current FDA clearance letter specifically advises techniques and to develop new device configurations to
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against the use of XStat on bleeding sites above the create a more economical product for military use.
clavicle, which would preclude its use in life-threatening
external hemorrhage from neck wounds. The reason for Conclusions
this exclusion is not addressed in the FDA clearance let-
ter. Weppner reported 43 combat casualties with pen- XStat is a novel hemostatic adjunct composed of chito-
etrating neck and/or maxillofacial trauma treated with san-coated compressed minisponges that expand when
tamponade of their bleeding vessels by inserting a Foley they come in contact with blood and absorb moisture.
catheter through the skin wound and then inflating the The expanding sponges, when confined within a cavitary
balloon. He demonstrated that mortality in this group wound, apply internal pressure to bleeding sites in the
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was reduced (from 23% to 5%) in comparison with a depths of the wound, as opposed to hemostatic dress-
similarly injured group of 35 casualties who were treated ings, which are designed and labeled for external use.
using direct pressure without the use of an inflated Foley
catheter balloon. This technique has also been used to XStat has been designed and tested specifically in a highly
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control hemorrhage from injured subclavian vessels. lethal junctional bleeding model for penetrating injury
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The compressed minisponges in XStat could theoretically that includes bleeding from both the subclavian artery
be used in a similar manner to create internal pressure in and vein at the depth of a wound with a 4.5cm tract.
a neck wound. One safety concern that would need to The key properties that differentiate this hemostatic ad-
be addressed in considering this option is the potential junct from other devices are as follows: (1) it is designed
for occlusion of the carotid or jugular vessels by one or such that the wound would be, in effect, packed from the
more of the minisponges. No adverse outcomes resulting inside of the wound out, whereas hemostatic dressings
from vascular occlusions by the XStat minisponges were are packed from the outside in; (2) the application time
reported in the Mueller or Cestero studies. has been shown to be shorter than Combat Gauze; and
(3) XStat does not require a 3-minute period of external
The Armed Forces Medical Examiner’s System (AFMES) manual pressure on the wound after application.
conducts autopsies on all US Servicemembers who die of
wounds sustained in combat. The subset of casualties Based on the demonstrated ability of XStat to control
who would in theory benefit the most from XStat would severe bleeding from vascular injury sites located at the
be those who have life-threatening hemorrhage originat- internal aspect of narrow-tract junctional wounds, this
ing in the depths of a wound with a narrow wound tract product offers an external hemorrhage control capabil-
in a junctional location (other than the neck) that is not ity that may be more efficacious than Combat Gauze for
amenable to the application of a limb tourniquet and these types of wounds. The Mueller and the Cestero
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would not be well-addressed by the use of one of the studies have shown that XStat achieved 100% survival
three TCCC–recommended junctional tourniquets. Pre- in subclavian vascular injuries, a wounding pattern that
ventable deaths due primarily to this particular wound- has been observed to be highly lethal in trauma patients.
ing pattern are uncommon (E. Mazuchowski, personal Furthermore, XStat may be a very valuable adjunct
communication, November 2015). in treating axillary wounds, which is a junctional site
that is relatively difficult to treat with the three current
XStat may also be beneficial by allowing for easier conver- TCCC-approved junctional tourniquets.
sion from extremity or junctional tourniquets to an alterna-
tive means of hemorrhage control when needed to prevent XStat may also be a valuable adjunct in enabling con-
ischemic damage from prolonged tourniquet use. XStat has version of both extremity and junctional tourniquets to
not yet been studied for this potential mode of use. other methods of hemorrhage control during casualty

24 Journal of Special Operations Medicine Volume 16, Edition 1/Spring 2016