Quantity of Research Available
The literature search yielded 147 citations. Upon screening titles and abstracts, 133 citations were excluded and 14 potentially relevant articles were retrieved for full-text review. No additional potentially relevant report was identified in grey literature. Of the 14 potentially relevant reports, 8 were excluded. Three case report studies, two observational studies and one guideline met the inclusion criteria. No economic evaluation was found. The process of study selection is outlined in the PRISMA flowchart (Appendix 1).
Additional references that did not meet the inclusion criteria but may be of potential interest are provided in Appendix 2.
Summary of Study Characteristics
The two non-comparative studies and three case reports are described below.
Lyon and colleagues6 conducted a prospective observational trial on the Abdominal Aortic tourniquet (AAT, now AAJT) effectiveness and safety involving nine human volunteers. The primary outcome was interruption of blood flow in the common femoral artery as measured by Doppler ultrasound. Safety was assessed by a qualitative statement of discomfort.
The report by Taylor and colleagues7 describes an independent prospective observational trial on AAJT effectiveness and safety involving 16 human volunteers. The primary outcome was interruption of blood flow in the common femoral artery as measured by Doppler ultrasound. Safety was assessed by a visual analog scale of pain.
A 2013 case report by an anonymous author8 describes the use of the AAJT in Afghanistan to treat a casualty suffering from bilateral amputation of the lower limbs. The report is narrative; it describes the procedure in detail and includes clinical readings.
Tovmassian and colleagues9 report on the battlefield use of the CRoC in 2011. The report begins with a detailed description of the technique with illustrations, followed by a qualitative description of the case. No quantitative medical data are provided.
Croushorn and collaborators10 report on a non-military case of axillary bleeding that was treated by the off-label (as of the time) use of the AAJT applied to an upper anatomical body junction. The narrative report provides a chronological description of the treatment with clinical data and pictures.
The included proposed guideline changes1 by the U.S. Department of Defense Joint Trauma System on Tactical Combat Casualty Care (TCCC) examined the performance of all four junctional tourniquets reviewed here. The publication was intended to update the 2012 TCCC guidelines.11 This guideline targets non-civilian tactical medical technicians who are required to perform emergency procedures on combat casualties. Collection of the evidence was not systematic; evidence was graded based on the American College of Cardiology/American Heart Association clinical practice guidelines.12
Summary of Critical Appraisal
The document on proposed guideline changes1 features a review based mostly on expert consensus, reportedly because of the scarcity of empirical evidence. However, the literature search methodology and selection criteria were not provided. Evidence was derived from case studies, observational studies, nonhuman or cadaver models and unpublished observations. The strengths and limitations of the guidelines are summarized in Appendix 3. Briefly, the guideline clearly defines the scope, purposes and target users, and the level of evidence is reported. However, its value suffers from a lack of clarity surrounding the literature search and review methods. No consideration appears to be given to patient preference (arguably a secondary issue in situations where a junctional tourniquet would be employed), and to risks and safety issues. The document does not describe the process used for formulating the recommendations and does not propose mechanisms to pilot or update the guidelines. This information is also absent from the parent guideline.11
Summary of Findings
Main findings of included studies and guidelines are summarized in detail in Appendix 4.
1. What is the clinical effectiveness of junctional tourniquets for controlling hemorrhagic wounds in adults?
All three case reports8–10 describe the successful use of either the CRoC or the AAJT junctional tourniquets. It was argued that the reported use of the AAJT in combat was instrumental in the survival of the casualty.8 The case report on the CRoC raised practical concerns about the device.9
Both observational studies report on the successful use of the AAJT in a non-combat, non-hemorrhagic situation. The studies consisted of applying the tourniquet to healthy volunteers and immediately measuring blood flow in the common femoral artery (CFA) as a surrogate outcome for hemorrhage. In the study by Lyon et al.,6 blood pressure in the CFA fell as the AAJT bladder pressure increased, and blood flow eventually ceased in seven of the nine subjects. The two subjects with incomplete occlusion were found to actively resist the pressure, a situation unlikely to arise in an unconscious or hypotensive individuals. The study by Taylor et al.7 had similar findings and demonstrated the effectiveness of the AAJT in a controlled, non-hemorrhagic environment, with a single case of failure.
2. What is the safety associated with using junctional tourniquets for controlling hemorrhagic wounds in adults?
No studies were identified which were purposely designed to assess the safety of junctional tourniquets. All case reports mention that the devices did not cause any complication, although Tovmassian9 warned against the lack of stability of the CRoC, which might put the patient at risk of further bleeding, if not properly addressed. Both observational studies on the AAJT recorded self-reported pain and discomfort as a measure of safety, but only the trial by Taylor et al.7 used a numerical scale for scoring the pain. No study documented the long term effects of junctional tourniquets.
3. What is the cost-effectiveness associated with the use of the following types of junctional tourniquets for controlling hemorrhagic wounds in adults: Abdominal Aortic Junctional Tourniquet, Junctional Emergency Treatment Tool, SAM Junctional TQ, and Combat Ready Clamp?
No article was found on the cost-effectiveness of the types of junctional tourniquets reviewed here.
4. What are the guidelines associated with the use of junctional tourniquets for controlling hemorrhagic wounds in adults?
Recommendations from the TCCC guidelines7 stated that junctional tourniquets can effectively suppress hemorrhages from wounds and have a high potential for saving lives. Faced with a lack of comparative clinical evidence, the Committee could not recommend a specific model, but advised against the use of the AAJT. The latter notice was based on an FDA contraindication for the AAJT in cases of penetrating abdominal injuries, which frequently occur in conjunction with junctional bleeding. However, such a contraindication has been removed from the latest FDA clearance documents,13 removing the main rationale for this recommendation. The guideline specified that junctional hemorrhage control should be started with Combat Gauze and direct pressure while the junctional tourniquet is being prepared and applied.
Limitations
The case reports included in this review must be solely viewed as supporting evidence to signal the potential usefulness of a technology and to promote further research. Case reports are not hypothesis-based and may not fully reflect the clinical context for which the device is indicated; hence, generalizability is hampered. The report on AAJT use in Afghanistan8 was written by an anonymous author, limiting the ability to assess potential conflicts of interest. It is not clear if the report by Croushorn et al.10 describes a case of military casualty. Moreover, this report has an increased risk of bias due to conflict of interest, with the primary author being both the inventor of the device and the founder of the manufacturing company.
The cited observational studies are limited by small sample sizes, a lack of long term safety outcomes, a single application/measurement per participant, a surrogate outcome that does not measure hemorrhage per se and thus may not reflect the targeted clinical state, and a controlled environment far removed from the fast-paced, unpredictable tactical context of use. All subjects were healthy volunteers, not injured patients. The study by Lyon and colleagues6 is also limited by conflict of interest issues and by the absence of statements on subject inclusion and exclusion criteria.
No study included a control group that would allow the comparison of the effectiveness of junctional tourniquets to that of standard care (e.g. manual compression with hemostatic gauze). Hence, based on the current state of the evidence, it cannot be formally stated that junctional tourniquets provide benefits over other procedures meant to control bleeding.
