A junctional tourniquet is a specialized medical device designed to control severe, life-threatening hemorrhage that occurs in areas of the body where standard limb tourniquets cannot be effectively applied. These devices were developed to address a gap in immediate trauma care, particularly for injuries involving the torso-to-limb junctions. The primary purpose of the junctional tourniquet is to provide rapid and reliable temporary hemorrhage control, allowing patients with catastrophic bleeding to be transported for definitive surgical treatment.
The Need for Junctional Tourniquets
The necessity for these specialized devices arises from the anatomy of the body’s “junctional zones.” These zones include the inguinal crease in the groin, the axilla in the armpit, and the base of the neck. These regions contain large, high-pressure blood vessels, such as the femoral and subclavian arteries, making injuries there especially life-threatening. Injuries in these areas were historically responsible for a significant percentage of preventable deaths by bleeding.
Standard circumferential tourniquets, which work by wrapping around a limb to compress all tissue uniformly, are ineffective in junctional zones. This failure is due to the conical shape and wide base of the body at these points, preventing the necessary uniform pressure to occlude the deep-seated vessels. The presence of the torso, pelvis, or shoulder girdle also means a traditional tourniquet cannot be positioned far enough “proximal” to stop the flow from the main trunk artery. Junctional tourniquets were therefore conceived to overcome these anatomical challenges and provide a practical method for stopping hemorrhage in these hard-to-access locations.
Mechanism of Action and Application
Junctional tourniquets operate on a principle fundamentally different from standard tourniquets, relying on direct, focused pressure rather than broad circumferential constriction. The devices work by driving a compression pad directly onto the underlying bone, such as the pelvis or the shoulder girdle, to physically pinch the major artery. This targeted compression is what achieves arterial occlusion.
Application begins with positioning the device’s belt-like structure around the torso, aligning the compression pad directly over the injured vessel, such as the femoral artery in the groin. Securing straps are then tightened to anchor the device firmly to the body. Finally, a mechanism—either mechanical or pneumatic—is activated to apply intense, localized force through the pad, pushing the artery against the bone and achieving hemostasis. Accurate placement is paramount; the device must be situated precisely over the major vessel to ensure total occlusion.
Primary Types and Design Differences
Junctional tourniquets fall into two main design types: pneumatic and mechanical systems.
Pneumatic Systems
Pneumatic devices, such as the SAM Junctional Tourniquet (SAM-JT) and the Abdominal Aortic and Junction Tourniquet (AAJT), use inflatable bladders or cuffs. Once the device is positioned, a hand pump or syringe rapidly inflates the bladder to apply focused pressure and occlude the artery.
Mechanical Systems
In contrast, mechanical systems rely on ratcheting or screw-driven mechanisms to achieve compression. The Combat Ready Clamp (CRoC) and the Junctional Emergency Treatment Tool (JETT) are examples of this design, which use a vise-like or windlass system to drive a rigid compression disc or pad downward. The choice between these systems depends on the specific anatomical site and the field environment, as some devices are better suited for the inguinal area while others are designed for the axilla.
Indications and Limitations
The indication for using a junctional tourniquet is uncontrolled, life-threatening hemorrhage from a junctional injury that cannot be stopped by direct pressure or wound packing. They manage severe bleeding in the groin and armpit regions where massive blood loss can occur quickly. Some models, like the SAM-JT, also offer the secondary benefit of stabilizing pelvic fractures, which frequently accompany junctional trauma.
Junctional tourniquets are subject to specific limitations and are not a universal solution for all proximal bleeding. They are explicitly not designed for use on the neck due to the high risk of compromising the airway or causing injury to the carotid arteries and other vital structures. These devices are a temporary measure for hemorrhage control, meaning they only buy time for the patient to reach definitive surgical care. This underscores their role as an immediate, life-saving bridge to the operating room.