Abdominal Aortic Tourniquet Application for Non-Traumatic Out-of-Hospital Cardiac Arrest

Overview

The aim of the study is to investigate whether occluding the abdominal aorta with an external device could be a potential therapeutic option in cases of non-traumatic cardiac arrest occurring outside of a hospital. In cardiac arrest, the heart suddenly stops beating, causing the circulation of blood to collapse. In this situation, vital organs-especially the brain and the heart itself-are no longer adequately supplied with oxygen. Without immediate treatment, severe damage or death occurs within minutes. The study therefore examines a specific intervention: the temporary occlusion of the abdominal aorta, which carries blood to the lower regions of the body. If this artery is blocked for a short period, the available blood can be redirected more effectively to the upper parts of the body. In theory, this could improve the oxygen supply to these organs and increase the likelihood that the heart will resume beating or that neurological damage can be reduced.

Detailed description

Background There is now a substantial body of experimental and clinical research on resuscitative endovascular balloon occlusion of the aorta (REBOA), highlighting its potential role in resuscitation medicine. As early as 1993, a porcine model was used for the first time to investigate the effect of REBOA on the quality of cardiopulmonary resuscitation. In this study on anesthetized pigs, temporary occlusion of the aorta during cardiopulmonary Resuscitation (CPR) resulted in a significant improvement in central hemodynamic parameters, particularly an increase in coronary perfusion pressure.

Initial case series from the past 10 years have also examined the use of REBOA in non-traumatic cardiac arrest. Despite overall small sample sizes, they demonstrated significant increases in end-tidal CO₂ (etCO₂) as well as higher rates of any ROSC. A common feature of both studies was the relatively long interval from emergency call to REBOA application, exceeding 45 minutes in each.

More recent studies from the past five years have confirmed these conclusions: REBOA placement led to improvements in various resuscitation indices. However, the procedure is often technically challenging, and when performed in-hospital, it typically took place more than 45 minutes after the initial emergency call. Two of the centers involved in these studies have now started to recruit for randomized controlled trials with more than 200 patients.

As an alternative to REBOA placement in Zone 3 for hemodynamically unstable patients in hemorrhagic shock due to pelvic or lower extremity injuries, the Abdominal Aortic Junctional Tourniquet (AAJT) is available. The first publication appeared in 2009, and market approval in the United States was granted in 2013. The device applies external pressure on the abdomen via balloon inflation under a abdominal binder with the goal of occluding flow in the abdominal aorta.

For non-traumatic cardiac arrest, there is currently only one animal study involving six pigs. In this study, AAJT application improved blood flow and diastolic pressure in the carotid artery, but did not confer a survival benefit.

During resuscitation, a diastolic blood pressure of over 30 mmHg should be achieved. This was reaffirmed in the latest European Resuscitation Council (ERC) guidelines of 2025, as it is associated with an increased rate of survival to hospital discharge.

Case series describing the application of the AAJT in traumatic cardiac arrest have demonstrated a notably high rate of favorable physiological responses. Reported positive outcomes include a change from non-perfusing or disorganized rhythms to more organized cardiac rhythms, an increase in end-tidal carbon dioxide (etCO₂) as a surrogate marker of improved circulation and perfusion, and, in several cases, the achievement of return of spontaneous circulation (ROSC). These findings suggest that temporary aortic occlusion using the AAJT may improve central blood flow and augment coronary as well as cerebral perfusion during resuscitation efforts.

Rationale The aortic occlusion during medical cardiac arrest with REBOA has shown promising results, but time-to-occlusion often requires a significant amount of time, with a high failure rate. The aortic occlusion with the AAJT device is a faster and non-invasive approach to the same problem. This study aims to show the feasibility of this rationale in a limited amount of patients.

Interventions

• Device Abdominal Aortic Junction Tourniquet in non-traumatic out-of-hospital cardiac arrest
  If a patient is found in cardiac arrest, eligibility is assessed. If the patient is deemed eligible, the following steps are performed: 1. Initiation of standard Advanced Cardiac Life Support (ACLS) 2. Endotracheal intubation and controlled mandatory ventilation according to ERC 2025 guidelines 3. Initiation of mechanical CPR 4. Arterial cannulation of an artery in the left upper extremity; access via the right upper extremity may be attempted after two unsuccessful attempts 5. Exclusion of rev

Primary outcome measures

• Time from initiation of AAJT application to complete inflation [Time frame: 1 hour]

Secondary outcome measures (7)

• Time from dispatch to application [Time frame: 1 hour]
• time from arrival on scene to application [Time frame: 1 hour]
• time from initiation of resuscitation to application [Time frame: 1 hour]
• change in end-tidal CO₂ (etCO₂) measured in mmHg [Time frame: 1 hour]
• measured change in arterial pressures (systolic/diastolic/mean arterial pressure) [Time frame: 1 hour]
• any ROSC rate [Time frame: 24 hours]
• sustained ROSC rate [Time frame: 24 hours]

Eligibility criteria

Inclusion criteria

• Cardiac arrest with indication for initiation of resuscitation
• Age ≥ 18 years

Exclusion criteria

• Pregnancy (suspected or confirmed)
• Age < 18 years
• Abdominal circumference does not allow application of the AAJT
• Traumatic etiology
• Planned eCPR or other intervention in which study inclusion would delay the standard of care
• Known abdominal aortic aneurysm

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

Austria · 1 center

• Klinikum Klagenfurt am Wörthersee — Klagenfurt

Publications

• Kim HE, Chu SE, Jo YH, Chiang WC, Jang DH, Chang CH, Oh SH, Chen HA, Park SM, Sun JT, Lee DK. Effect of resuscitative endovascular balloon occlusion of the aorta in nontraumatic out-of-hospital cardiac arrest: a multinational, multicenter, randomized, controlled trial. Trials. 2024 Feb 13;25(1):118. doi: 10.1186/s13063-024-07928-x. PMID 38347550
• Brede JR, Skulberg AK, Rehn M, Thorsen K, Klepstad P, Tylleskar I, Farbu B, Dale J, Nordseth T, Wiseth R, Kruger AJ. REBOARREST, resuscitative endovascular balloon occlusion of the aorta in non-traumatic out-of-hospital cardiac arrest: a study protocol for a randomised, parallel group, clinical multicentre trial. Trials. 2021 Jul 31;22(1):511. doi: 10.1186/s13063-021-05477-1. PMID 34332617
• Poliakova Y, Oshovskyy V. Temporary aortic occlusion with the abdominal tourniquet for refractory postpartum hemorrhage: A proof-of-concept study in a war-affected region. Int J Gynaecol Obstet. 2026 Jan;172(1):582-587. doi: 10.1002/ijgo.70395. Epub 2025 Jul 18. PMID 40679120
• Androshchuk D, Verba A. Successful Management of Battlefield Traumatic Cardiac Arrest Using the Abdominal Aortic and Junctional Tourniquet (AAJT): A Case Series. J Spec Oper Med. 2025 Apr 4;25(1):65-69. doi: 10.55460/7FEV-3ZRK. PMID 40063952
• Balian F, Garner AA, Weatherall A, Lee A. First experience with the abdominal aortic and junctional tourniquet in prehospital traumatic cardiac arrest. Resuscitation. 2020 Nov;156:210-214. doi: 10.1016/j.resuscitation.2020.09.018. Epub 2020 Sep 23. PMID 32979403
• Hewitt CW, Pombo MA, Blough PE, Castaneda MG, Percival TJ, Rall JM. Effect of the Abdominal Aortic and Junctional Tourniquet on chest compressions in a swine model of ventricular fibrillation. Am J Emerg Med. 2021 Jul;45:297-302. doi: 10.1016/j.ajem.2020.08.075. Epub 2020 Aug 27. PMID 33046311
• Smith TN, Beaven A, Handford C, Sellon E, Parker PJ. Abdominal Aortic Junctional Tourniquet - Stabilized (AAJTS) can be applied both successfully and rapidly by Combat Medical Technicians (CMTs). BMJ Mil Health. 2023 Nov 22;169(6):493-498. doi: 10.1136/bmjmilitary-2021-001881. PMID 34848491
• Daley J, Buckley R, Kisken KC, Barber D, Ayyagari R, Wira C, Aydin A, Latich I, Lozada JCP, Joseph D, Marino A, Mojibian H, Pollak J, Chaar CO, Bonz J, Belsky J, Coughlin R, Liu R, Sather J, Van Tonder R, Beekman R, Fults E, Johnson A, Moore C. Emergency department initiated resuscitative endovascular balloon occlusion of the aorta (REBOA) for out-of-hospital cardiac arrest is feasible and associa PMID 36176506

Identifiers

NCT: NCT07573566 · S2026-04

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗