Recent advances in austere combat surgery: Use of aortic balloon occlusion as well as blood challenges by special operations medical forces in recent combat operations

A PROMPT Update on Partial REBOA: Initial Clinical Data and Overview of the DoD-Funded Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) Study

INTRODUCTION

Retrograde Endovascular Balloon Occlusion of the Aorta (REBOA) is an effective management for the transient responder, but the ischemic consequences of complete aortic occlusion currently limit its use. Multiple DoD-funded preclinical studies have clearly demonstrated that partial REBOA reduces distal ischemia to potentially extend safe occlusion times, while still providing effective temporization of noncompressible torso hemorrhage. Early versions of REBOA devices were designed to completely occlude the aorta and had little ability to provide partial occlusion. Recently, a new REBOA device (pREBOA-PRO) was designed specifically to allow for partial occlusion, with the hypothesis that this may reduce the complications of aortic occlusion and extend safe occlusion times while maintaining the benefits on cardiac and cerebrovascular circulation as well as reductions in resuscitation requirements.

MATERIALS AND METHODS

To ascertain the impact of a new purpose-built partial REBOA device on the extension of safe occlusion time, the Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) trial compared available data from the pREBOA-PRO with existing data from 200 clinical uses of pREBOA-PRO and available data in the AAST AORTA Registry were reviewed to design primary endpoints and clinical evidence for a prospective multi-center trial, the PROMPT Study. Together with the endpoints identified in preclinical studies of partial REBOA, primary endpoints for the PROMPT study were identified and power analyses were conducted to determine the target patient enrollment goals.

RESULTS

Results from the clinical implementation of partial REBOA at a single trauma center were used to conduct the initial power analysis for the primary endpoint of Acute Kidney Injury (AKI) after prolonged occlusion. The rate of AKI after complete REBOA was 55% (12/20) compared to 33% (4/12) after partial REBOA (Madurska et al., 2021). With an alpha of 0.05 and power (β) of 0.8, the projected sample size for comparison on a dichotomous outcome is 85 patients for the assessment of AKI. Initial power and endpoint analyses have been confirmed and extended with the ongoing analysis of partial and complete REBOA reported in the AORTA database. These analyses confirm preclinical findings which show that compared to complete REBOA, partial REBOA is associated with extended occlusion time in zone 1 (complete: 31 min vs. partial: 45 min, P = 0.003), lower rates of AKI after zone 1 occlusion (complete: 33% vs. partial: 19%, P = 0.05) and reduced resuscitation requirements (e.g., 25% reduction in pRBC administration: complete: 18 units vs. partial: 13 units, P = 0.02).

CONCLUSIONS

The DoD-funded PROMPT study of partial REBOA will provide prospective observational clinical data on patients being treated with pREBOA-PRO. Outcomes will be stratified based on partial or complete occlusion to address whether partial REBOA has additional clinical benefits over complete REBOA, such as decreased distal ischemia, extension of safe occlusion time, improved hemodynamics during transition to and from occlusion, and reduced interoperative bleeding and blood product use. The results from this study are expected to confirm previous data demonstrating reduction of ischemic sequalae, improved transition to reperfusion, and reduced resuscitative requirements compared to complete REBOA.

Advanced Critical Care Techniques in the Field

Critical care principles and techniques continue to hold promise for improving patient outcomes in time-dependent diseases encountered by emergency medical services such as cardiac arrest, acute ischemic stroke, and hemorrhagic shock. In this review, the authors discuss several current and evolving advanced critical care modalities, including extracorporeal cardiopulmonary resuscitation, resuscitative endovascular occlusion of the aorta, prehospital thrombolytics for acute ischemic stroke, and low-titer group O whole blood for trauma patients. Two important critical care monitoring technologies-capnography and ultrasound-are also briefly discussed.

Consensus on resuscitative endovascular balloon occlusion of the aorta in civilian (prehospital) trauma care: A Delphi study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) could prevent lethal exsanguination and support cardiopulmonary resuscitation. In prehospital trauma and medical emergency settings, a small population with high mortality rates could potentially benefit from early REBOA deployment. However, its use in these situations remains highly disputed. Since publication of the first Delphi study on REBOA, in which consensus was not reached on all addressed topics, new literature has emerged. The aim of this study was to establish consensus on the use and implementation of REBOA in civilian prehospital settings for noncompressible truncal hemorrhage and out-of-hospital cardiac arrest as well as for various in-hospital settings.

METHODS

A Delphi study consisting of three rounds of questionnaires was conducted based on a review of recent literature. REBOA experts with different medical specialties, backgrounds, and work environments were invited for the international panel. Consensus was reached when a minimum of 75% of panelists responded to a question and at least 75% (positive) or less than 25% (negative) of these respondents agreed on the questioned subject.

RESULTS

Panel members reached consensus on potential (contra)indications, physiological thresholds for patient selection, the use of ultrasound and practical, and technical aspects for early femoral artery access and prehospital REBOA.

CONCLUSION

The international expert panel agreed that REBOA can be used in civilian prehospital settings for temporary control of noncompressible truncal hemorrhage, provided that personnel are properly trained and protocols are established. For prehospital REBOA and early femoral artery access, consensus was reached on (contra)indications, physiological thresholds and practical aspects. The panel recommends the initiation of a randomized clinical trial investigating the use of prehospital REBOA for noncompressible truncal hemorrhage.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level V.

The employment of resuscitative endovascular balloon occlusion of the aorta in deployed settings

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been often used in place of open aortic occlusion for management of hemorrhagic shock in trauma. There is a paucity of data evaluating REBOA usage in military settings.

STUDY DESIGN AND METHODS

We queried the Department of Defense Trauma Registry (DODTR) for all cases with at least one intervention or assessment available within the first 72 h after injury between 2007 and 2023. We used relevant procedural codes to identify the use of REBOA within the DODTR, and we used descriptive statistics to characterize its use.

RESULTS

We identified 17 cases of REBOA placed in combat settings from 2017 to 2019. The majority of these were placed in the operating room (76%) and in civilian patients (70%). A penetrating mechanism caused the injury in 94% of cases with predominantly the abdomen and extremities having serious injuries. All patients subsequently underwent an exploratory laparotomy after REBOA placement, with moderate numbers of patients having spleen, liver, and small bowel injuries. The majority (82%) of included patients survived to hospital discharge.

DISCUSSION

We describe 17 cases of REBOA within the DODTR from 2007 to 2023, adding to the limited documentation of patients undergoing REBOA in military settings. We identified patterns of injury in line with previous studies of patients undergoing REBOA in military settings. In this small sample of military casualties, we observed a high survival rate.

Management of non-compressible torso hemorrhage of the abdomen in civilian and military austere environments: a scoping review

Background

Non-compressible abdominal hemorrhage (NCAH) is the leading cause of potentially preventable deaths in both civilian and military austere environments, and an improvement in mortality due to this problem has not been demonstrated during the past quarter century. Several innovations have been developed to control hemorrhage closer to the point of injury.

Objective

This review assessed NCAH interventions in civilian and military settings, focusing on austere environments. It identified innovations, effectiveness, and knowledge gaps for future research.

Methodology

The Joanna Briggs Institute for Evidence Synthesis methodology guided this scoping review to completion. Studies evaluating NCAH with human participants in civilian and military austere environments that were eligible for inclusion were limited to English language studies published between December 1990 and January 2023. The PCC (Participant, Concept, Context) framework was used for data synthesis. Deductive and inductive thematic analyses were used to assess the literature that met inclusion criteria, identify patterns/themes to address the research questions and identify common themes within the literature. A stakeholder consultation was conducted to review and provide expert perspectives and opinions on the results of the deductive and inductive thematic analyses.

Results

The literature search identified 868 articles; 26 articles met the inclusion criteria. Textual narrative analysis of the 26 articles resulted in the literature addressing four main categories: NCAH, penetrating abdominal trauma, resuscitative endovascular balloon occlusion of the aorta (REBOA), and ResQFoam. The deductive thematic analysis aimed to answer three research questions. Research question 1 addressed the effectiveness of REBOA, damage control resuscitation, and damage control surgery in managing NCAH in austere environments. No effectiveness studies were found on this topic. Research question 2 identified three knowledge gaps in NCAH management in austere environments. The analysis identified early hemorrhage control, prehospital provider decision-making ability, and REBOA implementation as knowledge gaps in NCAH. Research question 3 identified five innovations that may affect the management of NCAH in the future: transport of patients, advanced resuscitative care, expert consultation, REBOA implementation, and self-expanding foam implementation. The inductive thematic analysis resulted in four recurrent themes from the literature: prehospital care, decision-making, hemorrhage control, and mortality in NCAH. During the stakeholders' consultation, the results of the deductive and inductive thematic analyses were reviewed and agreed on by the stakeholders. Special emphasis and discussion were given to prehospital management, expert opinions in the prehospital environment, decision-making in the prehospital environment, transport and resuscitation in the prehospital setting, REBOA, alternative discussion for research, and research gaps.

Conclusion

NCAH is still a significant cause of preventable death in both military and civilian austere environments, even with ongoing research and interventions aimed at extending survival in such conditions. This scoping review has identified several potential concepts that could reduce the mortality associated with a preventable cause of death due to hemorrhage in austere environments.

Ultra-forward surgical support for special operations forces. Conception, development and certification of the French Special Operations Surgical Team (SOST) airborne capability

When special operations forces (SOF) are in action, a surgical team (SOST) is usually ground deployed as close as possible to the combat area, to try and provide surgical support within the golden hour. The French SOST is composed of 6 people: 2 surgeons, 1 scrub nurse, 1 anaesthetist, 1 anesthetic nurse and 1 SOF paramedic. It can be deployed in 45 min under a tent or in a building. However, some tactical situations prevent the ground deployment. A solution is to deploy the SOST in a tactical unprepared aircraft hold, to make it possible to offer DCS, to treat non-compressible exsanguinating trauma, without any ground logistical footprint. This article describes the stages of the design, development and certification process of the airborne SOST capability. The authors report the modifications and adaptations of the equipment and the surgical paradigms which make it possible to solve the constraints linked to the aeronautical and combat environment. Study type/level of evidence Care management Level of Evidence IV.

Revisiting the promise, practice and progress of resuscitative endovascular balloon occlusion of the aorta

PURPOSE OF REVIEW

The use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) to temporarily control bleeding and improve central perfusion in critically injured trauma patients remains a controversial topic. In the last decade, select trauma services around the world have gained experience with REBOA. We discuss the recent observational data together with the initial results of the first randomized control trial and provide a view on the next steps for REBOA in trauma resuscitation.

RECENT FINDINGS

While the observational data continue to be conflicting, the first randomized control trial signals that in the UK, in-hospital REBOA is associated with harm. Likely a result of delays to haemorrhage control, views are again split on whether to abandon complex interventions in bleeding trauma patients and to only prioritize transfer to the operating room or to push REBOA earlier into the post injury phase, recognizing that some patients will not survive without intervention.

SUMMARY

Better understanding of cardiac shock physiology provides a new lens in which to evaluate REBOA through. Patient selection remains a huge challenge. Invasive blood pressure monitoring, combined with machine learning aided decision support may assist clinicians and their patients in the future. The use of REBOA should not delay definitive haemorrhage control in those patients without impending cardiac arrest.

Balloons on the battlefield: REBOA implementation in the UK Defence Medical Services

Established in 2018, the Defence Endovascular Resuscitation (DefER) group recognised that resuscitative endovascular balloon occlusion of the aorta (REBOA) offered an option to improve survival in battle casualties dying from haemorrhage, particularly in remote and austere surgical settings. Following a successful jHub opportunity assessment, DefER purchased training and operational kit at pace. By 1 April 2019, the first forward surgical group undertook a bespoke endovascular training and assessment package. Results of the pilot were presented back to a jHub 4* Innovation Board, which initially awarded £500 000 to fund the project to full implementation. Med Op Cap provided a solution to establish REBOA as a core capability on to the 370 modules. REBOA catheters and arterial access kit are now available to deployed Role 2 facilities across defence as an adjunct to damage control resuscitation in specific circumstances. REBOA has, from a standing start, gained pan-Defence Medical Services (DMS) endorsement and has been integrated into deployed damage control resuscitation. To establish a new resuscitation capability across all Role 2 platforms within 15 months of inception represents implementation at pace. This agility was unlocked by empowering clinicians to develop the platform in conjunction with commercial procurement. This article describes how this innovative pathway facilitated the rapid introduction of a lifesaving haemorrhage control technique to equip DMS clinicians.

Defence Medical Services' REBOA training course

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) enables temporary haemorrhage control and physiological stabilisation. This article describes the bespoke Defence Medical Services (DMS) training package for effectively using REBOA. The article covers how the course was designed, how the key learning objectives are taught, participant feedback and the authors' perceptions of future training challenges and opportunities. Since the inaugural training course in April 2019, the authors have delivered six courses, training over 100 clinicians. For the first time in the UK DMS, we designed and delivered a robust specialist endovascular training programme, with demonstrable, significant increases in confidence and competence. As a result of this course, the first DMS REBOA-equipped forward surgical teams deployed in June 2019. Looking to the future, there is a requirement to develop an assessment of skill retention and the potential need for revalidation.

Prolonging the zone 1 aortic occlusion time to 4 hours using a partial resuscitative endovascular balloon in a swine model

BACKGROUND

The clinical usage of the resuscitative endovascular balloon occlusion of the aorta (REBOA) is limited by distal ischemia resulting from complete aortic occlusion. We hypothesized that animals would physiologically tolerate the prolonged partial occlusion using the novel partially occluding REBOA (pREBOA) with survivable downstream injuries.

METHODS

This study used the pREBOA-PRO catheter in a previously established swine model. Female Yorkshire swine (n = 10) underwent a volume-controlled hemorrhage (40% estimated blood). After 1 hour of shock (mean arterial pressure, 28-32 mm Hg), animals were randomized to partial occlusion for either 2 hours or 4 hours. The pREBOA was inflated in zone 1 to achieve partial occlusion defined as a distal systolic blood pressure (SBP) of 20 ± 2 mm Hg. The balloon was deflated at the end of the occlusion period, and animals were resuscitated for 2 hours. Tissues were examined for gross and histologic injury. The primary endpoint was histologic organ injury, and secondary end points were hemodynamic variables and degree of distal organ ischemia.

RESULTS

All animals survived to the endpoint. Both groups had similar proximal and distal SBP at baseline, with a divergence of pressures ranging from 55 mm Hg to 90 mm Hg on inflation. The lactate levels increased throughout the occlusion and decreased approximately 40% during the observation period. More animals required norepinephrine and fluid in the 4-hour group compared with the 2-hour group. There was no gross small bowel ischemia noted in the 2-hour animals. The 4-hour group had surgically resectable patchy short segment ischemia. Neither group showed nonsurvivable organ ischemia on pathology or laboratory values.

CONCLUSION

This is the first study showing that the zone 1 aorta can be occluded for over 4 hours using a new pREBOA device without need for balloon titration. In conclusion, simple changes in balloon design offer reliable partial aortic occlusion, with potentially survivable and surgically manageable downstream injuries.

Advances in trauma care to save lives from traumatic injury: A narrative review

ABSTRACT

Recent advances on trauma management from the prehospital setting to in hospital care led to a better surviving severe trauma rate. Mortality from exsanguination remains the first preventable mortality. Damage-control resuscitation and surgery are evolving and thus some promising concepts are developing. Transfusion toolkit is brought on the prehospital scene while temporary bridge to hemostasis may be helpful. Panel transfusion products allow an individualized ratio assumed by fresh frozen or lyophilized plasma, fresh or cold-stored whole blood, fibrinogen, four-factor prothrombin complex concentrates. Growing interest is raising in whole blood transfusion, resuscitative endovascular balloon occlusion of the aorta use, hybrid emergency room, viscoelastic hemostatic assays to improve patient outcomes. Microcirculation, traumatic endotheliopathy, organ failures and secondary immunosuppression are point out since late deaths are increasing and may deserve specific treatment.As each trauma patient follows his own course over the following days after trauma, trauma management may be seen through successive, temporal, and individualized aims.

Editor's Choice - Systematic Review and Meta-Analysis of Lower Extremity Vascular Complications after Arterial Access for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): An Inevitable Concern?

OBJECTIVE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to temporise non-compressible torso haemorrhage. Recent data have suggested that vascular access complications secondary to REBOA placement are higher than initially anticipated. This updated systematic review and meta-analysis aimed to determine the pooled incidence rate of lower extremity arterial complications after REBOA.

DATA SOURCES

PubMed, Scopus, Embase, conference abstract listings, and clinical trial registries.

REVIEW METHODS

Studies including more than five adults undergoing emergency REBOA for exsanguinating haemorrhage that reported access site complications were eligible for inclusion. A pooled meta-analysis of vascular complications was performed using the DerSimonian-Laird weights for the random effects model, presented as a Forest plot. Further meta-analyses compared the relative risk of access complications between different sheath sizes, percutaneous access techniques, and indications for REBOA. Risk of bias was assessed using the Methodological Index for Non-Randomised Studies (MINORS) tool.

RESULTS

No randomised controlled trials were identified, and the overall study quality was poor. Twenty-eight studies including 887 adults were identified. REBOA was performed for trauma in 713 cases. The pooled proportion rate of vascular access complications was 8.6% (95% confidence interval 4.97 - 12.97), with substantial heterogeneity (I2 = 67.6%). There was no significant difference in the relative risk of access complications between 7 and > 10 F sheaths (p = .54), or between ultrasound guided and landmark guided access (p = .081). However, traumatic haemorrhage was associated with a significantly higher risk of complications compared with non-traumatic haemorrhage (p = .034).

CONCLUSION

This updated meta-analysis aimed to be as comprehensive as possible considering the poor quality of source data and high risk of bias. It suggested that lower extremity vascular complications were higher than originally suspected after REBOA. While the technical aspects did not appear to impact the safety profile, a cautious association could be drawn between REBOA use for traumatic haemorrhage and a higher risk of arterial complications.

A porcine study of ultrasound-guided versus fluoroscopy-guided placement of endovascular balloons in the inferior vena cava (REBOVC) and the aorta (REBOA)

Objectives

In fluoroscopy-free settings, alternative safe and quick methods for placing resuscitative endovascular balloon occlusion of the aorta (REBOA) and resuscitative endovascular balloon occlusion of the inferior vena cava (REBOVC) are needed. Ultrasound is being increasingly used to guide the placement of REBOA in the absence of fluoroscopy. Our hypothesis was that ultrasound could be used to adequately visualize the suprahepatic vena cava and guide REBOVC positioning, without significant time-delay, when compared with fluoroscopic guidance, and compared with the corresponding REBOA placement.

Methods

Nine anesthetized pigs were used to compare ultrasound-guided placement of supraceliac REBOA and suprahepatic REBOVC with corresponding fluoroscopic guidance, in terms of correct placement and speed. Accuracy was controlled by fluoroscopy. Four intervention groups: (1) fluoroscopy REBOA, (2) fluoroscopy REBOVC, (3) ultrasound REBOA and (4) ultrasound REBOVC. The aim was to carry out the four interventions in all animals. Randomization was performed to either fluoroscopic or ultrasound guidance being used first. The time required to position the balloons in the supraceliac aorta or in the suprahepatic inferior vena cava was recorded and compared between the four intervention groups.

Results

Ultrasound-guided REBOA and REBOVC placement was completed in eight animals, respectively. All eight had correctly positioned REBOA and REBOVC on fluoroscopic verification. Fluoroscopy-guided REBOA placement was slightly faster (median 14 s, IQR 13-17 s) than ultrasound-guided REBOA (median 22 s, IQR 21-25 s, p=0.024). The corresponding comparisons of the REBOVC groups were not statistically significant, with fluoroscopy-guided REBOVC taking 19 s, median (IQR 11-22 s) and ultrasound-guided REBOVC taking 28 s, median (IQR 20-34 s, p=0.19).

Conclusion

Ultrasound adequately and quickly guide the placement of supraceliac REBOA and suprahepatic REBOVC in a porcine laboratory model, however, safety issues must be considered before use in trauma patients.

Level of evidence

Prospective, experimental, animal study. Basic science study.

Zone 1 Endovascular Balloon Occlusion of the Aorta vs Resuscitative Thoracotomy for Patient Resuscitation After Severe Hemorrhagic Shock

Importance

Aortic occlusion (AO) is a lifesaving therapy for the treatment of severe traumatic hemorrhagic shock; however, there remains controversy whether AO should be accomplished via resuscitative thoracotomy (RT) or via endovascular balloon occlusion of the aorta (REBOA) in zone 1.

Objective

To compare outcomes of AO via RT vs REBOA zone 1.

Design, Setting, and Participants

This was a comparative effectiveness research study using a multicenter registry of postinjury AO from October 2013 to September 2021. AO via REBOA zone 1 (above celiac artery) was compared with RT performed in the emergency department of facilities experienced in both procedures and documented in the prospective multicenter Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) registry. Propensity score matching (PSM) with exact institution matching was used, in addition to subgroup multivariate analysis to control for confounders. The study setting included the ED, where AO via RT or REBOA was performed, and participants were adult trauma patients 16 years or older.

Exposures

AO via REBOA zone 1 vs RT.

Main Outcomes and Measures

The primary outcome was survival. Secondary outcomes were ventilation-free days (VFDs), intensive care unit (ICU)-free days, discharge Glasgow Coma Scale score, and Glasgow Outcome Score (GOS).

Results

A total of 991 patients (median [IQR] age, 32 [25-48] years; 808 male individuals [81.9%]) with a median (IQR) Injury Severity Score of 29 (18-50) were included. Of the total participants, 306 (30.9%) had AO via REBOA zone 1, and 685 (69.1%) had AO via RT. PSM selected 112 comparable patients (56 pairs). REBOA zone 1 was associated with a statistically significant lower mortality compared with RT (78.6% [44] vs 92.9% [52]; P = .03). There were no significant differences in VFD greater than 0 (REBOA, 18.5% [10] vs RT, 7.1% [4]; P = .07), ICU-free days greater than 0 (REBOA, 18.2% [10] vs RT, 7.1% [4]; P = .08), or discharge GOS of 5 or more (REBOA, 7.5% [4] vs RT, 3.6% [2]; P = .38). Multivariate analysis confirmed the survival benefit of REBOA zone 1 after adjustment for significant confounders (relative risk [RR], 1.25; 95% CI, 1.15-1.36). In all subgroup analyses (cardiopulmonary resuscitation on arrival, traumatic brain injury, chest injury, pelvic injury, blunt/penetrating mechanism, systolic blood pressure ≤60 mm Hg on AO initiation), REBOA zone 1 offered an either similar or superior survival.

Conclusions and Relevance

Results of this comparative effectiveness research suggest that REBOA zone 1 provided better or similar survival than RT for patients requiring AO postinjury. These findings provide the ethically necessary equipoise between these therapeutic approaches to allow the planning of a randomized controlled trial to establish the safety and effectiveness of REBOA zone 1 for AO in trauma resuscitation.

Validation of a miniaturized handheld arterial pressure monitor for guiding full and partial REBOA use during resuscitation

PURPOSE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a well-validated method for the control of noncompressible truncal hemorrhage. In lower resource or battlefield settings, the need for arterial line setup and monitoring is problematic and potentially prohibitive. We sought to evaluate the accuracy and precision of a miniaturized portable device (Centurion COMPASS^®) versus standard arterial pressure monitoring using standard ER-REBOA and partial REBOA (pREBOA) as a high-fidelity and space-/time-conserving alternative.

METHODS

A total of 40 swine underwent a four-phase validation/precision study (each phase using five ER-REBOAs and five pREBOAs). Phases I/II evaluated accuracy with full and pREBOA in uninjured animals. Phases III/IV duplicated the previous phases but in a severe hemorrhagic shock model. Carotid and femoral pressures were monitored with both intra-arterial pressure systems and the COMPASS^® device. The vascular flow was measured by aortic flow probes. Correlation and Bland-Altman analysis were performed.

RESULTS

There was a strong correlation in accuracy testing of proximal and distal COMPASS^® devices compared to standard intra-arterial pressure monitoring (r = 0.94, 0.8; p < 0.005) as well as during precision testing (r = 0.98, 0.89 p < 0.005) in the uninjured phases. Similar accuracy and reliability were demonstrated in hemorrhagic shock, with a strong correlation for the proximal and distal COMPASS^® devices (r = 0.98, 0.97; p < 0.005), as well as during precision testing (r = 0.99, 0.95; p < 0.005) in both full and pREBOA scenarios. Bland-Altman analysis showed extremely low bias between the COMPASS^® and arterial line for both proximal (bias = 1.9) and distal (bias = 0.8) pressure measurements.

CONCLUSION

The COMPASS^® provides accurate and precise pressure measurements during standard and partial REBOA in both uninjured and shock conditions. This device may help extend and enhance capability in any low-resource/battlefield settings, or even eliminate the need for standard intra-arterial invasive pressure monitoring and external setup.

Resuscitative endovascular balloon occlusion of the aorta in civilian pre-hospital care: a systematic review of the literature

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a damage control tool with a potential role in the hemodynamic resuscitation of severely ill patients in the civilian pre-hospital setting. REBOA ensures blood flow to vital organs by early proximal control of the source of bleeding. However, there is no consensus on the use of REBOA in the pre-hospital setting. This article aims to perform a systematic review of the literature about the feasibility, survival, indications, complications, and potential candidates for civilian pre-hospital REBOA.

Methods

A literature search was conducted using Medline, EMBASE, LILACS and Web of Science databases. Primary outcome variables included overall survival and feasibility. Secondary outcome variables included complications and potential candidates for endovascular occlusion.

Results

The search identified 8 articles. Five studies described the use of REBOA in pre-hospital settings, reporting a total of 47 patients in whom the procedure was attempted. Pre-hospital REBOA was feasible in 68–100% of trauma patients and 100% of non-traumatic patients with cardiac arrest. Survival rates and complications varied widely. Pre-hospital REBOA requires a coordinated and integrated emergency health care system with a well-trained and equipped team. The remaining three studies performed a retrospective analysis identifying 784 potential REBOA candidates.

Conclusions

Pre-hospital REBOA could be a feasible intervention for a significant portion of severely ill patients in the civilian setting. However, the evidence is limited. The impact of pre-hospital REBOA should be assessed in future studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00836-3.

Zone 1 REBOA in a combat DCBI swine model does not worsen brain injury

BACKGROUND

Zone 1 resuscitative endovascular balloon occlusion of the aorta has been recommended for refractory shock after a dismounted complex blast injury for the austere combat scenario. While resuscitative endovascular balloon occlusion of the aorta should enhance coronary perfusion, there is a potential risk of secondary brain injury due to loss of cerebral autoregulation. We developed a combat casualty relevant dismounted complex blast injury swine model to evaluate the effects of resuscitative endovascular balloon occlusion of the aorta zone I on intracranial pressure and cerebral edema. We hypothesized that zone 1 aortic occlusion with resuscitative endovascular balloon occlusion of the aorta would increase mean arterial pressure transmitted in excessive intracranial pressure, thereby worsening brain injury.

METHODS

50 kg male Yorkshire swine were subjected to a combination dismounted complex blast injury model consisting of blast traumatic brain injury (50 psi, ARA Mobile Shock Laboratory), tissue injury (bilateral femur fractures), and hemorrhagic shock (controlled bleeding to a base deficit goal of 10 mEq/L). During the shock phase, pigs were randomized to no aortic occlusion (n = 8) or to 30 minutes of zone 1 resuscitative endovascular balloon occlusion of the aorta (zone 1 aortic occlusion group, n = 6). After shock, pigs in both groups received a modified Tactical Combat Casualty Care-based resuscitation and were monitored for an additional 240 minutes until euthanasia/death for a total of 6 hours. Intracranial pressure was monitored throughout, and brains were harvested for water content. Linear mixed models for repeated measures were used to compare mean arterial pressure and intracranial pressure between zone 1 aortic occlusion and no aortic occlusion groups.

RESULTS

After dismounted complex blast injury, the zone 1 group had a significantly higher mean arterial pressure during hemorrhagic shock compared to the control group (41.2 mm Hg vs 16.7 mm Hg, P = .002). During balloon occlusion, intracranial pressure was not significantly elevated in the zone 1 aortic occlusion group vs control, but intracranial pressure was significantly lower in the zone 1 group at the end of the observation period. In addition, the zone 1 aortic occlusion group did not have increased brain water content (zone 1 aortic occlusion: 3.95 ± 0.1g vs no aortic occlusion: 3.95 ± 0.3 g, P = .87). Troponin levels significantly increased in the no aortic occlusion group but did not in the zone 1 aortic occlusion group.

CONCLUSION

Zone 1 aortic occlusion using resuscitative endovascular balloon occlusion of the aorta in a large animal dismounted complex blast injury model improved proximal mean arterial pressure while not significantly increasing intracranial pressure during balloon inflation. Observation up to 240 minutes postresuscitation did not show clinical signs of worsening brain injury or cardiac injury. These data suggest that in a dismounted complex blast injury swine model, resuscitative endovascular balloon occlusion of the aorta in zone 1 may provide neuro- and cardioprotection in the setting of blast traumatic brain injury. However, longer monitoring periods may be needed to confirm that the neuroprotection is lasting.

Percutaneous delivery of self-propelling thrombin-containing powder increases survival from non-compressible truncal hemorrhage in a swine model of coagulopathy and hypothermia

BACKGROUND

Non-compressible truncal hemorrhage (NCTH) remains a leading cause of preventable death on the battlefield. Definitively managing severe NCTH requires surgery within the first hour after injury, which is difficult when evacuating casualties from remote and austere environments. During delays to surgery, hemostatic interventions that are performed prehospital can prevent coagulopathy and hemorrhagic shock and increase the likelihood that casualties survive to receive definitive care. We previously reported that a self-propelling thrombin-containing powder (SPTP) can be delivered percutaneously into the abdomen as a minimally invasive intervention and can self-disperse through pooled blood to deliver the hemostatic agents thrombin and tranexamic acid (TXA) locally to noncompressible intracavitary wounds. We hypothesized that in swine with massive NCTH, dilutional coagulopathy and hypothermia, delivering SPTP could extend survival times.

METHODS

Ten swine (n = 5 per group) underwent NCTH from a Grade V liver injury following a midline laparotomy. The laparotomy was closed with sutures afterwards, creating a hemoperitoneum, and animals were managed with crystalloid fluid resuscitation, or crystalloid resuscitation and SPTP. SPTP was delivered into the closed abdomen using a CO2-powered spray device and a catheter placed into the hemoperitoneum, entering through the upper right quadrant using the Seldinger technique. Survival to one and three hours was recorded. In an additional animal, hemorrhage was created laparoscopically and SPTP was imaged in-situ within the abdomen to visually track dispersion of the particles.

RESULTS

SPTP dispersed as far as 35 +/- 5.0 cm within the abdomen. SPTP increased survival to one and three hours (Kaplan-Meier p = 0.007 for both). The median survival time was 61 minutes with SPTP and 31 minutes without (p = 0.016).

CONCLUSION

SPTP effectively disperses medications throughout a hemoperitoneum and increases survival in a model of NCTH. SPTP is a promising strategy for nonsurgical management of NCTH, warranting further testing of its safety and efficacy.

LEVEL OF EVIDENCE

Basic Science, N/A.

The Role of Prehospital REBOA for Hemorrhage Control in Civilian and Military Austere Settings: A Systematic Review

Despite the success of prehospital resuscitative endovascular balloon occlusion of the aorta (REBOA) in combat and civilian settings, the prevalence of complications and the lack of conclusive evidence has led to uncertainty and controversy. Therefore, this systematic review aimed to evaluate the role of prehospital REBOA for hemorrhage control in trauma populations. We systematically searched Cochrane, Ovid MEDLINE, EMBASE and Google Scholar for all relevant studies that investigated the efficacy of prehospital REBOA on trauma patients with massive hemorrhage. Primary outcome was evaluated by blood pressure elevation and secondary outcome was measured by 30-day mortality and complications. Our search identified 546 studies, but only six studies met the inclusion and exclusion criteria. Included studies were low to moderate quality due to limitations within the studies. However, all of the studies reported significant elevation of blood pressure and survival, demonstrating the potential benefits of REBOA. For example, the 30-day mortality rate reduced significantly after REBOA, but studies lacked long-term outcome assessments across the continuum of care. Due to the heterogeneity of the results, a meta-analysis was not possible. We conclude that prehospital REBOA is a feasible and effective resuscitative adjunct for shock patients with lethal non-compressible torso hemorrhage. However, due to the unclear causes of complications and the lack of high quality and homogeneous data, the effects of prehospital REBOA were not truly reflected and comparison between groups was not feasible. Thus, further high-quality studies are required to attest the causality between prehospital REBOA and outcomes.

Use of Haemostatic Devices for the Control of Junctional and Abdominal Traumatic Haemorrhage: A Systematic Review

Catastrophic haemorrhage accounts for up to 40% of global trauma related mortality and is the leading cause of preventable deaths on the battlefield. Controlling abdominal and junctional haemorrhage is challenging, especially in the pre-hospital setting or ‘under fire’, yet there is no haemostatic agent which satisfies the seven characteristics of an ‘ideal haemostat’. We conducted a systematic search of Embase, Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science to evaluate the feasibility and efficacy of three types of haemostatic devices. Participants included any trauma patient in a pre-hospital setting, perfused human cadavers, or healthy human volunteer simulations. The haemostatic devices reviewed were REBOA, iTClampTM, and four junctional tourniquets: AAJT, CRoC, JETT, and SJT. The SJT had the best user survey performance of the junctional tourniquets, and the four junctional tourniquets had an overall efficacy of 26.6–100% and an application time of 10–203 s. The iTClampTM had an efficacy of 60–100% and an application time of 10–60 s. REBOA had an efficacy of 71–100% and an application time ranging from 5 min to >80 min. In civilian and military trauma patients the use of junctional tourniquets, iTClamp, or REBOA, mortality varied from 0–100%. All of these studies were deemed low to very low in quality, hence the reliability of data presented in each of the studies is called into question. We conclude that despite limited data for these devices, their use in the pre-hospital environment or ‘under fire’ is feasible with the correct training, portable imaging, and patient selection algorithms. However, higher quality studies are required to confirm the true efficacy of these devices.

When REBOA grows wings: Resuscitative endovascular balloon occlusion of the aorta to facilitate aeromedical transport

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a helpful adjunct in the control of non-compressible truncal hemorrhage. Concerns regarding ischemia time limits its applicability in transfer. We describe the first reported case of civilian transfer via aeromedical transport to a higher level of care with a zone 3 REBOA catheter deployed.

Case report

We present the case of a patient in hemorrhagic shock with a complex pelvic fracture exceeding the capability of a rural level-two trauma center requiring the use of REBOA catheter to permit aeromedical transport to a level-one trauma center for definitive embolization.

Conclusion

Deployment of REBOA catheter to facilitate aeromedical transport to an appropriate level of care may be considered if travel times can be kept brief and there is a process and training in place to empower flight medics to consider transporting with a REBOA deployed.

Selective Prehospital Advanced Resuscitative Care - Developing a Strategy to Prevent Prehospital Deaths From Noncompressible Torso Hemorrhage

Hemorrhage, and particularly noncompressible torso hemorrhage remains a leading cause of potentially preventable prehospital death from trauma in the United States and globally. A subset of severely injured patients either die in the field or develop irreversible hemorrhagic shock before they can receive hospital definitive care, resulting in poor outcomes. The focus of this opinion paper is to delineate (a) the need for existing trauma systems to adapt so that potentially life-saving advanced resuscitation and truncal hemorrhage control interventions can be delivered closer to the point-of-injury in select patients, and (b) a possible mechanism through which some trauma systems can train and incorporate select prehospital advanced resuscitative care teams to deliver those interventions.

Challenges and Opportunities for Endovascular Treatment of Hemorrhage in Combat Casualty Care

ABSTRACT

The care of the hemorrhaging patient continues to evolve. The use of endovascular techniques to treat hemorrhage has increased significantly in civilian trauma care over the past 15 years and is identified as a major national trauma care research priority. Endovascular techniques are being increasingly employed to treat major thoracoabdominal arterial injuries and resuscitative endovascular balloon occlusion of the aorta is being adopted at trauma centers as a supportive adjunct to resuscitation in the exsanguinating patient. Emerging endovascular technology offers the opportunity to provide temporary or permanent control of non-compressible torso hemorrhage, which remains a vexing problem in combat casualty care. Endovascular advances have not been translated to the care of combat casualties to any significant degree, however. This review provides a summary and analysis of the gap between civilian endovascular hemorrhage control and combat casualty care practice to better align future research and development efforts.

The Battalion Aid Station-The Forgotten Frontier of the Army Health System During the Global War on Terrorism

BACKGROUND

The battalion aid station (BAS) has historically served as the first stop during which combat casualties would receive care beyond a combat medic. Since the conflicts in Iraq and Afghanistan, many combat casualties have bypassed the BAS for treatment facilities capable of surgery. We describe the care provided at these treatment facilities during 2007-2020.

METHODS

This is a secondary analysis of previously described data from the Department of Defense Trauma Registry. We included encounters with the documentation of an assessment or intervention at a BAS or forward operating base from January 1, 2007 to March 17, 2020. We utilized descriptive statistics to characterize these encounters.

RESULTS

There were 28,950 encounters in our original dataset, of which 3.1% (884) had the documentation of a prehospital visit to a BAS. The BAS cohort was older (25 vs. 24, P < .001) The non-BAS cohort saw a larger portion of pediatric (<18 years) patients (10.7% vs. 5.7%, P < .001). A higher proportion of BAS patients had nonbattle injuries (40% vs. 20.7%, P < .001). The mean injury severity score was higher in the non-BAS cohort (9 vs. 5, P < .001). A higher proportion of the non-BAS cohort had more serious extremity injuries (25.1% vs. 18.4%, P < .001), although the non-BAS cohort had a trend toward serious injuries to the abdomen (P = .051) and thorax (P = .069). There was no difference in survival.

CONCLUSIONS

The BAS was once a critical point in casualty evacuation and treatment. Within our dataset, the overall number of encounters that involved a stop at a BAS facility was low. For both the asymmetric battlefield and multidomain operations/large-scale combat operations, the current model would benefit from a more robust capability to include storage of blood, ventilators, and monitoring and hold patients for an undetermined amount of time.

Targeted Regional Optimization: Increasing the Therapeutic Window for Endovascular Aortic Occlusion In Traumatic Hemorrhage

ABSTRACT

Resuscitative endovascular balloon occlusion of the aorta (REBOA) allows for effective temporization of exsanguination from non-compressible hemorrhage (NCTH) below the diaphragm. However, the therapeutic window for aortic occlusion is time-limited given the ischemia-reperfusion injury generated. Significant effort has been put into translational research to develop new strategies to alleviate the ischemia-reperfusion injury and extend the application of endoaortic occlusion. Targeted regional optimization (TRO) is a partial REBOA strategy to augment proximal aortic and cerebral blood flow while targeting minimal threshold of distal perfusion beyond the zone of partial aortic occlusion. The objective of TRO is to reduce the degree of ischemia caused by complete aortic occlusion while providing control of distal hemorrhage. This review provides a synopsis of the concept of TRO, pre-clinical, translational experiences with TRO and early clinical outcomes. Early results from TRO strategies are promising; however, further studies are needed prior to large-scale implementation into clinical practice.

Prehospital aortic blood flow control techniques for non-compressible traumatic hemorrhage

Non-compressible hemorrhage in the junctional areas and torso could be life-threatening and its prehospital control remains extremely challenging. The aim of this review was to compare commonly used techniques for the control of non-compressible hemorrhage in prehospital settings, and thereby provide evidence for further improvements in emergency care of traumatic injuries. Three techniques were reviewed including external aortic compression (EAC), abdominal aortic junctional tourniquet (AAJT), and resuscitative endovascular balloon occlusion of the aorta (REBOA). In prehospital settings, all three techniques have demonstrated clinical effectiveness for the control of severe hemorrhage. EAC is a cost- and equipment-free, easy-to-teach, and immediately available technique. In contrast, AAJT and REBOA are expensive and require detailed instructions or systematic training. Compared with EAC, AAJT and REBOA have greater potentials in the management of traumatic hemorrhage. AAJT can be used not only in the junctional areas but also in pelvic and bilateral lower limb injuries. However, both AAJT and REBOA should be used for a limited time (less than 1 hour) due to possible consequences of ischemia and reperfusion. Compared with EAC and AAJT, REBOA is invasive, requiring femoral arterial access and intravascular guidance and inflation. Mortality from non-compressible hemorrhage could be reduced through the prehospital application of aortic blood flow control techniques. EAC should be considered as the first-line choice for many non-compressible injuries that cannot be managed with conventional junctional tourniquets. In comparison, AAJT or REBOA is recommended for better control of the aorta blood flow in prehospital settings. Although these three techniques each have advantages, their use in trauma is not widespread. Future studies are warranted to provide more data about their safety and efficacy.

Ultrasound-guided versus blind vascular access followed by REBOA on board of a medical helicopter in a hemorrhagic ovine model

BACKGROUND

The aim of this study is to evaluate the feasibility of en-route resuscitative endovascular balloon occlusion of the aorta (REBOA) on board of a helicopter.

METHODS

Six sedated male sheep (weighing 42-54 kg) underwent a controlled hemorrhage until the systolic blood pressure (BP) dropped to <90 mmHg, and were placed into a low capacity Eurocopter AS-350 (France). During the 30-minutes normal flight, every animal underwent blind (left side) and ultrasound-guided (US) (right side) vascular access (VA) to the femoral artery followed by REBOA: the first catheter (Rescue balloon, Japan) - into Zone I, the second one (MIT, Russia) - Zone III. In case of blind VA failure, an alternate US-puncture was attempted. Six experienced flight anesthetists were enrolled into the study. Vascular access and REBOA catheter placement (confirmed by X-Ray later) success rate and timing were recorded.

RESULTS

Among six blind punctures one was successful, 2/6 - were into the vein, 3/6 - completely failed and switched to US-punctures (making total number of US-punctures nine). Eight out of nine US-punctures were successful. However, correct wire insertion and sheath placement was performed in 1/6 animal in the 'blind' group and only in 6/9 animals in the 'US' group. It took a median of 65 seconds (range 5-260) for US-puncture and a median of 4 minutes to get the sheath in. Among the 9 VAs, there were 2 REBOA failures (1 ruptured balloon [MIT] and 1 mistaken vena cava placement primarily recognized by a sudden drop of BP and later confirmed by X-Ray). Five out of seven balloons were placed in a desired intra-aortic position: 4/5 in Zone I and 1/2 - in Zone III. A median time for a successful REBOA procedure was 5.0 (range 2.5-10.0) minutes (1 min after sheath placement).

CONCLUSION

Our study demonstrates the potential feasibility of the en-route REBOA which can be performed within 5 minutes. Ultrasound-guidance is critically important to achieve en-route VA.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): update and insights into current practices and future directions for research and implementation

Background

In this review, we assess the state of Resuscitative Endovascular Occlusion of the Aorta (REBOA) today with respect to out-of-hospital (OOH) vs. inhospital (H) use in blunt and penetrating trauma, as well as discuss areas of promising research that may be key in further advancement of REBOA applications.

Methods

To analyze the trends in REBOA use, we conducted a review of the literature and identified articles with human or animal data that fit the respective inclusion and exclusion criteria. In separate tables, we compiled data extracted from selected articles in categories including injury type, zone and duration of REBOA, setting in which REBOA was performed, sample size, age, sex and outcome. Based on these tables as well as more detailed review of some key cases of REBOA usage, we assessed the current state of REBOA as well as coagulation and histological disturbances associated with its usage. All statistical tests were 2-sided using an alpha=0.05 for significance. Analysis was done using SAS 9.5 (Cary, NC). Tests for significance was done with a t-test for continuous data and a Chi Square Test for categorical data.

Results

In a total of 44 cases performed outside of a hospital in both military and civilian settings, the overall survival was found to be 88.6%, significantly higher than the 50.4% survival calculated from 1,807 cases of REBOA performed within a hospital (p<.0001). We observe from human data a propensity to use Zone I in penetrating trauma and Zone III in blunt injuries. We observe lower final metabolic markers in animal studies with shorter REBOA time and longer follow-up times.

Conclusions

Further research related to human use of REBOA must be focused on earlier initiation of REBOA after injury which may depend on development of rapid vascular access devices and techniques more so than on any new improvements in REBOA. Future animal studies should provide detailed multisystem organ assessment to accurately define organ injury and metabolic burden associated with REBOA application. Overall, animal studies must involve realistic models of injury with severe clinical scenarios approximating human trauma and exsanguination, especially with long-term follow-up after injury.

Delays in Surgical Intervention and Temporary Hemostasis Using Resuscitative Endovascular Balloon Occlusion of the aorta (REBOA): Influence of Time to Operating Room on Mortality

BACKGROUND

The optimal candidates for resuscitative endovascular balloon occlusion of the aorta (REBOA) remain unclear. We hypothesized that patients who experience delays in surgical intervention would benefit from REBOA.

METHODS

Using the Japan Trauma Databank (2014-2019), patients transferred to the operating room (OR) within 3 h were identified. Patients treated with REBOA were matched with those without REBOA using propensity scores, and further divided based on the transfer time to OR: ≤ 1 h (early), 1-2 h (delayed), and >2 h (significantly-delayed). Survival to discharge was compared.

RESULTS

Among 5258 patients, 310 underwent REBOA. In 223 matched pairs, patients treated with REBOA had improved survival (56.5% vs. 31.8%; p < 0.01), although in-hospital mortality was reduced by REBOA only in the delayed and significantly-delayed subgroups (HR = 0.43 [0.28-0.65] and 0.42 [0.25-0.71]).

CONCLUSIONS

REBOA-treated trauma patients who experience delays in surgical intervention (>1 h) have improved survival.

A New Pressure-Regulated, Partial Resuscitative Endovascular Balloon Occlusion of the Aorta Device Achieves Targeted Distal Perfusion

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) reduces blood loss and improves hemodynamics. Complete occlusion results in distal ischemia, limiting its use for prolonged care. This study evaluated two next-generation partial REBOA (pREBOA) catheters and their ability to achieve targeted distal aortic flow.

MATERIALS AND METHODS

Swine underwent hemorrhagic shock, complete aortic occlusion, controlled continuous balloon deflation, and targeted distal perfusion (TDP; 300-mL/min) phases. They were randomized into three groups (n = 6/group), one managed with the current ER-REBOA (ER), and two with the new pREBOA technologies: a bilobed (BL) device and a semicompliant pREBOA-PRO (PRP). Hemodynamics including flow rates and mean arterial pressures at the carotid artery and infrarenal aorta were recorded.

RESULTS

Hemodynamics were comparable between groups during hemorrhage and complete occlusion phases. During the controlled continuous balloon deflation phase, the distal aortic flow rate strongly correlated with percent balloon volume in BL and PRP groups, suggesting a precise control of distal perfusion. The slope of flow-balloon-volume curves was greater in the ER group than BL and PRP groups, indicating the change in distal aortic flow rate was more sensitive to the balloon volume (less titratable) when using ER. During the TDP phase, variation in distal aortic flow and mean arterial pressure with respect to the target flow was lower in ER and PRP groups, than the BL group.

CONCLUSIONS

Pressure-regulated occlusion using the next-generation pREBOA catheters is more controlled than the first-generation ER-REBOA catheter and allow for targeted and precise distal perfusion.

First Russian experience with endovascular balloon occlusion of the aorta in a zone of combat operations

Resuscitative endovascular balloon occlusion of the aorta has increasingly been used all the world over for arresting ongoing intraabdominal and intrapelvic bleeding accompanied by unstable haemodynamics. However, the use of resuscitative endovascular balloon occlusion of the aorta in a zone of military operations has been limited to sporadic cases only. This article deals with 3 clinical case reports regarding rendering medical care for the wounded presenting with extremely unstable haemodynamics and/or a terminal state in a field hospital, where insertion of a balloon into the aorta made it possible to stabilize the condition, to perform the basic scope of diagnosis, and to finally control the continuing bleeding: in one case - intraabdominal (due to splenic rupture) and in 2 cases - intrapelvic (unstable fractures of pelvic bones). In two cases, despite low readings of blood pressure, puncture of the femoral artery was performed 'blindly' and in one case - in an open fashion. The balloons used were the 7 Fr Rescue Balloon (Japan) and 10 Fr balloons manufactured by the Limited Liability Company 'Minimally Invasive Technologies' (Russia). The balloons were positioned in the aorta also 'blindly' and only in one case we managed to perform an X-ray examination confirming the correct position of the balloon. The mean time of occlusion of the thoracic aorta in the survivors amounted to 20 minutes. The operations were accompanied by intensive therapy and massive haemotransfusion. The introducers were removed using the fascia suture technique (without closure of the arterial wall). Two of the three wounded were saved, to be evacuated to a central hospital and discharged 170 and 75 days thereafter, which was due to long-term treatment of severe concomitant fractures of pelvic bones and lower extremities. No complications on the background of resuscitative endovascular balloon occlusion of the aorta were revealed. Two years after surgery both men continue serving in the Armed Forces, with no significant functional impairments. Our third injured patient delivered in a condition of clinical death, despite restoration of the rhythm after inflation of the balloon unfortunately died. Our case reports demonstrate high efficacy of resuscitative endovascular balloon occlusion of the aorta in unstable haemodynamics induced by combat injury to the abdomen and pelvis. The technique of this method makes it possible not only to stabilize haemodynamics, to improve perfusion of the vital organs but also to staunch continuing haemorrhage, hence allowing additional time to carry out haemotransfusion. In future, resuscitative endovascular balloon occlusion of the aorta may become one of the methods of the extended protocol of prehospital care.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is associated with improved survival in severely injured patients: A propensity score matching analysis

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique for temporary control of arterial hemorrhage. However, its effectiveness and clinical outcomes are unclear.

METHODS

Using a nationwide database (2004-2016) in Japan, trauma patients with survival data were identified. Patients were divided between REBOA and non-REBOA groups, and a propensity score was developed using multivariate logistic regression. Survival to discharge was compared between the groups after propensity score matching.

RESULTS

Among 82,371 patients included in this study, 385 were treated with REBOA. After propensity score matching, 117 pairs were selected. Survival to discharge was significantly higher among patients treated with REBOA than among those treated without REBOA (53 [45.3%] vs. 38 [32.5%]; odds ratio = 1.72; 95% CI = 1.01-2.93; p = 0.04).

CONCLUSIONS

REBOA use was associated with improved survival to discharge and should therefore be considered during the management of severely injured trauma patients.

Thoracic trauma in military settings: a review of current practices and recommendations

PURPOSE OF REVIEW

To examine current literature on thoracic trauma related to military combat and to explore its relevance to the civilian population.

RECENT FINDINGS

Damage control resuscitation (DCR) has improved the management of hemorrhaging trauma patients. Permissive hypotension below 110 mmHg and antifibrinolytic use during DCR is widely accepted, whereas the use of freeze-dried plasma and whole blood is gaining popularity. The Modified Physiologic Triaging Tool can be used for primary triage and it may have applications in civilian trauma systems. Although Tactical Combat Casualty Care protocol recommends the Cric-Key device for surgical cricothyroidotomies, other devices may offer comparable performance. Recommendations for regional anesthesia after blunt trauma are not well defined. Increasing amounts of evidence favor the use of extracorporeal membrane oxygenation for refractory hypoxemia and resuscitative endovascular balloon occlusion of the aorta (REBOA) for severe hemorrhage. REBOA outcomes are potentially improved by partial occlusion and small 7 Fr catheters.

SUMMARY

The Global War on Terror has provided opportunities to better understand and treat thoracic trauma in military settings. Trauma registries and other data sources have contributed to significant advancements in the management of thoracic trauma in military and civilian populations.

Who Would Have Benefited from the Prehospital Use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA)? An Autopsy Study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been increasingly used as part of damage control resuscitation for patients with non-compressible truncal hemorrhage. We hypothesized that there might be a select group of patients that could have benefited from prehospital placement of the REBOA.

STUDY DESIGN

This was a retrospective cohort study including patients who presented to a Level I trauma center with cardiac arrest between January 2014 and March 2018. The findings of a full autopsy were reviewed for the details of internal injuries. A patient was determined to be a REBOA candidate if the patient sustained abdominal organ injuries or pelvic fractures and no associated severe head injuries. The candidate group was compared with the non-candidate group based on prehospital vital signs and other patient characteristics. A multiple logistic regression analysis was performed to identify certain prehospital factors associated with candidacy for prehospital REBOA.

RESULTS

A total of 198 patients met our inclusion criteria. Of those, 27 (13.6%) patients were deemed REBOA candidates. Median Injury Severity Score was 22 (interquartile range 17 to 29). Patients in the candidate group were more likely to have a Glasgow Coma Scale score ≥9 (48% vs 15%; p = 0.012), oxygen saturation >90% (56% vs 35%; p = 0.03), and systolic blood pressure <90 mmHg (48% vs 26%; p = 0.04) in the field. Logistic regression showed that these 3 clinical parameters of prehospital vital signs were significantly associated with REBOA candidacy.

CONCLUSIONS

Our data suggest that >10% of trauma patients who presented with cardiac arrest could have benefited from prehospital REBOA. Additional prospective studies are warranted to validate the use of field vital signs in selecting candidates.

Resuscitative endovascular balloon occlusion of the aorta: current evidence

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has recently gained popularity as a minimally invasive alternative to open aortic cross-clamping in the management of patients with non-compressible hemorrhage arising below the diaphragm. The purpose of this review is to provide a description of the technical aspects of REBOA use along with an overview of the current animal and clinical data regarding its use.

Three cases of resuscitative endovascular balloon occlusion of the aorta (REBOA) in austere pre-hospital environment-technical and methodological aspects

Background

The present paper describes three cases where ER-REBOA® was used with partial aorta occlusion (AO), by performing a partial resuscitative endovascular balloon occlusion of the aorta or pREBOA, in an austere pre-hospital military environment.

In addition, because no specific REBOA algorithm for pre-hospital environment exists yet, this paper seeks to fill this gap, proposing a new pragmatic REBOA algorithm.

Methods

Belgian Special Operations Surgical Team applied REBOA in three patients according to a decisional algorithm, based on the MIST acronym used for trauma patients. Only 3 ml, in the first instance, was inflated in the balloon to get AO. The balloon was then progressively deflated, and reperfusion was tracked through changes of end-tidal carbon dioxide (EtCO₂).

Results

Systolic blood pressure (SBP) before ER-REBOA® placement was not higher than 60 mmHg. However, within the first 5 min after AO, SBP improved in all three cases. Due to the aortic compliance, a self-made pREBOA was progressively achieved while proximal SBP was raising with intravenous fluid infusion. Afterwards, during deflation, a steep inflection point was observed in SBP and EtCO₂.

Conclusions

ER-REBOA® is suitable for use in an austere pre-hospital environment. The MIST acronym can be helpful to select the patients for which it could be beneficial. REBOA can also be performed with pREBOA in a dynamic approach, inflating only 3 mL in the balloon and using the aortic compliance. Furthermore, while proximal SBP can be convenient to follow the occlusion, EtCO₂ can be seen as an easy and interesting marker to follow the reperfusion.