Endovascular balloon occlusion of the aorta is superior to resuscitative thoracotomy with aortic clamping in a porcine model of hemorrhagic shock

Advances in Combat Vascular Trauma Care Through Translational Animal Research Across United States Military Service Branches

The innovation achieved through animal models for hemorrhage-generated knowledge and advancements in combat casualty care. This historical review focuses on 3 key advancements: hemostatic agents, tourniquets, and endovascular approaches. Each played a vital role in the way combat casualty care is delivered, leading to improved patient outcomes.

Resuscitative Endovascular Balloon Occlusion of the Aorta in surgical and trauma patients: a systematic review, meta-analysis and practice management guideline from the Eastern Association for the Surgery of Trauma

Background

The role of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in the management of patients with subdiaphragmatic bleeding, as well as its utility in traumatic cardiac arrest (TCA), is unknown.

Methods

A working group from the Eastern Association for the Surgery of Trauma (EAST) applied the Grading of Recommendations Assessment, Development and Evaluation methodology (GRADE) to perform a systematic review and meta-analysis, assess the level of evidence, and create recommendations pertaining to the use of REBOA in the management of trauma or non-trauma patients, as well as those in TCA (1946 to 2024).

Results

Thirty-one studies were included in the meta-analysis. In unstable trauma patients with subdiaphragmatic bleeding, there was no significant difference in mortality among patients who were treated with REBOA vs no REBOA [OR 0.86, 95% CI 0.37, 2.04]. Subgroup analysis for individuals with pelvic fractures demonstrated higher mortality for REBOA vs no REBOA [OR=2.15, CI 1.35, 3.42]. In patients with TCA, pooled analysis demonstrated decreased mortality with REBOA vs resuscitative thoracotomy (OR 0.32, 95% CI 0.15, 0.69). Compared with no REBOA, prophylactic placement of REBOA prior to cesarean section in placenta accreta syndrome (PAS) had lower intra-operative blood loss [-1.06 L, CI -1.57 to -0.56] and red blood cell transfusion [-2.44 units, CI -4.27 to -0.62]. Overall, the level of evidence was assessed by the working group as very low.

Conclusion

Considering the risks associated with its use and lack of discernible benefit, the committee conditionally recommends against the use of REBOA in trauma patients who are hemodynamically unstable due to suspected subdiaphragmatic hemorrhage. Further research is needed to identify specific subpopulations who may benefit. For individuals with TCA due to suspected subdiaphragmatic bleeding and for prophylactic placement in PAS, the committee conditionally recommends for the use of REBOA.

Level of Evidence

IV.

Implementation and Adaptation of Pathway of Resuscitative Endovascular Balloon Occlusion of the Aorta after Traumatic Injury

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an invented method to facilitate a minimally invasive occlusion of the aorta to stop a life-threatening hemorrhage. This review described an established pathway for noncompressible exsanguination (REBOA procedures) in trauma patients at a Level 1 trauma center. A detailed description starting from the structural changes of the hospital and facilities itself, the initial thoughts, implementation of the process, and continuous revision and improvement of guidelines were discussed. A multidisciplinary core team consisting of trauma surgeons, anesthesiologists, interventional radiologists, and operating room (OR) staff developed step-by-step clinical practice guidelines for using REBOA at our trauma center. A comprehensive training program for specialized procedural training was implemented to ensure the competency of all relevant medical personnel in managing trauma patients. The REBOA guidelines underwent plan-do-check-act quality cycle improvement until the latest guidelines were reached with each use of REBOA in a trauma patient, leading to further auditing of the guidelines to identify areas for improvement. The current review discusses the critical role of adopting innovative technologies and adapting protocols in trauma care, particularly for vulnerable patients with a high risk of morbidity and mortality. Continuous process improvement, procedural refinement, and evolving guidelines are essential prerequisites for optimizing patient outcomes. We described a valuable framework for other trauma programs to implement and adapt similar endovascular bleeding control approaches, thereby potentially enhancing patient care.

Cerebral haemodynamics and intracranial pressure during haemorrhagic shock and resuscitation with total endovascular balloon occlusion of the aorta in an animal model

PURPOSE

To assess changes of cerebral haemodynamic and intracranial pressure (ICP) in animals, with or without elevated ICP, during controlled haemorrhagic shock and resuscitation with Total REBOA (tREBOA).

METHOD

In 22 anaesthetized and normoventilated pigs, after placement of catheters for monitoring invasive proximal blood pressure (pMAP), ICP, and vital parameters, and 60 min stabilisation phase, a controlled haemorrhagic shock (HS), was conducted. In 11 pigs (EICPG), an elevated ICP of 25-30 mmHg at the end HS was achieved by simulating an epidural mass. In 11 pigs (NICPG), the ICP was normal. tREBOA was then applied for 120 min. The changes of pMAP and ICP were followed, and cerebral perfusion pressure (CPP) calculated. The integrity of the autoregulation was estimated using a calculated Modified-Long Pressure Reactivity Index (mL-PRx).

RESULTS

After stabilisation, hemodynamics and physiological parameters were similar and normal in both groups. At the end of the HS, ICP was 16 mmHg in NICPG vs. 32 in EICPG (p = 0.0010). CPP was 30 mmHg in NICPG vs. 6 mmHg in EICPG (p = 0.0254). After aorta occlusion CPP increased immediately in both groups reaching after 15 min up to104 mmHg in NICPG vs. 126 mmHg in EICPG. Cerebrovascular reactivity seems to be altered during bleeding and occlusion phases in both groups with positive mL-PRx. The alteration was more pronounced in EICPG, but reversible in both groups.

CONCLUSION

tREBOA is lifesaving by restoration the cerebral circulation defined as CPP in animals with HS with normal or elevated ICP. Despite the observation of short episodes of cerebral autoregulation impairment during the occlusion, mainly in EICPG, tREBOA seems to be an effective tool for improving cerebral perfusion in HS that extends the crucial early window sometimes known as the "golden hour" for resuscitation even after a traumatic brain injury.

Placental Adhesion Subsequent to Uterine Preservation via Resuscitative Endovascular Balloon Occlusion of the Aorta: A Case Report

An adherent placenta is a life-threatening condition that impairs the mother's life owing to hemorrhagic shock and disseminated intravascular coagulation. Profound hemorrhage resulting from placental abruption is often managed using hysterectomy to preserve the mother's life, although the consequent loss of fertility can be devastating, particularly in younger women. Thus, strategies that facilitate fertility preservation while effectively controlling hemorrhage should be considered viable alternatives. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is commonly performed in patients experiencing traumatic hemorrhagic shock; however, its application in obstetric cases remains infrequent. Herein, we report a case in which REBOA was used to control hemorrhage following the manual removal of an adherent placenta, with the aim of preserving the uterus. A 28-year-old woman presented to our hospital with hemorrhagic shock owing to extensive bleeding from an adherent placenta. As the patient was a young, primiparous woman with a strong desire to preserve her uterus, we opted for manual placental removal. However, manual removal poses a risk of exacerbating the hemorrhage. Therefore, REBOA was performed by emergency physicians to reduce bleeding during placental abruption, and intrauterine balloon tamponade was used to achieve hemostasis without compromising the patient's condition. The use of REBOA in the management of placenta accreta not only improves survival rates but may also provide crucial time for fertility-preserving interventions.

An assessment of nationwide trends in emergency department (ED) resuscitative endovascular balloon occlusion of the aorta (REBOA) use - A trauma quality improvement program registry analysis

BACKGROUND

Use of resuscitative endovascular balloon occlusion of the aorta (REBOA) for temporary hemorrhage control in severe non-compressible torso trauma remains controversial, with limited data on patient selection and outcomes. This study aims to analyze the nationwide trends of its use in the emergency department (EDs).

METHODS

A retrospective analysis of the American College of Surgeons Trauma Quality Improvement Program (ACS-TQIP) from 2017 to 2022 was performed, focusing on REBOA placements in EDs.

RESULTS

The analysis included 3398 REBOA procedures. Majority patients were male (76 ​%) with a median age of 40 years (27-58) and injury severity score of 20 (20-41). The most common mechanism was collision (64 ​%), with emergency surgeries most frequently performed for pelvic trauma (14 ​%). Level 1 trauma centers performed 82 ​% of these procedures, with consistent low annual utilization (<200 facilities). Survival rates were 85 ​% at 1-h post-placement, decreasing significantly to 42 ​% by discharge.

CONCLUSIONS

REBOA usage in remains limited but steady, primarily occurring at level 1 trauma center EDs. While short-term survival rates are favorable, they drop significantly by the time of discharge.

The UK resuscitative endovascular balloon occlusion of the aorta in trauma patients with life-threatening torso haemorrhage: the (UK-REBOA) multicentre RCT

Background

The most common cause of preventable death after injury is haemorrhage. Resuscitative endovascular balloon occlusion of the aorta is intended to provide earlier, temporary haemorrhage control, to facilitate transfer to an operating theatre or interventional radiology suite for definitive haemostasis.

Objective

To compare standard care plus resuscitative endovascular balloon occlusion of the aorta versus standard care in patients with exsanguinating haemorrhage in the emergency department.

Design

Pragmatic, multicentre, Bayesian, group-sequential, registry-enabled, open-label, parallel-group randomised controlled trial to determine the clinical and cost-effectiveness of standard care plus resuscitative endovascular balloon occlusion of the aorta, compared to standard care alone.

Setting

United Kingdom Major Trauma Centres.

Participants

Trauma patients aged 16 years or older with confirmed or suspected life-threatening torso haemorrhage deemed amenable to adjunctive treatment with resuscitative endovascular balloon occlusion of the aorta.

Interventions

Participants were randomly assigned 1 : 1 to: standard care, as expected in a major trauma centre standard care plus resuscitative endovascular balloon occlusion of the aorta.

Main outcome measures

Primary: Mortality at 90 days. Secondary: Mortality at 6 months, while in hospital, and within 24, 6 and 3 hours; need for haemorrhage control procedures, time to commencement of haemorrhage procedure, complications, length of stay (hospital and intensive care unit-free days), blood product use. Health economic: Expected United Kingdom National Health Service perspective costs, life-years and quality-adjusted life-years, modelled over a lifetime horizon.

Data sources

Case report forms, Trauma Audit and Research Network registry, NHS Digital (Hospital Episode Statistics and Office of National Statistics data).

Results

Ninety patients were enrolled: 46 were randomised to standard care plus resuscitative endovascular balloon occlusion of the aorta and 44 to standard care. Mortality at 90 days was higher in the standard care plus resuscitative endovascular balloon occlusion of the aorta group (54%) compared to the standard care group (42%). The odds ratio was 1.58 (95% credible interval 0.72 to 3.52). The posterior probability of an odds ratio > 1 (indicating increased odds of death with resuscitative endovascular balloon occlusion of the aorta) was 86.9%. The overall effect did not change when an enthusiastic prior was used or when the estimate was adjusted for baseline characteristics. For the secondary outcomes (3, 6 and 24 hours mortality), the posterior probability that standard care plus resuscitative endovascular balloon occlusion of the aorta was harmful was higher than for the primary outcome. Additional analyses to account for intercurrent events did not change the direction of the estimate for mortality at any time point. Death due to haemorrhage was more common in the standard care plus resuscitative endovascular balloon occlusion of the aorta group than in the standard care group. There were no serious adverse device effects. Resuscitative endovascular balloon occlusion of the aorta is less costly (probability 99%), due to the competing mortality risk but also substantially less effective in terms of lifetime quality-adjusted life-years (probability 91%).

Limitations

The size of the study reflects the relative infrequency of exsanguinating traumatic haemorrhage in the United Kingdom. There were some baseline imbalances between groups, but adjusted analyses had little effect on the estimates.

Conclusions

This is the first randomised trial of the addition of resuscitative endovascular balloon occlusion of the aorta to standard care in the management of exsanguinating haemorrhage. All the analyses suggest that a strategy of standard care plus resuscitative endovascular balloon occlusion of the aorta is potentially harmful.

Future work

The role (if any) of resuscitative endovascular balloon occlusion of the aorta in the pre-hospital setting remains unclear. Further research to clarify its potential (or not) may be required.

Trial registration

This trial is registered as ISRCTN16184981.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 14/199/09) and is published in full in Health Technology Assessment; Vol. 28, No. 54. See the NIHR Funding and Awards website for further award information.

A Novel REBOA Training Curriculum for Emergency Medicine Residents: A Pilot Study

BACKGROUND

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is a potentially life-saving intervention to treat noncompressible torso hemorrhage. Traditionally, REBOA use has been limited to surgeons. However, emergency physicians are often the first point-of-contact and are well-versed in obtaining rapid vascular access and damage control resuscitation, making them ideal candidates for REBOA training.

STUDY OBJECTIVES

To fill this gap, we designed and evaluated a REBOA training curriculum for emergency medicine (EM) residents.

METHODS

Participants enrolled in an accredited 4-year EM residency program (N = 11) completed a 12-hour REBOA training course. Day 1 included lectures, case studies, and hands-on training using REBOA task trainers and perfused cadavers. Day 2 included additional practice and competency evaluations. Assessments included a 25-item written knowledge exam, decision-making on case studies, REBOA placement success, and time-to-placement. Participants returned at 4 months to assess long-term retention. Data were analyzed using t-tests and nonparametric statistics at p < 0.05.

RESULTS

Scores on a 25-item multiple choice test significantly increased from pre-training (65% ± 5%) to post-training (92% ± 1%), p < 0.001. On Day 2, participants scored 100% on correct recognition of REBOA indications and scored 100% on correct physical placement of REBOA. Exit surveys indicated increased preparedness, confidence, and support for incorporating this course into EM training. Most importantly, REBOA knowledge, correct recognition of REBOA indications, and correct REBOA placement skills were retained by the majority of participants at 4 months.

CONCLUSION

This course effectively teaches EM residents the requisite skills for REBOA competence and proper placement. This study could be replicated at other facilities with larger, more diverse samples, aiming to expand the use of REBOA in emergency physicians and reducing preventable deaths in trauma.

Damage control surgery: old concepts and new indications

PURPOSE OF REVIEW

While the principles of damage control surgery - rapid hemorrhage and contamination control with correction of physiologic derangements followed by delayed definitive reconstruction - have remained consistent, forms of damage control intervention have evolved and proliferated dramatically. This review aims to provide a historic perspective of the early trends of damage control surgery as well as an updated understanding of its current state and future trends.

RECENT FINDINGS

Physiologically depleted patients in shock due to both traumatic and nontraumatic causes are often treated with damage control laparotomy and surgical principles. Damage control surgery has also been shown to be safe and effective in thoracic and orthopedic injuries. Damage control resuscitation is used in conjunction with surgical source control to restore patient physiology and prevent further collapse. The overuse of damage control laparotomy, however, is associated with increased morbidity and complications. With advancing technology, catheter- and stent-based endovascular modalities are playing a larger role in the resuscitation and definitive care of patients.

SUMMARY

Optimal outcome in the care of the most severely injured patients requires judicious use of damage control surgery supplemented by advancements in resuscitation and surgical adjuncts.

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.

Emergency Department Resuscitative Endovascular Balloon Occlusion of the Aorta in Trauma Patients With Exsanguinating Hemorrhage: The UK-REBOA Randomized Clinical Trial

Importance

Bleeding is the most common cause of preventable death after trauma.

Objective

To determine the effectiveness of resuscitative endovascular balloon occlusion of the aorta (REBOA) when used in the emergency department along with standard care vs standard care alone on mortality in trauma patients with exsanguinating hemorrhage.

Design, Setting, and Participants

Pragmatic, bayesian, randomized clinical trial conducted at 16 major trauma centers in the UK. Patients aged 16 years or older with exsanguinating hemorrhage were enrolled between October 2017 and March 2022 and followed up for 90 days.

Intervention

Patients were randomly assigned (1:1 allocation) to a strategy that included REBOA and standard care (n = 46) or standard care alone (n = 44).

Main Outcomes and Measures

The primary outcome was all-cause mortality at 90 days. Ten secondary outcomes included mortality at 6 months, while in the hospital, and within 24 hours, 6 hours, or 3 hours; the need for definitive hemorrhage control procedures; time to commencement of definitive hemorrhage control procedures; complications; length of stay; blood product use; and cause of death.

Results

Of the 90 patients (median age, 41 years [IQR, 31-59 years]; 62 [69%] were male; and the median Injury Severity Score was 41 [IQR, 29-50]) randomized, 89 were included in the primary outcome analysis because 1 patient in the standard care alone group declined to provide consent for continued participation and data collection 4 days after enrollment. At 90 days, 25 of 46 patients (54%) had experienced all-cause mortality in the REBOA and standard care group vs 18 of 43 patients (42%) in the standard care alone group (odds ratio [OR], 1.58 [95% credible interval, 0.72-3.52]; posterior probability of an OR >1 [indicating increased odds of death with REBOA], 86.9%). Among the 10 secondary outcomes, the ORs for mortality and the posterior probabilities of an OR greater than 1 for 6-month, in-hospital, and 24-, 6-, or 3-hour mortality were all increased in the REBOA and standard care group, and the ORs were increased with earlier mortality end points. There were more deaths due to bleeding in the REBOA and standard care group (8 of 25 patients [32%]) than in standard care alone group (3 of 18 patients [17%]), and most occurred within 24 hours.

Conclusions and Relevance

In trauma patients with exsanguinating hemorrhage, a strategy of REBOA and standard care in the emergency department does not reduce, and may increase, mortality compared with standard care alone.

Trial Registration

isrctn.org Identifier: ISRCTN16184981.

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.

Common complications and prevention strategies for resuscitative endovascular balloon occlusion of the aorta: A narrative review

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is considered a key measure of treatment due to its use in stabilizing patients in shock through temporary inflow occlusion for noncompressible torso hemorrhage as well as its supportive role in myocardial and cerebral perfusion. Although its clinical efficacy in trauma has been widely recognized, concerns over related complications, such as vascular access and ischemia-reperfusion, are on the rise. This paper aims to investigate complications associated with REBOA and identify current and emerging prevention or mitigation strategies through a literature review based on human or animal data. Common complications associated with REBOA include ischemia/reperfusion injuries, vessel injuries, venous thromboembolism, and worsening proximal bleeding. REBOA treatment outcomes can be improved substantially with the help of precise selection of patients, better visualization tools, improvement in balloon catheters, blockage strategies, and medication intervention measures. Better understanding of REBOA-related complications and further research on the strategies to mitigate the occurrence of such complications will be of vital importance for the optimization of the clinical outcomes in patients.

Resuscitative balloon occlusion of the aorta in the modern era: Expanding indications, optimal techniques, unresolved issues, and current results

Resuscitative endovascular balloon occlusion of the aorta has been used by trauma surgeons at the bedside for more than a decade in civilian and military settings. Translational and clinical research suggests it is superior to resuscitative thoracotomy for select patients. Clinical research suggests outcomes are superior in patients who received resuscitative balloon occlusion of the aorta compared with those who did not. Technology has advanced considerably in the past several years, leading to the improved safety profile and wider adoption of resuscitative balloon occlusion of the aorta. In addition to trauma patients, resuscitative balloon occlusion of the aorta has been rapidly implemented for patient with nontraumatic hemorrhage.

One-dimensional analysis method of pulsatile blood flow in arterial network for REBOA operations

Based on the generalized Darcy model, here we develop a linear one-dimensional (1D) composite model to predict the effects of the inserted balloon under REBOA operations on the dynamic characteristics of blood flow in flexible arterial networks. We first consider the effect of the decrease of cardiac output under different degrees of blood loss through employing the fourth-order lumped parameter model of cardiovascular system. Then, the effect of the inserted balloon is included by developing the relation between flow resistance and occlusion ratio with the neural network approach. Finally, the accuracy of the developed 1D composite model for REBOA operations, which can be solved analytically in the frequency domain, is verified by comparing to computational fluid dynamics (CFD) simulations. It is demonstrated that the 1D model is able to reproduce main features of the systemic circulation under balloon occlusion of the aorta during REBOA surgery. The 1D composite model could substantially reduce the computational time, which makes it possible to give the instant prediction of the working parameters during RABOA operations.

Advanced diagnostic and therapeutic techniques for anaesthetists in thoracic trauma: an evidence-based review

Anaesthetists play an important role in the evaluation and treatment of patients with signs of thoracic trauma. Anaesthesia involvement can provide valuable input using both advanced diagnostic and therapeutic interventions. Commonly performed interventions may be complicated in this setting including airway management, damage control resuscitation, and acute pain management. Anaesthetists must consider additional factors including airway injuries, vascular injuries, and coagulopathy when treating this population. This evidence-based review discusses traumatic thoracic injuries with a focus on new interventions and modern anaesthesia techniques. This review further serves to support the early involvement of anaesthetists in the emergency department and other areas where they can provide value to the trauma care pathway.

Traumatic Cardiac Arrest: Scoping Review of Utilization of Resuscitative Endovascular Balloon Occlusion of the Aorta

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is increasingly used in trauma resuscitation for patients with life-threatening hemorrhage below the diaphragm and may also be used for patients with traumatic cardiac arrest (TCA). Resuscitative thoracotomy with aortic cross clamping (RT-ACC) maneuver was traditionally performed for patients with TCA due to hemorrhagic shock; however, REBOA has been substituted for RT-ACC in selected TCA cases. During cardiopulmonary resuscitation (CPR) in TCA, REBOA increases cerebral and coronary perfusion, and temporary bleeding control. Both animal and clinical studies have reported the efficacy of REBOA for TCA, and a recent observational study suggested that REBOA may contribute to the return of spontaneous circulation after TCA. Although multiple questions remain unanswered, REBOA has been applied to trauma fields as a novel technology.

Evaluation of resuscitative endovascular balloon occlusion of the aorta catheter placement and comparison to resuscitative thoracotomy with aortic clamping in cadaver dogs

OBJECTIVE

To describe placement of an aortic occlusion catheter in aortic zone 1 (Z1) and aortic zone 3 (Z3) in dogs and to compare time to placement in these zones with and without external chest compressions (ECC). Additional evaluations of time to placement in Z1 with time for resuscitative thoracotomy with aortic clamping (RT-AC) were performed.

DESIGN

Prospective ex vivo study.

SETTING

University teaching hospital.

ANIMALS

Ten canine cadavers.

INTERVENTIONS

Ten cadaver dogs were obtained from client donation after euthanasia. Cadavers were randomized to have balloon catheter placement into the right or left femoral artery via cutdown, with or without ECC. The xiphoid was used as an external anatomical landmark for Z1, and the spinous process of the 5th lumbar vertebra was used for Z3. Balloon placement was confirmed with radiography. Time to balloon placement in Z1 and Z3 and time to RT-AC were recorded.

MEASUREMENTS AND MAIN RESULTS

Median body weight was 23.5 kg (9-40 kg). Median time to Z1 placement was 6.6 minutes (4.6-12.4 minutes) with ECC and 6.9 minutes (3.3-13.1 minutes) without ECC and was not statistically different (P = 0.5). Median time to RT-AC was 1 minute (0.6-1.4 minutes), which was significantly faster than time to balloon placement in Z1 with or without ECC (P = 0.004 and P = 0.002, respectively).

CONCLUSIONS

Endovascular balloon occlusion of the aorta can be achieved by cutdown with and without ECC, but RT-AC is faster. Successful balloon position in Z1 could be achieved with knowledge of external anatomical landmarks, but landmarks for Z3 need further study.

The effectiveness and cost-effectiveness of resuscitative endovascular balloon occlusion of the aorta (REBOA) for trauma patients with uncontrolled torso haemorrhage: study protocol for a randomised clinical trial (the UK-REBOA trial)

BACKGROUND

Haemorrhage is the most common cause of preventable death after injury. REBOA is a novel technique whereby a percutaneously inserted balloon is deployed in the aorta, providing a relatively quick means of temporarily controlling haemorrhage and augmenting cerebral and coronary perfusion, until definitive control of haemorrhage can be attained. The aim of the UK-REBOA trial is to establish the clinical and cost-effectiveness of a policy of standard major trauma centre treatment plus REBOA, as compared with standard major trauma centre treatment alone, for the management of uncontrolled torso haemorrhage caused by injury.

METHODS

Pragmatic, Bayesian, group-sequential, randomised controlled trial, performed in 16 major trauma centres in England. We aim to randomise 120 injured patients with suspected exsanguinating haemorrhage to either standard major trauma centre care plus REBOA or standard major trauma centre care alone. The primary clinical outcome is 90-day mortality. Secondary clinical outcomes include 3-h, 6-h, and 24-h mortality; in-hospital mortality; 6-month mortality; length of stay (in hospital and intensive care unit); 24-h blood product use; need for haemorrhage control procedure (operation or angioembolisation); and time to commencement of haemorrhage control procedure (REBOA, operation, or angioembolisation). The primary economic outcome is lifetime incremental cost per QALY gained, from a health and personal social services perspective.

DISCUSSION

This study, which is the first to randomly allocate patients to treatment with REBOA or standard care, will contribute high-level evidence on the clinical and cost-effectiveness of REBOA in the management of trauma patients with exsanguinating haemorrhage and will provide important data on the feasibility of implementation of REBOA into mainstream clinical practice.

TRIAL REGISTRATION

ISRCTN16184981.

The Underlying Cardiovascular Mechanisms of Resuscitation and Injury of REBOA and Partial REBOA

Introduction: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is used for aortic control in hemorrhagic shock despite little quantification of its mechanism of resuscitation or cardiac injury. The goal of this study was to use pressure-volume (PV) loop analysis and direct coronary blood flow measurements to describe the physiologic changes associated with the clinical use of REBOA. Methods: Swine underwent surgical and vascular access to measure left ventricular PV loops and left coronary flow in hemorrhagic shock and subsequent placement of occlusive REBOA, partial REBOA, and no REBOA. PV loop characteristics and coronary flow are compared graphically with PV loops and coronary waveforms, and quantitatively with measures of the end systolic and end pressure volume relationship, and coronary flow parameters, with accounting for multiple comparisons. Results: Hemorrhagic shock was induced in five male swine (mean 53.6 ± 3.6 kg) as demonstrated by reduction of stroke work (baseline: 3.1 vs. shock: 1.2 L*mmHg, p < 0.01) and end systolic pressure (ESP; 109.8 vs. 59.6 mmHg, p < 0.01). ESP increased with full REBOA (178.4 mmHg; p < 0.01), but only moderately with partial REBOA (103.0 mmHg, p < 0.01 compared to shock). End systolic elastance was augmented from baseline to shock (1.01 vs. 0.39 ml/mmHg, p < 0.01) as well as shock compared to REBOA (4.50 ml/mmHg, p < 0.01) and partial REBOA (3.22 ml/mmHg, p = 0.01). Percent time in antegrade coronary flow decreased in shock (94%-71.8%, p < 0.01) but was rescued with REBOA. Peak flow increased with REBOA (271 vs. shock: 93 ml/min, p < 0.01) as did total flow (peak: 2136, baseline: 424 ml/min, p < 0.01). REBOA did not augment the end diastolic pressure volume relationship. Conclusion: REBOA increases afterload to facilitate resuscitation, but the penalty is supraphysiologic coronary flows and imposed increase in LV contractility to maintain cardiac output. Partial REBOA balances the increased afterload with improved aortic system compliance to prevent injury.

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.

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.

Pelvic fracture-related hypotension: A review of contemporary adjuncts for hemorrhage control

ABSTRACT

Major pelvic hemorrhage remains a considerable challenge of modern trauma care associated with mortality in over a third of patients. Efforts to improve outcomes demand continued research into the optimal employment of both traditional and newer hemostatic adjuncts across the full spectrum of emergent care environments. The purpose of this review is to provide a concise description of the rationale for and effective use of currently available adjuncts for the control of pelvic hemorrhage. In addition, the challenges of defining the optimal order and algorithm for employment of these adjuncts will be outlined.

LEVEL OF EVIDENCE

Review, level IV.

When the balloon goes up, blood transfusion goes down: a pilot study of REBOA in placenta accreta spectrum disorders

Background

Patients with placenta accreta spectrum (PAS) disorders often suffer massive hemorrhage during cesarean hysterectomies (CHyst). A novel strategy to decrease blood loss and minimize perioperative morbidity associated with PAS is utilization of ER-REBOA Catheter intraoperatively. In this study, we explore the use of ER-REBOA Catheter during CHyst with the goal of minimizing perioperative morbidity and packed red blood cell (PRBC) transfusions.

Methods

We conducted a retrospective case-control study at a regional referral center of consecutive patients with PAS undergoing CHyst. The primary outcomes were PRBC transfusions of ≥4 units. Secondary outcomes included surgical intensive care unit admissions, postoperative length of stay (LOS), postoperative ileus, and vascular complication rate. We also explored utilization of manual palpation and omission of precesarean fluoroscopy for resuscitative endovascular balloon occlusion of the aorta (REBOA) placement verification in distal aortic zone 3.

Results

90 patients were included in the study. REBOA and non-REBOA cases were similar in clinicodemographic characteristics. 17.7% of REBOA cases received ≥4 units of PRBC compared with 49.3% of non-REBOA cases (p=0.03). Zero REBOA patients developed postoperative ileus, whereas 18 (25%) non-REBOA patients did (p=0.02). LOS was reduced in the REBOA group. Postplacement fluoroscopy was omitted in all REBOA cases. Two postoperative arterial thrombotic events (2 of 19, 11% of REBOA patients) were identified in the REBOA group, one requiring a thrombectomy (1 of 19, 5%).

Discussion

Decrease in blood transfusions of ≥4 units of PRBC is demonstrated when ER-REBOA Catheter is placed in distal aortic zone 3 during CHyst performed for severe PAS disorders. The incidence of postoperative ileus and LOS are reduced in the ER-REBOA Catheter group. Placement and utilization of ER-REBOA Catheter during CHyst may be feasible without fluoroscopy when manual placement verification is performed by an experienced operator. Protocol modifications focusing on reducing thrombotic rate are ongoing.

Level of evidence

IV.

Emerging approaches to pre-hospital hemorrhage control: a narrative review

In the United States, trauma claims the lives of over 150,000 civilians each year. In military settings, trauma and exsanguination result in 50% of combat related deaths. The majority of these deaths result from uncontrolled non-compressible hemorrhage. Non-compressible hemorrhage often results from deep vascular injuries within the torso, however can also occur secondary to penetrating injuries that involve the extremities. Given the high mortality rates for non-compressible hemorrhage, rapid and effective management of patients suffering from hemorrhage is essential to good patient outcomes. Consequently, there has been increasing interest in solutions for point-of-injury hemorrhage control in trauma and military medicine. Undoubtedly there is a great need for prehospital hemostatic interventions that can be deployed by trained and untrained personnel. Since 2001, various hemostatic agents have been developed, each with its advantages based upon the type and severity of injury, wound size, wound location, accessibility to injury site, and the coagulation status of the patient. These agents are often used in the military setting as a temporizing measure prior to definitive therapy and include techniques such as resuscitative endovascular balloon occlusion of the aorta (REBOA) and bioengineered agents including ResQFoam, RevMedx’s XSTAT, Tranexamic acid (TXA), and QuikClot Combat Gauze (QCG). Here, we review the indications, composition, technique, efficacy, and outcomes of these hemostatic agents.

[Emergency thoracotomy in a severely injured patient after hemorrhagic shock in traumatic pelvic bleeding : Case report]

A case of in-hospital thoracotomy with subsequent open chest cardiopulmonary resuscitation of a polytraumatized patient is reported. Emergency thoracotomies are rare interventions in challenging situations. Up to now there are only few standards or uniform education and training concepts. The indications are often a borderline decision. The aim of thoracotomy and open resuscitation in combination with a reduction in circulation, for example by cross-clamping the aorta, is to save time to address reversible causes of the hemorrhage, redirect the blood volume into the vital cerebral and coronary circulation and minimize bleeding from subdiaphragmatic bleeding sources. Ultimately, in case of doubt, the thoracotomy can be performed for the patient's benefit with the appropriate indications.

Comparative angiotomographic study of swine vascular anatomy: contributions to research and training models in vascular and endovascular surgery

Background

Medium and large animal models allow researchers to evaluate the efficacy and safety of cardiovascular procedures in systems that resemble human anatomy and can be used to simulate scenarios for training purposes. Although porcine models have been used extensively, many physiological and anatomical features remain unknown or only superficially described.

Objectives

To describe the normal porcine vascular anatomy on computed tomography scans, compare it to human vascular anatomy, and discuss the application of porcine models for open and endovascular procedures.

Methods

Three male Landrace pigs underwent computed tomography. The vascular anatomy of the neck, thorax, abdomen, and limbs was analyzed and described; relevant similarities and differences between porcine and human vascular anatomies and the implications for vascular procedures in pigs are highlighted.

Results

The carotid territory, aortic arch, and terminal aorta branches all show marked differences in pigs compared to their human counterparts. Compressions of both left renal and common iliac veins were detected, analogous to those seen in human Nutcracker and May-Thurner syndromes. Vascular measurements (diameters, lengths, and angles) of several different porcine territories are presented.

Conclusions

The data presented should be useful for planning preclinical trials and basic research and for refining surgical training using porcine models in vascular fields.

Gastroesophageal resuscitative occlusion of the aorta: Physiologic tolerance in a swine model of hemorrhagic shock

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been shown to be effective for management of noncompressible torso hemorrhage. However, this technique requires arterial cannulation, which can be time-consuming and not amendable to placement in austere environments. We present a novel, less invasive aortic occlusion device and technique designated gastroesophageal resuscitative occlusion of the aorta (GROA). In this study, we aimed to characterize the physiological tolerance and hemodynamic effects of a prototype GROA device in a model of severe hemorrhagic shock and resuscitation and compare with REBOA.

METHODS

Swine (N = 47) were surgically instrumented for data collection. A 35% controlled arterial hemorrhage was followed by randomizing animals to 30-minute, 60-minute, or 90-minute interventions of GROA, REBOA, or control. Following intervention, devices were deactivated, and animals received whole blood and crystalloid resuscitation. Animals were monitored for an additional 4 hours.

RESULTS

All animals except one GROA 90-minute application survived the duration of their intervention periods. Survival through resuscitation phase in GROA, REBOA, and control groups was similar in the 30-minute and 60-minute groups. The 90-minute occlusion groups exhibited deleterious effects upon device deactivation and reperfusion with two GROA animals surviving and no REBOA animals surviving. Mean (SD) arterial pressure in GROA and REBOA animals increased across all groups to 98 (31.50) mm Hg and 122 (24.79) mm Hg, respectively, following intervention. Lactate was elevated across all GROA and REBOA groups relative to controls during intervention but cleared by 4 hours in the 30-minute and 60-minute groups. Postmortem histological examination of the gastric mucosa revealed mild to moderate inflammation across all GROA groups.

CONCLUSION

In this study, the hemodynamic effects and physiological tolerance of GROA was similar to REBOA. The GROA device was capable of achieving high zone II full aortic occlusion and may be able to serve as an effective method of aortic impingement.

State-of-the-Art Review-Endovascular Resuscitation

ABSTRACT

The emerging concept of endovascular resuscitation applies catheter-based techniques in the management of patients in shock to manipulate physiology, optimize hemodynamics, and bridge to definitive care. These interventions hope to address an unmet need in the care of severely injured patients, or those with refractory non-traumatic cardiac arrest, who were previously deemed non-survivable. These evolving techniques include Resuscitative Endovascular Balloon Occlusion of Aorta, Selective Aortic Arch Perfusion, and Extracorporeal Membrane Oxygenation and there is a growing literature base behind them. This review presents the up-to-date techniques and interventions, along with their application, evidence base, and controversy within the new era of endovascular resuscitation.

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.

Emerging hemorrhage control and resuscitation strategies in trauma: Endovascular to extracorporeal

This article reviews four emerging endovascular hemorrhage control and extracorporeal perfusion techniques for management of trauma patients with profound hemorrhagic shock including hemorrhage-induced traumatic cardiac arrest: resuscitative endovascular balloon occlusion of the aorta, selective aortic arch perfusion, extracorporeal life support, and emergency preservation and resuscitation. The preclinical and clinical studies underpinning each of these techniques are summarized. We also present an integrated conceptual framework for how these emerging technologies may be used in the future care of trauma patients in both resource-rich and austere environments.

Reperfusion repercussions: A review of the metabolic derangements following resuscitative endovascular balloon occlusion of the aorta

BACKGROUND

Current resuscitative endovascular balloon occlusion of the aorta (REBOA) literature focuses on improving outcomes through careful patient selection, diligent catheter placement, and expeditious definitive hemorrhage control. However, the detection and treatment of post-REBOA ischemia-reperfusion injury (IRI) remains an area for potential improvement. Herein, we provide a review of the metabolic derangements that we have encountered while managing post-REBOA IRI in past swine experiments. We also provide data-driven clinical recommendations to facilitate resuscitation post-REBOA deflation that may be translatable to humans.

METHODS

We retrospectively reviewed the laboratory data from 25 swine across three varying hemorrhagic shock models that were subjected to complete REBOA of either 45 minutes, 60 minutes, or 90 minutes. In each model the balloon was deflated gradually following definitive hemorrhage control. Animals were then subjected to whole blood transfusion and critical care with frequent electrolyte monitoring and treatment of derangements as necessary.

RESULTS

Plasma lactate peaked and pH nadired long after balloon deflation in all swine in the 45-minute, 60-minute, and 90-minute occlusion models (onset of peak lactate, 32.9 ± 6.35 minutes, 38.8 ± 10.55 minutes, and 49.5 ± 6.5 minutes; pH nadir, 4.3 ± 0.72 minutes, 26.9 ± 12.32 minutes, and 42 ± 7.45 minutes after balloon deflation in the 45-, 60-, and 90-minute occlusion models, respectively). All models displayed persistent hypoglycemia for more than an hour following reperfusion (92.1 ± 105.5 minutes, 125 ± 114.9 minutes, and 96 ± 97.8 minutes after balloon deflation in the 45-, 60-, and 90-minute occlusion groups, respectively). Hypocalcemia and hyperkalemia occurred in all three groups, with some animals requiring treatment more than an hour after reperfusion.

CONCLUSION

Metabolic derangements resulting from REBOA use are common and may worsen long after reperfusion despite resuscitation. Vigilance is required to detect and proactively manage REBOA-associated IRI. Maintaining a readily available "deflation kit" of pharmacological agents needed to treat common post-REBOA electrolyte abnormalities may facilitate management.

LEVEL OF EVIDENCE

Level V.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) in a swine model of hemorrhagic shock and blunt thoracic injury

PURPOSE

While resuscitative endovascular balloon occlusion of the aorta (REBOA) is contraindicated in patients with aortic injuries, this technique may benefit poly-trauma patients with less extreme thoracic injuries. The purpose of this study was to characterize the effects of thoracic injury on hemodynamics during REBOA and the changes in pulmonary contusion over time in a swine model.

METHODS

Twelve swine were anesthetized, instrumented, and randomized to receive either a thoracic injury with 5 impacts to the chest or no injury. All animals underwent controlled hemorrhage of 25% blood volume followed by 45 min of Zone 1 REBOA. Animals were then resuscitated with shed blood, observed during a critical care period, and euthanized after 6 h of total experimental time.

RESULTS

There were no differences between the groups at baseline. The only difference after 6 h was a lower hemoglobin in the thoracic trauma group (8.4 ± 0.8 versus 9.4 ± 0.6 g/dL, P = 0.04). The average proximal mean arterial pressures were significantly lower in the thoracic trauma group during aortic occlusion [103 (98-108) versus 117 (115-124) mmHg, P = 0.04]. There were no differences between the pulmonary contusion before REBOA and at the end of the experiment in size (402 ± 263 versus 356 ± 291 mL, P = 0.782) or density (- 406 ± 127 versus - 299 ± 175 HFU, P = 0.256).

CONCLUSIONS

Thoracic trauma blunted the proximal arterial pressure augmentation during REBOA but had minimal impacts on resuscitative outcomes. This initial study indicates that REBOA does not seem to exacerbate pulmonary contusion in swine, but blunt thoracic injuries may attenuate the expected rises in proximal blood pressure during REBOA.

Distal organ inflammation and injury after resuscitative endovascular balloon occlusion of the aorta in a porcine model of severe hemorrhagic shock

BACKGROUND AND OBJECTIVE

Resuscitative Endovascular Balloon Occlusion of Aorta (REBOA) has emerged as a potential life-saving maneuver for the management of non-compressible torso hemorrhage in trauma patients. Complete REBOA (cREBOA) is inherently associated with the burden of ischemia reperfusion injury (IRI) and organ dysfunction. However, the distal organ inflammation and its association with organ injury have been little investigated. This study was conducted to assess these adverse effects of cREBOA following massive hemorrhage in swine.

METHODS

Spontaneously breathing and consciously sedated Sinclair pigs were subjected to exponential hemorrhage of 65% total blood volume over 60 minutes. Animals were randomized into 3 groups (n = 7): (1) Positive control (PC) received immediate transfusion of shed blood after hemorrhage, (2) 30min-cREBOA (A30) received Zone 1 cREBOA for 30 minutes, and (3) 60min-cREBOA (A60) given Zone 1 cREBOA for 60 minutes. The A30 and A60 groups were followed by resuscitation with shed blood post-cREBOA and observed for 4h. Metabolic and hemodynamic effects, coagulation parameters, inflammatory and end organ consequences were monitored and assessed.

RESULTS

Compared with 30min-cREBOA, 60min-cREBOA resulted in (1) increased IL-6, TNF-α, and IL-1β in distal organs (kidney, jejunum, and liver) (p < 0.05) and decreased reduced glutathione in kidney and liver (p < 0.05), (2) leukopenia, neutropenia, and coagulopathy (p < 0.05), (3) blood pressure decline (p < 0.05), (4) metabolic acidosis and hyperkalemia (p < 0.05), and (5) histological injury of kidney and jejunum (p < 0.05) as well as higher levels of creatinine, AST, and ALT (p < 0.05).

CONCLUSION

30min-cREBOA seems to be a feasible and effective adjunct in supporting central perfusion during severe hemorrhage. However, prolonged cREBOA (60min) adverse effects such as distal organ inflammation and injury must be taken into serious consideration.

A three-tier Rescue stent improves outcomes over balloon occlusion in a porcine model of noncompressible hemorrhage

BACKGROUND

Noncompressible hemorrhage remains a high-mortality injury, and aortic balloon occlusion poses limitations in terms of distal ischemic injury. Our hypothesis was that a retrievable Rescue stent would confer improved outcome over aortic balloon occlusion.

METHODS

A three-tier, retrievable stent graft was laser welded from nitinol and polytetrafluoroethylene to provide rapid thoracic and abdominal coverage with an interval bare metal segment to preserve visceral flow. Anesthetized swine had injury of the thoracic or abdominal aorta followed by balloon occlusion or a Rescue stent. A 1-hour long damage-control phase with blood repletion was used to simulate the prolonged interval between injury and repair, especially in the battlefield setting. Following the damage-control phase, the balloon or stent were retrieved followed by vascular repair and recovery to 48 hours. Animals were compared in terms of hemodynamics, blood loss, neurophysiologic spinal cord ischemia, ischemic organ injury, and survival.

RESULTS

Despite antegrade hemorrhage control, balloon occlusion averaged 3.5 L of retrograde hemorrhage, loss of visceral perfusion, and permanent spinal cord ischemia by neurophysiology in six of seven animals. After permanent repair, all balloon occlusion animals died with only a single short term (5 hours) survivor. Conversely, Rescue stent animals revealed rapid hemorrhage control (in under 2 minutes) whether the injury was thoracic or abdominal with improved hemodynamics, preserved visceral flow, reduced spinal cord ischemia, negligible histologic organ injury and survival to end of study in all abdominal injured animals (n = 6) and four of six thoracic injured animals, with two deaths related to arrhythmia.

CONCLUSION

Compared with aortic balloon occlusion, a Rescue stent offers superior hemorrhage control and survival by virtue of reduced ischemic injury and direct control of the hemorrhagic injury. The Rescue stent may become a useful tool for damage control, especially on the battlefield where definitive repair presents logistical challenges.

Feasibility and Clinical Outcome of Reboa in Patients with Impending Traumatic Cardiac Arrest

BACKGROUND

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) may improve Systolic Blood Pressure (SBP) in hypovolemic shock. It has, however, not been studied in patients with impending traumatic cardiac arrest (ITCA). We aimed to study the feasibility and clinical outcome of REBOA in patients with ITCA using data from the ABOTrauma Registry.

METHODS

Retrospective and prospective data on the use of REBOA from 16 centers globally were collected. SBP was measured both at pre- and post-REBOA inflation. Data collected included patients' demography, vascular access technique, number of attempts, catheter size, operator, zone and duration of occlusion, and clinical outcome.

RESULTS

There were 74 patients in this high-risk patient group. REBOA was performed on all patients. A 7-10Fr catheter was used in 66.7% and 58.5% were placed on the first attempt, 52.1% through blind insertion and 93.2% inflated in Zone I, 64.8% for a period of 30 to 60 min, 82.1% by ER doctors, trauma surgeons, or vascular surgeons. SBP significantly improved to 90 mm Hg following the inflation of REBOA. 36.6% of the patients survived.

CONCLUSIONS

Our study has shown that REBOA may be performed in patients with ITCA, SBP can be elevated, and 36.6% of the patients survived if REBOA placement is successful.

Resuscitative endovascular balloon occlusion of the aorta and traumatic out-of-hospital cardiac arrest: A nationwide study

OBJECTIVE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a less-invasive method for temporary hemostasis compared with cross-clamping the aorta through resuscitative thoracotomy (RT). Although the survival benefits of REBOA remained unclear, pathophysiological benefits were identified in patients with traumatic out-of-hospital cardiac arrest (t-OHCA). We examined the clinical outcomes of t-OHCA with the hypothesis that REBOA would be associated with higher survival to discharge compared with RT.

METHODS

A retrospective cohort study was conducted using the Japan Trauma Data Bank (2004-2019). Adult patients with t-OHCA who had arrived without a palpable pulse and undergone aortic occlusion were included. Patients were divided into REBOA or RT groups, and propensity scores were developed using age, mechanism of injury, presence of signs of life, presence of severe head and/or chest injury, Injury Severity Score, and transportation time. Inverse probability weighting by propensity scores was performed to compare survival to discharge between the 2 groups.

RESULTS

Among 13,247 patients with t-OHCA, 1483 were included in this study. A total of 144 (9.7%) patients were treated with REBOA, and 5 of 144 (3.5%) in the REBOA group and 10 of 1339 (0.7%) in the RT group survived to discharge. The use of REBOA was significantly associated with increased survival to discharge (odds ratio, 4.78; 95% confidence interval, 1.61-14.19), which was confirmed by inverse probability weighting (adjusted odds ratio, 3.73; 95% confidence interval, 1.90-7.32).

CONCLUSIONS

REBOA for t-OHCA was associated with higher survival to discharge. These results should be validated by further research.

[Resuscitative endovascular balloon occlusion of the aorta (REBOA) : Current aspects of material, indications and limits: an overview]

Hintergrund

„Resuscitative endovascular balloon occlusion of the aorta“ (REBOA) stellt ein endovaskuläres Verfahren dar, bei dem ein Blockballon in die Aorta eingeführt wird, um eine distal des Ballons gelegene Blutung zu verringern und gleichzeitig die kardiale und zerebrale Oxygenierung zu verbessern.

Ziel der Arbeit

Vorstellung der REBOA-Technik, der möglichen Indikationen, der benötigen Materialien und der möglichen Komplikationen des Verfahrens.

Material und Methoden

Nichtsystematischer Übersichtsartikel über die aktuelle Literatur.

Ergebnisse

REBOA stellt gerade bei traumatisch bedingten Blutungen und rupturierten Aortenaneurysmen ein mögliches additives Verfahren zur hämodynamischen Stabilisierung dar. Die Komplikationsrate des Verfahrens liegt bei ungefähr 5 %, wobei Zugangskomplikationen im Vordergrund stehen, jedoch auch letale Komplikationen möglich sind.

Diskussion

Eine aortale Ballonblockade wird bei der Versorgung rupturierter Aortenaneurysmen standardmäßig eingesetzt. Es gibt wachsende Evidenz, dass REBOA bei der Versorgung polytraumatisierter Patienten mit einem hämorrhagischen Schock aufgrund einer abdominellen oder viszeralen Blutung eine vergleichsweise minimal-invasive Alternative zur offen chirurgischen Aortenklemmung mittels Thorakotomie darstellt. Mit der Entwicklung neuer Ballonkatheter, die ohne Führungsdraht und mit geringeren Schleusendurchmessern auskommen, wird auch ein Einsatz bei anderen Krankheitsbildern wie postoperativen abdominellen Nachblutungen, gynäkologischen Blutungen oder als additives Verfahren bei der kardiopulmonalen Reanimation diskutiert.

The potential use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in a Brazilian hospital

AIM

To evaluate the potential use of REBOA in a Brazilian hospital.

METHODS

We performed a retrospective analysis of all requests for emergency surgical evaluation for patients with suspected massive hemorrhage, hospitalized in a private Brazilian general hospital, from April 1, 2017 to March 31, 2018. Inclusion criteria for REBOA eligibility were: suspected abdominal and/or pelvic bleeding, hemorrhagic shock and older than 18 years of age. Exclusion criteria were: older than 70 years of age, and pre-existing terminal disease or significant comorbidities.

RESULTS

90 evaluations were requested during the study period. However, according to our inclusion/exclusion criteria, only on 14 occasions (15.6%) there was a recommendation for the use of REBOA. Gynecological/obstetric conditions were the indication in 11 cases (78.6%) and elective oncologic surgery in three cases (21.4%).

CONCLUSIONS

The use of REBOA is not common in our country, but it can be an essential tool, and perhaps the last resource in extremely severe conditions until the definitive surgical, endovascular or endoscopic treatment is performed.

A contemporary assessment of devices for Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): resource-specific options per level of care

PURPOSE

Use of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) as adjunct for temporary hemorrhage control in patients with exsanguinating torso hemorrhage is increasing. Characteristics of aortic occlusion balloons (AOB) are diverse and evolving as efforts are made to improve the technology. It is important to select a device that fits the requirements of the medical situation to minimize the risk of failure and complications. The aim of this study is to appraise guidance in the choice of an AOB in a specific situation.

METHODS

We assessed 29 AOB for differences and outline possible advantages and disadvantages of each. Bending stiffness was measured with a three-point bending device.

RESULTS

Diameter of the AOB ranged from 6 (ER-REBOA™) to 10 (Coda^®-46) French. However, some need large-bore access sheaths up to 22 French (Fogarty^®-45 and LeMaitre^®-45) or even insertion via cut-down (Equalizer™-40). Bending stiffness varied from 0.08 N/mm (± 0.008 SD; Coda^®-32) to 0.72 N/mm (± 0.024 SD; Russian prototype). Rescue Balloon™ showed kinking of the shaft at low bending pressures. The only non-compliant AOB is REBOA Balloon^®. ER-REBOA™, Fogarty^®, LeMaitre^®, REBOA Balloon^®, and Rescue Balloon™ are provided with external length marks to assist blind positioning.

CONCLUSION

In resource-limited settings, a guidewire- and fluoroscopy-free, rather stiff device, such as ER-REBOA™, Fogarty^®, and LeMaitre^®, is warranted. Of these devices, ER-REBOA™ is the only catheter compatible with seven French sheaths and specifically designed for emergency hemorrhage control. Of the over-the-wire devices, Q50^® has several features that facilitate use and reduce the risk of malplacement or vessel damage.

Aortic branch vessel flow during resuscitative endovascular balloon occlusion of the aorta

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a torso hemorrhage control adjunct. Aortic branch vessel flow (BVF) during REBOA is poorly characterized and has implications for ischemia-reperfusion injury. The aim of this study is to quantify BVF in hypovolemic shock with and without REBOA.

METHODS

Female swine (79-90 kg) underwent anesthesia, 40% controlled hemorrhage and sonographic flow monitoring of the carotid, hepatic, superior mesenteric, renal, and femoral arteries. Animals were randomized to REBOA (n = 5) or no-REBOA (n = 5) for 4 hours, followed by full resuscitation and balloon deflation for 1 hour.

RESULTS

All animals were successfully induced into hemorrhagic shock with a mean decrease of flow in all vessels of 50% from baseline (p < 0.001). Deployment of REBOA resulted in a 200% to 400% increase in carotid flow, but near complete abolition of BVF distal to the balloon. The no-REBOA group saw recovery of BVF to 100% of baseline in all measured vessels, except the hepatic at 50% to 75%. two-way analysis of variance confirmed a significant difference between the groups throughout the protocol (p < 0.001). During resuscitation, the REBOA group saw BVF restore to between 25% and 50%, but never achieving baseline values. The lactate at 4 hours was significantly higher in the REBOA versus no-REBOA group (17.2 ± 0.1 vs. 4.9 ± 1.4; p < 0.001).

CONCLUSION

REBOA not only abolishing BVF during occlusion, but appears to have a post-REBOA effect, reducing visceral perfusion. This may be a source of REBOA associated ischemia-reperfusion injury and warrants further investigation in order to mitigate this effect.

Effect of partial and complete aortic balloon occlusion on survival and shock in a swine model of uncontrolled splenic hemorrhage with delayed resuscitation

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is accepted as a resuscitation adjunct and bridge to definitive hemostasis. The ischemic burden of REBOA may be mitigated by a partial REBOA (P-REBOA) strategy permitting longer occlusion times and military use for combat trauma. We evaluated REBOA and P-REBOA in a swine multiple trauma model with uncontrolled solid organ hemorrhage and delayed resuscitation and surgical hemostasis.

METHODS

Anesthetized swine (51.9 ± 2.2 kg) had 20 mL/kg hemorrhage and closed femur fracture. Splenic transection was performed and free bleeding permitted for 10 minutes. Controls (n = 5) were hemorrhaged but had no REBOA, REBOA (n = 8) had 60 minutes complete zone 1 occlusion, P-REBOA (n = 8) had 15 minutes complete occlusion and 45 minutes 50% occlusion. Splenectomy was performed and plasma (15 mL/kg) resuscitation initiated 5 minutes prior to deflation. Resuscitation goal was 80 mm Hg systolic with epinephrine as needed. Animals were monitored for 6 hours.

RESULTS

An initial study with 120-minute occlusion had universal fatality in three REBOA (upon deflation) and three P-REBOA animals (after 60 minutes inflation). With 60-minute occlusion, mortality was 100%, 62.5%, and 12.5% in the control, REBOA, and P-REBOA groups, respectively (p < 0.05). Survival time was shorter in controls (120 ± 89 minutes) than REBOA and P-REBOA groups (241 ± 139, 336 ± 69 minutes). Complete REBOA hemorrhaged less during inflation (1.1 ± 0.5 mL/kg) than Control (5.6 ± 1.5) and P-REBOA (4.3 ± 1.4), which were similar. Lactate was higher in the REBOA group compared with the P-REBOA group after balloon deflation, remaining elevated. Potassium increased in REBOA after deflation but returned to similar levels as P-REBOA by 120 minutes.

CONCLUSION

In a military relevant model of severe uncontrolled solid organ hemorrhage 1-hour P-REBOA improved survival and mitigated hemodynamic and metabolic shock. Two hours of partial aortic occlusion was not survivable using this protocol due to ongoing hemorrhage during inflation. There is potential role for P-REBOA as part of an integrated minimally invasive field-expedient hemorrhage control and resuscitation strategy.

Delta Systolic Blood Pressure (SBP) Can be a Stronger Predictor of Mortality Than Pre-Aortic Occlusion SBP in Non-Compressible Torso Hemorrhage; an Abotrauma and AORTA Analysis

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is becoming a standardized adjunct for the management in patients with severe non-compressible torso hemorrhage (NCTH). Although guidelines have been developed to help with the best indications for REBOA utilization, no studies have addressed the significance of change in systolic blood pressure (ΔSBP) after REBOA insufflation. We hypothesized that ΔSBP would predict mortality in patients with NCTH and have utility as a surrogate marker for hemorrhage status.

STUDY DESIGN

This was an international, multicenter retrospective review of all patients managed with REBOA from the ABOTrauma Registry and the AORTA database. ΔSBP was defined as the difference between pre- and post-REBOA insertion SBP. Based on post-insertion SBP, patient hemorrhage status was categorized as responder or non-responder. A non-responder was defined as a hypotensive patient with systolic blood pressure (SBP) < 90 mmHg after REBOA placement with full aortic occlusion. Significance was set at P < 0.05.

RESULTS

A total of 524 patients with NCTH were included. Most (74%) were male, 77% blunt injured with a median (IQR) age of 40 (27 - 58) years and ISS 34 (25 - 45). Overall mortality was 51.0%. 20% of patients were classified as non-responders. Demographic and injury descriptors did not differ between groups. Mortality was significantly higher in non-responders vs responders (64% vs 46%, respectively; P = 0.001). Non-responders had lower median pre-insertion SBP (50mmHg vs 67mmHg; P < 0.001) and lower ΔSBP (20mmHg vs 48mmHg; P < 0.001).

CONCLUSION

REBOA non-responders present and remain persistently hypotensive and are more likely to die than responders, indicating a potential direct correlation between ΔSBP as a surrogate marker of hemorrhage volume status and mortality. Future prospective studies will need to further elucidate the impact of Damage Control Resuscitation efforts on ΔSBP and mortality.

The REBOA window: a cadaveric study delineating the optimum site for austere cannulation of the femoral artery for resuscitative endovascular balloon occlusion of the aorta

INTRODUCTION

Haemorrhage is the major cause of early mortality following traumatic injury. Patients suffering from non-compressible torso haemorrhage are more likely to suffer early death. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) can be effective in initial resuscitation; however, establishing swift arterial access is challenging, particularly in a severe shock. This is made more difficult by anatomical variability of the femoral vessels.

METHODS

The femoral vessels were characterised in 81 cadaveric lower limbs, measuring specifically the distance from the inferior border of the inguinal ligament to the distal part of the origin of the profunda femoris artery (PFA), and from the distal part of the origin of the PFA to where the femoral vein lies posterior to and is completely overlapped by the femoral artery.

RESULTS

The femoral vein lay deep to the femoral artery at a mean distance of 105 mm from the inferior border of the inguinal ligament. The PFA arose from the femoral artery at a mean distance of 51.1 mm from the inguinal ligament. From the results, it is predicted that the PFA originates from the common femoral artery approximately 24 mm from the inguinal ligament, and the femoral vein is completely overlapped by the femoral artery by 67.7 mm distal from the inguinal ligament, in 95% of subjects.

CONCLUSIONS

Based on the results, proposed is an 'optimal access window' of up to 24 mm inferior to the inguinal ligament for common femoral arterial catheterisation for pre-hospital REBOA, or more simply within one finger breadth.