The inflammatory sequelae of aortic balloon occlusion in hemorrhagic shock

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.

REBOA Improves Outcomes in Hybrid Surgery for Ruptured Abdominal Aortic Aneurysms

BACKGROUND

Despite advancements in diagnostic methods and emergency interventions, mortality rates of ruptured abdominal aortic aneurysm (rAAA) continue to remain high. To address this issue, the resuscitative endovascular balloon occlusion of the aorta (REBOA) technique has been designed to provide temporary control of bleeding. We aimed to compare the impact of the REBOA technique during open aortic surgery for rAAA.

METHODS

Between January 2014 and November 2021, 53 consecutive patients (46 males, 7 females; mean age 71.9 ± 7.9 years; range 51-89 years) who underwent emergency open aortic surgery for rAAA were retrospectively analyzed. Patients were divided into REBOA (21 patients) and non-REBOA (32 patients) groups. The primary outcomes were postoperative 24-hr and 30-day mortality. The secondary outcomes were intensive care unit (ICU) stay, in-hospital stay, bleeding, postoperative renal failure, bowel ischemia, and transient ischemic attack (TIA)/stroke rate.

RESULTS

The REBOA group showed a significant reduction in mortality rates at both 24 hr (9.5% vs. 37.5%, P = 0.029) and 30 days (14.2% vs. 43.7%, P = 0.035) compared to the non-REBOA group. In-hospital stay (12.8 ± 3.48 vs. 15.6 ± 4.74 days, P = 0.02) and ICU stay (2.42 ± 2.08 vs. 5.09 ± 5.79 days, P = 0.048) were shorter among the REBOA group. Total procedure time and bleeding were reduced among the REBOA group without significant differences in terms of postoperative renal failure, bowel ischemia, and TIA/stroke rate.

CONCLUSIONS

The REBOA group demonstrated significantly improved survival rates compared to the non-REBOA group, without a significant difference in complication rates. REBOA is considered a less invasive option compared to the traditional method for open aortic cross-clamping. This study demonstrated that the use of REBOA may be considered as a first-line treatment option for open surgery in cases of rAAA particularly when an off-the-shelf endovascular aneurysm repair device is not suitable.

Impact of resuscitative endovascular balloon occlusion of the aorta on gastrointestinal function with a matched cohort study

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) can temporarily control arterial hemorrhage in torso trauma; however, the abdominal visceral blood flow is also blocked by REBOA. The aim of this study was to evaluate the influence of REBOA on gastrointestinal function.

Methods

A retrospective review identified all trauma patients admitted to our trauma center between 2008 and 2019. We used propensity score matching analysis to compare the gastrointestinal function between subjects who underwent REBOA and those who did not. Data on demographics, feeding intolerance (FI), time to feeding goal achievement, and complications were retrieved.

Results

During the study period, 55 patients underwent REBOA. A total of 1694 patients met the inclusion criteria, 27 of whom were a subset of those who underwent REBOA. After 1:1 propensity score matching, the REBOA and no-REBOA groups were assigned 22 patients each. Patients in the REBOA group had a significantly higher incidence of FI (77% vs. 27%; OR, 9.1; 95% CI, 2.31 to 35.7; p=0.002) and longer time to feeding goal achievement (8 vs. 6 days, p=0.022) than patients in the no-REBOA group. Patients in the REBOA group also showed significantly prolonged durations of ventilator use (8 vs. 4 days, p=0.023). Furthermore, there was no difference in the mortality rate between the groups (9% vs. 9%, p=1.000).

Conclusions

REBOA was associated with gastrointestinal dysfunction. Our study findings can be useful in providing guidance on managing nutrition in trauma patients who undergo REBOA.

Level of evidence

Level IV.

Study type

Care management.

Transition of Resuscitative Endovascular Balloon Occlusion of the Aorta from Zone 3 to Zone 1 to Treat Hemodynamic Collapse during Continued Hemorrhage

INTRODUCTION

Noncompressible torso hemorrhage (NCTH) accounts for most potentially survivable deaths on the battlefield. Treatment of NCTH is challenging, especially in far-forward environments with limited capabilities. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has shown promise in the care of patients with NCTH. REBOA involves introducing a balloon catheter into the descending aorta in a specific occlusion region (zones 1, 2, or 3) and acts as a hemorrhage control adjunct with resuscitative support. The balloon is placed in zone 3 in the infrarenal aorta for high junctional or pelvic injuries and in zone 1 proximal to the diaphragm for torso hemorrhage. Zone 1 REBOA provides more resuscitative support than zone 3; however, the potential for ischemia and reperfusion injuries is greater with zone 1 than with zone 3 REBOA placement. This study aims to determine the possible benefit of transitioning the REBOA balloon from zone 3 to zone 1 to rescue a patient with ongoing venous bleeding and impending cardiovascular collapse.

MATERIALS AND METHODS

Yorkshire male swine (70-90 kg, n = 6 per group) underwent injury to the femoral artery, which was allowed to bleed freely for 60 s, along with a simultaneous controlled venous hemorrhage. After 60 s, the arterial bleed was controlled with hemostatic gauze and zone 3 REBOA was inflated. Five hundred milliliters of Hextend was used for initial fluid resuscitation. The controlled venous bleed continued until a mean arterial pressure (MAP) of 30 mmHg was reached to create an impending cardiovascular collapse. The animals were then randomized into either continued zone 3 REBOA or transition from zone 3 to zone 1 REBOA. Following 30 min, a "hospital phase" was initiated, consisting of cessation of the venous hemorrhage, deflation of the REBOA balloon, and transfusion of one unit of whole blood administered along with saline and norepinephrine to maintain a MAP of 60 mmHg or higher. The animals then underwent a 2-h observation period. Survival, hemodynamics, and blood chemistries were compared between groups.

RESULTS

No significant differences between groups were observed in hemodynamic or laboratory values at baseline, postinitial injury, or when MAP reached 30 mmHg. Survival was significantly longer in animals that transitioned into zone 1 REBOA (log-rank analysis, P = .012). The average time of survival was 14 ± 10 min for zone 3 animals vs. 65 ± 59 min for zone 1 animals (P = .064). No animals in the zone 3 group survived to the hospital phase. Zone 1-treated animals showed immediate hemodynamic improvement after transition, with maximum blood pressure reaching near baseline values compared to those in the zone 3 group.

CONCLUSIONS

In this swine model of NCTH, hemodynamics and survival were improved when the REBOA balloon was transitioned from zone 3 to zone 1 during an impending cardiovascular collapse. Furthermore, these improved outcome data support the pursuit of additional research into mitigating ischemia-reperfusion insult to the abdominal viscera while still providing excellent resuscitative support, such as intermittent or partial REBOA.

Efficacy of partial and complete resuscitative endovascular balloon occlusion of the aorta in the hemorrhagic shock model of liver injury

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) can temporarily control traumatic bleeding. However, its prolonged use potentially leads to ischemia-reperfusion injury (IRI). Partial REBOA (pREBOA) can alleviate ischemic burden; however, its security and effectiveness prior to operative hemorrhage control remains unknown. Hence, we aimed to estimate the efficacy of pREBOA in a swine model of liver injury using an experimental sliding-chamber ballistic gun.

METHODS

Twenty Landrace pigs were randomized into control (no aortic occlusion) (n=5), intervention with complete REBOA (cREBOA) (n=5), continuous pREBOA (C-pREBOA) (n=5), and sequential pREBOA (S-pREBOA) (n=5) groups. In the cREBOA and C-pREBOA groups, the balloon was inflated for 60 min. The hemodynamic and laboratory values were compared at various observation time points. Tissue samples immediately after animal euthanasia from the myocardium, liver, kidneys, and duodenum were collected for histological assessment using hematoxylin and eosin staining.

RESULTS

Compared with the control group, the survival rate of the REBOA groups was prominently improved (all P<0.05). The total volume of blood loss was markedly lower in the cREBOA group (493.14±127.31 mL) compared with other groups (P<0.01). The pH was significantly lower at 180 min in the cREBOA and S-pREBOA groups (P<0.05). At 120 min, the S-pREBOA group showed higher alanine aminotransferase (P<0.05) but lower blood urea nitrogen compared with the cREBOA group (P<0.05).

CONCLUSION

In this trauma model with liver injury, a 60-minute pREBOA resulted in improved survival rate and was effective in maintaining reliable aortic pressure, despite persistent hemorrhage. Extended tolerance time for aortic occlusion in Zone I for non-compressible torso hemorrhage was feasible with both continuous partial and sequential partial measures, and the significant improvement in the severity of acidosis and distal organ injury was observed in the sequential pREBOA.

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.

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.

Abdominal aortic junctional tourniquet (AAJT-S): a systematic review of utility in military practice

INTRODUCTION

Haemorrhage is the leading cause of potentially survivable death on the battlefield. Despite overall improvement in battlefield mortality, there has been no improvement in survival following non-compressible torso haemorrhage (NCTH). The abdominal aortic junctional tourniquet-stabilised (AAJT-S) is a potential solution that may address this gap in improving combat mortality. This systematic review examines the evidence base for the safety and utility of the AAJT-S for prehospital haemorrhage control in the combat setting.

METHODS

A systematic search of MEDLINE, Cumulated Index to Nursing and Allied Health Literature and Embase (inception to February 2022) was performed using exhaustive terms, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The search was limited to English-language publications in peer-reviewed journals; grey literature was not included. Human, animal and experimental studies were included. Papers were reviewed by all authors to determine inclusion. Each study was assessed for level of evidence and bias.

RESULTS

14 studies met the inclusion criteria: 7 controlled swine studies (total n=166), 5 healthy human volunteer cases series (total n=251), 1 human case report and 1 mannikin study. The AAJT-S was demonstrated to be effective at cessation of blood flow when tolerated in healthy human and animal studies. It was easy to apply by minimally trained individuals. Complications were observed in animal studies, most frequently ischaemia-reperfusion injury, which was dependent on application duration. There were no randomised controlled trials, and the overall evidence base supporting the AAJT-S was low.

CONCLUSIONS

There are limited data of safety and effectiveness of the AAJT-S. However, there is a requirement for a far-forward solution to improve NCTH outcomes, the AAJT-S is an attractive option and high-quality evidence is unlikely to be reported in the near future. Therefore, if this is implemented into clinical practice without a solid evidence base it will need a robust governance and surveillance process, similar to resuscitative endovascular balloon occlusion of the aorta, with regular audit of use.

Partial vs Full Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in a Swine Model of Raised Intracranial Pressure and Hemorrhagic Shock

BACKGROUND

Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is a potential method to mitigate the ischemia observed in full REBOA (fREBOA). However, the effect of pREBOA on cerebral perfusion in the setting of raised intracranial pressure (rICP) is unknown. The aim was to evaluate the effects of no REBOA (nREBOA) vs pREBOA vs fREBOA on cerebral perfusion in a swine model of rICP and hemorrhagic shock.

STUDY DESIGN

Anesthetized swine (n = 18) underwent instrumentation. Controlled hemorrhage was performed over 30 minutes. rICP was achieved using an intracranial Fogarty catheter inflated to achieve an ICP of 20 mmHg. Animals underwent intervention for 30 minutes, followed by resuscitation. The primary outcome was cerebral perfusion measured by ICP (millimeters of mercury), cerebral perfusion pressure (CPP; millimeters of mercury), and cerebral blood flow (CBF; milliliters per minute per 100 g) derived from CT perfusion. The secondary outcomes included hemodynamics and lactate (millimoles per liter).

RESULTS

The peak ICP of pREBOA animals (22.7 ± 2.5) was significantly lower than nREBOA and fREBOA. pREBOA CPP was significantly higher compared with nREBOA and fREBOA during resuscitation. The pREBOA CBF was greater during intervention and resuscitation compared with nREBOA (p < 0.001). Systolic blood pressure was similar between pREBOA and fREBOA, and coronary perfusion was significantly greater in pREBOA. fREBOA had significantly higher lactate during the intervention (9.3 ± 1.3) and resuscitation (8.9 ± 3.5) compared with nREBOA and pREBOA.

CONCLUSION

pREBOA produced greater cerebral perfusion, as demonstrated by more favorable CPP, CBF, and ICP values. fREBOA was associated with metabolic derangement and diminished pressure during resuscitation. pREBOA is superior to fREBOA in a swine model and should be considered over fREBOA for aortic occlusion.

Tandem use of gastroesophageal resuscitative occlusion of the aorta followed by resuscitative endovascular balloon occlusion of the aorta in a lethal liver laceration model

BACKGROUND

Gastroesophageal resuscitative occlusion of the aorta (GROA) has been shown effective in creating zone II aortic occlusion capable of temporarily improving survival in animal models of lethal noncompressible torso hemorrhage. In this study, tandem application of GROA transitioning to resuscitative endovascular balloon occlusion of the aorta (REBOA) is explored to demonstrate feasibility as a potential point-of-injury bridge to more advanced care, using a swine model of lethal abdominal hemorrhage.

METHODS

Swine (n = 19) were anesthetized, instrumented, and subjected to a combination of controlled and uncontrolled hemorrhage from a grade-V liver laceration. Animals were designated as intervention (n = 9; GROA to REBOA) or control (n = 10), for 60 minutes. Following intervention, devices were deactivated, and animals received blood and crystalloid resuscitation. Animals were monitored for 4 hours.

RESULTS

Injury resulted in onset of class IV shock in all animals with a mean arterial pressure (SD) of 24.5 (4.11) mm Hg at the start of intervention. Nine of 10 controls died during the intervention period with a median (interquartile) survival time of 8.5 (9.25) minutes. All animals receiving the intervention survived both the 60-minute intervention period demonstrating a significant survival improvement ( p = 0.0007). Transition from GROA to REBOA was successful in all animals with a transition time ranging from 30 to 90 seconds. Mean arterial pressure significantly improved in animals receiving GROA to REBOA for the duration of intervention, regardless of the method of aortic occlusion, with a range of 70.9 (16.04) mm Hg to 101.1 (15.3) mm Hg. Additional hemodynamics, metrics of shock, and oxygenation remained stable during intervention.

CONCLUSION

Less invasive technologies such as GROA may present an opportunity to control noncompressible torso hemorrhage more rapidly, with a subsequent transition to more advanced care such as REBOA.

Autologous blood resuscitation for large animals in a research setting using the Hemafuse device: Preliminary data of device use for controlled and real-world hemorrhage

Introduction

New low-cost technologies are needed to salvage lost blood in low-resource settings and large animal laboratories. The Hemafuse device is a simple mechanical device that can recover lost blood during surgery. The aim of this study is to assess the feasibility of this device for resuscitating large animals with controlled and unintended hemorrhage and to provide device considerations for use in this context.

Methods

This study had two experimental components: (1) the Hemafuse device was kept on-shelf and used as needed to assess real-world use for unintended hemorrhage during experiments, and (2) animals underwent a controlled hemorrhage protocol, where four anesthetized swine underwent aortic and external jugular vein catheterization for pressure monitoring. Animals were hemorrhaged into the pelvis, and the Hemafuse device was used to suction the blood through a filter and pushed into a heparinized bag for subsequent retransfusion. Blood samples were collected at baseline, hemorrhage, within the device, and post-retransfusion and laboratory tests were performed.

Results

Animals that underwent controlled hemorrhage had a baseline mean arterial pressure of 83.6 ± 7.8 mmHg, and central venous pressure of 12.8 ± 1.9 mmHg, with expected changes throughout hemorrhage and resuscitation. Following resuscitation, pH was similar to baseline (7.39 ± 0.05 vs. 7.31 ± 0.03, p = 0.24). Lactate increased throughout the experiment with no significant differences after autotransfusion compared to baseline (2.7 ± 0.7 vs. 4.1 ± 1.4 mmol/L, p = 0.37). There were no significant changes in metabolic physiology. Compared to baseline, the hemoglobin (7.8 ± 2.4 vs. 7.3 ± 1.8 g/dL, p = 0.74), hematocrit (23% ± 6.9 vs. 21.3% ± 5.6, p = 0.71), and activated clotting time (268.5 ± 44.5 vs. 193 ± 24.6 s, p = 0.35) were similar after retransfusion. When used for unintended hemorrhage, the animals were resuscitated using the device with a mean time to retransfusion time of 128.7 ± 13.3 s and 100% survival throughout the experiment.

Conclusion

The Hemafuse device is feasible and efficacious for supporting large animal resuscitation. This is preliminary evidence that the device is a low-risk and low-cost off-the-shelf option for resuscitation using autologous blood with no significant effect on physiology post-retransfusion. We recommend that research laboratories consider the Hemafuse device for emergency use, particularly for highly invasive surgical laboratories where banked blood is not readily available.

Organ perfusion during partial REBOA in haemorrhagic shock: dynamic 4D-CT analyses in swine

Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal blood pressure while inducing distal ischemia of visceral organs. The evaluation of distal ischemia severity during REBOA is a prerequisite for safe resuscitation of haemorrhagic shock patients with REBOA. We evaluated changes in blood flow and organ perfusion due to the degree of occlusion using dynamic 4D-computed tomography (CT). We compared the results with those of a previous study on euvolemic status. Delayed enhancement of the inferior vena cava (IVC) without retrograde flow was observed in the 4D-volume rendering images in the high-degree occlusion. The time-density curve (TDC) of the liver parenchyma (liver perfusion) and superior mesenteric vein (SMV) demonstrated a decreased peak density and a delayed peak in high-degree occlusion. The change rate of the area under the TDC of the liver and SMV decreased linearly as the degree of occlusion increased (PV, Y = -1.071*X + 106.8, r² = 0.972, P = 0.0003; liver, Y = -1.050*X + 101.8, r² = 0.933, P = 0.0017; SMV, Y = -0.985*X + 100.3, r² = 0.952, P = 0.0009). Dynamic 4D-CT revealed less severe IVC congestion during P-REBOA in haemorrhagic shock than in euvolemia. Analyses of TDC of the liver and SMV revealed a linear change in organ perfusion, regardless of intravascular volume.

A clinical study of the hemodynamic and metabolic effects of Zone 3 REBOA for sacral and pelvic tumor resections

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a key procedure in sacral and pelvic tumor resection that provides hemorrhage control. However, few studies have been performed to capture the effects of REBOA in a nonshock condition and provide a detailed description of the changes occurring with prolonged occlusion time. This study aimed to examine the hemodynamic and metabolic effects of Zone 3 REBOA for sacral and pelvic tumor resections following different periods of REBOA.

Methods

In total, 121 patients who underwent surgical tumor resections of the pelvis and/or the sacrum with the use of aortic balloon occlusion were prospectively enrolled from October 2020 to December 2021. All cases were divided into Group A (occlusion time ≤ 60 min, n = 57) and Group B (occlusion time ≥ 90 min, n = 64). Physiologic parameters were continuously recorded, and laboratory specimens were obtained at regular intervals.

Results

Balloon inflation resulted in a significant increase in SBP from 106 to 120 mmHg and decreased to 96 mmHg immediately following balloon deflation. With the application of REBOA, the median blood loss was only 1200 ml (range, 400–7900). When deflating the REBOA, the arterial pH was lower than baseline (7.36 vs. 7.41, p < 0.01), the arterial lactate concentration increased from 0.9 to 1.4 mmol/L (p < 0.01), serum potassium measurements increased from 3.99 to 4.12 mmol/L, serum calcium measurements decreased from 2.31 to 2.04 mmol/L, and blood creatinine decreased from 64 to 60 µmol/L. The operating time of Group B was longer than that of patients in Group A, and the patients in Group B needed more blood units to be transfused. Although laboratory measurements, including pH, potassium, calcium, and blood creatinine, were at the same level in two groups comparison, the lactate was significantly higher in Group B after deflation (p = 0.01).

Conclusions

The results of this study showed that acceptable hemodynamic and metabolic stability can be attained when the occlusion time of REBOA is more than 90 min, although the long duration of occlusion caused relatively higher lactate levels.

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.

Safety and Effectiveness of Aortic Occlusion for Those Undergoing Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): A Retrospective Single-Center Study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to temporarily control bleeding and maintain the cerebral and coronary blood flow in cases in which it is difficult to control hemorrhagic shock. However, the safety and effectiveness of REBOA remains uncertain.

OBJECTIVES

This study aimed to estimate the safety and effectiveness of aortic occlusion in patients who undergo REBOA catheter placement.

METHODS

We conducted a retrospective study of patients who underwent REBOA catheter placement at Fukuyama City Hospital Emergency Medical Center from August 1, 2008 to March 31, 2020. A propensity score-matching analysis was used to compare 30-day survival between patients who undergo REBOA catheter placement with and without aortic occlusion.

RESULTS

Overall, 122 of the 147 who underwent REBOA catheter placement at Fukuyama City Hospital were eligible for inclusion. Thirty-five patients in the Occlusion group and 35 patients in the Nonocclusion group were selected by propensity score matching. According to the 30-day survival rate, the difference between the two groups was not statistically significant (p = 0.288 log-rank test). Moreover, the required treatment, the types and incidence of complications, and other outcomes did not differ according to the presence or absence of aortic occlusion in patients who underwent REBOA catheter placement.

CONCLUSION

According to the results of this study, in trauma patients who undergo REBOA catheter placement, the presence of aortic occlusion was not significantly associated with 30-day mortality. Furthermore, the performance of aortic occlusion was not associated with a significant increase in complications.

Endovascular Perfusion Augmentation for Critical Care Decreases Vasopressor Requirements while Maintaining Renal Perfusion

BACKGROUND

Ischemia reperfusion injury causes a profound hyperdynamic distributive shock. Endovascular perfusion augmentation for critical care (EPACC) has emerged as a hemodynamic adjunct to vasopressors and crystalloid. The objective of this study was to examine varying levels of mechanical support for the treatment of ischemiareperfusion injury in swine.

METHODS

Fifteen swine underwent anesthesia and then a controlled 30% blood volume hemorrhage followed by 30 min of supra-celiac aortic occlusion to create an ischemia-reperfusion injury Animals were randomized to standardized critical care (SCC), EPACC with low threshold (EPACC-Low), and EPACC with high threshold (EPACC-High). The intervention phase lasted 270 min after injury Hemodynamic markers and laboratory values of ischemia were recorded.

RESULTS

During the intervention phase, SCC spent 82.4% of the time avoiding proximal hypotension (>60 mm Hg), while EPACC-Low spent 97.6% and EPACC-High spent 99.5% of the time avoiding proximal hypotension, P  < 0.001. Renal artery flow was statistically increased in EPACC-Low compared with SCC (2.29 mL/min/kg vs. 1.77 mL/ min/kg, P  < 0.001), while renal flow for EPACC-High was statistically decreased compared with SCC (1.25 mL/min/kg vs. 1.77 mL/min/kg, P  < 0.001). EPACC animals required less intravenous norepinephrine, (EPACC-Low: 16.23mcg/kg and EPACC-High: 13.72 mcg/kg), compared with SCC (59.45 mcg/kg), P = 0.049 and P = 0.013 respectively.

CONCLUSIONS

Compared with SCC, EPACC-High and EPACC-Low had decreased norepinephrine requirements with decreased frequency of proximal hypotension. EPACC-Low paradoxically had increased renal perfusion despite having a mechanical resistor in the aorta proximal to the renal arteries. This is the first description of low volume mechanical hemodynamic support in the setting of profound shock from ischemia-reperfusion injury in swine demonstrating stabilized proximal hemodynamics and augmented distal perfusion.

Adenosine, lidocaine, and magnesium for attenuating ischemia reperfusion injury from resuscitative endovascular balloon occlusion of the aorta in a porcine model

BACKGROUND

Minimally invasive resuscitative endovascular balloon occlusion of the aorta (REBOA) following noncompressible hemorrhage results in significant ischemia reperfusion injury (IRI). Adverse outcomes from IRI include organ dysfunction and can result in profound hemodynamic and molecular compromise. We hypothesized that adenosine, lidocaine, and magnesium (ALM) attenuates organ injury and inflammation responses following REBOA IRI in a porcine model of hemorrhage.

METHODS

Animals underwent a 20% controlled hemorrhage followed by 45 minutes of supraceliac balloon occlusion. They were randomized into two groups: control (n = 9) and ALM intervention (n = 9) to include a posthemorrhage, pre-REBOA bolus (200 mL of 3% NaCl ALM) followed by a continuous drip (2 mL/kg per hour of 0.9% NaCl ALM) during the 4-hour resuscitative period. Primary outcomes included hemodynamic parameters, gene expression of inflammatory signaling molecules, and plasma concentrations of select cytokines and chemokines.

RESULTS

The ALM cohort demonstrated a significant reduction in cardiac output and cardiac index. Plasma concentrations of interleukin 2 and interleukin 10 were significantly lower 3 hours post-REBOA in animals treated with ALM versus vehicle. Interleukin 4 levels in plasma were also lower with ALM at 3 and 4 hours post-REBOA (p < 0.05). Liver expression of IL1RN, MTOR, and LAMP3 messenger RNA was significantly lower with ALM as compared with the vehicle. No significant difference in large bowel gene expression was observed between treatments.

CONCLUSION

In a porcine model of hemorrhage, ALM treatment mitigated inflammatory responses early during post-REBOA resuscitation. Our findings suggest that ALM use with trauma may reduce inflammatory injury and improve outcomes related to REBOA utilization.

Combatting ischemia reperfusion injury from resuscitative endovascular balloon occlusion of the aorta using adenosine, lidocaine and magnesium: A pilot study

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA), a minimally invasive alternative to resuscitative thoracotomy, has been associated with significant ischemia reperfusion injury (IRI). Resuscitation strategies using adenosine, lidocaine, and magnesium (ALM) have been shown to mitigate similar inflammatory responses in hemorrhagic and septic shock models. This study examined the effects of ALM on REBOA-associated IRI using a porcine model.

METHODS

Animals underwent a 20% controlled hemorrhage followed by 30 minutes of supraceliac balloon occlusion. They were assigned to one of four groups: control (n = 5), 4-hour ALM infusion starting at occlusion, 2-hour (n = 5) and 4-hour (n = 5) interventional ALM infusions starting at reperfusion. Adenosine, lidocaine, and magnesium cohorts received a posthemorrhage ALM bolus followed by their respective ALM infusion. Primary outcomes for the study assessed physiologic and hemodynamic parameters.

RESULTS

Adenosine, lidocaine, and magnesium infusion after reperfusion cohorts demonstrated a significant improvement in lactate, base deficit, and pH in the first hour following systemic reperfusion. At study endpoint, continuous ALM infusion initiated after reperfusion over 4 hours resulted in an overall improved lactate clearance when compared with the 2-hour and control cohorts. No differences in hemodynamic parameters were noted between ALM cohorts and controls.

CONCLUSION

Adenosine, lidocaine, and magnesium may prove beneficial in mitigating the inflammatory response seen from REBOA-associated IRI as evidenced by physiologic improvements early during resuscitation. Despite this, further refinement should be sought to optimize treatment strategies.

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.

Femoral vascular access for endovascular resuscitation

ABSTRACT

Endovascular resuscitation is an emerging area in the resuscitation of both severe traumatic hemorrhage and nontraumatic cardiac arrest. Vascular access is the critical first procedural step that must be accomplished to initiate endovascular resuscitation. The endovascular interventions presently available and emerging are routinely or potentially performed via the femoral vessels. This may require either femoral arterial access alone or access to both the femoral artery and vein. The time-critical nature of resuscitation necessitates that medical specialists performing endovascular resuscitation be well-trained in vascular access techniques. Keen knowledge of femoral vascular anatomy and skill with vascular access techniques are required to meet the needs of critically ill patients for whom endovascular resuscitation can prove lifesaving. This review article addresses the critical importance of femoral vascular access in endovascular resuscitation, focusing on the pertinent femoral vascular anatomy and technical aspects of ultrasound-guided percutaneous vascular access and femoral vessel cutdown that may prove helpful for successful endovascular resuscitation.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA): Zone I Balloon Occlusion Time Affects Spinal Cord Injury in the Nonhuman Primate Model

OBJECTIVES

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) has been used clinically to limit torso bleeding and restore central perfusion. The objective of this study was to determine the sequelae of prolonged REBOA in a nonhuman primate animal model.

SUMMARY BACKGROUND DATA

Prolonged duration of REBOA is associated with adverse clinical outcomes. Threshold occlusion values tied to relative risk have yet to be determined.

METHODS

Juvenile baboons were subjected to 40% to 55% total blood volume hemorrhage to achieve profound hypotension and shock. Zone I REBOA was performed for 60 minutes to assess acute injury and survival at 4 hours (group 1; n = 7). Post-REBOA 10-day survival and complications were then compared between 60 minutes (group 2; n = 8) and 30 minutes (group 3; n = 6) REBOA animals.

RESULTS

Overall survival was 20/21 (95%). IL-6 and IL-8 were elevated at 1 and 4 hours in group 1 (P = 0.005; P = 0.001). Comparing 60-minute REBOA with 30-minute REBOA, there was (1) hypertension compared with normotension (P = 0.005), (2) increased base deficit (P = 0.003), (3) elevated Troponin I (P = 0.04), and histological evidence of kidney injury (P = 0.004). In addition, group 2 demonstrated paralysis with histopathologic changes of spinal cord ischemia (SCI) in 4/8 (50%), with no SCI in group 3 (P = 0.033).

CONCLUSIONS

REBOA limits mortality in the primate model of severe hemorrhagic shock. However, unopposed balloon inflation in the distal thoracic aorta for 60 minutes results in high rates of spinal cord ischemia, an effect mitigated by limiting balloon inflation to 30 minutes.

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.

Zone-dependent acute circulatory changes in abdominal organs and extremities after resuscitative balloon occlusion of the aorta (REBOA): an experimental model

Introduction

Resuscitative endovascular balloon occlusion of the aorta (REBOA) may be used in severely injured patients with uncontrollable bleeding. However, zone-dependent effects of REBOA are rarely described. We compared the short-term zone- and organ-specific microcirculatory changes in abdominal organs and the extremity during occlusion of the aorta in a standardized porcine model.

Methods

Male pigs were placed under general anesthesia, for median laparotomy to expose intra-abdominal organs. REBOA placement occurred in Zone 1 (from origin left subclavian artery to celiac trunk), Zone 2 (between the coeliac trunk and most caudal renal artery) and Zone 3 (distal most caudal renal artery to aortic bifurcation). Local microcirculation of the intra-abdominal organs were measured at the stomach, colon, small intestine, liver, and kidneys. Furthermore, the right medial vastus muscle was included for assessment. Microcirculation was measured using oxygen-to-see device (arbitrary units, A.U). Invasive blood pressure measurements were recorded in the carotid and femoral artery (ipsilateral). Ischemia/Reperfusion (I/R)-time was 10 min with complete occlusion.

Results

At baseline, microcirculation of intra-abdominal organs differed significantly (p < 0.001), the highest flow was in the kidneys (208.3 ± 32.9 A.U), followed by the colon (205.7 ± 36.2 A.U.). At occlusion in Zone 1, all truncal organs showed significant decreases (p < 0.001) in microcirculation, by 75% at the colon, and 44% at the stomach. Flow-rate changes at the extremities were non-significant (n.s). During occlusion in Zone 2, a significant decrease (p < 0.001) in microcirculation was observed at the colon (− 78%), small intestine (− 53%) and kidney (− 65%). The microcirculatory changes at the extremity were n.s. During occlusion in Zone 3, truncal and extremity microcirculatory changes were n.s.

Conclusion

All abdominal organs showed significant changes in microcirculation during REBOA. The intra-abdominal organs react differently to the same occlusion, whereas local microcirculation in extremities appeared to be unaffected by short-time REBOA, regardless of the zone of occlusion.

Lessons Learned From the Battlefield and Applicability to Veterinary Medicine-Part 1: Hemorrhage Control

In humans, the leading cause of potentially preventable death on the modern battlefield is undoubtedly exsanguination from massive hemorrhage. The US military and allied nations have devoted enormous effort to combat hemorrhagic shock and massive hemorrhage. This has yielded numerous advances designed to stop bleeding and save lives. The development of extremity, junctional and truncal tourniquets applied by first responders have saved countless lives both on the battlefield and in civilian settings. Additional devices such as resuscitative endovascular balloon occlusion of the aorta (REBOA) and intraperitoneal hemostatic foams show great promise to address control the most difficult forms (non-compressible) of hemorrhage. The development of next generation hemostatic dressings has reduced bleeding both in the prehospital setting as well as in the operating room. Furthermore, the research and fielding of antifibrinolytics such as tranexamic acid have shown incredible promise to ameliorate the effects of acute traumatic coagulopathy which has led to significant morbidity and mortality in service members. Advances from lessons learned on the battlefield have numerous potential parallels in veterinary medicine and these lessons are ripe for translation to veterinary medicine.

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.

Use of bilobed partial resuscitative endovascular balloon occlusion of the aorta is logistically superior in prolonged management of a highly lethal aortic injury

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a viable technique for management of noncompressible torso hemorrhage. The major limitation of the current unilobed fully occlusive REBOA catheters is below-the-balloon ischemia-reperfusion complications. We hypothesized that partial aortic occlusion with a novel bilobed partial (p)REBOA-PRO would result in the need for less intraaortic balloon adjustments to maintain a distal goal perfusion pressure as compared with currently available unilobed ER-REBOA.

METHODS

Anesthetized (40-50 kg) swine randomized to control (no intervention), ER-REBOA, or pREBOA-PRO underwent supraceliac aortic injury. The REBOA groups underwent catheter placement into zone 1 with initial balloon inflation to full occlusion for 10 minutes followed by gradual deflation to achieve and subsequently maintain half of the baseline below-the-balloon mean arterial pressure (MAP). Physiologic data and blood samples were collected at baseline and then hourly. At 4 hours, the animals were euthanized, total blood loss and urine output were recorded, and tissue samples were collected.

RESULTS

Baseline physiologic data and basic laboratories were similar between groups. Compared with control, interventions similarly prolonged survival from a median of 18 minutes to over 240 minutes with comparable mortality trends. Blood loss was similar between partial ER-REBOA (41%) and pREBOA-PRO (51%). Partial pREBOA-PRO required a significantly lower number of intraaortic balloon adjustments (10 ER-REBOA vs. 3 pREBOA-PRO, p < 0.05) to maintain the target below-the-balloon MAP. The partial ER-REBOA group developed significantly increased hypercapnia, fibrin clot formation on TEG, liver inflammation, and IL-10 expression compared with pREBOA-PRO.

CONCLUSION

In this highly lethal aortic injury model, use of bilobed pREBOA-PRO for a 4-hour partial aortic occlusion was logistically superior to unilobed ER-REBOA. It required less intraaortic balloon adjustments to maintain target MAP and resulted in less inflammation.

A feasibility study of partial REBOA data in a high-volume trauma center

PURPOSE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to temporize patients with infradiaphragmatic hemorrhage. Current guidelines advise < 30 min, to avoid ischemia/ reperfusion injury, whenever possible. The technique of partial REBOA (P-REBOA) has been developed to minimize the effects of distal ischemia. This study presents our clinical experience with P-REBOA, comparing outcomes to complete occlusion (C-REBOA).

PATIENTS AND METHODS

Retrospective analysis of patients' electronic data and local REBOA registry between January 2016 and May 2019.

INCLUSION CRITERIA

adult trauma patients who received Zone I C-REBOA or P-REBOA for infradiaphragmatic hemorrhage, who underwent attempted exploration in the operating room. Comparison of outcomes based on REBOA technique (P-REBOA vs C-REBOA) and occlusion time (> 30 min, vs ≤ 30 min) RESULTS: 46 patients were included, with 14 treated with P-REBOA. There were no demographic differences between P-REBOA and C-REBOA. Prolonged (> 30 min) REBOA (regardless of type of occlusion) was associated with increased mortality (32% vs 0%, p = 0.044) and organ failure. When comparing prolonged P-REBOA with C-REBOA, there was a trend toward lower ventilator days [19 (11) vs 6 (9); p = 0.483] and dialysis (36.4% vs 16.7%; p = 0.228) with significantly less vasopressor requirement (72.7% vs 33.3%; p = 0.026).

CONCLUSION

P-REBOA can be delivered in a clinical setting, but is not currently associated with improved survival in prolonged occlusion. In survivors, there is a trend toward lower organ support needs, suggesting that the technique might help to mitigate ischemic organ injury. More clinical data are needed to clarify the benefit of partial occlusion REBOA.

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.

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.

Novel use of XSTAT 30 for mitigation of lethal non-compressible torso hemorrhage in swine

Background

Management of Non-Compressible Torso Hemorrhage (NCTH) consists primarily of aortic occlusion which has significant adverse outcomes, including ischemia-reperfusion injury, in prolonged field care paradigms. One promising avenue for treatment is through use of RevMedx XSTAT 30™ (an FDA approved sponge-based dressing utilized for extremity wounds). We hypothesized that XSTAT 30™ would effectively mitigate NCTH during a prolonged pre-hospital period with correctable metabolic and physiologic derangements.

Methods and findings

Twenty-four male swine (53±2kg) were anesthetized, underwent line placement, and splenectomy. Animals then underwent laparoscopic transection of 70% of the left lobe of the liver with hemorrhage for a period of 10min. They were randomized into three groups: No intevention (CON), XSTAT 30™-Free Pellets (FP), and XSTAT 30™-Bagged Pellets (BP). Animals were observed for a pre-hospital period of 180min. At 180min, animals underwent damage control surgery (DCS), balanced blood product resuscitation and removal of pellets followed by an ICU period of 5 hours. Postoperative fluoroscopy was performed to identify remaining pellets or bags. Baseline physiologic and injury characteristics were similar. Survival rates were significantly higher in FP and BP (p<0.01) vs CON. DCS was significantly longer in FP in comparison to BP (p = 0.001). Two animals in the FP group had pellets discovered on fluoroscopy following DCS. There was no significant difference in blood product or pressor requirements between groups. End-ICU lactates trended to baseline in both FP and BP groups.

Conclusions

While these results are promising, further study will be required to better understand the role for XSTAT in the management of NCTH.

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.

The Effects of the Duration of Aortic Balloon Occlusion on Outcomes of Traumatic Cardiac Arrest in a Porcine Model

Aortic balloon occlusion (ABO) facilitates the success of cardiopulmonary resuscitation (CPR) in non-traumatic cardiac arrest, and is also effective in controlling traumatic hemorrhage; however, a prolonged occlusion results in irreversible organ injury and death. In this study, we investigated the effects of ABO on CPR outcomes and its optimal duration for post-resuscitation organ protection in a porcine model of traumatic cardiac arrest (TCA).Twenty-seven male domestic pigs weighing 33 ± 4 kg were utilized. Forty percent of estimated blood volume was removed within 20 min. The animals were then subjected to 5 min of untreated ventricular fibrillation and 5 min of CPR. Coincident with the start of CPR, the animals were randomized to receive either 30-min ABO (n = 7), 60-min ABO (n = 8) or control (n = 12). Meanwhile, fluid resuscitation was initiated by the infusion of normal saline with 1.5 times of hemorrhage volume in 1 h, and finished by the reinfusion of 50% of the shed blood in another 1 h. The resuscitated animals were monitored for 6 h and observed for an additional 18 h.During CPR, coronary perfusion pressure was significantly increased followed by a higher rate of resuscitation success in the 30 and 60-min ABO groups compared with the control group. However, post-resuscitation cardiac, neurologic dysfunction, and injuries were significantly milder accompanied with less renal and intestinal injuries in the 30-min ABO group than in the other two groups.In conclusion, ABO augmented the efficacy of CPR after TCA, and furthermore a 30-min ABO improved post-resuscitation cardiac and neurologic outcomes without exacerbating the injuries of kidney and intestine.

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.

Partial Versus Complete Resuscitative Endovascular Balloon Occlusion of the Aorta in Exsanguinating Trauma Patients With Non-Compressible Torso Hemorrhage

Hemorrhage is a major cause of death globally, yet our options to control the condition have remained limited. The standard intervention for patients suffering from a non-compressible torso hemorrhage (NCTH) typically involves resuscitative thoracotomy (RT) with aortic cross-clamping. Apart from being extraordinarily invasive, the survival rates for this procedure remain low. Over the years, research has surfaced that offers much promise regarding the use of resuscitative endovascular balloon occlusion of the aorta (REBOA) in exsanguinating patients. Although this type of procedure is not yet universally recognized as a gold standard, it holds some hope for the development of additional research regarding how we can make use of this advancement to improve survival in trauma patients. Complete REBOA (c-REBOA) has not gained wide acceptance due to the undeniable effects it has on normal physiology, metabolic effects, long-term complications, and mortality. Partial REBOA (p-REBOA) is not yet fully validated by research but could potentially be the answer to our problem. The critical question that we should address at this juncture is as follows: how can we improve the survival of patients with an NCTH in the least invasive way possible, while also reducing the feared complications associated with c-REBOA?

Endovascular Perfusion Augmentation for Critical Care: Partial Aortic Occlusion for Treatment of Severe Ischemia-Reperfusion Shock

BACKGROUND

The resuscitation of patients in shock is materially intensive and many patients are refractory to maximal therapy. We hypothesized that partial inflation of an intra-aortic balloon, termed Endovascular Perfusion Augmentation for Critical Care (EPACC), would minimize material requirements while improving physiologic metrics.

METHODS

Swine underwent a 25% controlled bleed and 45 min of complete aortic occlusion to create a severe ischemia-reperfusion shock state. Animals received either standardized critical care (SCC) composed of IV fluids and norepinephrine delivered through an algorithmically controlled platform or EPACC in addition to SCC. Physiologic parameters were collected, and blood was sampled for analysis. Primary outcomes were total IV fluids and average MAP during the critical care phase. Differences (P < 0.05) were measured with t test (continuous data) and Wilcoxon rank-sum test (ordinal data).

RESULTS

There were no differences in baseline characteristics. There were no differences in the maximum lactate; however, animals in the EPACC group had a higher average MAP (EPACC 65 mmHg, 95% confidence interval [CI], 65-66; SCC 60 mmHg, 95% CI, 57-63; P < 0.01) and remained within goal MAP for a greater period of time (EPACC 95.3%, 95% CI, 93.2-97.4; SCC 51.0%, 95% CI, 29.5-72.6; P < 0.01). EPACC animals required less IV fluids when compared with the SCC group (EPACC 21 mL/kg, 95% CI, 0-42; SCC 96 mL/kg, 95% CI, 76-117; P < 0.01). There were no differences in final lactate. Animals in the EPACC group had a higher final creatinine (EPACC 2.3 mg/dL, 95% CI, 2.1-2.5; SCC 1.7 mg/dL, 95% CI, 1.4-2.0; P < 0.01), but there were no differences in renal cellular damage on histology (P = 0.16).

CONCLUSION

Using a swine model of severe shock, the addition of EPACC to SCC significantly reduced fluid resuscitation requirements and improved blood pressure. This is the first description of a new therapy for patients in refractory shock or in resource-limited settings.

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.

Organ ischemia during partial resuscitative endovascular balloon occlusion of the aorta: Dynamic 4D Computed tomography in swine

Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal pressure, and simultaneously induces distal ischemia. We aimed to evaluate organ ischemia during partial REBOA (P-REBOA) with computed tomography (CT) perfusion in a swine model. The maximum balloon volume was recorded as total REBOA when the distal pulse pressure ceased. The animals (n = 4) were scanned at each 20% of the maximum balloon volume, and time-density curve (TDC) were analysed at the aorta, portal vein (PV), liver parenchyma, and superior mesenteric vein (SMV, indicating mesenteric perfusion). The area under the TDC (AUTDC), the time to peak (TTP), and four-dimensional volume-rendering images (4D-VR) were evaluated. The TDC of the both upper and lower aorta showed an increased peak and delayed TTP. The TDC of the PV, liver, and SMV showed a decreased peak and delayed TTP. The dynamic 4D-CT analysis suggested that organ perfusion changes according to balloon volume. The AUTDC at the PV, liver, and SMV decreased linearly with balloon inflation percentage to the maximum volume. 4D-VR demonstrated the delay of the washout in the aorta and retrograde flow at the inferior vena cava in the highly occluded status.

Total resuscitative endovascular balloon occlusion of the aorta causes inflammatory activation and organ damage within 30 minutes of occlusion in normovolemic pigs

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) causes physiological, metabolic, end-organ and inflammatory changes that need to be addressed for better management of severely injured patients. The aim of this study was to investigate occlusion time-dependent metabolic, end-organ and inflammatory effects of total REBOA in Zone I in a normovolemic animal model.

Methods

Twenty-four pigs (25-35 kg) were randomized to total occlusion REBOA in Zone I for either 15, 30, 60 min (REBOA15, REBOA30, and REBOA60, respectively) or to a control group, followed by 3-h reperfusion. Hemodynamic variables, metabolic and inflammatory response, intraperitoneal and intrahepatic microdialysis, and plasma markers of end-organ injuries were measured during intervention and reperfusion. Intestinal histopathology was performed.

Results

Mean arterial pressure and cardiac output increased significantly in all REBOA groups during occlusion and blood flow in the superior mesenteric artery and urinary production subsided during intervention. Metabolic acidosis with increased intraperitoneal and intrahepatic concentrations of lactate and glycerol was most pronounced in REBOA30 and REBOA60 during reperfusion and did not normalize at the end of reperfusion in REBOA60. Inflammatory response showed a significant and persistent increase of pro- and anti-inflammatory cytokines during reperfusion in REBOA30 and was most pronounced in REBOA60. Plasma concentrations of liver, kidney, pancreatic and skeletal muscle enzymes were significantly increased at the end of reperfusion in REBOA30 and REBOA60. Significant intestinal mucosal damage was present in REBOA30 and REBOA60.

Conclusion

Total REBOA caused severe systemic and intra-abdominal metabolic disturbances, organ damage and inflammatory activation already at 30 min of occlusion.

Resuscitative endovascular balloon occlusion of the aorta induced myocardial injury is mitigated by endovascular variable aortic control

BACKGROUND

The cardiac effects of resuscitative endovascular balloon occlusion of the aorta (REBOA) are largely unknown. We hypothesized that increased afterload from REBOA would lead to cardiac injury, and that partial flow using endovascular variable aortic control (EVAC) would mitigate this injury.

METHODS

Eighteen anesthetized swine underwent controlled 25% blood volume hemorrhage. Animals were randomized to either Zone 1 REBOA, Zone 1 EVAC, or no intervention (control) for 45 minutes. Animals were then resuscitated with shed blood, observed during critical care, and euthanized after a 6-hour total experimental time. Left ventricular function was measured with a pressure-volume catheter, and blood samples were drawn at routine intervals.

RESULTS

The average cardiac output during the intervention period was higher in the REBOA group (9.3 [8.6-15.4] L/min) compared with the EVAC group (7.2 [5.8-8.0] L/min, p = 0.01) and the control group (6.8 [5.8-7.7] L/min, p < 0.01). At the end of the intervention, the preload recruitable stroke work was significantly higher in both the REBOA and EVAC groups compared with the control group (111.2 [102.5-148.6] and 116.7 [116.6-141.4] vs. 67.1 [62.7-87.9], p = 0.02 and p < 0.01, respectively). The higher preload recruitable stroke work was maintained throughout the experiment in the EVAC group, but not in the REBOA group. Serum troponin concentrations after 6 hours were higher in the REBOA group compared with both the EVAC and control groups (6.26 ± 5.35 ng/mL vs 0.92 ± 0.61 ng/mL and 0.65 ± 0.38 ng/mL, p = 0.05 and p = 0.03, respectively). Cardiac intramural hemorrhage was higher in the REBOA group compared with the control group (1.67 ± 0.46 vs. 0.17 ± 0.18, p = 0.03), but not between the EVAC and control groups.

CONCLUSION

In a swine model of hemorrhagic shock, complete aortic occlusion resulted in cardiac injury, although there was no direct decrease in cardiac function. EVAC mitigated the cardiac injury and improved cardiac performance during resuscitation and critical care.

Selective aortic arch perfusion with fresh whole blood or HBOC-201 reverses hemorrhage-induced traumatic cardiac arrest in a lethal model of noncompressible torso hemorrhage

BACKGROUND

Hemorrhage-induced traumatic cardiac arrest (HiTCA) has a dismal survival rate. Previous studies demonstrated selective aortic arch perfusion (SAAP) with fresh whole blood (FWB) improved the rate of return of spontaneous circulation (ROSC) after HiTCA, compared with resuscitative endovascular balloon occlusion of the aorta and cardiopulmonary resuscitation (CPR). Hemoglobin-based oxygen carriers, such as hemoglobin-based oxygen carrier (HBOC)-201, may alleviate the logistical constraints of using FWB in a prehospital setting. It is unknown whether SAAP with HBOC-201 is equivalent in efficacy to FWB, whether conversion from SAAP to extracorporeal life support (ECLS) is feasible, and whether physiologic derangement post-SAAP therapy is reversible.

METHODS

Twenty-six swine (79 ± 4 kg) were anesthetized and underwent HiTCA which was induced via liver injury and controlled hemorrhage. Following arrest, swine were randomly allocated to resuscitation using SAAP with FWB (n = 12) or HBOC-201 (n = 14). After SAAP was initiated, animals were monitored for a 20-minute prehospital period prior to a 40-minute damage control surgery and resuscitation phase, followed by 260 minutes of critical care. Primary outcomes included rate of ROSC, survival, conversion to ECLS, and correction of physiology.

RESULTS

Baseline physiologic measurements were similar between groups. ROSC was achieved in 100% of the FWB animals and 86% of the HBOC-201 animals (p = 0.483). Survival (t = 320 minutes) was 92% (11/12) in the FWB group and 67% (8/12) in the HBOC-201 group (p = 0.120). Conversion to ECLS was successful in 100% of both groups. Lactate peaked at 80 minutes in both groups, and significantly improved by the end of the experiment in the HBOC-201 group (p = 0.001) but not in the FWB group (p = 0.104). There was no significant difference in peak or end lactate between groups.

CONCLUSION

Selective aortic arch perfusion is effective in eliciting ROSC after HiTCA in a swine model, using either FWB or HBOC-201. Transition from SAAP to ECLS after definitive hemorrhage control is feasible, resulting in high overall survival and improvement in lactic acidosis over the study period.

Efficacy of intermittent versus standard resuscitative endovascular balloon occlusion of the aorta in a lethal solid organ injury model

BACKGROUND

High-grade solid organ injury is a major cause of mortality in trauma. Use of resuscitative endovascular balloon occlusion of the aorta (REBOA) can be effective but is limited by ischemia-reperfusion injury. Intermittent balloon inflation/deflation has been proposed as an alternative, but the safety and efficacy prior to operative hemorrhage control is unknown.

METHODS

Twenty male swine underwent standardized high-grade liver injury, then randomization to controls (N = 5), 60-min continuous REBOA (cR, n = 5), and either a time-based (10-minute inflation/3-minute deflation, iRT = 5) or pressure-based (mean arterial pressure<40 during deflation, iRP = 5) intermittent schedule. Experiments were concluded after 120 minutes or death.

RESULTS

Improved overall survival was seen in the iRT group when compared to cR (p < 0.01). Bleeding rate in iRT (5.9 mL/min) was significantly lower versus cR and iRP (p = 0.02). Both iR groups had higher final hematocrit (26% vs. 21%) compared to cR (p = 0.03). Although overall survival was lower in the iRP group, animals surviving to 120 minutes with iRP had decreased end organ injury (Alanine aminotransferase [ALT] 33 vs. 40 in the iRT group, p = 0.03) and lower lactate levels (13 vs. 17) compared with the iRT group (p = 0.03). No differences were seen between groups in terms of coagulopathy based on rotational thromboelastometry.

CONCLUSION

Intermittent REBOA is a potential viable adjunct to improve survival in lethal solid organ injury while minimizing the ischemia-reperfusion seen with full REBOA. The time-based intermittent schedule had the best survival and prolonged duration of tolerable zone 1 placement. Although the pressure-based schedule was less reliable in terms of survival, when effective, it was associated with decreased acidosis and end-organ injury.

Intraoperative REBOA: an analysis of the American Association for the Surgery of Trauma AORTA registry

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a less-invasive technique for aortic occlusion (AO). Commonly performed in the emergency department (ED), the role of intraoperative placement is less defined. We hypothesized that operating room (OR) placement is associated with increased in-hospital mortality.

Methods

The American Association for the Surgery of Trauma AORTA registry was used to identify patients undergoing REBOA. Injury characteristics and outcomes data were compared between OR and ED groups. The primary outcome was in-hospital mortality; secondary outcomes included total AO time, transfusion requirements, and acute kidney injury.

Results

Location and timing of catheter insertion were available for 305 of 321 (95%) subjects. 58 patients underwent REBOA in the OR (19%). There were no differences with respect to sex, admission lactate, and Injury Severity Score. The OR group was younger (33 years vs. 41 years, p=0.01) and with more penetrating injuries (36% vs. 15%, p<0.001). There were significant differences with respect to admission physiology. Time from admission to AO was longer in the OR group (75 minutes vs. 23 minutes, p<0.001) as was time to definitive hemostasis (116 minutes vs. 79 minutes, p=0.01). Unadjusted mortality was lower in the OR group (36.2% vs. 68.8%, p<0.001). There were no differences in secondary outcomes. After controlling for covariates, there was no association between insertion location and in-hospital mortality (OR 1.8, 95% CI 0.30 to 11.50).

Discussion

OR REBOA placement is common and generally employed in patients with more stable admission physiology. OR placement was not associated with increased in-hospital mortality despite longer times to AO and definite hemostasis when compared with catheters placed in the ED.

Level of evidence

IV; therapeutic/care management.

The 10 commandments of exsanguinating pelvic fracture management

Background:

Unstable pelvic fractures are highly lethal injuries.

Objective:

The review aims to summarize the landmark management changes in the past two decades.

Methods:

Structured review based on pertinent published literatures on severe pelvic fracture was performed.

Results:

Ten key management points were identified.

Conclusion:

These 10 recommendations help diminish and prevent the mortality. (1) Before the ABCDE management, preparedness, protection, and decision are essential to optimize patient outcome and to conserve resources. (2) Do not rock the pelvis to check stability, avoid logrolling but prophylactic pelvic binder can be life-saving. (3) Computed tomography scanner can be the tunnel to death for hemodynamically unstable patients. (4) Correct application of pelvic binder at the greater trochanter level to achieve the most effective compression. (5) Choose the suitable binder (BEST does not exist, always look for BETTER) to facilitate body examination and therapeutic intervention. (6) Massive transfusion protocol is only a temporizing measure to sustain the circulation for life maintenance. (7) Damage control operation aims to promptly stop the bleeding to restore the physiology by combating the trauma lethal triad to be followed by definitive anatomical repair. (8) Protocol-driven teamwork management expedites the completion of the multi-phase therapy including external pelvic fixation, pre-peritoneal pelvic packing, and angio-embolization, preceded by laparotomy when indicated. (9) Resuscitation endovascular balloon occlusion of aorta can reduce the pelvic bleeding while awaiting hospital transfer or operation theater access. (10) Operation is the definitive therapy for trauma but prevention is the best treatment, comprising primary, secondary, and tertiary levels.

Colonic ischemia possibly due to resuscitative endovascular balloon occlusion of the aorta (REBOA) used to manage amniotic fluid embolism: a case report

Background

Resuscitative endovascular balloon occlusion of the aorta (REBOA) can control massive postpartum hemorrhage.

Case presentation

A 41-year-old woman transferred to hospital following cesarean section presented in refractory hemorrhagic shock. REBOA was blindly performed in the emergency department. She immediately underwent hysterectomy and damage control surgery in the operating room. The aortic balloon, whose position was confirmed at zone II by postoperative X-ray, provided intermittent occlusion for 40 min during surgery. Hemodynamics were stabilized with these interventions, with massive transfusion required for severe coagulopathy perioperatively. She gradually recovered with intensive care but suffered ascending colon ischemia with perforation on day 16. She received a colostomy and was discharged without sequelae after 130 days. Amniotic fluid embolism was diagnosed according to clinical criteria and supplemental serum markers.

Conclusions

This patient suffered colonic ischemia possibly due to REBOA used to manage amniotic fluid embolism. REBOA requires careful consideration to avoid complications.