Arterial Access Complications Following Percutaneous Femoral Access in 24-Hour Resuscitative Endovascular Balloon Occlusion of the Aorta Survivors

INTRODUCTION

With the use of resuscitative endovascular balloon occlusion of the aorta (REBOA) comes the potential for vascular access site complications (VASCs) and limb ischemic sequelae. We aimed to determine the prevalence of VASC and associated clinical and technical factors.

METHODS

A retrospective cohort analysis of 24-h survivors undergoing percutaneous REBOA via the femoral artery in the American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute care surgery registry between Oct 2013 and Sep 2021 was performed. The primary outcome was VASC, defined as at least one of the following: hematoma, pseudoaneurysm, arteriovenous fistula, arterial stenosis, or the use of patch angioplasty for arterial closure. Associated clinical and procedural variables were examined. Data were analyzed using Fisher exact test, Mann-Whitney-U tests, and linear regression.

RESULTS

There were 34 (7%) cases with VASC among 485 meeting inclusion criteria. Hematoma (40%) was the most common, followed by pseudoaneurysm (26%) and patch angioplasty (21%). No differences in demographics or injury/shock severity were noted between cases with and without VASC. The use of ultrasound (US) was protective (VASC, 35% versus no VASC, 51%; P = 0.05). The VASC rate in US cases was 12/242 (5%) versus 22/240 (9.2%) without US. Arterial sheath size >7 Fr was not associated with VASC. US use increased over time (R2 = 0.94, P < 0.001) with a stable rate of VASC (R2 = 0.78, P = 0.61). VASC were associated with limb ischemia (VASC, 15% versus no VASC, 4%; P = 0.006) and arterial bypass procedures (VASC 3% versus no VASC 0%; P < 0.001) but amputation was uncommon (VASC, 3% versus no VASC, 0.4%; P = 0.07).

CONCLUSIONS

Percutaneous femoral REBOA had a 7% VASC rate which was stable over time. VASC are associated with limb ischemia but need for surgical intervention and/or amputation is rare. The use of US-guided access appears to be protective against VASC and is recommended for use in all percutaneous femoral REBOA procedures.

Investigating the variability in pressure-volume relationships during hemorrhage and aortic occlusion

Introduction

The pressure-volume (P-V) relationships of the left ventricle are the classical benchmark for studying cardiac mechanics and pumping function. Perturbations in the P-V relationship (or P-V loop) can be informative and guide the management of heart failure, hypovolemia, and aortic occlusion. Traditionally, P-V loop analyses have been limited to a single-beat P-V loop or an average of consecutive P-V loops (e.g., 10 cardiac cycles). While there are several algorithms to obtain single-beat estimations of the end-systolic and end-diastolic pressure-volume relations (i.e., ESPVR and EDPVR, respectively), there remains a need to better evaluate the variations in P-V relationships longitudinally over time. This is particularly important when studying acute and transient hemodynamic and cardiac events, such as active hemorrhage or aortic occlusion. In this study, we aim to investigate the variability in P-V relationships during hemorrhagic shock and aortic occlusion, by leveraging on a previously published porcine hemorrhage model.

Methods

Briefly, swine were instrumented with a P-V catheter in the left ventricle of the heart and underwent a 25% total blood volume hemorrhage over 30 min, followed by either Zone 1 complete aortic occlusion (i.e., REBOA), Zone 1 endovascular variable aortic control (EVAC), or no occlusion as a control, for 45 min. Preload-independent metrics of cardiac performance were obtained at predetermined time points by performing inferior vena cava occlusion during a ventilatory pause. Continuous P-V loop data and other hemodynamic flow and pressure measurements were collected in real-time using a multi-channel data acquisition system.

Results

We developed a custom algorithm to quantify the time-dependent variance in both load-dependent and independent cardiac parameters from each P-V loop. As expected, all pigs displayed a significant decrease in the end-systolic pressures and volumes (i.e., ESP, ESV) after hemorrhage. The variability in response to hemorrhage was consistent across all three groups. However, upon introduction of REBOA, we observed significantly high levels of variability in both load-dependent and independent cardiac metrics such as ESP, ESV, and the slope of ESPVR (Ees). For instance, pigs receiving REBOA experienced a 342% increase in ESP from hemorrhage, while pigs receiving EVAC experienced only a 188% increase. The level of variability within the EVAC group was consistently less than that of the REBOA group, which suggests that the EVAC group may be more supportive of maintaining healthier cardiac performance than complete occlusion with REBOA.

Discussion

In conclusion, we successfully developed a novel algorithm to reliably quantify the single-beat and longitudinal P-V relations during hemorrhage and aortic occlusion. As expected, hemorrhage resulted in smaller P-V loops, reflective of decreased preload and afterload conditions; however, the cardiac output and heart rate were preserved. The use of REBOA and EVAC for 44 min resulted in the restoration of baseline afterload and preload conditions, but often REBOA exceeded baseline pressure conditions to an alarming level. The level of variability in response to REBOA was significant and could be potentially associated to cardiac injury. By quantifying each P-V loop, we were able to capture the variability in all P-V loops, including those that were irregular in shape and believe that this can help us identify critical time points associated with declining cardiac performance during hemorrhage and REBOA use.

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.

Ultrasound Localization of Resuscitative Endovascular Balloon Occlusion of the Aorta in a Human Cadaver Model

OBJECTIVE

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a method of gaining proximal control of noncompressible torso hemorrhage (NCTH). Catheter placement is traditionally confirmed with fluoroscopy, but few studies have evaluated whether ultrasound (US) can be used.

METHODS

Using a pressurized human cadaver model, a certified REBOA placer was shown one of four randomized cards that instructed them to place the REBOA either correctly or incorrectly in Zone 1 (the distal thoracic aorta extending from the celiac artery to the left subclavian artery) or Zone 3 (in the distal abdominal aorta, from the aortic bifurcation to the lowest renal artery). Once the REBOA was placed, 10 US-trained locators were asked to confirm balloon placement via US. The participants were given 3 minutes to determine whether the catheter had been correctly placed, repeating this 20 times on two cadavers.

RESULTS

Overall, US exhibited an average sensitivity of 83%, specificity of 76%, and accuracy of 80%. For Zone 1, US showed a sensitivity of 78% and specificity of 83%, and for Zone 3, a sensitivity of 88% and specificity of 76%. In addition, US exhibited a likelihood positive ratio (LR+) of 3.73 and a likelihood negative ratio (LR-) of 0.22 for either position, with similar numbers for Zone 1 (+4.57, -0.26) and Zone 3 (+3.16, -0.16).

CONCLUSION

Ultrasound could prove to be a useful tool for confirming placement of a REBOA catheter, especially in austere environments.

Efficacy of resuscitative endovascular balloon occlusion of the aorta for hemorrhage control in patients with abnormally invasive placenta: a historical cohort study

BACKGROUND

Patients with abnormally invasive placenta (AIP) are at high risk of massive postpartum hemorrhage. Resuscitative endovascular balloon occlusion of the aorta (REBOA), as an adjunct therapeutic strategy for hemostasis, offers the obstetrician an alternative for treating patients with AIP. This study aimed to evaluate the role of REBOA in hemorrhage control in patients with AIP.

METHODS

This was a historical cohort study with prospectively collected data between January 2014 to July 2021 at a single tertiary center. According to delivery management, 364 singleton pregnant AIP patients desiring uterus preservation were separated into two groups. The study group (balloon group, n = 278) underwent REBOA during cesarean section, whereas the reference group (n = 86) did not undergo REBOA. Surgical details and maternal outcomes were collected. The primary outcome was estimated blood loss and the rate of uterine preservation.

RESULTS

A total of 278 (76.4%) participants experienced REBOA during cesarean section. The patients in the balloon group had a smaller blood loss during cesarean Sect. (1370.5 [752.0] ml vs. 3536.8 [1383.2] ml; P < .001) and had their uterus salvaged more often (264 [95.0%] vs. 23 [26.7%]; P < .001). These patients were also less likely to be admitted to the intensive care unit after delivery (168 [60.4%] vs. 67 [77.9%]; P = .003) and had a shorter operating time (96.3 [37.6] min vs. 160.6 [45.5] min; P < .001). The rate of neonatal intensive care unit admission (176 [63.3%] vs. 52 [60.4%]; P = .70) and total maternal medical costs ($4925.4 [1740.7] vs. $5083.2 [1705.1]; P = .13) did not differ between the two groups.

CONCLUSIONS

As a robust hemorrhage-control technique, REBOA can reduce intraoperative hemorrhage in patients with AIP. The next step is identifying associated risk factors and defining REBOA inclusion criteria to identify the subgroups of AIP patients who may benefit more.

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.

REBOA Zone Estimation from the Body Surface Using Semantic Segmentation

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an endovascular procedure for hemorrhage control. In REBOA, the balloon must be placed in the precise place, but it may be performed without X-ray fluoroscopy. This study aimed to estimate the REBOA zones from the body surface using deep learning for safe balloon placement. A total of 198 abdominal computed tomography (CT) datasets containing the regions of the REBOA zones were collected from open data libraries. Then, depth images of the body surface generated from the CT datasets and the images corresponding to the zones were labeled for deep learning training and validation. DeepLabV3+, a deep learning semantic segmentation model, was employed to estimate the zones. We used 176 depth images as training data and 22 images as validation data. A nine-fold cross-validation was performed to generalize the performance of the network. The median Dice coefficients for Zones 1-3 were 0.94 (inter-quarter range: 0.90-0.96), 0.77 (0.60-0.86), and 0.83 (0.74-0.89), respectively. The median displacements of the zone boundaries were 11.34 mm (5.90-19.45), 11.40 mm (4.88-20.23), and 14.17 mm (6.89-23.70) for the boundary between Zones 1 and 2, between Zones 2 and 3, and between Zone 3 and out of zone, respectively. This study examined the feasibility of REBOA zone estimation from the body surface only using deep learning-based segmentation without aortography.

Do we need pre-hospital resuscitative endovascular balloon occlusion of the aorta (REBOA) in the civilian helicopter emergency medical services (HEMS)?

Pre-hospital resuscitative endovascular balloon occlusion of the aorta (REBOA) can be a life-saving procedure for patients with non-compressible torso hemorrhage. We aimed to evaluate the potential eligibility for REBOA in trauma patients of a civilian helicopter emergency medical service (HEMS) using a stepwise approach. A retrospective analysis using the electronic database (HEMSDER) of "DRF Luftrettung" HEMS covering the period from January 2015 to June 2021 was performed. Trauma patients aged ≥ 16 years and with a National Advisory Committee for Aeronautics (NACA) score of ≥ 4 were assessed for potential REBOA eligibility using two different decision trees based on assumed severe bleeding due to injuries of the abdomen, pelvis, and/or lower extremities and different vital signs on the scene and at hospital handover. Non-parametric statistical methods were used for comparison. A total of 22.426 patients met the inclusion criteria for data analysis. Of these, 0.15-2.24% were possible candidates for pre-hospital REBOA. No significant differences between groups on scene and at hospital handover regarding demographics, assumed injuries, and pre-hospital interventions were found. In the on-scene group, 21.1% of the patients remained unstable even at hospital handover despite pre-hospital care. In the handover group, 42.8% of the patients seemed initially stable but then deteriorated during the pre-hospital course. The number of potential pre-hospital REBOA in severely injured patients with a NACA score of ≥ 4 is < 3% or can be even < 1% if more strict criteria are used. There are some patients who may benefit from pre-hospital REBOA as a life-saving procedure. Further research on earlier diagnosis of life-threatening bleeding and proper indications of REBOA in trauma patients is needed.

Case report: Resuscitative endovascular balloon occlusion after iatrogenic injury of the common iliac artery during neurosurgical dorsal lumbar microdiscectomy

Introduction and importance

This case report describes resuscitative endovascular balloon occlusion (REBOA) of the aorta in a patient with life-threatening iatrogenic bleeding of the right common iliac artery during elective dorsal lumbar spine surgery. REBOA is an emergency procedure for temporary intra-aortic balloon occlusion being increasingly reported and published since its inauguration in 1954. The interdisciplinary management of hemorrhage and technical notes for a successful REBOA procedure will be presented.

Case presentation

A 53-year-old female patient was admitted to the neurosurgery clinic suffering from left-sided L5 radiculopathy. During surgery, the anterior longitudinal ligament was perforated and an arterial vessel was lacerated. The patient became hemodynamically unstable demanding prompt supine repositioning and cardiopulmonary resuscitation (CPR). REBOA enabled cardiovascular stabilization after 90 min of CPR and laparotomy with vascular reconstruction and contributed to the survival of the patient without major clinical deficits. The patient was discharged from the ICU after 7 days.

Clinical discussion

Resuscitative endovascular balloon occlusion of the aorta is an emergency procedure to control life-threatening hemorrhage. REBOA should be available on-scene and applied by well-trained vascular surgery personnel to control vascular complications or extend to emergency laparotomy and thoracotomy with aortic cross-clamping in case of in-hospital non-controllable hemorrhages. In case of ongoing CPR, we recommend surgical groin incision, open puncture of the pulseless common femoral artery, and aortic balloon inflation in REBOA zone I. Hereby, fast access and CPR optimization for heart and brain perfusion are maintained.

Conclusion

Training for REBOA is the decisive factor to control selected cases of in-house and outpatient massive arterial abdominal bleeding complications.

Worse outcomes with resuscitative endovascular balloon occlusion of the aorta in severe pelvic fracture: A matched cohort study

BACKGROUND

Severe pelvic fracture is the most common indication for resuscitative endovascular balloon occlusion of the aorta (REBOA). This matched cohort study investigated outcomes with or without REBOA use in isolated severe pelvic fractures.

METHODS

Trauma Quality Improvement Program database study, included patients with isolated severe pelvic fracture (AIS≥3), excluded associated injuries with AIS >3 for any region other than lower extremity. REBOA patients were propensity score matched to similar patients without REBOA. Outcomes were mortality and complications.

RESULTS

93 REBOA patients were matched with 279 without. REBOA patients had higher rates of in-hospital mortality (32.3% vs 19%, p = 0.008), higher rates of venous thromboembolism (14% vs 6.5%, p = 0.023) and DVT (11.8% vs 5.4%, p = 0.035). In multivariate analysis, REBOA use was independently associated with increased mortality and venous thromboembolism.

CONCLUSIONS

REBOA in severe pelvic fractures is associated with higher rates of mortality, venous thromboembolism.

REBOA: Expanding Applications From Traumatic Hemorrhage to Obstetrics and Cardiopulmonary Resuscitation, From the AJR Special Series on Emergency Radiology

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has emerged over the past decade as a technique to control life-threatening hemorrhage and treat hemorrhagic shock, being increasingly used to treat noncompressible traumatic torso hemorrhage. Reports during this time also support the use of a REBOA device for an expanding range of indications including nontraumatic abdominal hemorrhage, postpartum hemorrhage, placenta accreta spectrum (PAS) disorder, and cardiopulmonary resuscitation (CPR). The strongest available evidence supports REBOA as a lifesaving adjunct to definitive surgical management in trauma and as a method to help avoid hysterectomy in select patients with postpartum hemorrhage or PAS disorder. In comparison with initial descriptions of complete REBOA inflation, techniques for partial REBOA inflation have been introduced to achieve hemodynamic stability while minimizing adverse events relating to reperfusion injuries. Fluoroscopy-free REBOA has been described in various settings, including trauma, obstetrics, and out-of-hospital cardiac arrest. As the use of REBOA expands outside the trauma setting and into nontraumatic abdominal hemorrhage, obstetrics, and CPR, it is imperative for radiologists to become familiar with this technology, its proper placement, and its potential adverse sequelae.

TEE guided REBOA deflation following ROSC for non-traumatic cardiac arrest

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is most commonly used to manage non-compressible torso hemorrhage. It is also emerging as a promising treatment for non-traumatic refractory cardiac arrest. Aortic occlusion during chest compressions increases cardio-cerebral perfusion, increasing the potential for sustained return of spontaneous circulation (ROSC) or serving as a bridge to extracorporeal cardiopulmonary resuscitation (ECPR). Optimal patient selection and post-ROSC management in such cases is uncertain and not well reported in the literature. We present a case of non-traumatic out-of-hospital cardiac arrest in which REBOA was placed in the emergency department with subsequent ROSC. Transesophageal echocardiography was used to guide post-ROSC REBOA management and balloon deflation.

A comparison of mortality and indicators of treatment success of resuscitative endovascular balloon occlusion of aorta (REBOA): a systematic review and meta-analysis

Background

Emergency resuscitative thoracotomy (RT) is a recognised method of controlling non-compressible torso haemorrhage (NCTH) often in adjunct to emergency surgery. Recently, there is much debate regarding resuscitative endovascular balloon occlusion of aorta (REBOA) on its role in civilian trauma cases in controlling NCTH. This study aims to provide an updated review on in-hospital mortality rates in patients who underwent REBOA versus RT and standard care without REBOA (non-REBOA) and to identify the potential indicators of REBOA survival.

Methods

Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were used to perform the study. All adult trauma cases were included, while pre-hospital, military and non-English studies were excluded. A literature search was done on studies from 01 January 2005 to 30 June 2020 using EMBASE, MEDLINE and COCHRANE databases. Risk of bias was assessed using the Methodological Index for Non-Randomised Studies (MINORS) tool. Meta-analysis was conducted using a random effects model and the DerSimonian and Laird estimation method. A significance level of p < 0.05 was used.

Results

Twenty-five studies were included in this study. The odds of in-hospital mortality of patients who underwent REBOA compared to RT was 0.18 (p < 0.01, 0.12-0.26). The odds of in-hospital survival of patients who underwent REBOA compared to non-REBOA was 1.28 (p = 0.62, 0.46-3.53). There was a significant difference found between survivors and non-survivors in terms of their pre-REBOA systolic blood pressure (SBP) (19.26 mmHg, p < 0.01), post-REBOA SBP (20.73 mmHg, p < 0.01), duration of aortic occlusion (- 40.57 min, p < 0.01) and injury severity score (- 8.50, p < 0.01).

Conclusions

REBOA has a potential for wider application in civilian settings, with our study demonstrating lower in-hospital mortality compared to RT. Prospective multi-centre studies are needed for further evaluation of the indications and feasibility of REBOA.Level of Evidence + Study Type: Level IV. Systematic review with meta-analysis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-022-01413-3.

Commonly performed pelvic binder modifications for femoral access may hinder binder efficacy

BACKGROUND

Pelvic fractures are common and potentially life-threatening. Pelvic circumferential compression devices (PCCD) can temporize hemorrhage, but more invasive strategies that involve femoral access may be necessary for definitive treatment. The aim of our study was to evaluate the efficacy of PCCDs reducing open book pelvic fractures when utilizing commonly described modifications and placement adjustments that allow for access to the femoral vasculature.

METHODS

Open book pelvic fractures were created in adult cadavers. Three commercially available PCCDs were used to reduce fractures. The binders were properly placed, moved caudally, or moved cranially and modified. Fracture reduction rates were then recorded.

RESULTS

The pelvic fracture was completely reduced with every PCCD tested when properly placed. Reduction rates decreased with improper placement and modifications.

CONCLUSION

Modifying PCCD placement to allow femoral access decreased the effectiveness of these devices Clinicians should be aware of this possibility when caring for critically injured trauma patients with pelvic fractures.

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

Background

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

Emergency department initiated resuscitative endovascular balloon occlusion of the aorta (REBOA) for out-of-hospital cardiac arrest is feasible and associated with improvements in end-tidal carbon dioxide

Objectives

Out-of-hospital cardiac arrest (OHCA) claims the lives of approximately 350,000 people in the United States each year. Resuscitative endovascular balloon occlusion of the aorta (REBOA) when used as an adjunct to advanced cardiac life support may improve cardio-cerebral perfusion. Our primary research objective was to determine the feasibility of emergency department (ED)-initiated REBOA for OHCA patients in an academic urban ED.

Methods

This was a single-center, single-arm, early feasibility trial that used REBOA as an adjunct to advanced cardiac life support (ACLS) in OHCA. Subjects under 80 years with witnessed OHCA and who received cardiopulmonary rescuitation (CPR) within 6 minutes were eligible.

Results

Five patients were enrolled between February 2020 and April 2021. The procedure was successful in all patients and 4 of 5 (80%) patients had transient return of spontaneous circulation (ROSC) after aortic occlusion. Unfortunately, all patients re-arrested soon after intra-aortic balloon deflation and none survived to hospital admission. At 30 seconds post-aortic occlusion, investigators noted a statistically significant increase in end tidal carbon dioxide of 26% (95% confidence interval, 10%, 44%).

Conclusion

Initiating REBOA for OHCA patients in an academic urban ED setting is feasible. Aortic occlusion during chest compressions is temporally associated with improvements in end tidal carbon dioxide 30 seconds after aortic occlusion. Four of 5 patients achieved ROSC after aortic occlusion; however, deflation of the intra-aortic balloon quickly led to re-arrest and death in all patients. Future research should focus on the utilization of partial-REBOA to prevent re-arrest after ROSC, as well as the optimal way to incorporate this technique with other endovascular reperfusion strategies.

Unmasking the Confounder: The Inherent Physiologic Variability of Swine During an Automated Experimental Model of Ischemia-Reperfusion Injury

BACKGROUND

We sought to determine the magnitude of the inherent inter-animal physiologic variability by automating a porcine Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) protocol to minimize external influences that might alter physiology and confound experimental results.

METHODS

Swine (n = 42) underwent a controlled 30% blood volume hemorrhage followed by 30 minutes of REBOA (ie, ischemic phase). The animals were weaned from REBOA autonomously over 15 minutes, beginning the reperfusion phase, while continuing to provide partial flow balloon support to maintain a target proximal mean arterial pressure (pMAP) of 65 mmHg. Simultaneously, shed blood was re-transfused as part of the resuscitation efforts. Physiologic data were continuously recorded, and serum samples were serially collected. Baseline characteristics, variance in vital signs, and 8-isoprostane levels were quantified during hemorrhage, REBOA, and reperfusion phases.

RESULTS

There was no significant difference in baseline physiology across animals (P > .05). Hemodynamic variability was highest for pMAP during the ischemic phase (P = .001) and for distal mean arterial pressure (dMAP) during the weaning/reperfusion phase (P = .001). The latter finding indicated the variable physiologic response to ischemia-reperfusion injury, as the automated balloon support required by each animal to maintain pMAP was highly variable. Circulating 8-isoprostane variance was significantly higher following the start of reperfusion compared to baseline levels (P = .001).

DISCUSSION

Despite subjecting animals to a highly consistent ischemia-reperfusion injury through automation, we noted significant variability in the hemodynamic and biochemical response. These findings illustrate the inherent physiologic variability and potential limitations of porcine large animal models for the study of shock.

Comparison of aortic zones for endovascular bleeding control: age and sex differences

PURPOSE

To gain insight into anatomical variations between sexes and different age groups in intraluminal distances and anatomical landmarks for correct insertion of resuscitative endovascular balloon occlusion of the aorta (REBOA) without fluoroscopic confirmation.

MATERIALS

All non-trauma patients receiving a computed tomography angiography (CT-A) scan of the aorta, iliac bifurcation and common femoral arteries from 2017 to 2019 were eligible for inclusion.

METHODS

Central luminal line distances from the common femoral artery (CFA) to the aortic occlusion zones were measured and diameters of mid zone I, II and III were registered. Anatomical landmarks and correlations were assessed. A simulated REBOA placement was performed using the Joint Trauma System Clinical Practice Guideline (JTSCPG).

RESULTS

In total, 250 patients were included. Central luminal line (CLL) measurements from mid CFA to aortic bifurcation (p = 0.000), CLL measurements from CFA to mid zone I, II and III (p = 0.000) and zone I length (p = 0.000) showed longer lengths in men. The length of zone I and III (p = 0.000), CLL distance measurements from the right CFA to mid zone I (p = 0.000) and II (p = 0.013) and aortic diameters measured at mid zone I, II and III increased in higher age groups (p = 0.000). Using the JTSCPG guideline, successful deployment occurred in 95/250 (38.0%) in zone III and 199/250 (79.6%) in zone I. Correlation between mid-sternum and zone I is 100%. Small volume aortic occlusion balloons (AOB) have poor occlusion rates in zone I (0-2.8%) and III (4.4-34.4%).

CONCLUSIONS

Men and older age groups have longer CLL distances to zone I and III and introduction depths of AOB must be adjusted. The risk of not landing in zone III with standard introduction depths is high and balloon position for zone III REBOA is preferably confirmed using fluoroscopy. Mid-sternum can be used as a landmark in all patient groups for zone I. In older patients, balloon catheters with larger inflation volumes must be considered for aortic occlusion.

The Effects of Increasing Aortic Occlusion Times at the Level of the Highest Renal Artery (Zone II) in the Normovolemic Rabbit Model

PURPOSE

The purpose of this study was to evaluate the effects of increasing zone II resuscitative endovascular balloon occlusion of the aorta (REBOA) occlusion times on physiological, end-organ and inflammatory responses in rabbits to assess the safe aortic occlusion time in a normovolemic rabbit model.

METHODS

The zone ll aorta was occluded with a balloon in 32 rabbits (8 animals each for 15, 30, 60, and 90 min). 8 rabbits served as a control. ELISAs were used to examine the serum levels of ALT, AST, Cr, BUN, MDA, SOD, IL-8, IL-6, and TNF-α; HE staining was used to identify the morphological changes in the kidney; RT-PCR was used to detect the mRNA levels of IL-6, IL-8, TNF-α and NF-κB in the kidney and uterus; and Western blotting was used to measure the protein expression levels of IL-6, IL-8, TNF-α and NF-κB in the kidney and uterus.

RESULTS

Plasma concentrations of liver markers, kidney markers, inflammatory factors and oxidative stress indicators were significantly increased at the end of reperfusion in the 30 min, 60 min and 90 min groups. Damage to the kidney occurred in the 30 min, 60 min and 90 min groups. The mRNA and protein expression levels of IL-6, IL-8, TNF-α and NF-κB in the kidney and uterus were significantly increased at the end of reperfusion in the 30 min group, and as the time of occlusion extended, these levels continued to increase.

CONCLUSION

Activation of systemic inflammation and ischaemia-reperfusion injury of end-organs occurred when the occlusion time reached 30 min. Therefore, 15 min should be regarded as a safe period of REBOA in zone II.

Survival benefit for pelvic trauma patients undergoing Resuscitative Endovascular Balloon Occlusion of the Aorta: Results of the AAST Aortic Occlusion for Resuscitation in Trauma Acute Care Surgery (AORTA) Registry

BACKGROUND

Aortic occlusion (AO) to facilitate the acute resuscitation of trauma and acute care surgery patients in shock remains a controversial topic. Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is an increasingly deployed method of AO. We hypothesized that in patients with non-compressible hemorrhage below the aortic bifurcation, the use of REBOA instead of open AO may be associated with a survival benefit.

METHODS

From the AAST Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) registry, we identified 1494 patients requiring AO from 45 Level I and 4 Level II trauma centers. Presentation, intervention, and outcome variables were analyzed to compare REBOA vs open AO in patients with non-compressible hemorrhage below the aortic bifurcation.

RESULTS

From December 2014 to January 2019, 217 patients with Zone 3 REBOA or Open AO who required pelvic packing, pelvic fixation or pelvic angio-embolization were identified. Of these, 109 AO patients had injuries isolated to below the aortic bifurcation (REBOA, 84; open AO, 25). Patients with intra-abdominal or thoracic sources of bleeding, above deployment Zone 3 were excluded. Overall mortality was lower in the REBOA group (35.% vs 80%, p <.001). Excluding patients who arrived with CPR in progress, the REBOA group had lower mortality (33.33% vs. 68.75%, p = 0.012). Of the survivors, systemic complications were not significantly different between groups. In the REBOA group, 16 patients had complications secondary to vascular access. Intensive care lengths of stay and ventilator days were both significantly shorter in REBOA patients who survived to discharge.

CONCLUSIONS

This study compared outcomes for patients with hemorrhage below the aortic bifurcation treated with REBOA to those treated with open AO. Survival was significantly higher in REBOA patients compared to open AO patients, while complications in survivors were not different. Given the higher survival in REBOA patients, we conclude that REBOA should be used for patients with hemorrhagic shock secondary to pelvic trauma instead of open AO.

LEVEL III EVIDENCE

Therapeutic.

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.