Resuscitative Endovascular Balloon Occlusion of the Aorta: A Review for Emergency Clinicians

Dynamic response of the aortic hemodynamic status to endovascular occlusion: A computational fluid dynamics study

The hemodynamic status following occlusion is crucial to the efficacy of resuscitative endovascular balloon occlusion of the aorta (REBOA), but existing information on this topic remains limited. This study clarifies the remodeling effects of REBOA on aortic hemodynamics. A geometric model of the aorta, derived from human imaging, is used to simulate various hemorrhagic scenarios (blood loss = 10 %, 25 %, 35 %, and 40 %) through reductions in cardiac output and increases in heart rate. Fluid-structure interaction simulations are performed to explore the relationship between blood pressure, cerebral perfusion, arterial deformation, and blood loss following thoracic aortic occlusion. The results indicated that, when the cerebral blood flow tolerance is reduced by 50 %, the recommended blood loss range for REBOA use is approximately 23.9-30.8 %, corresponding to an initial blood pressure range of 53-71 mmHg. Blood loss < 16.8 % (>90 mmHg) does not necessitate occlusion, whereas blood loss between 16.8 % and 23.9 % (71-90 mmHg) may lead to supraphysiological blood pressure and excessive arterial wall deformation. Blood loss > 30.8 % (<53 mmHg) impedes the achievement of reasonable pressure levels. These findings suggest that REBOA is effective only within a specific range of blood loss. Exceeding or falling below these thresholds can lead to adverse effects, such as hypertension or hemodynamic instability. These findings hold significant clinical relevance for emergency care.

Tranexamic acid as an adjunct to resuscitative endovascular balloon occlusion of the aorta does not worsen outcomes in a porcine model of hemorrhage

Background

Non-compressible torso hemorrhage (NCTH) represents a leading cause of preventable mortality in trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) stabilizes NCTH but may predispose patients to thrombus generation. REBOA must therefore be prospectively evaluated for coagulation risks with concomitant usage of anti-fibrinolytic tranexamic acid (TXA). Using a porcine model of hemorrhage, it was hypothesized that TXA with REBOA would worsen coagulation outcomes and organ damage.

Materials and methods

Thirty-two male Yorkshire swine underwent 30% blood volume hemorrhage with randomization to vehicle control (VC; normal saline), VC+REBOA, TXA, or TXA+REBOA. At T0, animals received 10 mL/minute of group-specific infusion (GSI) followed at T10 by 500 mL of whole blood (WB), second GSI at 13 mL/hour, and Zone 1 REBOA inflation in REBOA groups. At T40, REBOA was deflated, with additional 500 mL WB, and continuation of GSI for 3 hours. Physiological, coagulation, and inflammatory parameters were measured throughout the protocol, with postmortem histopathology.

Results

After REBOA deflation at T40, lactate was significantly higher for the REBOA groups versus the non-REBOA groups, and pH, bicarbonate, and base excess were all significantly lower than the non-REBOA groups. There were no significant differences observed between groups in coagulation, inflammatory, metabolic, or histopathologic parameters.

Conclusions

Administration of TXA with REBOA did not cause more deleterious coagulation outcomes. All significant changes were expected results of REBOA ischemia, and not attributable to TXA treatment. This suggests NCTH can safely be treated with both hemorrhage control methods without exacerbating clotting outcomes.

Level of evidence

Not applicable-basic animal research.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) in the Field Setting: A Case Report From China

BACKGROUND

The widespread use of agricultural machinery in China has increased the incidence of agricultural machinery-related injuries, posing challenges to on-site medical rescue. This study explores resuscitative endovascular balloon occlusion of the aorta (REBOA) as a life-saving intervention for a patient with severe trauma from agricultural machinery.

CASEPRESENTATION

This study reviews the emergency medical response for a 70-year-old male who suffered machinery entanglement injuries in an agricultural field in western China. The intervention involved a tiered multidisciplinary medical response, including the implementation of REBOA.

CONCLUSION

This case demonstrates the successful use of REBOA in the prehospital setting in China. While prehospital REBOA use is rare, it is increasingly reported in both military and civilian contexts in austere environments in different countries. Further research is required to validate the feasibility and efficacy of REBOA as a prehospital resuscitation strategy.

Electrospun nanofiber membranes for rapid liver hemostasis via N-alkylated chitosan doped chitosan/PEO

The ideal hemostatic agents should be able to stop bleeding quickly and avoid secondary bleeding caused by adhesion with blood clots during dressing change. Herein, a hydrophobic electrospun nanofiber membrane was prepared for achieving hemostasis, rationally targeting both attributes, via doping N-alkylated chitosan (N-CS) grafted with octadecyl into chitosan/polyethylene oxide (PEO). In vitro and in vivo coagulation tests showed that CPNs doped with small amounts of N-CS (CPN31) could significantly shorten hemostasis time and promote the formation of more stable and stronger blood clots. In particular, the whole blood clotting time of CPN31 (58.8 ± 2.2 s) was significantly lower than that of chitosan/PEO (CPN0) nanofiber membrane (67 ± 3.5 s) and the medical sterile gauze (86.7 ± 0.6 s). Furthermore, due to the hemophobic nature of CPNs, blood wetting of the dressing was severely limited and blood can coagulated at the site of liver injury in rats, thus reducing blood loss and allowing rapid removal of the dressing without triggering secondary hemorrhage. The CPN31 exhibited excellent hemostasis properties, easy to remove, blood compatibility, biocompatibility and promoting fibroblast proliferation properties. This hydrophobic CPNs is a promising biological adhesive for hemorrhage control.

Development and usability testing of a fully immersive VR simulation for REBOA training

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a potentially life-saving procedure for bleeding trauma patients. Being a rare and complex procedure performed in extreme situations, repetitive training of REBOA teams is critical. Evidence-based guidelines on how to train REBOA are missing, although simulation-based training has been shown to be effective but can be costly and complex. We aimed to determine the feasibility and acceptance of REBOA training using a fully immersive virtual reality (VR) REBOA simulation, as well as assess the confidence in conducting the REBOA procedure before and after the training.

METHODS

Prospective feasibility pilot study of prehospital emergency physicians and paramedics in Bern, Switzerland, from November 2020 until March 2021. Baseline characteristics of trainees, prior training and experience in REBOA and with VR, variables of media use (usability: system usability scale, immersion/presence: Slater-Usoh-Steed, workload: NASA-TLX, user satisfaction: USEQ) as well as confidence prior and after VR training were accessed.

RESULTS

REBOA training in VR was found to be feasible without relevant VR-specific side-effects. Usability (SUS median 77.5, IQR 71.3-85) and sense of presence and immersion (Slater-Usoh-Steed median 4.8, IQR 3.8-5.5) were good, the workload without under-nor overstraining (NASA-TLX median 39, IQR 32.8-50.2) and user satisfaction high (USEQ median 26, IQR 23-29). Confidence of trainees in conducting REBOA increased significantly after training (p < 0.001).

CONCLUSIONS

Procedural training of the REBOA procedure in immersive virtual reality is possible with a good acceptance and high usability. REBOA VR training can be an important part of a training curriculum, with the virtual reality-specific advantages of a time- and instructor-independent learning.

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.

Comparison of hydroxocobalamin with other resuscitative fluids in volume-controlled and uncontrolled hemorrhage models in swine ( Sus-scrofa )

BACKGROUND

Traumatic hemorrhage is the leading cause of preventable death in military environments. Treatment with resuscitative fluids and blood components is based on availability, thus, frequently unavailable in the prehospital setting, due to lack of resources and costs. Hydroxocobalamin (HOC), increases blood pressure via nitric oxide scavenging. We evaluated HOC as a resuscitation fluid, in two swine hemorrhage models. Our objectives were to (1) evaluate whether HOC treatment following hemorrhagic shock improves hemodynamic parameters and (2) determine whether those effects are comparable to whole blood (WB) and lactated ringers (LR).

METHODS

Yorkshire swine (S us scrofa ) (n = 72) were used in models of controlled hemorrhage (CH) (n = 36) and uncontrolled hemorrhage (UH) (n = 36). Randomized animals received treatment with 500 mL of either WB, LR, HOC (150 mg/kg), followed by a six-hour observation (n = 6 each group). Survival, hemodynamics, blood gases (ABGs) and chemistries were collected. Data reported as mean ± standard error of the mean and statistical analysis by ANOVA ( p < 0.05).

RESULTS

Blood loss for CH was 41% ± 0.02 versus 33% ± 0.07 for UH. For CH, HOC treatment maintained higher systolic blood pressure (sBP, mm Hg) compared with WB and LR (72 ± 1.1; 60 ± 0.8; 58 ± 1.6; respectively). Heart rate (HR), cardiac output (CO), Sp o2 and vascular resistance were comparable with WB and LR. The ABG values were comparable between HOC and WB. For UH, HOC treatment maintained sBP levels comparable to WB and higher than LR (70 ± 0.9; 73 ± 0.5; 56 ± 1.2). HR, CO, Sp o2 , and systemic vascular resistance were comparable between HOC and WB. Survival, hemodynamics, blood gases were comparable between HOC and WB. No survival differences were found between cohorts.

CONCLUSION

Hydroxocobalamin treatment improved hemodynamic parameters and Ca 2+ levels compared with LR and equivalent to WB, in both models. Hydroxocobalamin may be a viable alternative when WB is not available.

Therapeutic Induction of Collateral Flow

Therapeutic induction of collateral flow as a means to salvage tissue and improve outcome from acute ischemic stroke is a promising approach in the era in which endovascular therapy is no longer time-dependent but collateral-dependent. The importance of collateral flow enhancement as a therapeutic for acute ischemic stroke extends beyond those patients with large amounts of salvageable tissue. It also has the potential to extend the time window for reperfusion therapies in patients who are ineligible for endovascular thrombectomy. In addition, collateral enhancement may be an important adjuvant to neuroprotective agents by providing a more robust vascular route for which treatments can gain access to at risk tissue. However, our understanding of collateral hemodynamics, including under comorbid conditions that are highly prevalent in the stroke population, has hindered the efficacy of collateral flow augmentation for improving stroke outcome in the clinical setting. This review will discuss our current understanding of pial collateral function and hemodynamics, including vasoactivity that is critical for enhancing penumbral perfusion. In addition, mechanisms by which collateral flow can be increased during acute ischemic stroke to limit ischemic injury, that may be different depending on the state of the brain and vasculature prior to stroke, will also be reviewed.

Hysteroscopic resection of retained products of conception combined with uterine artery balloon occlusion: A novel case report

Retained products of conception can cause massive bleeding that can be prevented by uterine artery embolization before resection; however, uterine artery balloon occlusion is less invasive. While scattered reports of its use for postpartum hemorrhage exist, no indications have been described. We report a case of hysteroscopic resection of retained products of conception using uterine artery balloon occlusion instead of uterine artery embolization. A 29-year-old woman, gravida 2 para 0, noted an intrauterine mass after an abortion at 7 weeks' gestation. Follow-up visits showed insufficient lowering of human chorionic gonadotropin levels, necessitating surgical treatment. Considering the patient's desire to conceive, we performed uterine artery balloon occlusion to reduce the risk of perinatal complications associated with uterine artery embolization. The operation was completed without complications. The patient conceived spontaneously and had a live baby 7 months after surgery, thus proving the benefits of uterine artery balloon occlusion before hysteroscopic resection.

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.

Difference in postcourse knowledge and confidence between Web-based and on-site training courses on resuscitative endovascular balloon occlusion of the aorta

Aim

Effective courses are essential for highly invasive procedures such as resuscitative endovascular balloon occlusion of the aorta. However, the coronavirus disease pandemic has forced the postponement of on‐site educational courses due to transmission concerns. Few studies have examined the effectiveness of Web‐based education in highly invasive procedures. To address this knowledge gap, this study aimed to investigate whether knowledge acquisition and confidence after the Web‐based course are different from those acquired after the on‐site course, using pre‐ and postcourse test scores.

Methods

The increase in scores before and after the course was compared between the on‐site and Web‐based courses. The questions reflected knowledge about seven different topics in the course modules. In addition, participants were asked about their self‐rated confidence about three topics before and after the course.

Results

Thirty learners completed the on‐site course, and 21 learners completed the Web‐based course. Forty‐seven learners completed both the precourse and postcourse tests. In both courses, the difference between the precourse and postcourse test scores showed a statistically significant increase in knowledge (on‐site course: increased score, 1.8; 95% confidence interval, 0.8 to 2.8; Web‐based course: increased score, 1.6, 95% confidence interval, 0.5 to 2.5). However, the difference was not statistically significant in the self‐rated confidence scores about “sheath and catheter removal” among learners of the Web‐based course.

Conclusion

Knowledge increased significantly in both the on‐site and Web‐based courses. However, the Web‐based course might not be sufficient to give learners confidence in the procedures.

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

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

Is cerebral perfusion maintained during full and partial resuscitative endovascular balloon occlusion of the aorta in hemorrhagic shock conditions?

BACKGROUND

Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is a technology that occludes aortic flow and allows for controlled deflation and restoration of varying distal perfusion. Carotid flow rates (CFRs) during partial deflation are unknown. Our aim was to measure CFR with the different pREBOA balloon volumes and correlate those to the proximal mean arterial pressure (PMAP) and a handheld pressure monitoring device (COMPASS; Mirador Biomedical, Seattle, WA).

METHODS

Ten swine underwent a hemorrhagic injury model with carotid and iliac arterial pressures monitored via arterial lines. Carotid and aortic flow rates were monitored with Doppler flow probes. A COMPASS was placed to monitor proximal pressure. The pREBOA was inflated for 15 minutes then partially deflated for an aortic flow rate of 0.7 L/min for 45 minutes. It was then completely deflated. Proximal mean arterial pressures and CFR were measured, and correlation was evaluated. Correlation between CRF and COMPASS measurements was evaluated.

RESULTS

Carotid flow rate increased 240% with full inflation. Carotid flow rate was maintained at 100% to 150% of baseline across a wide range of partial deflation. After full deflation, CFR transiently decreased to 45% to 95% of baseline. There was strong positive correlation (r > 0.85) between CFR and PMAP after full inflation, and positive correlation with partial inflation (r > 0.7). Carotid flow rate had strong correlation with the COMPASS with full REBOA (r > 0.85) and positive correlation with pREBOA (r > 0.65).

CONCLUSION

Carotid flow rate is increased in a hemorrhagic model during full and partial inflation of the pREBOA and correlates well with PMAP. Carotid perfusion appears maintained across a wide range of pREBOA deflation and could be readily monitored with a handheld portable COMPASS device instead of a standard arterial line setup.

Hemostatic Strategies in Trauma

Bleeding is a leading cause of early death from trauma. Consequently, effective hemostasis can improve the odds of survival after severe traumatic injury. Understanding the pathophysiology of trauma-induced coagulopathy can provide insights into effective strategies to assess and halt hemorrhage. Both physical assessment and appropriate laboratory studies are important in the diagnosis and evaluation of coagulopathy to identify the most effective mechanical and pharmacological strategies to achieve hemostasis. This article uses a case study approach to explore evidence-based techniques to evaluate hemorrhage and strategies to promote hemostasis.

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.

Penetrating injuries of the inferior vena cava

Inferior vena cava (IVC) injuries occur in 0.5-5% of cases of penetrating abdominal injury. Uncommonly encountered in general surgical and trauma practice, they remain extremely lethal despite advances in resuscitation and critical care. Important factors determining treatment outcomes are the hemodynamic status of the patient at presentation, the level and extent of injury, and the presence of associated injuries. Operative approaches and techniques for definitive repair are to be tailored to the condition of the patient, type of injury, and available expertise. In a patient with severe hemodynamic compromise, damage control principles take priority to stop bleeding and save life. The most commonly employed strategies are venorrhaphy or ligation. Retro-hepatic and supra-hepatic caval injuries are particularly challenging in terms of exposure and repair, and are associated with high fatality. Endovascular approaches are being used in select cases with success. This paper reviews in detail the epidemiology, injury patterns, management protocols, and outcomes of IVC injuries due to penetrating abdominal trauma.

Resuscitative endovascular balloon of the aorta is feasible in penetrating chest trauma with major hemorrhage: Proposal of a new institutional deployment algorithm

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging option for hemorrhage control, but its use is limited in scenarios such as penetrating chest trauma. The aim of this study was to describe the use of REBOA as a resuscitative adjunct in these cases with major hemorrhage and to propose a new clinical management algorithm.

METHODS

This was a prospective, observational study conducted at a single Level I trauma center in Colombia. We included all patients older than 14 years with severe trauma who underwent REBOA from January 2015 to December 2019. Patients received REBOA if they were in hemorrhagic shock and were unresponsive to resuscitation.

RESULTS

A total of 56 patients underwent REBOA placement of which 37 had penetrating trauma and 23 had chest trauma. All patients were hemodynamically unstable upon arrival to the emergency department, with a median systolic blood pressure of 69 mm Hg (interquartile range [IQR], 57-90 mm Hg) and median Injury Severity Score was 25 (IQR, 25-41). All REBOAs were deployed and inflated in zone 1, median inflation time was 40 minutes (IQR, 26-55 minutes), and no adverse neurologic outcomes were observed. Fifteen patients had REBOA and a median sternotomy. Eleven patients had concomitant abdominal wounds. Overall mortality was 28.6%, and there was no significant difference between penetrating versus blunt trauma patients (21.6% vs. 42.1%, p = 0.11). The survival rate of thoracic injured patients was similar to the predicted survival (65.2% vs. 63.3%).

CONCLUSION

Resuscitative endovascular balloon occlusion of the aorta can be used safely in penetrating chest trauma, and the implementation of a REBOA management algorithm is feasible with a well-trained multidisciplinary team.

LEVEL OF EVIDENCE

Therapeutic, level V.