Small changes, big effects: The hemodynamics of partial and complete aortic occlusion to inform next generation resuscitation techniques and technologies

INVESTIGATING THE RELATIONSHIP BETWEEN BLEEDING, CLOTTING, AND COAGULOPATHY DURING AUTOMATED PARTIAL REBOA STRATEGIES IN A HIGHLY LETHAL PORCINE HEMORRHAGE MODEL

ABSTRACT

Background: Death due to hemorrhagic shock, particularly, noncompressible truncal hemorrhage, remains one of the leading causes of potentially preventable deaths. Automated partial and intermittent resuscitative endovascular balloon occlusion of the aorta (i.e., pREBOA and iREBOA, respectively) are lifesaving endovascular strategies aimed to achieve quick hemostatic control while mitigating distal ischemia. In iREBOA, the balloon is titrated from full occlusion to no occlusion intermittently, whereas in pREBOA, a partial occlusion is maintained. Therefore, these two interventions impose different hemodynamic conditions, which may impact coagulation and the endothelial glycocalyx layer. In this study, we aimed to characterize the clotting kinetics and coagulopathy associated with iREBOA and pREBOA, using thromboelastography (TEG). We hypothesized that iREBOA would be associated with a more hypercoagulopathic response compared with pREBOA due to more oscillatory flow. Methods: Yorkshire swine (n = 8/group) were subjected to an uncontrolled hemorrhage by liver transection, followed by 90 min of automated pREBOA, iREBOA, or no balloon support (control). Hemodynamic parameters were continuously recorded, and blood samples were serially collected during the experiment (i.e., eight key time points: baseline (BL), T0, T10, T30, T60, T90, T120, T210 min). Citrated kaolin heparinase assays were run on a TEG 5000 (Haemonetics, Niles, IL). General linear mixed models were employed to compare differences in TEG parameters between groups and over time using STATA (v17; College Station, TX), while adjusting for sex and weight. Results: As expected, iREBOA was associated with more oscillations in proximal pressure (and greater magnitudes of peak pressure) because of the intermittent periods of full aortic occlusion and complete balloon deflation, compared to pREBOA. Despite these differences in acute hemodynamics, there were no significant differences in any of the TEG parameters between the iREBOA and pREBOA groups. However, animals in both groups experienced a significant reduction in clotting times (R time: P < 0.001; K time: P < 0.001) and clot strength (MA: P = 0.01; G: P = 0.02) over the duration of the experiment. Conclusions: Despite observing acute differences in peak proximal pressures between the iREBOA and pREBOA groups, we did not observe any significant differences in TEG parameters between iREBOA and pREBOA. The changes in TEG profiles were significant over time, indicating that a severe hemorrhage followed by both pREBOA and iREBOA can result in faster clotting reaction times (i.e., R times). Nevertheless, when considering the significant reduction in transfusion requirements and more stable hemodynamic response in the pREBOA group, there may be some evidence favoring pREBOA usage over iREBOA.

Prehospital Partial Resuscitative Endovascular Balloon Occlusion of the Aorta for Exsanguinating Subdiaphragmatic Hemorrhage

Importance

Hemorrhage is the most common cause of preventable death after injury. Most deaths occur early, in the prehospital phase of care.

Objective

To establish whether prehospital zone 1 (supraceliac) partial resuscitative endovascular balloon occlusion of the aorta (Z1 P-REBOA) can be achieved in the resuscitation of adult trauma patients at risk of cardiac arrest and death due to exsanguination.

Design, Setting, and Participants

This was a prospective observational cohort study (Idea, Development, Exploration, Assessment and Long-term follow-up [IDEAL] 2A design) with recruitment from June 2020 to March 2022 and follow-up until discharge from hospital, death, or 90 days evaluating a physician-led and physician-delivered, urban prehospital trauma service in the Greater London area. Trauma patients aged 16 years and older with suspected exsanguinating subdiaphragmatic hemorrhage, recent or imminent hypovolemic traumatic cardiac arrest (TCA) were included. Those with unsurvivable injuries or who were pregnant were excluded. Of 2960 individuals attended by the service during the study period, 16 were included in the study.

Exposures

ZI REBOA or P-REBOA.

Main Outcomes and Measures

The main outcome was the proportion of patients in whom Z1 REBOA and Z1 P-REBOA were achieved. Clinical end points included systolic blood pressure (SBP) response to Z1 REBOA, mortality rate (1 hour, 3 hours, 24 hours, or 30 days postinjury), and survival to hospital discharge.

Results

Femoral arterial access for Z1 REBOA was attempted in 16 patients (median [range] age, 30 [17-76] years; 14 [81%] male; median [IQR] Injury Severity Score, 50 [39-57]). In 2 patients with successful arterial access, REBOA was not attempted due to improvement in clinical condition. In the other 14 patients (8 [57%] of whom were in traumatic cardiac arrest [TCA]), 11 successfully underwent cannulation and had aortic balloons inflated in Z1. The 3 individuals in whom cannulation was unsuccessful were in TCA (failure rate = 3/14 [21%]). Median (IQR) pre-REBOA SBP in the 11 individuals for whom cannulation was successful (5 [46%] in TCA) was 47 (33-52) mm Hg. Z1 REBOA plus P-REBOA was associated with a significant improvement in BP (median [IQR] SBP at emergency department arrival, 101 [77-107] mm Hg; 0 of 10 patients were in TCA at arrival). The median group-level improvement in SBP from the pre-REBOA value was 52 (95% CI, 42-77) mm Hg (P < .004). P-REBOA was feasible in 8 individuals (8/11 [73%]) and occurred spontaneously in 4 of these. The 1- and 3-hour postinjury mortality rate was 9% (1/11), 24-hour mortality was 27% (3/11), and 30-day mortality was 82% (9/11). Survival to hospital discharge was 18% (2/11). Both survivors underwent early Z1 P-REBOA.

Conclusions and Relevance

In this study, prehospital Z1 P-REBOA is feasible and may enable early survival, but with a significant incidence of late death.

Trial Registration

ClinicalTrials.gov Identifier: NCT04145271.

Complications associated with the use of resuscitative endovascular balloon occlusion of the aorta (REBOA): an updated review

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has become part of the arsenal to temporize patients in shock from severe hemorrhage. REBOA is used in trauma to prevent cardiovascular collapse by preserving heart and brain perfusion and minimizing distal hemorrhage until definitive hemorrhage control can be achieved. Significant side effects, including death, ischemia and reperfusion injuries, severe renal and lung damage, limb ischemia and amputations have all been reported. The aim of this article is to provide an update on complications related to REBOA. REBOA has emerged as a critical intervention for managing severe hemorrhagic shock, aiming to temporize patients and prevent cardiovascular collapse until definitive hemorrhage control can be achieved. However, this life-saving procedure is not without its challenges, with significant reported side effects. This review provides an updated overview of complications associated with REBOA. The most prevalent procedure-related complication is distal embolization and lower limb ischemia, with an incidence of 16% (range: 4-52.6%). Vascular and access site complications are also noteworthy, documented in studies with incidence rates varying from 1.2% to 11.1%. Conversely, bleeding-related complications exhibit lower documentation, with incidence rates ranging from 1.4% to 28.6%. Pseudoaneurysms are less likely, with rates ranging from 2% to 14%. A notable incidence of complications arises from lower limb compartment syndrome and lower limb amputation associated with the REBOA procedure. Systemic complications include acute kidney failure, consistently reported across various studies, with incidence rates ranging from 5.6% to 46%, representing one of the most frequently documented systemic complications. Infection and sepsis are also described, with rates ranging from 2% to 36%. Pulmonary-related complications, including acute respiratory distress syndrome and multisystem organ failure, occur in this population at rates ranging from 7.1% to 17.5%. This comprehensive overview underscores the diverse spectrum of complications associated with REBOA.

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.

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.

Next-Generation REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta) Device Precisely Achieves Targeted Regional Optimization in a Porcine Model of Hemorrhagic Shock

INTRODUCTION

Limitations such as time-dependent distal ischemia have slowed the adoption of resuscitative endovascular balloon occlusion of the aorta (REBOA) for noncompressible hemorrhage. Next-generation REBOA technologies may allow for controlled partial flow, known as targeted regional optimization, to reduce distal ischemia. We aimed to characterize the efficacy of one such catheter in a porcine model of lethal hemorrhagic shock.

METHODS

Noncompressible hemorrhage from an iliac injury was induced in anesthetized swine (Sus scrofa) (70-90 kg), targeting 30% total blood volume. Animals were then randomized to partial aortic occlusion (PO) with targeted distal mean arterial pressure (MAP) of 35-40 mm of mercury (mm Hg) and complete aortic occlusion (CO) (n = 8 per group) for 90 min. All groups were then resuscitated during a two-h critical care (CC) phase, with flow rate and MAP recorded continuously at the distal infrarenal aorta and proximal carotid artery, and analyzed with two-way repeated measures analysis of variance with S-N-K post-hoc test.

RESULTS

During aortic occlusion, MAP distal to the balloon was consistently maintained at 35.8 ± 0.3 mm Hg in the PO group compared to 27.1 ± 0.3 mm Hg in the CO group (P < 0.05), which also corresponded to higher flow rates (202.9 ± 4.8 mL/min PO versus 25.9 ± 0.8 mL/min CO; P < 0.05). MAP proximal to the balloon was significantly higher with CO versus PO (109.2 ± 2.3 mm Hg versus 85.2 ± 2.3 mm Hg; P < 0.05). During the CC phase, distal aortic flow and MAP were not significantly different between groups. However, creatinine returned to baseline levels by the end of the study in the PO group, but not the CO group. One animal died in the CO group, whereas none died in the PO group.

CONCLUSIONS

This is the first examination of the next-generation pREBOA-PRO in a porcine model of lethal hemorrhagic shock. We show technical feasibility of this technique to precisely achieve targeted regional optimization without device failure or complication. The ability to titrate balloon inflation and thus distal flow/pressure may extend the therapeutic window of REBOA by mitigating distal ischemia.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Automated aortic endovascular balloon volume titration prevents re-arrest immediately after return of spontaneous circulation in a swine model of nontraumatic cardiac arrest

Objectives

Endovascular aortic occlusion as an adjunct to cardiopulmonary resuscitation (CPR) for non-traumatic cardiac arrest is gaining interest. In a recent clinical trial, return of spontaneous circulation (ROSC) was achieved despite prolonged no-flow times. However, 66% of patients re-arrested upon balloon deflation. We aimed to determine if automated titration of endovascular balloon volume following ROSC can augment diastolic blood pressure (DBP) to prevent re-arrest.

Methods

Twenty swine were anesthetized and placed into ventricular fibrillation (VF). Following 7 minutes of no-flow VF and 5 minutes of mechanical CPR, animals were subjected to complete aortic occlusion to adjunct CPR. Upon ROSC, the balloon was either deflated steadily over 5 minutes (control) or underwent automated, dynamic adjustments to maintain a DBP of 60 mmHg (Endovascular Variable Aortic Control, EVAC).

Results

ROSC was obtained in ten animals (5 EVAC, 5 REBOA). Sixty percent (3/5) of control animals rearrested while none of the EVAC animals rearrested (p = 0.038). Animals in the EVAC group spent a significantly higher proportion of the post-ROSC period with a DBP > 60 mmHg [median (IQR)] [control 79.7 (72.5–86.0)%; EVAC 97.7 (90.8–99.7)%, p = 0.047]. The EVAC group had a statistically significant reduction in arterial lactate concentration [7.98 (7.4–8.16) mmol/L] compared to control [9.93 (8.86–10.45) mmol/L, p = 0.047]. There were no statistical differences between the two groups in the amount of adrenaline (epinephrine) required.

Conclusion

In our swine model of cardiac arrest, automated aortic endovascular balloon titration improved DBP and prevented re-arrest in the first 20 minutes after ROSC.

THE PHYSIOLOGY OF AORTIC FLOW AND PRESSURES DURING PARTIAL RESUSCITATIVE ENDOVASCULAR BALLOON OCCLUSION OF THE AORTA (pREBOA) IN A SWINE MODEL OF HEMORRHAGIC SHOCK

BACKGROUND

Partial resuscitative endovascular balloon occlusion of the aorta (REBOA) has shown promise as a method to extend REBOA, but there lacks a standard definition of the technique. The purpose of this study was to investigate the relationships between distal and proximal mean arterial blood pressure (MAP) and distal aortic flow past a REBOA catheter. We hypothesize that a relationship between distal aortic flow and distal MAP in Zone 1 partial REBOA (pREBOA) is conserved and that there is no apparent relationship between aortic flow and proximal MAP.

METHODS

A retrospective data analysis of swine, cohort one underwent 20% controlled hemorrhage and then randomized to aortic flow of 400 ml/min or complete occlusion for 20 minutes (n = 11). Cohort two underwent 30% controlled hemorrhage followed by complete aortic occlusion for 30 minutes (n = 29). Then they all underwent REBOA wean in a similar stepwise fashion. Blood pressure was collected from above (proximal) and below (distal) the REBOA balloon. Aortic flow was measured using a surgically implanted supraceliac aortic perivascular flow probe. The time period of balloon wean was taken as the time point of interest.

RESULTS

A linear relationship between distal MAP and aortic flow was observed (R 2 value: 0.80), while no apparent relationship appeared between proximal MAP and aortic flow (R 2 value: 0.29). The repeated measures correlation coefficient for distal MAP (0.94, 95% Confidence Interval: 0.94 - 0.94) was greater than proximal MAP (-0.73, 95% Confidence Interval: -0.74 - -0.72).

CONCLUSION

The relationship between MAP and flow will be a component of next generation pREBOA control inputs. This study provides evidence that pREBOA techniques should rely on distal rather than proximal MAP for control of distal aortic flow. These data could inform future inquiry into optimal flow rates and parameters based on distal MAP in both translational and clinical contexts.

LEVEL OF EVIDENCE

Level V.

Maintaining Zone 1 Occlusion is a Dynamic Process: The Effects of Proximal Pressure and Blood Transfusion During REBOA

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) provides hemodynamic support to patients with non-compressible truncal hemorrhage. As cardiac output increases due to aortic occlusion (AO), aortic diameter will increase as a function of compliance, potentially causing unintended flow around the balloon.

MATERIALS AND METHODS

Swine (N = 10) were instrumented to collect proximal mean arterial blood pressure (pMAP), distal MAP (dMAP), balloon pressure (bP), balloon volume (bV), and distal aortic flow (Qaorta). A 7-Fr automated REBOA catheter was positioned in Zone 1. At T0, animals underwent 30% total blood volume hemorrhage over 30 min followed by balloon inflation to complete AO. Automated balloon inflation occurred from T30-T60 when Qaorta was detected. Period of interest was T55-T60, while the balloon actively worked to maintain AO during transfusion of shed blood.

RESULTS

Median weight of the cohort was 73.75 [IQR:71.58-74.45] kg. During T40-T55 and T55-T60, median pMAP was 88.95 [IQR:76.80-109.92] and 108.13 [IQR:99.13-119.51] mmHg, P = 0.07. Median Qaorta during T40-T55, and T55-T60 was 0.81 [IQR:0.41-0.96], and 1.53 [IQR:1.07-1.96] mL/kg/min, P = 0.06. Median number of balloon inflations during T40-T55 was 0.00 [IQR:0.00-0.75] and increased during active transfusion to 10.00 [IQR:5.25-14.00], P = 0.001.

DISCUSSION

In clinical practice, following initial establishment of AO, progressive balloon inflations are required to maintain AO in response to intrinsic and transfusion-mediated increases in cardiac output, blood pressure, and aortic diameter.

Advanced partial occlusion controller allows for increased precision during targeted regional optimization in a porcine model of hemorrhagic shock

BACKGROUND

Targeted regional optimization (TRO), a partial resuscitative endovascular balloon occlusion of the aorta strategy, may mitigate distal ischemia and extend the window of effectiveness for this adjunct. An automated device may allow greater control and precise regulation of flow past the balloon, while being less resource-intensive. The objective of this study was to assess the technical feasibility of the novel advanced partial occlusion controller (APOC) in achieving TRO at multiple distal pressures.

METHODS

Female swine (n = 48, 68.1 ± 0.7 kg) were randomized to a target distal mean arterial pressure (MAP) of 25 mm Hg, 35 mm Hg, or 45 mm Hg by either manual (MAN) or APOC regulation (n = 8 per group). Uncontrolled hemorrhage was generated by liver laceration. Targeted regional optimization was performed for 85 minutes, followed by surgical control and a 6-hour critical care phase. Proximal and distal MAP and flow rates were measured continuously.

RESULTS

At a target distal MAP of 25 mm Hg, there was no difference in the MAP attained (APOC: 26.2 ± 1.05 vs. MAN: 26.1 ± 1.78 mm Hg) but the APOC had significantly less deviance (10.9%) than manual titration (14.9%, p < 0.0001). Similarly, at a target distal MAP of 45 mm Hg, there was no difference in mean pressure (44.0 ± 0.900 mm Hg vs. 45.2 ± 1.31 mm Hg) but APOC had less deviance (9.34% vs. 11.9%, p < 0.0001). There was no difference between APOC and MAN in mean (34.6 mm Hg vs. 33.7 mm Hg) or deviance (9.95% vs. 10.4%) at a target distal MAP of 35 mm Hg, respectively. The APOC made on average 77 balloon volume adjustments per experiment compared with 29 by manual titrations.

CONCLUSION

The novel APOC consistently achieved and sustained precisely regulated TRO across all groups and demonstrated reduced deviance at the 25 mm Hg and 45 mm Hg groups compared with manual titration.

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.

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.

Real-time bedside management and titration of partial resuscitative endovascular balloon occlusion of the aorta without an arterial line: Good for pressure, not for flow!

BACKGROUND

Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) attempts to minimize ischemia/reperfusion injury while controlling hemorrhage. There are little data on optimal methods to evaluate and titrate partial flow, which typically requires invasive arterial line monitoring. We sought to examine the use of a miniaturized handheld digital pressure device (COMPASS; Mirador Biomedical, Seattle, WA) for pREBOA placement and titration of flow.

METHODS

Ten swine underwent standardized hemorrhagic shock. Carotid and iliac pressures were monitored with both arterial line and COMPASS devices, and flow was monitored by aortic and superior mesenteric artery flow probes. Partial resuscitative endovascular balloon occlusion of the aorta was inflated to control hemorrhage for 15 minutes before being deflated to try targeting aortic flow of 0.7 L/min (using only the COMPASS device) by an operator blinded to the arterial line pressures and aortic flow. Correlations between COMPASS and proximal/distal arterial line were evaluated, as well as actual aortic flow.

RESULTS

There was strong correlation between the distal mean arterial pressure (MAP) and the distal COMPASS MAP (r = 0.979, p < 0.01), as well as between the proximal arterial line and the proximal COMPASS on the pREBOA (r = 0.989, p < 0.01). There was a significant but weaker correlation between the distal compass MAP reading and aortic flow (r = 0.47, p < 0.0001), although it was not clinically significant and predicted flow was not achieved in a majority of the procedures. Of 10 pigs, survival times ranged from 10 to 120 minutes, with a mean survival of 50 minutes, and 1 pig surviving to 120 minutes.

CONCLUSION

Highly reliable pressure monitoring is achieved proximally and distally without arterial lines using the COMPASS device on the pREBOA. Despite accurate readings, distal MAPs were a poor indicator of aortic flow, and titration based upon distal MAPs did not provide reliable results. Further investigation will be required to find a suitable proxy for targeting specific aortic flow levels using pREBOA.

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.

Partial Resuscitative Endovascular Balloon Occlusion of the Aorta: A Systematic Review of the Preclinical and Clinical Literature

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has become a standard adjunct for the management of life-threatening truncal hemorrhage, but the technique is limited by the sequalae of ischemia distal to occlusion. Partial REBOA addresses this limitation, and the recent Food and Drug Administration approval of a device designed to enable partial REBOA will broaden its application. We conducted a systematic review of the available animal and clinical literature on the methods, impacts, and outcomes associated with partial REBOA as a technique to enable targeted proximal perfusion and limit distal ischemic injury. We hypothesize that a systematic review of the published animal and human literature on partial REBOA will provide actionable insight for the use of partial REBOA in the context of future wider clinical implementation of this technique.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols guidelines, we conducted a search of the available literature which used partial inflation of a REBOA balloon catheter. Findings from 22 large animal studies and 14 clinical studies met inclusion criteria.

RESULTS

Animal and clinical results support the benefits of partial REBOA including extending the resuscitative window extended safe occlusion time, improved survival, reduced proximal hypertension, and reduced resuscitation requirements. Clinical studies provide practical physiologic targets for partial REBOA including a period of total occlusion followed by gradual balloon deflation to achieve a target proximal pressure and/or target distal pressure.

CONCLUSIONS

Partial REBOA has several benefits which have been observed in animal and clinical studies, most notably reduced ischemic insult to tissues distal to occlusion and improved outcomes compared with total occlusion. Practical clinical protocols are available for the implementation of partial REBOA in cases of life-threatening torso hemorrhage.

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.

Validation of a novel partial resuscitative endovascular balloon occlusion of the aorta device in a swine hemorrhagic shock model: Fine tuning flow to optimize bleeding control and reperfusion injury

OBJECTIVES

Partial restoration of aortic flow during resuscitative endovascular balloon occlusion of the aorta (REBOA) is advocated by some to mitigate distal ischemia. Our laboratory has validated the mechanics and optimal partial REBOA (pREBOA) flow rates using a prototype device. We hypothesize that pREBOA will increase survival when compared with full REBOA (fREBOA) in prolonged nonoperative management of hemorrhagic shock.

METHODS

Twenty swine underwent placement of aortic flow probes, zone 1 REBOA placement, and 20% blood volume hemorrhage. They were randomized to either solid organ or abdominal vascular injury. The pREBOA arm (10 swine) underwent full inflation for 10 minutes and then deflation to a flow rate of 0.5 L/min for 2 hours. The fREBOA arm (10 swine) underwent full inflation for 60 minutes, followed by deflation/resuscitation. The primary outcome is survival, and secondary outcomes are serologic/pathologic signs of ischemia-reperfusion injury and quantity of hemorrhage.

RESULTS

Two of 10 swine survived in the fREBOA group (2/5 solid organ injury; 0/5 abdominal vascular injury), whereas 7 of 10 swine survived in the pREBOA group (3/5 solid organ injury, 4/5 abdominal vascular injury). Survival was increased (p = 0.03) and hemorrhage was higher in the pREBOA group (solid organ injury, 1.36 ± 0.25 kg vs. 0.70 ± 0.33 kg, p = 0.007; 0.86 ± 0.22 kg vs. 0.71 ± 0.28 kg, not significant). Serum evidence of ischemia was greater with fREBOA, but this was not significant (e.g., lactate, 16.91 ± 3.87 mg/dL vs. 12.96 ± 2.48 mg/dL at 120 minutes, not significant). Swine treated with pREBOA that survived demonstrated trends toward lower alanine aminotransferase, lower potassium, and higher calcium. The potassium was significantly lower in survivors at 60 minutes and 90 minutes time points (5.97 ± 0.60 vs. 7.53 ± 0.90, p = 0.011; 6.67 ± 0.66 vs. 8.15 ± 0.78, p = 0.029). Calcium was significantly higher at 30 minutes, 60 minutes, and 90 minutes (8.56 ± 0.66 vs. 7.50 ± 0.40, p = 0.034; 8.63 ± 0.62 vs. 7.15 ± 0.49, p = 0.019; 8.96 ± 0.64 vs. 7.00, p = 0.028).

CONCLUSION

Prolonged pREBOA at a moderate distal flow rate provided adequate hemorrhage control, improved survival, and had evidence of decreased ischemic injury versus fREBOA. Prophylactic aggressive calcium supplementation may have utility before and during the reperfusion phase.

Titrate to equilibrate and not exsanguinate! Characterization and validation of a novel partial resuscitative endovascular balloon occlusion of the aorta catheter in normal and hemorrhagic shock conditions

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a significant advancement in the control of noncompressible truncal hemorrhage. However, its ischemic burden and reperfusion injury following balloon deflation limits its utilization. Partial restoration of aortic flow during REBOA has the potential to balance hemorrhage control and ischemia. This study validates the mechanics, physiology, and optimal partial flow rates using a prototype partial REBOA (pREBOA) device.

METHODS

Twenty-five swine underwent placement of aortic flow probes and zone 1 pREBOA. Experiment 1 (N = 5) animals were not injured and assessed the tested the catheters ability to titrate and control flow. Experiment 2 (N = 10) added 20% hemorrhage and either solid organ, or abdominal vascular injury to compare flow rate and rebleeding from injuries. Experiment 3 (N = 10) swine were similarly prepared, hemorrhaged, and underwent pREBOA at set partial flow rates for 2 hours followed by complete deflation for 30 minutes.

RESULTS

Balloon volume at minimum flow (mean, 0.09 L/min) was 3.5 mL to 6.0 mL. Half maximal flow was achieved with 56.5% of maximum balloon inflation. Partial REBOA allowed very fine titration of flow rates. Rebleeding occurred at 0.45 L/min to 0.83 L/min. Distal flow of 0.7 L/min had 50% survival, 0.5 had 100% survival, and 0.3 L had 50% survival with mean end lactates of 9.6, 12.6, and 13.3, respectively. There was a trend toward hyperkalemia and hypocalcemia in nonsurvivors.

CONCLUSION

The pREBOA device demonstrated a high level of titratability for restoration of aortic flow. An optimal partial flow of 0.5 L/min was effective at hemorrhage control while limiting the burden of ischemic injury, and extending the tolerable duration of zone 1 occlusion. Aggressive calcium supplementation prior to and during partial occlusion and reperfusion may be warranted to prevent hyperkalemic arrest.

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.

Preperitoneal balloon tamponade and resuscitative endovascular balloon occlusion of the aorta: Alternatives to open packing for pelvic fracture-associated hemorrhage

BACKGROUND

The objective of this study was to compare the efficacy of preperitoneal balloon tamponade (PPB), resuscitative endovascular balloon occlusion of the orta (REBOA), and open preperitoneal packing (OP) in a realistic animal model of pelvic fracture-associated hemorrhage.

METHODS

Thirty-nine swine underwent creation of open-book pelvic fracture and iliac vascular injury. Animals were randomized to no intervention (n = 7), OP (n = 10), PPB (n = 9), zone 1 REBOA (n = 7), and zone 3 REBOA (n = 6) at a mean arterial pressure less than 40 mm Hg from uncontrolled hemorrhage. Primary outcome was survival at 1 hour. Secondary outcomes included survival in the immediate 10 m following intervention reversal, peak preperitoneal pressure (PP), blood loss, bleed rate, and peak lactate.

RESULTS

Prior to injury, no difference was measured between groups for weight, hemodynamics, lactate, and hematocrit (all p = NS). The injury was uniformly lethal without intervention, with survival time (mean) of 5 m, peak PP of 14 mm Hg, blood loss of 960 g, bleed rate of 450 g/m, and peak lactate of 2.6 mmol/L. Survival time (m) was extended to 44 with OP, 60 with PPB, and 60 with REBOA (p < 0.01). Peak PP (mm Hg) was 19 with OP, 23 with PPB, 10 with zone 1 REBOA, and 6 with zone 3 REBOA (p < 0.05). Blood loss (g) was 850 with OP, 930 with PPB, 610 with zone 1 REBOA, and 370 with zone 3 REBOA (p < 0.01). Peak lactate (mmol/L) was 3.3 with OP, 4.3 with PPB, 13.4 with zone 1 REBOA, and 5.3 with zone 3 REBOA (p < 0.01). Only 33% of zone 1 REBOA animals survived the initial 10 m after balloon deflation, compared to 60% for OP, 67% for PPB, and 100% for zone 3 REBOA (p < 0.01).

CONCLUSION

Preperitoneal balloon tamponade and zone 3 REBOA are effective alternatives to OP in this animal model of lethal pelvic fracture-associated hemorrhage. Zone 1 REBOA extends survival time but with high mortality upon reversal.

Large Animal Models of Proximal Aortic Balloon Occlusion in Traumatic Hemorrhage: Review and Identification of Knowledge Gaps Relevant to Expanded Use

BACKGROUND

The aim of this study was to review and summarize the large animal data on resuscitative endovascular balloon occlusion of the aorta (REBOA) for traumatic hemorrhage and identify knowledge gaps pertinent to the proposed broader use of the technique in prehospital situations.

METHODS

A review of published large animal models of traumatic hemorrhage incorporating REBOA with a primary outcome of the effect of aortic occlusion was performed. Data were collected on experimental protocols, hemodynamic effects, resuscitation requirements, mortality, metabolic and tissue consequences of induced ischemia-reperfusion, and effects on hemorrhage volume and other injuries.

RESULTS

A limited number of REBOA studies exist, and there is variability in the species and size of animals used. Various controlled and uncontrolled hemorrhage protocols have been studied, and a number of balloon devices used. Hemodynamic effects of occlusion were consistent as were basic systemic physiological effects. Minimal study of the effects of partial aortic occlusion and hemodynamic and metabolic physiology distal to the balloon has been performed, and partial or complete occlusion times >90 min have not been studied.

CONCLUSIONS

Significant knowledge gaps exist, which are potentially relevant to the expanded use of REBOA. Investigation into the physiology of partial occlusion and the metabolic effects and potential mitigation strategies for large-scale ischemia and reperfusion are particularly needed.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) Not Yet Applicable for Widespread Out-of-Hospital Use: A Case of Nonsurvivable Complication from Prolonged REBOA Inflation

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is being considered for temporizing catastrophic hemorrhage before arriving at a specialty center for definitive surgical management.

CASE

We describe the clinical case of a 72-year-old male with a ruptured infrarenal aortic abdominal aneurysm initially stabilized with REBOA at an outside facility and transferred to our care. Transport time was >100 minutes. Despite successful surgical repair of the ruptured aneurysm, the patient expired from multiple-organ failure likely related to ischemia-reperfusion injuries from prolonged balloon occlusion of the aorta.

CONCLUSIONS

Ischemia-mitigating techniques and therapies need to improve drastically before the clinical application of REBOA can be effectively extended to outside the vicinity of specialty centers.

Effect of resuscitative endovascular balloon occlusion of the aorta in hemodynamically unstable patients with multiple severe torso trauma: a retrospective study

Background

Although resuscitative endovascular balloon occlusion of the aorta (REBOA) may be effective in trauma management, its effect in patients with severe multiple torso trauma remains unclear.

Methods

We performed a retrospective study to evaluate trauma management with REBOA in hemodynamically unstable patients with severe multiple trauma. Of 5899 severe trauma patients admitted to our hospital between January 2011 and January 2018, we selected 107 patients with severe torso trauma (Injury Severity Score > 16) who displayed persistent hypotension [≥ 2 systolic blood pressure (SBP) values ≤ 90 mmHg] regardless of primary resuscitation. Patients were divided into two groups: trauma management with REBOA (n = 15) and without REBOA (n = 92). The primary endpoint was the effectiveness of trauma management with REBOA with respect to in-hospital mortality. Secondary endpoints included time from arrival to the start of hemostasis. Multivariable logistic regression analysis, adjusted for clinically important variables, was performed to evaluate clinical outcomes.

Results

Trauma management with REBOA was significantly associated with decreased mortality (adjusted odds ratio of survival, 7.430; 95% confidence interval, 1.081–51.062; p = 0.041). The median time (interquartile range) from admission to initiation of hemostasis was not significantly different between the two groups [with REBOA 53.0 (40.0–80.3) min vs. without REBOA 57.0 (35.0–100.0) min ]. The time from arrival to the start of balloon occlusion was 55.7 ± 34.2 min. SBP before insertion of REBOA was 48.2 ± 10.5 mmHg. Total balloon occlusion time was 32.5 ± 18.2 min.

Conclusions

The use of REBOA without a delay in initiating resuscitative hemostasis may improve the outcomes in patients with multiple severe torso trauma. However, optimal use may be essential for success.

Deployment of a Resuscitative Endovascular Balloon Occlusion of the Aorta Device in a Case of Gunshot Wound Injury to a Horseshoe Kidney

A horseshoe kidney (HSK) is a urological malformation that is typically found incidentally after a traumatic injury due to its asymptomatic nature. We present a 25-year-old male with multiorgan injuries secondary to blunt abdominal trauma caused by a gunshot wound. We report the courses of action taken that led to the identification of the HSK and other associated intra-abdominal injuries and the subsequent surgical management. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an improving minimally invasive technique that was used to control hemorrhage in the early preoperative stages and during surgical repair of the injuries. Multiorgan injuries that involve an HSK are uncommon. Our interest in the case relies on the rarity and unique aspects of the injuries and the recovery of the patient following the use of REBOA.

The complications associated with Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA)

Non-compressible torso hemorrhage (NCTH) remains a significant cause of morbidity and mortality in the field of trauma and emergency medicine. In recent times, there has been a resurgence in the adoption of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) for patients who present with NCTH. Like all medical procedures, there are benefits and risks associated with the REBOA technique. However, in the case of REBOA, these complications are not unanimously agreed upon with varying viewpoints and studies. This article aims to review the current knowledge surrounding the complications of the REBOA technique at each step of its application.

Resuscitative endovascular balloon occlusion of the aorta (REBOA): an updated review

In a current scenario where trauma injury and its consequences account for 9% of the worlds causes of death, the management of non-compressible torso hemorrhage can be problematic. With the improvement of medicine, the approach of these patients must be accurate and immediate so that the consequences may be minimal. Therefore, aiming the ideal method, studies have led to the development of Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA). This procedure has been used at select trauma centers as a resuscitative adjunct for trauma patients with non-compressible torso hemorrhage. Although the use of this technique is increasing, its effectiveness is still not clear. This article aims, through a detailed review, to inform an updated view about this procedure, its technique, variations, benefits, limitations and future.

The pitfalls of resuscitative endovascular balloon occlusion of the aorta: Risk factors and mitigation strategies

Despite technological advancements, REBOA is associated with significant risks due to complications of vascular access and ischemia-reperfusion. The inherent morbidity and mortality of REBOA is often compounded by coexisting injury and hemorrhagic shock. Additionally, the potential for REBOA-related injuries is exaggerated due to the growing number of interventions being performed by providers who have limited experience in endovascular techniques, inadequate resources, minimal training in the technique, and who are performing this maneuver in emergency situations. In an effort to ultimately improve outcomes with REBOA, we sought to compile a list of complications that may be encountered during REBOA usage. To address the current knowledge gap, we assembled a list of anecdotal complications from high-volume REBOA users internationally. More importantly, through a consensus model, we identify contributory factors that may lead to complications and deliberate on how to recognize, mitigate, and manage such events. An understanding of the pitfalls of REBOA and strategies to mitigate their occurrence is of vital importance to optimize patient outcomes.