A novel partial resuscitative endovascular balloon aortic occlusion device that can be deployed in zone 1 for more than 2 hours with minimal provider titration

Partial REBOA Zone 1 is associated with lower mortality compared to complete REBOA Zone 1 and emergency department thoracotomy: A cohort study using the AORTA registry

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) and emergency department thoracotomy (EDT) are effective methods of aortic occlusion (AO) for life-threatening bleeding; however, complete AO can lead to visceral ischemia. Partial REBOA (P-REBOA) has been proposed as an alternative to the completely occlusive REBOA (C-REBOA) to balance hemorrhage control and perfusion. Using the Aortic Occlusion for Resuscitation in Trauma (AORTA) multicenter, observational registry, we tested the hypothesis that P-REBOA resulted in better outcomes compared to EDT and C-REBOA.

STUDY DESIGN AND METHODS

We queried the 2017-2023 AORTA registry for adults who underwent EDT, C-REBOA, or P-REBOA in the emergency department (ED). Patients with chest penetrating injuries were excluded. We compared mortality, ventilator-free-days (VFD), and ICU-free-days (ICUFD) using survival analysis or generalized linear models to adjust for confounders.

RESULTS

Overall, 921 patients underwent EDT (n = 613, 66.6%), C-REBOA (n = 224, 24.3%), or P-REBOA (n = 84, 9.1%); 83.1% died. After confounder adjustment, compared to P-REBOA, both C-REBOA and EDT were associated with a lower likelihood of attaining hemodynamic improvement and stability as well as with higher mortality (adjusted hazard ratio, aHR = 1.84; 95% CI: 1.01-1.60 and aHR = 3.32; 95% CI: 1.96-2.78, respectively). EDT patients had less VFD and ICUFD than those undergoing C-REBOA and P-REBOA, but there were no differences between the two endovascular procedures. Among patients who survived >48 h, EDT was more likely to be associated with complications compared to the other two procedures.

DISCUSSION

P-REBOA was more likely to be associated with improved hemodynamic stability and reduced mortality compared to C-REBOA and EDT, suggesting this modality may be a better AO procedure for patients with no penetrating thoracic injuries.

Use of resuscitative endovascular balloon occlusion of the aorta (REBOA) in a multidisciplinary approach for management of traumatic haemorrhagic shock: 10-year retrospective experience from a French level 1 trauma centre

BACKGROUND

The present study investigated an institutional multidisciplinary strategy for managing traumatic haemorrhagic shock by integrating the placement of REBOA (resuscitative endovascular balloon occlusion of the aorta) by anaesthesiologist-intensivists.

METHODS

All severe trauma patients who received percutaneous REBOA placement between January 2013 and December 2022 in our level 1 trauma centre were retrospectively analysed. The data collected included the clinical context, indications and location of REBOA, durations of aortic occlusion (AO), choice of haemostatic procedures and surgical teams, and specific complications.

RESULTS

In total, 38 trauma patients were included in the present study (mean age = 41 years [standard deviation = 21 years], 31 [82 %] were male, and median injury severity score was 62.5 [inter-quartile range (IQR) = 45-75]). REBOA was always placed by anaesthesiologist-intensivists, who comprised 68 % of the senior physicians (13/19) in our trauma team over the period. Twenty-eight AOs (74 %) were performed in zone 1 and 10 (26 %) in zone 3. Twelve patients (32 %) received REBOA upon circulatory arrest. Routes following REBOA placement comprised: computed tomography scan = 47 %, operating room = 34 %, angiography = 3 %, emergency room thoracotomy = 5 %, and prematurely died = 11 %. Duration of AO was 38 min (IQR = 32-44 min) in zone 1 and 78 min (IQR = 48-112 min) in zone 3. Mortality rate was 66 % (95 % CI 51-81 %) and higher in cases of AO in zone 1 (79 % versus 30 %, p = 0.018) or concomitant with circulatory arrest (92 % versus 54 %, p = 0.047). No ischemic limb needed an intervention and three endothelial injuries required delayed endovascular stenting.

CONCLUSIONS

Percutaneous REBOA placement by anaesthesiologist-intensivists included in the multidisciplinary management of traumatic haemorrhagic shock was associated with acceptable time of AO and local complications similar to those observed in other series.

A PROMPT Update on Partial REBOA: Initial Clinical Data and Overview of the DoD-Funded Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) Study

INTRODUCTION

Retrograde Endovascular Balloon Occlusion of the Aorta (REBOA) is an effective management for the transient responder, but the ischemic consequences of complete aortic occlusion currently limit its use. Multiple DoD-funded preclinical studies have clearly demonstrated that partial REBOA reduces distal ischemia to potentially extend safe occlusion times, while still providing effective temporization of noncompressible torso hemorrhage. Early versions of REBOA devices were designed to completely occlude the aorta and had little ability to provide partial occlusion. Recently, a new REBOA device (pREBOA-PRO) was designed specifically to allow for partial occlusion, with the hypothesis that this may reduce the complications of aortic occlusion and extend safe occlusion times while maintaining the benefits on cardiac and cerebrovascular circulation as well as reductions in resuscitation requirements.

MATERIALS AND METHODS

To ascertain the impact of a new purpose-built partial REBOA device on the extension of safe occlusion time, the Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) trial compared available data from the pREBOA-PRO with existing data from 200 clinical uses of pREBOA-PRO and available data in the AAST AORTA Registry were reviewed to design primary endpoints and clinical evidence for a prospective multi-center trial, the PROMPT Study. Together with the endpoints identified in preclinical studies of partial REBOA, primary endpoints for the PROMPT study were identified and power analyses were conducted to determine the target patient enrollment goals.

RESULTS

Results from the clinical implementation of partial REBOA at a single trauma center were used to conduct the initial power analysis for the primary endpoint of Acute Kidney Injury (AKI) after prolonged occlusion. The rate of AKI after complete REBOA was 55% (12/20) compared to 33% (4/12) after partial REBOA (Madurska et al., 2021). With an alpha of 0.05 and power (β) of 0.8, the projected sample size for comparison on a dichotomous outcome is 85 patients for the assessment of AKI. Initial power and endpoint analyses have been confirmed and extended with the ongoing analysis of partial and complete REBOA reported in the AORTA database. These analyses confirm preclinical findings which show that compared to complete REBOA, partial REBOA is associated with extended occlusion time in zone 1 (complete: 31 min vs. partial: 45 min, P = 0.003), lower rates of AKI after zone 1 occlusion (complete: 33% vs. partial: 19%, P = 0.05) and reduced resuscitation requirements (e.g., 25% reduction in pRBC administration: complete: 18 units vs. partial: 13 units, P = 0.02).

CONCLUSIONS

The DoD-funded PROMPT study of partial REBOA will provide prospective observational clinical data on patients being treated with pREBOA-PRO. Outcomes will be stratified based on partial or complete occlusion to address whether partial REBOA has additional clinical benefits over complete REBOA, such as decreased distal ischemia, extension of safe occlusion time, improved hemodynamics during transition to and from occlusion, and reduced interoperative bleeding and blood product use. The results from this study are expected to confirm previous data demonstrating reduction of ischemic sequalae, improved transition to reperfusion, and reduced resuscitative requirements compared to complete REBOA.

The Role of Resuscitative Endovascular Balloon Occlusion of the Aorta

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been utilized by trauma surgeons at the bedside for over a decade in both civilian and military settings. Both translational and clinical research suggest it is superior to resuscitative thoracotomy for specific patient populations. Technological advancements in recent years have significantly enhanced the safety profile of REBOA. Resuscitative balloon occlusion of the aorta has also swiftly found implementation in patients in shock from non-traumatic hemorrhage.

Balloon Rises Above: REBOA at Zone 1 May Be Superior to Resuscitative Thoracotomy

BACKGROUND

The use of Zone 1 REBOA for life-threatening trauma has increased dramatically.

STUDY DESIGN

The Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery database was queried for blunt and penetrating trauma between 2013 and 2021. Outcomes were examined both for mechanisms of injury combined and separately and for combinations of abdominal injury with and without traumatic brain injury and chest injuries (Abbreviated Injury Scale [AIS] score >2).

RESULTS

A total of 531 patients underwent REBOA (408 with blunt injury and 123 with penetrating injury) and 1,603 (595 with blunt injury and 1,008 with penetrating injury) underwent resuscitative thoracotomy (RT). Mean age was 38.5 ± 16 years and mean injury severity score was 34.5 ± 21; 57.7% had chest AIS score of more than 2, 21.8% had head AIS score of more than 2, and 37.3% had abdominal AIS score of more than 2. Admission Glasgow Coma Scale was 4.9 + 4, and systolic blood pressure at aortic occlusion (AO) was 22 + 40 mmHg. No differences in outcomes in REBOA or RT patients were identified between institutions (p > 0.5). After inverse probability weighting, Glasgow Coma Scale, age, injury severity score, systolic blood pressure at AO, CPR at AO, and blood product transfusion, REBOA was superior to RT in both blunt (odds ratio [OR] 4.7, 95% CI 1.9 to 11.7) and penetrating (OR 4.9, 95% CI 1.7 to 14) injuries, across all spectrums of injury (p < 0.01). Overall mortality was significantly higher for AO more than 90 minutes compared with less than 30 minutes in blunt (OR 4.6, 95% CI 1.5 to 15) and penetrating (OR 5.4, 95% CI 1.1 to 25) injuries. Duration of AO more than 60 minutes was significantly associated with mortality after penetrating abdominal injury (OR 5.1, 95% CI 1.1 to 22) and abdomen and head (OR 5.3, 95% CI 1.6 to 18).

CONCLUSIONS

In-hospital survival is higher for patients undergoing REBOA than RT for all injury patterns. Complete AO by REBOA or RT should be limited to less than 30 minutes. Neither hospital and procedure volume nor trauma verification level impacts outcomes for REBOA or RT.

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.

Finding the Right Balance: Partial REBOA in a Swine Model of Uncontrolled Vascular Injury

BACKGROUND

We have previously shown that partial REBOA (pREBOA) deployment in the thoracic aorta is safe for 2 to 4 hours, but it is unclear whether the distal blood flow after partial aortic occlusion would lead to ongoing hemorrhage. The objective of this study was to evaluate the hemostatic efficacy of pREBOA in a model of uncontrolled vascular injury.

STUDY DESIGN

Female Yorkshire swine (n = 10, 40 to 45 kg) were anesthetized and instrumented. A through-and-through injury was created in the common iliac artery. The animals were randomly assigned to: (1) pREBOA-PRO deployment after 3 minutes and (2) control. Both groups were given normal saline resuscitation for hypotension. The pREBOA was adjusted to partial occlusion (distal mean arterial pressure of 30 mmHg), and then left without titration for 2 hours. Then, fresh frozen plasma was transfused and the vessel repaired. The balloon was deflated and the animals were monitored for 2 hours. In the critical care period, 2 L of normal saline was infused, norepinephrine was given for mean arterial pressure ≤55, and electrolytes and acidosis were corrected. Organs were examined for gross and histologic evidence of ischemic injuries. The primary endpoint was post-inflation blood loss.

RESULTS

All the pREBOA animals survived until the end, whereas control animals had a mean survival time of 38.2 minutes (p < 0.05). The pREBOA group showed significantly less bleeding after balloon deployment (93.8 vs 1,980.0 mL, p < 0.05), and had appropriate lactate clearance, with minimal histologic distal organ ischemia.

CONCLUSIONS

Partial aortic occlusion with the newly designed balloon can achieve the desired balance between effective hemorrhage control and adequate distal flow, without a need for ongoing balloon titration.

Ultrasound assessment is useful for evaluating balloon volume of resuscitative endovascular balloon occlusion of the aorta

BACKGROUND

Endovascular balloon occlusion of the aorta (EBOA) increases proximal arterial pressure but may also induce life-threatening ischemic complications. Although partial REBOA (P-REBOA) mitigates distal ischemia, it requires invasive monitoring of femoral artery pressure for titration. In this study, we aimed to titrate P-REBOA to prevent high-degree P-REBOA using ultrasound assessment of femoral arterial flow.

METHODS

Proximal (carotid) and distal (femoral) arterial pressures were recorded, and perfusion velocity of distal arterial pressures was measured by pulse wave Doppler. Systolic and diastolic peak velocities were measured among all ten pigs. Total REBOA was defined as a cessation of distal pulse pressure, and maximum balloon volume was documented. The balloon volume (BV) was titrated at 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the perfusion velocity of distal arterial pressures were recorded.

RESULTS

Proximal blood pressure increased with increasing BV. Distal pressure decreased with increasing BV, and distal pressure sharply decreased by > 80% of BV. Both systolic and diastolic velocities of the distal arterial pressure decreased with increasing BV. Diastolic velocity could not be recorded when the BV of REBOA was > 80%.

CONCLUSION

The diastolic peak velocity in the femoral artery disappeared when %BV was > 80%. Evaluation of the femoral artery pressure by pulse wave Doppler may predict the degree of P-REBOA without invasive arterial monitoring.

Prolonging the zone 1 aortic occlusion time to 4 hours using a partial resuscitative endovascular balloon in a swine model

BACKGROUND

The clinical usage of the resuscitative endovascular balloon occlusion of the aorta (REBOA) is limited by distal ischemia resulting from complete aortic occlusion. We hypothesized that animals would physiologically tolerate the prolonged partial occlusion using the novel partially occluding REBOA (pREBOA) with survivable downstream injuries.

METHODS

This study used the pREBOA-PRO catheter in a previously established swine model. Female Yorkshire swine (n = 10) underwent a volume-controlled hemorrhage (40% estimated blood). After 1 hour of shock (mean arterial pressure, 28-32 mm Hg), animals were randomized to partial occlusion for either 2 hours or 4 hours. The pREBOA was inflated in zone 1 to achieve partial occlusion defined as a distal systolic blood pressure (SBP) of 20 ± 2 mm Hg. The balloon was deflated at the end of the occlusion period, and animals were resuscitated for 2 hours. Tissues were examined for gross and histologic injury. The primary endpoint was histologic organ injury, and secondary end points were hemodynamic variables and degree of distal organ ischemia.

RESULTS

All animals survived to the endpoint. Both groups had similar proximal and distal SBP at baseline, with a divergence of pressures ranging from 55 mm Hg to 90 mm Hg on inflation. The lactate levels increased throughout the occlusion and decreased approximately 40% during the observation period. More animals required norepinephrine and fluid in the 4-hour group compared with the 2-hour group. There was no gross small bowel ischemia noted in the 2-hour animals. The 4-hour group had surgically resectable patchy short segment ischemia. Neither group showed nonsurvivable organ ischemia on pathology or laboratory values.

CONCLUSION

This is the first study showing that the zone 1 aorta can be occluded for over 4 hours using a new pREBOA device without need for balloon titration. In conclusion, simple changes in balloon design offer reliable partial aortic occlusion, with potentially survivable and surgically manageable downstream injuries.

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.

Advanced bleeding control in combat casualty care: An international, expert-based Delphi consensus

BACKGROUND

Hemorrhage from truncal and junctional injuries is responsible for the vast majority of potentially survivable deaths in combat casualties, causing most of its fatalities in the prehospital arena. Optimizing the deployment of the advanced bleeding control modalities required for the management of these injuries is essential to improve the survival of severely injured casualties. This study aimed to establish consensus on the optimal use and implementation of advanced bleeding control modalities in combat casualty care.

METHODS

A Delphi method consisting of three rounds was used. An international expert panel of military physicians was selected by the researchers to complete the Delphi surveys. Consensus was reached if 70% or greater of respondents agreed and if 70% or greater responded.

RESULTS

Thirty-two experts from 10 different nations commenced the process and reached consensus on which bleeding control modalities should be part of the standard equipment, that these modalities should be available at all levels of care, that only trained physicians should be allowed to apply invasive bleeding control modalities, but all medical and nonmedical personnel should be allowed to apply noninvasive bleeding control modalities, and on the training requirements for providers. Consensus was also reached on the necessity of international registries and guidelines, and on certain indications and contraindications for resuscitative endovascular balloon occlusion of the aorta (REBOA) in military environments. No consensus was reached on the role of a wound clamp in military settings and the indications for REBOA in patients with chest trauma, penetrating axillary injury or penetrating neck injury in combination with thoracoabdominal injuries.

CONCLUSION

Consensus was reached on the contents of a standard bleeding control toolbox, where it should be available, providers and training requirements, international registries and guidelines, and potential indications for REBOA in military environments.

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.