UK-REBOA Trial

In this Papercut we review the UK-REBOA Trial.

Rapid and effective control of haemorrhage in trauma results in better outcomes. Abdominal bleeding which cannot be controlled by any other means other than surgery is challenging and results in mortality, in many cases, prior to arriving in the operating theatre.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique where a percutaneous balloon can be inserted and inflated in the aorta. 

The American College of Emergency Physicians and the American College of Surgeons recommend REBOA for traumatic life threatening haemorrhage below the diaphragm in patients not responding to resuscitation. These recommendations are based on retrospective studies, systematic reviews and meta-analysis results. There have been no randomised controlled trials until now.

The UK Resuscitative Endovascular Balloon Occlusion of the Aorta (UK REBOA) Trial(1) is the first randomised controlled trial on this topic.

The Question Asked

"Does the addition of resuscitative endovascular balloon occlusion of the aorta (REBOA) to standard care reduce mortality in trauma patients with exsanguinating hemorrhage?"

What They Did

This was a Multicenter, open label, randomised trial. It was conducted at 16 major trauma centres in the UK.

Patients were > 16 yo.
Randomisation occurred on a 1:1 ratio and was web-based

Standard care included:

• Intubation
• Balanced Blood Product transfusion
• Early operative control of haemorrhage
• Open aortic occlusion of thoracic or abdominal aorta.

Primary Outcome: All cause mortality at 90 days.

Secondary Outcomes:

• 3, 6 and 24 hour mortality in hospital.
• Mortality at 6 months
• Need for definitive haemorrhage control
• Complications
• Length of Stay
• Blood product use
• Cause of Death

What They Found

The trial was stopped after second interim analysis, as a pre-specified rule for harm was met (>90% posterior probability or OR > 1 for mortality at 90 days) At this point 90 patients were enrolled, and the study did not achieve the originally planned 120 patients.

46 patients assigned to REBOA and Standard Care

44 Patients were assigned to Standard Care.

Patient Characteristics  that are important

• 69% of patients were male
• 97% had blunt trauma
• Median age was 41 years
• Only 19 of the 46 patients(41%) in the REBOA group had a device inserted
  • 17 patients (37%) responded to other resuscitation and balloon inflation was not necessary.
  • 2 patients (4%) deteriorated before access
  • In 8 patients (17%) access could not be established.
• In the REBOA Group that had a device inserted:
  • 53% had balloon inflation in zone I (descending thoracic aorta)
  • 47% had balloon inflation in zone III (above aortic bifurcation)
• Median time from arrival in ED to balloon inflation was 32 minutes
• Duration of inflation was 29 minutes.
• The median time to definitive haemorrhage control procedure was 83 minutes in the REBOA group compared to 64 minutes in standard care group.
• Death due to haemorrhage was more common in the REBOA group and occurred early.
• 23% required CPR on ED arrival.

Primary Outcome

25 deaths (54%) in REBOA and standard care group versus 18 deaths (42%) in standard care alone group at 90 days. 

Secondary Outcomes

Mortality in the REBOA group was increased at all time points:

• 3 hours (24% vs 5%)
• 6 hours(28% vs 9%) and
• 24 hours (37% vs 23%)

Authors' Conclusion

"In trauma patients with exsanguinating hemorrhage, a strategy of REBOA and standard care in the emergency department does not reduce, and may increase, mortality compared with standard care alone."

Stengths of this Study

• Pragmatic Design
• Patient outcome focused
• Randomised controlled, multiceter study

Limitations of the Study

• Small sample size
• The majority of the patients had suffered blunt trauma
• A significant number of the patients were recruited from 3 of the 16 centers.
• Only 41% of the REBOA allocated group actually got REBOA insertion and inflation.

My Take on This

This was the first RCT that aimed to answer a very important question. It is important as it may assist in trauma management, not just in trauma-designated centres, but could potentially give us a temporising technique. It is an important study.

Although we would like to think that REBOA may be 'that' procedure that buys us time and saves lives, there are aspects of this study, that shows that this is not the case. However we also need to beware of the limitations here.

• This was a small sample study of predominant blunt trauma patients,
• The procedure that was only performed in less than half of the cases that were assigned to it.
• Almost half of the patients came from a small number of the total included trauma centres and
• It was conducted in one country's trauma system.

The 'in series' method is used ie., REBOA first and then definitive therapy, which may also not be the best approach. REBOA may need to occur in unison with preparation for definitive surgical intervention. 

What this study reinforces for me is timely control of haemorrhage. Delays in that control result in greater mortality.

References

1. Jansen J O et al. Emergency Department Resuscitative Endovascular Balloon Occlusion of the Aorta in Trauma Patients with Exsanguinating Haemorrhage. The UK-REBOA Randomised Clinical Trial. JAMA. 2023;330(19):1862-1871