Tag Archives: REBOA

Best of AAST #7: What’s New With Reboa

Despite all you read about it these days, REBOA is still very new. The first papers describing use in humans are barely 5 years old! A few select centers have been early adopters and are publishing a regular flow of research on their experience.

But we need more numbers! Many trauma centers have considered, or actually adopted the use of REBOA already. However, we are still working out a lot of the nuts and bolts of this very invasive procedure. The group at University of Arizona – Tucson reviewed the national experience over a two year period by massaging the data in the Trauma Quality Improvement Program (TQIP) database. All Level I-III trauma centers in the US are required to report their experience to this large, detailed collection of trauma data.

They performed a retrospective review of REBOA vs non-REBOA patients matched for demographics, prehospital and emergency department vital signs, mechanism of injury, degree of pelvic disruption in pelvic fracture patients, solid organ injuries, and lower extremity fractures and vascular injuries. The studied outcomes were complications and mortality.

Here are the factoids:

  • Nearly 600,000 records were scanned for the two year period, and only 140 REBOA patients were identified (!)
  • These 140 REBOA patients were matched with 280 similar non-REBOA patients
  • Average age was 44 and average ISS was 29, 74% were males and 92% were blunt trauma
  • Overall complication rate was 7.4% and mortality was 25%
  • There was no difference in 4-hour or 24-hour numbers of blood, plasma, or platelets transfused
  • ICU and hospital length of stay were identical
  • 24-hour mortality in the REBOA group was significantly higher (36% vs 19%)
  • REBOA patients were significantly more likely to require amputation (5% vs 1%)

Bottom line: These are not great numbers for REBOA! What gives? There are a number of possibilities:

  • It’s a database study, so some key information might be missing
  • The numbers remain small, only 140 patients out of half a million records in two years!
  • There is no way to know how the patients were selected for REBOA
  • The experience and skill level at the hospital performing the procedure is not known
  • The interplay of other injuries and comorbidities is unclear
  • And many more…

BUT, the numbers are concerning. The early adopter centers have better outcomes, and this has prompted many centers with fewer eligible patients to jump on the bandwagon. We all need to remember that this is a brand new procedure and we are still learning the nuances. It is extremely important that every center performing REBOA contribute their results to a national registry. We still need to figure out which patients will benefit from it, how it should be used, and how we can minimize complications and maximize survival in our patients.

Reference: Nationwide analysis of resuscitative endovascular balloon occlusion of the aorta (REBOA) in civilian trauma. Session I Paper 5, AAST 2018.

REBOA At An Academic Trauma Center

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is the big thing these days. I’ve written about this topic in the past, and a number of centers continue to refine our understanding of this new(er) tool.  A recent paper from the University of Florida – Gainesville outlines their experience in implementing this procedure at an academic Level I trauma center.

This trauma program is staffed by a group of surgeons who have considerable experience in guidewire-based skills, fellowship or military exposure, and/or completion of a vascular fellowship. One surgeon attended a trauma endovascular skills course (6 hrs).  An internal education program with a 1.5 hour slide presentation and some hands-on simulation training was developed. All surgeons and residents completed this program.

A retrospective review of their experience from June 2015 to March 2017 was carried out on unstable trauma patients due to hemorrhage. All cases were performed in a hybrid OR with imaging capabilities. A 12Fr REBOA catheter was initially used, but was changed to 7Fr once that catheter became commercially available.

Here are the factoids:

  • 16 patients underwent REBOA in this 22 month period; mean SBP was 97 torr and mean ISS was 39
  • Hemodynamic status improved in 10 of 16 patients to a mean SBP 132
  • 14 survived the initial operative procedure, but only 6 survived to hospital day 30. It appears that all of these patients were neurologically normal (GCS 15+0).
  • 1 survivor developed a common femoral artery pseudoaneurysm
  • The authors made the interesting comment that they also performed 8 ED thoracotomies (EDT) during this period and that there were no survivors
  • The authors concluded that the procedure was beneficial, that extensive training was not needed, and that it should be available trauma centers

Bottom line: But not so fast! This was a very select academic Level I center. The surgeons had extensive wire skills and vascular experience. All procedures were performed in a hybrid room, which is a very controlled OR setting. And they only performed REBOA every 6 weeks or so. 

REBOA is still an advanced procedure, and the average trauma surgeon would probably benefit from some more intensive training to ensure adequate initial skills. But if the surgeon can’t then maintain their skills via somewhat regular practice, errors may creep in. In a group of 6-8 surgeons, each may only get to perform the procedure once a year! Add in some interested emergency physicians, and no one can keep in practice.

The bit about ED thoracotomy is a bit of a red herring. Typically, this procedure is performed once the patient has lost their vital signs. Comparing mortality from REBOA with EDT here is not valid, because it appears that most of the REBOA patients in this study still had vital signs when it was inserted. It would be interesting if the authors shared the outcomes in the REBOA patients who had the device inserted after arrest to level the playing field with EDT.

So what to do? Be cautious and thorough if you are planning to try out REBOA at your center. Do the math. On how many patients per year can I expect to perform this? How many physicians want credentialing to do it? How many procedures can the typical physician expect per year? What is the baseline level of physician training and what additional training is needed? Will I report my experience to a national registry or write it up for sharing?

These are important questions! Everyone wants to play with the newest shiny toy in the toybox. But make sure that when you do play with it, you are able to provide the maximum benefit to your patients with the least amount of harm!

ACS Trauma Abstracts #1: REBOA! (And CT???)

This paper is from the group at ShockTrauma in Baltimore, who are really pushing the envelope of REBOA. We always worry about distal ischemia after balloon inflation, because the ischemia produced can be detrimental to the gut and lower extremities. This group was curious about what the flow patterns looked like with  inflation of the balloon. So in select cases, they obtained CT scans with contrast in patients while the balloon was fully inflated (!!).

They reviewed their experience over a four year period, looking at patients receiving a CT scan with the REBOA balloon partially or fully inflated.

Here are the factoids:

  • Nine patients were included. This makes sense because unstable patients should not go to CT scan, so this should be a very limited group.
  • Mean injury severity score (ISS) was 48, which makes sense. These patients are hurt bad!
  • Four patients had supraceliac REBOA (aortic zone I) and five had infrarenal (zone III)
  • Contrast was seen below the REBOA balloon in all patients, and was seen distal to the insertion site in half
  • Collateral flow around the balloon was identified in all patients

Bottom line: The authors found that REBOA decreased blood flow to the distal aorta, but certainly did not stop it. Collateral flow is underestimated, and probably provides a protective effect for the viscera and other structures while inflated. This is good news for REBOA proponents, because it suggests that placement may not cause as much risk from ischemia as originally thought.

But why oh why did they have to go to  CT in the first place?

Reference: Assessment of blood flow patterns distal to aortic occlusion (AO) using computed tomography in patients with resuscitative endovascular balloon occlusion of the aorta. JACS 225(4S1):S50, 2017.

REBOA vs ED Thoracotomy: Which One Is Winning?

Many trauma centers are talking about REBOA (resuscitative endovascular balloon occlusion of the aorta), but only a few are actually doing it. And of those, only a handful are doing it regularly and closely studying how it’s working.

The RA Cowley Shock Trauma Center is one of those very few. They have integrated the preparation phase for REBOA (femoral art line insertion) into their initial resuscitation protocols. This allows them to actually perform the technique quickly in any patient who starts to go bad and meets criteria. This center has been using REBOA nearly exclusively since they began studying it  a few years ago. They have actually supplanted ED thoracotomy (EDT) with this technique, and are a leader in producing data and studies on its nuances.

They compared short term outcomes in patients suffering traumatic arrest undergoing REBOA  (2013-2015) to those in patients with EDT (2008-2013). This was a simple study, with easy to understand statistical analyses.

Here are the factoids:

  • 19 thoracotomies and 17 REBOA were performed during the study periods (this shows how uncommon these procedures are, even at a busy center)
  • Average ISS was about the same (31 vs 26). Median GCS was 3 in both groups.
  • Return of spontaneous circulation (ROSC) occurred in 7 EDT and 9 REBOA
  • 13 EDT and 9 REBOA patients survived long enough to get to the OR
  • Mean systolic BP after occlusion was higher after REBOA (80 vs 46 torr)
  • There was only one survivor of the 36, and they received REBOA. This patient actually discharged home. (!)

Bottom line: Shock Trauma is a very busy center, and as you can see, even their REBOA numbers are low. This is why it is so critically important that all REBOA patients be part of a study. We really need to know how well it works, who it works best in, and what the downsides are. In this study, ROSC and survival to OR were statistically identical, but blood pressure was higher with REBOA compared to cross-clamping. Survival was also the same (abysmal), with one excellent outcome in the REBOA group.

The authors believe that REBOA and EDT are equivalent in terms of the variables they looked at. But remember, there are many other factors we need to look at, including things like resource utilization and healthcare worker safety. I strongly urge every center that is performing or considering REBOA to join a multi-center trial and/or report the the REBOA registry to hasten our understanding of this procedure.

Related posts:

Reference: Paradigm shift in hemorrhagic traumaic arrest: REBOA is at least as effective as resuscitative thoracotomy with aortic crossclamping. ACS Scientific Forum, trauma abstracts, 2016.

REBOA: The References

Here are a few references for some of the significant work on REBOA. Be aware that new research is now being published every month! Good luck keeping up!

References:

1. Resuscitative endovascular balloon occlusion of the aorta (REBOA) as an adjunct for hemorrhagic shock. J Trauma 71(6):1869-1872, 2011.

2. A novel fluoroscopy-free, resuscitative endovascular aortic balloon occlusion system in a model of hemorrhagic shock. J Trauma 75(1):122-128, 2013.

3. Survival of severe blunt trauma patients treated with resuscitative endovascular balloon occlusion of the aorta compared with propensity score-adjusted untreated patients. J Trauma 78(4):721-728, 2015.

4. Evaluation of the safety and feasibility of resuscitative endovascular balloon occlusion of the aorta. J Trauma 78(5):897-023, 2015.

5. The role of REBOA in the control of exsanguinating torso hemorrhage. J Trauma 78(5):1054-1058, 2015.

6. Resuscitative endovascular balloon occlusion of the aorta. Resuscitation 96:275-279, 2015.

Direct links to the REBOA series: