Tag Archives: REBOA

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:

REBOA Part 5: The Real Bottom Line

We are now entering the “golden age” of REBOA. A number of small, single-institution studies are beginning to appear, most of which tout reasonably positive results. And enough articles are now available to even support a few authors seeking to publish review articles.

Yes, REBOA shows a great deal of promise. But there are a lot of details yet to be worked out. Here are some of the items on the REBOA “questions to answer” list:

  • What are the best indications (and contraindications) when considering this highly invasive technique? You will notice that I only listed general indications here. There is some agreement at the major REBOA centers in the US, but there are a lot of differences of opinion as well.
  • What kind of training is required to assure competence with this technique?
  • What kind of experience, supervision, performance standards should be required for credentialing?
  • What about the anatomic, physiologic, and metabolic complications of this technique?
  • How long can the catheter be left in place?
  • What kind of monitoring is required to assure limb and overall patient safety?
  • What about the inevitable technical improvements that are ongoing? In only a few years we have moved from 12 Fr catheters to 7 Fr. From guidewire systems to wireless ones. Expect numerous advancements that will reduce complications and improve survival.

Bottom line: This is a very exciting new technique. But we are still very early in the REBOA life cycle. Everybody wants to be doing the next great thing, but be careful! We are still working with a huge knowledge deficit, and additional published work is essential. If you are working outside of an established REBOA center, I highly recommend you do two things. First, get some training for this complicated technique (see page 1). And don’t let your experience go to waste. Design or join a good study that will contribute to the global knowledge base on REBOA.

Tomorrow: References (if you want to look this stuff up)

Direct links to the REBOA series:

REBOA Part 4: What Are The Results?

The first modern paper published on REBOA for trauma in 2011 was really a description of the technique using the catheters available “back in the day” (only 5 years ago!). There were six papers published in 2012 through 2015 which I term the years of the pig, as we sought to figure out if this was really something we could and should do in people. The answer in all six was a resounding yes.

Next, a Japanese group published a retrospective database review of 45,153 humans, of whom 452 patients underwent REBOA placement. REBOA has been in use in Japan for a number of years. It is typically placed by emergency physicians, for whom it is a competency requirement for board certification. Raw mortality numbers were worse (76% with REBOA vs 16% without). This poor result persisted even when the patients were matched for their ISS difference (35 with REBOA vs 13 without).

This was troubling, but it was a registry study and questions also arose regarding experience levels of the clinicians. Major trauma is a less frequent event in Japan, and trauma surgeons do not typically take in-house call, which may have resulted in delays to definitive control of hemorrhage.

Another Japanese study published last year was a single center review of 24 insertions over a 7-year period. REBOA survival was 29% vs a TRISS probability of survival rate of only 13%. Better news! However, temper this with one vascular injury and two ischemic limbs, all of which required amputation.

And now, more human studies are beginning to trickle down into the journals, with promising results.

Tomorrow: The real bottom line.

Direct links to the REBOA series: