Good morning or good afternoon. This is Megan Brenner. I am delighted to talk to you today about RBOA indications and contraindications of RBOA in non-traumatic hemorrhage. Thank you to the SCCM Program Committee for the opportunity to present. The following are my disclosures. So today I'm going to briefly discuss some clinical reports and examples of use of RBOA for non-trauma, talk about its use in cardiac arrest, postpartum hemorrhage, as well as touch on some current and future technology. So as we all understand, RBOA is intra-aortic balloon occlusion. We describe it in three places in the aorta, Zone 1, Zone 2, and Zone 3. Zone 1 is between the left subclavian and celiac arteries. The balloon is inflated in Zone 1 in instances of intra-abdominal hemorrhage or intra-abdominal and pelvic and junctional hemorrhage. Zone 2 is where the visceral vessels originate, and we try not to occlude the balloon in that area. Zone 3 is below the lowest renal artery and just above the aortic bifurcation. Occlusion at Zone 3 is predominantly for pelvic and junctional hemorrhage. Zone 1 occlusion also is important for patients, regardless of bleeding source, for those that are in arrest. It's used as a resuscitative measure primarily and secondarily as a hemorrhagic temporization. For Zone 3, the most common use is for pelvic fractures and pelvic hemorrhage and trauma, as well as junctional hemorrhage and postpartum hemorrhage. So, REBO for non-trauma hemorrhage is not new. It's been used for decades in non-trauma patients. It has been used by surgeons through open approaches and arteriotomies. It has been used by interventionalists, such as interventional radiologists and endovascular surgeons, through percutaneous access. What is new, however, in the last almost 10 years, it now has a name, standardized steps, formal training platforms for non-interventionalists, as well as some clinical data for use both in trauma and non-trauma by acute care surgeons. So, this is just an example of a summary paper which demonstrated the use of REBO for ruptured AAAs, which has improved the mortality of this almost uniformly fatal problem down to 13%. So, it has been proven in the vascular field to significantly improve outcomes for patients with ruptured AAAs. The other most important, most importantly, it has also been demonstrated to allow patients to tolerate the induction of anesthesia, despite being profoundly hemodynamically compromised. The balloon is inserted and inflated in the thoracic aorta and that allows central and centralized perfusion to the coronaries in cerebral circulation, allowing them to tolerate induction of anesthesia and prevent arrest. This is a paper we published from the University of Maryland, taking a look at our non-trauma REBO uses by acute care surgeons. So, this included many different etiologies of bleeding. The biggest difference between our use for non-trauma and trauma in this first series was that the majority of the REBOs were occurring in the operating room, so the patients were already ready, and the time from the procedure to hemorrhagic control was much shorter than what we have seen in trauma, because we place the REBO in the ED and usually travel to a different location for hemorrhage control. So, this particular series demonstrated our use mostly in the operating room. And just a quick overview, the complications, not surprisingly, as we've seen with trauma, and really any patient with life-threatening hemorrhage, AKI, is certainly significant. The mortality was certainly significantly high, but this was a last ditch effort to salvage these patients who were bleeding to death. So, we developed a pathway and an algorithm for use for REBO for non-trauma. It looks a lot like our algorithm for non-trauma, but the indications would be things like GI bleeds, RP hematomas, any ruptured visceral aneurysms, any iatrogenic injury in the abdomen or pelvis, placental abnormalities such as postpartum hemorrhage or accreta spectrum and accreta spectrums, any obstetric emergencies. So, essentially, the life-threatening abdominal or pelvic hemorrhage would lead you down a pathway either to yes or no. Obviously, if it's yes, if the patient is near or in cardiac arrest, the patient receives a Zone 1 REBO regardless of where the bleeding is coming from. If they are hypotensive and you can at least resuscitate them and they are responsive to initial resuscitation, that is a great time to be sure you have an arterial line in the common femoral artery just in case that response is transient and hold off the REBO if that patient does respond to traditional resuscitation. But if they don't, their hypotension is refractory to resuscitation, just like we do in trauma. If the source of bleeding is pelvic or junctional, the patient receives a Zone 3 REBO and a Zone 1 if the hemorrhage is in the abdomen. So, just examples of how REBO is being used in non-trauma currently. So, cardiac arrest, you're all very familiar with the mortality of this issue. Everyone here knows CPR alone is absolutely inadequate and the mortality is extremely high. And if they do work, they work for a very brief time, if at all. So, where does REBO fit in, in patients that are in cardiac arrest from non-traumatic causes? So, you're all familiar also with entities like ECMO and ACPR, selective aortic arch perfusion. A lot of work has been done by James Manning on that. So, where does REBO fit into all of these entities? Well, there's definitely a little bit of overlap with all of these entities, but where does it fit in in the clinical setting? So, obviously, it depends what resources you have at your institution. REBO is a fantastic bridge to return ROSC rapidly while ECMO or ACPR is being set up to occur. And obviously, SAP is still in development, but certainly can be used in this setting to bring patients certainly back from cardiac arrest. So, aortic occlusion, as you all know, improves coronary perfusion pressure. This is not a surprise to anyone in this audience, improving both coronary and cerebral perfusion pressure. And then, obviously, the CPP doubles with occlusion. But obviously, aortic occlusion is alone not sufficient. We certainly need high-quality CPR in order to have our patients with return of spontaneous circulation. So, obviously, again, I stress high-quality CPR because you've probably all seen different qualities of CPR, but high-quality CPR and a CPP greater than 15 certainly has a higher chance of patients obtaining ROSC. So, this is one of the more recent case series. This is a large, the largest clinical observational series of 10 patients that are in arrest from non-traumatic etiologies. This was written by the HEMS unit, the Norwegian Air Ambulance System. They have a seizure on board who performs these procedures, and they perform ROBOA, aortic occlusion, with ultrasound guidance in these patients. The technology that they used was developed actually over there. It is now FDA-approved. It is called the Nurescue, and it is a small, really handheld, automatic balloon management system. It goes through a seven-front sheath, and you can actually just program the small battery-operated device. You can program the proximal blood pressure, so the balloon will adapt automatically to whichever blood pressure that you set for the patient. It's a seven-front device that goes through an eight-front introducer sheath. It has, as I mentioned, an automated inflation and deflation and obviously pressure release if there's no longer a need for aortic occlusion. So, again, newly updated, but it is FDA-approved now in the U.S. So, for this particular study, six out of 10 of these patients obtained ROSC. They also found that entitled CO2 increased after aortic occlusion, which is what we have documented as well in cases of trauma. Four patients re-arrested after ROSC, and three patients survived hospital admission. There were no ROBOA-related complications, and one patient survived more than a month. One of the more important demonstrations that this series came out with is that it did not delay transport time. This is obviously a huge issue, you know, where the procedure takes place, where is the time going to come from to do this, but they found that it certainly did not delay transport time. I imagine that this occurred en route. So, another review of out-of- hospital cardiac arrest patients. This is just a great review and discussion about ROBOA being performed in the ED by ER physicians for out-of-hospital cardiac arrest. The phase one trial is ongoing, was FDA-approved, and so far there's been ROSC in four out of five patients with cardiac activity on ultrasound after aortic occlusion, and it is currently undergoing midterm FDA review. So, unlike trauma, you know, the tank is full, they are in arrest, but the tank is full, they are not in hemorrhagic shock, so circulation isn't occurring, although there is a full tank, but no squeeze. So, cardiopulmonary disease obviously will limit the tolerance of aortic occlusion. Unlike our healthy young trauma patients who can tolerate the afterload increase with aortic occlusion, the cardiopulmonary etiology of the arrest will limit the tolerance of AO, which means that we really need extremely limited full occlusion times. That is also probably a great indication for partial ROBOA as well. We need to refine that also in trauma, but just like trauma, ROBOA is only a bridge to definitive treatment, and technology will certainly advance to provide specific devices for us. So, another use, and the one that I am most frequently called to do currently is ROBOA for postpartum hemorrhage. It is certainly not new. Many case reports out there talking about prophylactic and emergent hemorrhage control with interior balloons. Bilateral internal iliac artery balloons have been described over the past few decades, but those have never become really the standard of care. Source control could be a reason. The source of hemorrhage can be certainly above the internal iliac arteries in the distal and even the mid-abdominal aorta. There can certainly be large collaterals and branches causing hemorrhage. So, bilateral iliac artery balloons may just never really obtain source control. It also has required consultants, which may not be available. Interventional radiologists or endovascular surgeons are certainly not always in the hospital in the middle of the night or available during the day, unlike acute care surgeons who certainly are enabled now to do this procedure. So, as I mentioned before, zone 3 ROBOA is indicated in postpartum hemorrhage. This is for pelvic bleeding. And here's just an overview. We placed the balloon in zone 3, just above the bifurcation. But just like trauma, if the patient is in arrest, then ROBOA at zone 1 is indicated. In these cases of profound circulatory collapse, the balloon provides a resuscitative measure. Secondary is the hemorrhage temporization. So, currently we use ROBOA for postpartum hemorrhage in three clinical scenarios. One is the emergent intra-op consult. Our in-subject colleagues are not aware that there is a patient who is somewhere on the placental creative spectrum. Another one is a planned C-section that has a preoperative diagnosis or pre-C-section diagnosis of Procreta and Orcreta. And then there's a very small number of patients, although they certainly do exist, that present to the ED with postpartum hemorrhage or are in the ICU and develop postpartum hemorrhage. So, this is another review from Norway. Patients with severe postpartum hemorrhage, just looked at 36 of them. Again, as we've noted in trauma, the systolic blood pressure increases significantly after aortic occlusion. They had no deaths and certainly a high number of thrombotic complications. But these devices were at least seven French sheets that they used, and there was one aortic complication that required a stent graft for repair. Another observational meta-analysis on the prophylactic use of Roboa for placentas on the placenta spectrum noted that really the blood product transfusion was significantly lower by over two units of blood products used. So, we recently had, as you all know, a huge blood shortage nationally and ended up really being grateful that we had Roboa, certainly for these women who were undergoing C-sections during this blood shortage. Another rationale for Roboa and postpartum hemorrhage, those of you who work closely with your OB colleagues know that the Joint Commission evaluated and made a statement that, you know, July of 2020, which probably got pushed back because of the pandemic, but they were looking at really the timely treatment for maternal hemorrhage and how institutions who wanted to be Joint Commission accredited required a comprehensive review and plan to move forward in order to improve the outcome of these patients. So, we got together with our colleagues and started training for an overhead page that we called CODE-OB-MTP, which is for emergency consultation. These are the patients that are in the OR getting a C-section without the preoperative diagnosis, placenta accreta or procreta or increta. So, this is a multidisciplinary response. We trained to do this and we do it in practice now. This is when the blood bank, the trauma team, the trauma nurses, the MTP team, the ICU team, if available, comes and responds to the hemorrhage. Of course, we place the A-line and the Roboa if that is indicated. And then the post-op ICU management is also done by us, which is really a great continuity of care for these patients. So, if you're interested in using Roboa for postpartum hemorrhage, I would certainly create a multidisciplinary protocol for both elective and emergent use of Roboa. We schedule these elective cases that we know about in the main operating room, not in labor and delivery. Just make sure to keep the access groin extended and the patient supine during and after the procedure. A lot of times a cystogram is required, especially if it had been inherent to the bladder or any of the structures near. So, if the cysto is performed, just keep the access extended. The other leg can certainly be in lithotomy, but make sure to keep that access leg supine and not flexed at all times. And, of course, the most important thing if the patient's in profound shock, and this is an emergent call for help, place the balloon at zone one until there's some hemodynamic improvement, which can be sustained enough to bring the balloon down to zone three. Another critical component of Roboa, both in trauma and non-trauma, is vigilance with the pulse exam for the 24 hours after the procedure. Very low threshold for angiograms and duplex ultrasounds. The coagulopathy of pregnancy is certainly not well understood by me, and I'm shocked every time I do this, just really how thrombotic the state of pregnancy is, and it really makes Roboa certainly higher risk for this procedure and really any other where any artery is cannulated. So, we've seen, you know, higher incidence of thromboembolic events than we did in trauma, and we need to understand that much better. Obviously, smaller profile devices will reduce these events, and anecdotally they certainly have so far. So, technology, those of you who are familiar with the Roboa technology, if you are aware that ER Roboa Plus has been replaced last year with the ER Roboa Plus, pardon me, replaces the original ER Roboa. There are a few differences on the catheter. There's dual-sided markers you can see now on both sides. There's a documentation tag to remind you to write down the time of aortic occlusion, what the inflation volume, the insertion distance was, as well as the blood pressure. It's also guidewire compatible, so if the patient needs an angiogram after a wire can be inserted, it comes out really through just the beginning part of the P-tip, and this device can be exchanged over a guidewire. So, the P-Roboa Pro is also a technology from Prytime. This has been FDA approved, but is currently in clinical trials at select sites across the country. It requires two A-line transducers and gives you a blood pressure both above and below the balloon, and allows you to set proximal and distal pressure. Some newer technology, the Frontline MedTech Cobra OS device has been both FDA approved and is available on the market. This is a balloon catheter that goes through a forefront sheath. The diameter is 28 millimeters wide. It is also a wire-free balloon device. It is compliant and fits through, again, a forefront sheath. So, this is a new technology on the market, and we look forward to learning more about all of these new products that are coming out for Roboa. So, Roboa is not just a tool for trauma, as I've been mentioning. It is used for non-traumatic hemorrhage as well as non-hemorrhagic shock. It can be part of a comprehensive service offered to other specialties and provide temporization of hemorrhage resuscitation. We can provide SICU care and complication mitigation as acute care surgeons and as a specialty team. Data, just like trauma, will help us determine which patients can benefit the most, and technology will definitely expand the indications, providers, and improve the safety profile. Thank you.

RBOA

indications

contraindications

non-traumatic hemorrhage

aorta

improving outcomes