Melanie Cole, MS (Host): Welcome to UAB MedCast. I'm Melanie Cole, and today we're highlighting mechanical thrombectomy for stroke. Joining me in this Physician Roundtable panel, we have Dr. Michael Lyerly. He's a Neurologist in Vascular Neurology and an Associate Professor at UAB Medicine, and Dr. Elizabeth Liptrap. She's a Neuroendovascular and Vascular Neurosurgeon and an Assistant Professor at UAB Medicine.

Doctors, thank you so much for joining us for this update today. Dr. Lyerly, I'd like to start with you. Please begin with the pre-hospital management and field treatment. Start with the chain of events that favor good functional outcome for stroke. What are some of the most important factors as far as the latest clinical guidelines? What would you like other providers to know and update?

Michael Lyerly, MD: Thanks, Melanie. Really, we've always highlighted the stroke chain of survival, which starts with early detection of stroke in the field and routing the patient to the appropriate level of care. Detection starts with either patient recognition or bystander recognition. And there've been a lot of public education campaigns, both locally here in our community, as well as nationally from the American Heart Association to really educate the population on signs and symptoms of stroke and the timeliness of needing to activate 911 and get an ambulance dispatched to pick the patient up.

Where we're starting to see some changes, is that we used to just take the patient to the closest hospital to potentially receive a life saving therapy called TPA or a thrombolytic. That's a clot busting medicine that is available at essentially every hospital in the state. But as we're going to talk about today, we are now having more options for treating patients who are having certain types of strokes using mechanical thrombectomy.

And this has led to changes statewide and nationwide in how we route patients to try to get them to the correct hospital as early as possible. For many patients, that may still involve getting them to their nearest hospital to receive the clot busting medicine and then transferring them on to a higher level of care where they might undergo a mechanical thrombectomy.

But for some patients, it may make more sense to bypass that initial hospital and take them straight to the comprehensive stroke center or the thrombectomy capable center so they can be considered for those therapies. So we're starting to see a lot of changes in this area, including in the state of Alabama.

We're locally, having a what we call a severity based triage, where our EMS providers are examining the patient, collecting history, and then based on a scale that we developed here at UAB, determining if the patient may potentially qualify to bypass that initial hospital and go straight to the thrombectomy capable center.

We went live with this several months ago in the Birmingham region, and now we're starting to spread this out statewide, as a pilot to see if we can get the patient to the correct level of care as early as possible.

Host: Dr. Lyerly, can you expand for just a minute on thrombectomy capable stroke center and the importance and how is this designated?

Michael Lyerly, MD: Sure. This skit set will be called Stroke Center Designation. There are different credentialing bodies that designate different hospitals as being comprehensive or primary stroke centers or even acute stroke ready hospitals. That can be done at the national level through the Joint Commission, although many states including Alabama also have state level designation.

A comprehensive stroke center, which is what we are here at UAB, is a facility that is able to provide 24-7 access to neurologists, neurointerventionalists like Dr. Liptrap, neurointensive care specialists, and also people who are actively engaged in research, including offering clinical trials.

The next level is a thrombectomy capable center, which is a hospital that can perform mechanical thrombectomy, although it may not be offered 24-7, so it's a little more limited, and they don't have all the resources that a comprehensive stroke center has.

The next level down, which is more common, is a primary stroke center. These have been designated in the United States for over 20 years now, and these are hospitals that can deliver acute stroke care, including the provision of IV thrombolytics, such as alteplase or tenecteplase, but they're not engaged in providing mechanical thrombectomy. That may be the correct level of care for many of the stroke patients that we have, but it's not going to be the correct level of care for a patient who has a large vessel occlusion who needs to undergo a mechanical thrombectomy.

The, final tier down is what we call an acute stroke capable hospital. These are hospitals, that we find throughout the community that are able to provide the initial stabilization and in many cases can deliver the initial thrombolytic treatment, but that typically the stroke patient will then transfer out to a higher level of care for ongoing workup and monitoring.

Host: Thank you for that. And Dr. Liptrap, why don't you speak about the current standard of care for thrombectomy. Tell us a little bit about anything that's changed in the field, patient selection, benefits of this treatment, and how it compares to medical management alone.

Elizabeth Liptrap, MD: Thanks, Melanie. So we work with our stroke neurologists, like Dr. Lyerly, to select patients who are appropriate candidates for thrombectomy. So, often we'll get a call about a patient, and go over it with our stroke neurologist, the imaging findings and the history to, determine their eligibility.

And so, as time has gone on, we've had sort of extended the windows for patients who are eligible for a thrombectomy. So, in the past, when we first started doing this procedure, patients who had their onset of stroke within six hours were the only ones who were eligible, but that has gone on to be extended out, to 24 hours and sometimes even longer, depending on imaging findings, which may indicate that there still is brain tissue that can be salvaged.

 As well as, we've extended it to patients who we're not sure if they have brain tissue to salvage. That's sort of a newer indication. So that's kind of the biggest thing that has changed, in terms of patient selection. As far as the procedure itself, we have our attending interventionalists, as well as our neurointerventional teams who are available, 24-7 here at University of Alabama, to provide care for our patients.

And so we, get our patients in as quickly as possible to the interventional suite. We're always trying to lower our times from the door to the time of our onset of our procedure and we use a variety of techniques to take out the thrombus causing the stroke. And so, the techniques include, using stent retrievers, which are like little metal mesh devices that can help pull out a clot, aspiration catheters to suck out the clot, and bloom guide catheters, which, help us get up to the area of the stroke and can help facilitate pulling out the clot more effectively. So we can use these as a single strategy or in combination with each other, to help improve the success rate of pulling out that thrombus.

Host: Dr. Lyerly, what would you like to add about patient selection? Because it's quite important for other providers to hear and what UAB is doing.

Michael Lyerly, MD: I think there are a lot of differences in how various hospitals across the country do patient selection. Sometimes this is done by a vascular neurologist such as myself. Some places it's done by the interventionalist like Dr. Liptrap. Here we tend to have a very collaborative relationship where both the stroke neurologist and the interventional vascular neurosurgeon, review the case together and determine the best next step, whether it be going forward with a mechanical thrombectomy or potentially just doing medical management.

One thing that has changed in the past few years is we're seeing more utilization of telemedicine systems to select patients, before they even get to a tertiary center like UAB. Particularly in a rural state like Alabama, many patients initially present to a hospital in the community that may be hours away from a thrombectomy capable center and networks that utilize telemedicine can have a stroke specialist make that initial evaluation of the patient, look at imaging, and determine very quickly if the patient needs to be transferred to a higher level of care.

As an example, when I started doing telemedicine here at UAB, we actually had a patient present to a hospital two hours away from here, and within a couple of minutes of coming on camera and examining the patient, we immediately were able to make a determination that the patient needed to be urgently transferred out.

And in that case, the ambulance that initially brought the patient to the hospital was actually on standby. And they were able to load the patient right back up in the same ambulance and transfer them up to UAB in Birmingham, where he underwent mechanical thrombectomy. So I think we're going to see more and more selection outside of centers like UAB in the pre hospital setting or outlying hospitals to determine if patients are eligible before they even get to UAB.

Host: Well, then, Dr. Liptrap, speak a little bit about mechanical thrombectomy itself and do you see that all other institutions, is there any limitations with this? What do you see happening in the future with it as far as widespread awareness, more hospitals being designated? Tell us a little bit about that.

Elizabeth Liptrap, MD: So mechanical thrombectomy, is quite an effective tool in stroke treatment and it's a way to potentially reverse the possibility of damage to the brain tissue when a stroke is occurring. There are a lot of centers that are trying to recruit interventionalists to have the ability to perform mechanical thrombectomy and other neurointerventional procedures. As we had discussed before, the indications for mechanical thrombectomy have been expanding, over time and I think that's going to continue to progress in the future. Our devices that we use are constantly improving and I'm sure that those are going to become more effective. We are always trying to figure out ways to decrease the time to get the patient from sort of our hospital doors to the angiosuite to perform the thrombectomy.

And there are a number of centers that have sort of like mobile stroke centers, stroke, mechanical thrombectomy capable vehicles, that can help decrease the time that a patient would have their stroke onset to getting the procedure done.

Host: That really is an exciting time in your field, and Dr. Lyerly, as we get ready to wrap up, I'd like you to speak to other providers about what you see as the most exciting advancements in that pre hospital. You mentioned multidisciplinary and the communication. And Dr. Liptrap just mentioned even mobile stroke centers, which we're hearing more and more about. Where do you see this all tying together? Bring it all home for us.

Michael Lyerly, MD: For me, I think the most exciting thing is the new collaborations that we're developing across the state. Doctors in outlying ERs aren't just taking care of stroke by themselves now. Most hospitals have relationships with tertiary referral centers and in particular telemedicine networks, and now we're really bringing a more collaborative approach to the bedside of the patient where you have the local provider, you have the neurologist potentially either in person or on video, you have trained stroke teams and stroke nurses who are up to date on current stroke management.

And we're really seeing these developing across the community and that's really exciting that we're offering higher level of care than what we have previously.

Host: Thank You both for joining us and giving us an update on the exciting advancements in mechanical thrombectomy at UAB Medicine. And for more information, please visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast.

I'm Melanie Cole. Thanks so much for joining us today.