Opinions on mechanical thrombectomy in acute ischemic stroke?

[Zebra Hunter]

Currently on my elective radiology rotation and had a lecture given by an interventional neuroradiologist who mentioned that the "standard of care" for acute ischemic stroke w/ large vessel occlusion has recently changed. Based on 4 recent RCTs evaluating the efficacy of mechanical thrombectomy in acute ischemic stroke (2/4 demonstrating mortality benefit, all demonstrating functional benefit), he states that large vessel occlusion (LVO, pronounced El-Voh) should be thought of as the STEMI for neurology. Rather than rushing them to the cath lab, we should be rushing them to a facility with the capability to perform mechanical thrombectomy for acute ischemic stroke w/ LVO (if occlusion is located in anterior circulation, posterior circulation was not studied).

His recommendations for mechanical thrombectomy were, in addition to intravenous thrombolysis within 4.5 hours when eligible, is recommended to treat acute stroke patients with large artery occlusions in the anterior circulation up to 6 hours after symptom onset. He stated that for patients within the therapeutic window, they should be receiving CT upon admission to the ED and CTA immediately afterward if NIHSS>8.

Here's a link to some info regarding the studies mentioned and the recommendations: http://2014.strokeupdate.org/consensus-statement-mechanical-thrombectomy-acute-ischemic-stroke

What's y'alls opinions regarding the subject? Anyone have experience with this? Is anyone changing their practice regarding acute ischemic strokes?

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[Rendar5]

The trials are not consistently positive and only recently has there been benefit shown iirc. Neurologists love to jump forward stroke care the instant there is a single positive study without regarding th historical studies and without as much an established benefit as there is in cardiology. That said my gut feeling is that there is promise with this and perhaps better than tpa itself, but we need a lot more solid data before this is considered standard of care.

 

[shookwell]

Same as TPA. Let's ignore all the negative studies and jump on the newest thing once we manage to manipulate the data to show benefit. It's insane.



There might be patients who will benefit. The numbers seem impressive, maybe even too impressive. But there have to be consistently positive studies, not just some glimmer of hope. It's too early.

 

[Apollyon]

Based on 4 recent RCTs evaluating the efficacy of mechanical thrombectomy in acute ischemic stroke (2/4 demonstrating mortality benefit, all demonstrating functional benefit)

The trials are not consistently positive.

So which is it? Honest question. I mean, if they are RCTs, then they're level 1 evidence. I do not know the study design or power, or quality of the studies, but it's not like it's expert opinion only.

 

[Zebra Hunter]

So which is it? Honest question. I mean, if they are RCTs, then they're level 1 evidence. I do not know the study design or power, or quality of the studies, but it's not like it's expert opinion only.

There were 4 very recent RCTs (I'm talking a couple that were just published in the last few months) which had positive results. There were previous studies that had negative results (such as the MR RESCUE trial); however, based on what I was told, the studies utilized outdated equipment and were not as selective in the patients most likely to benefit from treatment (those with LVOs). Apparently clot retrievers have become more efficacious in recent years, and these studies are reflecting that, or so the story goes.

 

[xaelia]

Patient selection also improved – the RCTs specifically included only patients with LVOs and small ischemic infarct cores surrounded by viable areas of perfusion. To say "all LVOs" go to endovascular therapy is nonsense. To say "all LVOs" should go to a center with the capability of perfusion imaging, and an expedited referral to endovascular would be a better statement.

But people like to make thems money, and procedures makes thems money.

 

[TooMuchResearch]

There were 4 very recent RCTs (I'm talking a couple that were just published in the last few months) which had positive results. There were previous studies that had negative results (such as the MR RESCUE trial); however, based on what I was told, the studies utilized outdated equipment and were not as selective in the patients most likely to benefit from treatment (those with LVOs). Apparently clot retrievers have become more efficacious in recent years, and these studies are reflecting that, or so the story goes.

They retrieved the clots just fine in MR RESCUE,even with the older devices.

 

[Old_Mil]

Currently on my elective radiology rotation and had a lecture given by an interventional neuroradiologist who mentioned that the "standard of care" for acute ischemic stroke w/ large vessel occlusion has recently changed. Based on 4 recent RCTs evaluating the efficacy of mechanical thrombectomy in acute ischemic stroke (2/4 demonstrating mortality benefit, all demonstrating functional benefit), he states that large vessel occlusion (LVO, pronounced El-Voh) should be thought of as the STEMI for neurology. Rather than rushing them to the cath lab, we should be rushing them to a facility with the capability to perform mechanical thrombectomy for acute ischemic stroke w/ LVO (if occlusion is located in anterior circulation, posterior circulation was not studied).

His recommendations for mechanical thrombectomy were, in addition to intravenous thrombolysis within 4.5 hours when eligible, is recommended to treat acute stroke patients with large artery occlusions in the anterior circulation up to 6 hours after symptom onset. He stated that for patients within the therapeutic window, they should be receiving CT upon admission to the ED and CTA immediately afterward if NIHSS>8.

Here's a link to some info regarding the studies mentioned and the recommendations: http://2014.strokeupdate.org/consensus-statement-mechanical-thrombectomy-acute-ischemic-stroke

What's y'alls opinions regarding the subject? Anyone have experience with this? Is anyone changing their practice regarding acute ischemic strokes?

He is essentially correct. I believe the trials he references are MRsomething, ESCAPE, and one other. I would not push TPA at six hours as without a CTA and perfusion scan your information about clot size and location is limited. CTA and perfusion scan sere part of our standard stroke workup in residency - our interventionists were this combination of Hippocrates, Osler, and Jesus and as as good as that description - but usually not available out here in the real world. But you need to be talking to an interventional stroke shop about all your CVAs even if you don't end up transferring them. The evidence for mechanical thrombectomy in CVA is stronger than TPA for most STEMIs.

 

[xaelia]

This is what I wrote about the publications after their presentation in Nashville:
http://www.emlitofnote.com/2015/02/christmas-comes-early-for-endovascular.html

Re: talking to an interventional stroke shop – maybe. These trials only found eligible patients at a rate of 1-2 patients per month, or 1 in 100 screened, so it's going to be quite uncommon to identify patients with the same potential for benefit as these trials. Don't forget the earlier, unselected trials were negative – and unselected LVO intervention probably erases a ton of the benefit advantage: http://www.ncbi.nlm.nih.gov/pubmed/25451851

Not as though unbiased physicians will be any part of the discussion between Covidien/Medtronic and the AHA/ASA when coming up with new guidelines ....

 

[erdoc00]

Lol... i'm sure the neurointerventionalists did indeed find a treatment benefit from a very expensive technique that they just so happen to profit from. RCTs are about as unbiased as the lobbyists to congress.

Also, I always love these guidelines which are very clearly written by academic people who have no familiarity with how things actually work in the community. My favorite STEMI one (transferring from a single coverage shop to the tertiary center) was always "Just give them lovenox and hold the thrombolytics. We'll get them to the cath lab when they get here..." I've never once seen this transfer happen within 90 minutes, let alone actually get to the cath lab within that timeframe. A lot of these things sound great when you don't have to consider the logistics involved.

 

[Apollyon]

RCTs are about as unbiased as the lobbyists to congress.

Isn't that just a bit to the absurd side? I mean, usually, the fix isn't in with "randomization".

 

[erdoc00]

Isn't that just a bit to the absurd side? I mean, usually, the fix isn't in with "randomization".

The process isn't to blame. It's choosing an outcome to fit your agenda that's to blame. Choosing to make sure you get the results you want and not publishing anything you can't shoehorn to show the outcome you want. "See right here, if your name begins with M and you come into the hospital on a Tuesday when the crescent moon flies in the night sky, you are better able to repeat 5 words than people who don't get the procedure."

And while that's bad enough, it becomes a complete disaster when these things become "standard of care" and there's no recourse against it because of the inertia generated by the original study.

 

[e30ftw]

If I had a proximal MCA infarct and could be in the neurointerventional suite getting clot retrieval within 3 minutes of the embolization I would want a neurointerventional clot removal.

if it's more than 20 minutes just stop spending money cause my brain is dead.

dust to dust.

what they really should do is fit everyone over 65 with a tPA pump and the minute the pump senses a muscular hemiparesis it would mix and infuse 90mg of tpa. the hemorrhagics would just crump then and there and maybe the ischemics would improve and we could finally see improvement in outcomes from tPA.

 

[Zebra Hunter]

This is what I wrote about the publications after their presentation in Nashville:
http://www.emlitofnote.com/2015/02/christmas-comes-early-for-endovascular.html

Re: talking to an interventional stroke shop – maybe. These trials only found eligible patients at a rate of 1-2 patients per month, or 1 in 100 screened, so it's going to be quite uncommon to identify patients with the same potential for benefit as these trials. Don't forget the earlier, unselected trials were negative – and unselected LVO intervention probably erases a ton of the benefit advantage: http://www.ncbi.nlm.nih.gov/pubmed/25451851

Not as though unbiased physicians will be any part of the discussion between Covidien/Medtronic and the AHA/ASA when coming up with new guidelines ....

So xaelia, considering that you seem to be quite knowledgeable on the subject, if you don't mind answering, what are you doing with those patients that show up to your ED with an acute ischemic stroke that meet the NIHSS cutoff, and are within the therapeutic window for mechanical thrombectomy? Are you getting the CTA immediately after the initial CT shows no hemorrhage, or are you just consulting neuro and waiting for their recs?

 

[xaelia]

The CTA with perfusion happens while on the table for the NCCT. Then neurology decides what to do.

 

[engineeredout]

If I had a proximal MCA infarct and could be in the neurointerventional suite getting clot retrieval within 3 minutes of the embolization I would want a neurointerventional clot removal.

if it's more than 20 minutes just stop spending money cause my brain is dead.

dust to dust.

what they really should do is fit everyone over 65 with a tPA pump and the minute the pump senses a muscular hemiparesis it would mix and infuse 90mg of tpa. the hemorrhagics would just crump then and there and maybe the ischemics would improve and we could finally see improvement in outcomes from tPA.

Ever hear of the ischemic penumbra? The thought that yes the epicenter of the stroke is dead, however there is potentially a larger area with a (albeit crappy) blood supply that is able to keep it somewhat perfused for just a little while longer. Long enough for some intervention to open things up? I don't know. Believe me, I'm not a huge tPA proponent, however if you get me somewhere within 4.5 hours that has tPA, I'm not already bleeding into my brain, and half my body is paralyzed and I can't speak a coherent word, tPA MY ASS. Little to lose at that point.

 

[Birdstrike]

Ever hear of the ischemic penumbra?

No. What's that?

 

[e30ftw]

Ever hear of the ischemic penumbra?.

ahh the penumbra.. the part of the brain all the neuroscientists in med school told me was the target for the thrombolytic therapy that would revolutionize stroke treatment.. the main purpose of the thousands upon thousands of dollars I spent today in acute stroke patients ordering CT perfusion studies.

meh. physiologically it makes sense but I have yet to see good externally validated evidence supporting really any treatment for acute stroke, especially at 4.5 hours. other than prevention and long term rehab of course.

I mean, I could write a research proposal for banging stroke patients in the head with one of those padded bats from american gladiator to mechanically break up the clot via repeated head bashing and with good enough statisticians make it show benefit p< 0.05.

Believe me, I'm not a huge tPA proponent, however if you get me somewhere within 4.5 hours that has tPA, I'm not already bleeding into my brain, and half my body is paralyzed and I can't speak a coherent word, tPA MY ASS. Little to lose at that point.

the only reason I would want tPA 4.5 hours after an acute stroke that left me hemiplegic and globally aphasic is in the hope that it causes a fatal intracranial hemorrhage.

make mine a double.

 

[Hooper]

So our hospital got a neuro-IR guy within the past year and at our ER resident grand rounds we just had a multi-disciplinary meeting with neurology, neuro-IR, and all the EM residents to discuss this very topic. Whether to call stroke alerts on pts who aren't TPA candidates and when to order CTAs and stuff. One of the residents questioned the neuro-IR guy about the previous studies in NEJM which showed no benefit and increased harm with intra-arterial therapy. His answer was basically the evolution of the equipment and more experienced people doing it, but he stands to make a crap ton of money with this therapy so take it with a grain of salt. Also, I think the person doing it and their expertise is a factor, like any other complex procedure.

I've done this to two pts. Both of them were on Xarelto and therefore not TPA candidates. One came in with TIA symptoms with normal neuro exam. Then she proceeded to have a massive MCA stroke right in front of my eyes. CTA confirmed it. IR (not neuro-IR) took the clot out. She was randomly my pt in the ICU 6 months later and had absolutely no neurologic deficits. Pretty amazing.

A couple of days ago: Guy in his 60's who is functionally independent, lives with his wife, also on Xarelto. Stroke like symptoms for an hour and a half which mostly resolved except for expressive aphasia. Mild but significant enough that he couldn't actually express himself and had difficulty naming certain objects. That was his only deficit. CTA showed filling defect in M2 of right MCA. After long discussion with the family, weighing risks and benefits, they opted for clot retrieval. Clot was removed approximately 3.5 hours after pt was last seen normal. Neuro-IR came down a couple of hours later and said the guy is talking completely normally. Thankfully, procedure was without complications.

That's my N of 2. I think this therapy has a lot of potential and if it gets good enough, maybe will even supplant TPA, similar to treatment of MI. I agree that more research probably needs to be done, though.

 

[Doctor Bob]

I mean, I could write a research proposal for banging stroke patients in the head with one of those padded bats from american gladiator to mechanically break up the clot via repeated head bashing...

Ohhh... I want this therapy to be available... I would use it off-label on every shift.

"Fibromyalgia flare? Hang on, I think I have a novel treatment around here somewhere..."

the only reason I would want tPA 4.5 hours after an acute stroke that left me hemiplegic and globally aphasic is in the hope that it causes a fatal intracranial hemorrhage.

This was what we told our stroke neurologists... that if any of us came into our ED with a stroke we wanted them to push TPA. And if we had a hemorragic conversion, we wanted them to push more TPA.