Treating a Blockage-Type Stroke – Free Page

Did You Know That…  Luke Perry died of a stroke.  He died on March 4 of this year (2019).  Everyone knew Luke and most ladies loved him after he played Dylan McKay on Beverly Hills 90210.  He was on the show from 1990 to 1995 and from 1998 to 2000.  He had another star-power role playing the character Fred Andrews on the CW network series Riverdale.  His popularity brought him to roles on many shows, such as Will & Grace, Criminal Minds, The Simpsons, and Law & Order: Special Victims Unit.  His filmography includes the hits Buffy the Vampire Slayer, The Fifth Element, and Once Upon a Time in Hollywood.  This final movie in the list was his last big movie performance.  His death from a massive stroke shocked all his fans; he was only 52.  Far too young to die!

First Things First

We apologize if it feels like we’re giving orders right here at the top of the page, but…  A stroke cannot be treated unless it is recognized, 911 is called, the person is in an ambulance, and makes it alive quickly to a Certified U.S. Stroke Center.

If someone is having a stroke, call 911 immediately.

Even a few minutes delay in calling 911 can make a huge difference.  Those few minutes can mean the death, rather than the rescue, of a part of the brain.  Death of brain tissue translates into disability for the person, or, if more of the brain dies, the individual dies. 

First – We Need a Definition

Okay, we know, first we start by giving you orders, then we lapse into definitions.  Yes, unbelievable behavior on our part, we agree!  In this case, though, this medical definition is important to understand so that one can understand about strokes, stroke treatment, and medical terms for stroke time periods.  The word we’re defining is “acute”.  Acute is a measure of time, not a measure of severity.

Treating the Acute Stroke

A stroke is acute if it occurs suddenly, it strikes out of the blue, a complete surprise.  To be successful, treatment for an acute stroke needs to be acute treatment, that is, treatment now with a capital “N”, not just soon, but right now.

More on “Acute”

In medical terminology, the word “acute” means a short interval of time.  As we said above, “acute” is about time.  It’s not about severity, not about how severe or critical a situation is, though we understand that many people incorrectly use it that way.  If just now you cut your finger on a broken glass, you have an acute laceration.  It was quick and just happened.  Not severe, maybe, but acute.  If you’ve had cancer for 5 years and you’re dying, and you’ll die in the next week or two, your cancer and death are severe but not “acute”.  Your medical condition and situation certainly are awful, but they are chronic, happening over a long period of time, not acute.  The opposite of acute is chronic, that is, of long duration.

Now That We’ve Bored You so badly with Definitions That You’ve Quit Reading…

Acute Treatment (treatment right now) for an Acute Stroke (a stroke that just happened) Caused by a Blockage (Thrombus or Embolism)

The concept of an “acute stroke” is important because currently in the medical world of neurology, cardiovascular intervention, and emergency medicine there are important discussions about the best treatment for strokes.  It’s a valuable discussion for many reasons, including that the debate and maybe even some sense of competition among physicians, institutions, and companies for the best treatment drives the evolution of ever better stroke treatments.

tPA – Intravenous Medication

One such area of discussion concerns which of the three available tPAs to infuse during the first four hours after an acute thrombotic or embolic stroke.  But we’re getting ahead of ourselves.

tPA is “tissue plasminogen activator”.  tPA is known as a “clot buster” drug.  It’s able to dissolve the clot, melt it away, and reopen the previously-blocked artery.  A thrombus is a clot that forms at the point of an arterial blockage.  The thrombus is usually caused by local atherosclerosis in a brain artery.  An embolus is a clot that forms somewhere else in the body, in an artery leading to the brain.  Again, arterial atherosclerosis is likely the precipitant or at least part of the cause.  A piece of this distant-from-the-brain clot breaks loose, travels through the artery to the brain, and gets stuck at some point.  The place where it lodges in the artery in the brain is the location of the stroke.

tPA cannot be given by mouth, it’s given by intravenous infusion.  An infusion of a tPA can dissolve a thrombus or embolus in an artery in an hour or two. 

Which tPA Will the ER Use?

The health care providers in the Certified U.S. Stroke Center Emergency Room will decide which tPA medicine to use.  The available tPAs are alteplase (Activase), tenecteplase (TNKase), and reteplase (Retavase, Rapilysin).  Currently only alteplase is FDA-approved for these types of acute blood-clot-blockage strokes.  It could be, however, that tenecteplase might be better in some situations.  The physicians at any Certified U.S. Stroke Center will know what to do.

Local Intra-Arterial Thrombolysis

This method of disruption of a blood clot is not a drug but a mechanical device that breaks up the clot.  As with IV tPA, this mechanical method, local intra-arterial thrombolysis (IAT), improves the stroke outcome.

The Length of Time That Has Passed is Central to the Decision

The time factor is the central reason for deciding between tPA or IAT.  As anyone might imagine, for those around a person having a stroke, realizing that a person is having a stroke and getting him/her to a Certified U.S. Stroke Center ER in under 4 hours takes not only a sense of urgency but sadly some element of luck as well.  So IAT can be used when it is too late to use tPA.  And physicians who prefer mechanical retrieval of the clot vs. tPA make another good point.  Using tPA, while it breaks up the clot, it can increase bleeding tendency and set the stage for an intracranial hemorrhage, bleeding into the brain, the bleeding type of stroke that is harder to treat.

IAT Can Be Done Up to 24 Hours after a Stroke

Using a tPA to treat an acute stroke has that 4-hour time limit.  A mechanical clot retrieval or disruption can succeed up to 24 hours after the stroke.   Mechanical thrombectomy or clot retrieval or disruption can clear the artery of the clot in perhaps a few minutes.  After tPA is started it might take two hours for clot dissolution.

Several Methods

There are different methods of mechanical clot retrieval or disruption and a variety of devices available.  Here we mention a few.

Microcatheters

One method of IAT is thrombus retrieval, a straightforward mechanical procedure using a microcatheter (really small micro!) and a coil retriever pushed into and through the clot like a corkscrew going through a wine bottle cork.  Once the end of the coil is beyond the clot (the corkscrew is all the way through the cork), it expands.  By expanding in the artery the coil establishes a firm hold on the main part of the clot so that, when the microcatheter is pulled back and out of the artery, the thrombus comes out, snagged by the coil.  The artery is clear and the blood flows freely again. 

Stents

Then there are stents, a second IAT way to mechanically and smashingly deal with a clot.  Stents are small wire cylinders that are supplied to the physician in a compressed state, that is, wrapped really tightly so that the coil is quite thin.  The stent is pushed into and all the way through the clot so that the far end is just beyond the far side of the clot and the near end is still sticking out of the near end of the clot.  The physician then lets the stent expand.  It goes from a thin coil to a fat coil, smashing the clot against the vessel wall and opening a channel through the middle of the stent, and thus through the middle of the clot, for the blood to flow freely.  While a great short-term remedy, there is a concern that soon, or at least eventually, the hole though the middle of the stent will develop a clot and again close off the artery.

Mechanical Thrombectomy

Finally, we will mention a third IAT way, mechanical thrombectomy, for example, thrombectomy using suction through the catheter to pull out the clot, like a tiny clot vacuum cleaner.  Early versions had problems with the tip of the sucking catheter getting itself clogged with the clot material.  Special systems have been developed to allow this procedure to work without the catheter tip getting clogged.  So, the vacuum cleaner catheter just sucks the clot right out of the artery.

We’ll Stop There with the Lectures

We actually had written another whole paragraph, similar to the one at the top of the page, about calling 911 right away.  Our page editor made us take it out.  Sound advice is one thing, she said, preaching is another.

Helpful links:

ClinicalTrials.gov has 52 studies (as of 3/17/2019) recruiting or to be recruiting for acute stroke in the United States.

https://clinicaltrials.gov/ct2/results?recrs=ab&cond=Stroke,+Acute&term=&cntry=US&state=&city=&dist=

Department of Health and Human Services (Unites States), National Institutes of Health, National Heart, Lung, and Blood Institute

https://www.nhlbi.nih.gov/health-topics/stroke

Centers for Disease Control and Prevention

https://www.cdc.gov/stroke/treatments.htm

American Stroke Association – American Heart Association

http://strokeassociation.org/STROKEORG/AboutStroke/Treatment/Stroke-Treatment_UCM_492017_SubHomePage.jsp

The Mayo Clinic

https://www.mayoclinic.org/diseases-conditions/stroke/diagnosis-treatment/drc-20350119

National Stroke Association

https://www.stroke.org/we-can-help/survivors/just-experienced-stroke/stroke-treatments/