Hour of Need

Thrombectomy technology means stroke patients have a wider window of time to receive treatment, preventing brain damage

Back Longreads Apr 19, 2016 By Russell Nichols

It was time for Lola’s afternoon nap. Her mother, Melissa Logue, was all set to read Thomas the Tank Engine. But as she walked to her 3-year-old daughter’s bedroom, she dropped the book. Her right side felt numb and a sharp pain suddenly seized her head. She couldn’t speak. Her husband came into the bedroom.

“Are you OK?”

All Logue could do was shake her head.

“Do I need to call an ambulance?” he asked.

All she could do was nod emphatically. A friend and ER nurse who was staying with the couple at the time verified what they all thought: Logue was having a stroke.

They called 911. Forty minutes later, she was at Mercy San Juan hospital in Carmichael, hooked up to an IV to receive the tissue plasminogen activator (tPA), which breaks down blood clots to improve blood flow in stroke patients. But this drug alone didn’t save Logue.

“tPA is not a silver bullet,” says  Dr. Lucian Maidan, the medical director at Mercy San Juan Medical Center, part of the Dignity Health Neurological Institute of Northern California. “It is 30 to 40 percent effective at best. But we were stuck with this for decades.”

Figures of Stroke

May is National Stroke Awareness Month. If you want to be aware, you should start with these critical facts:

  • 800,000: The estimated number of strokes each year in the U.S.
  • 130,000:The estimated number of Americans killed by a stroke every year. (one out of every 20 deaths)
  • 87:The percentage of strokes that are ischemic strokes, which blocks blood flow in the brain.
  • 25:The percentage of stroke survivors who will have another stroke within five years.
  • 5:Where stroke ranks on the list of leading causes of disability in the U.S., (just below unintentional injuries).
  • ¾:The fraction of strokes that occur in people over the age of 65.

The main issue is time. Patients must receive tPA three hours (up to 4.5 hours in some cases) after stroke symptoms begin. For that reason, only 5 percent of stroke patients in the U.S. receive the treatment. Most are not identified in time to beat the strict deadline. This is a major problem because acute stroke is a leading cause of death in this country, causing more serious long-term disabilities than any other disease, according to the National Institute of Neurological Disorders and Stroke.

But in the past few years, a new method has emerged: mechanical thrombectomy, which is the fancy medical phrase for manually removing a blood clot from the brain. The time window for this procedure is much wider (up to eight hours after stroke onset). Not every patient qualifies. However, those who successfully receive this endovascular (inside the blood vessel) treatment come away with remarkably less permanent neurological damage.

In 2014, Mercy San Juan was named the first comprehensive stroke center in the region, responding to acute stroke emergencies. The various members of the neurocritical care team work around the clock. As part of Dignity Health, Mercy is linked into a robust teleneurology program with 30 sites, delivering care throughout California, flying patients in by helicopter if necessary. The highly specialized team performed 123 mechanical thrombectomies in 2015. If stroke victims don’t get treatment as soon as possible, dying brain cells can cause long-term damage like trouble speaking or walking, other disabilities that may require special care or, in the worst cases, death.

“We need to bring these people in fast,” says Maidan, one of the interventional neuroradiologists. “Each minute you lose, you lose 1.9 million neurons.”

Logue is 41. She works at home as an environmental consultant. Her initial ranking on the National Institutes of Health Stroke Scale was 16, which is a moderate to severe stroke. That afternoon in January, minutes after receiving the tPA, Logue was moved into Mercy San Juan’s biplane angiography suite for a mechanical thrombectomy — a procedure that actually removed the blood clot that had caused her stroke. She stayed awake the whole time. Watching her own surgery live on the monitor, she panicked at the thought that she might never again be able to take care of her daughter.

“That was my main concern,” Logue says. She pauses, overcome with sudden emotion. “Am I going to be able to take care of her? Be there for her? Do everything I want to do as her mother? I didn’t have a whole lot of time to think about anything else.”

LEFT BRAIN CLOSED AHEAD

You can lose part of your heart muscle, but that won’t stop it from beating. You can injure your quadriceps without destroying your leg. But the brain? That’s a different story.

“The brain is very unforgiving,” says Dr. Richard Atkinson, a neurologist and medical director of the stroke program for Sutter Health, a not-for-profit health system in Sacramento with regional hospitals that see about 800 stroke patients a year.

Related: There is another potential path for treating ischemic stroke

There are two types of strokes. The most common one, an ischemic stroke, occurs when a blood clot blocks a vessel in the brain. A hemorrhagic stroke occurs when a blood vessel in the brain breaks and bleeds. Any part of the brain that doesn’t get enough blood supply (i.e. oxygen and nutrients) or overflows with blood dies within minutes.

In the event of a blood clot, the brain will try to find work-arounds. Other arteries will open up emergency detours around the blockage to get blood to the dead tissue area (the infarct). These arteries act like surface streets when a major freeway closes due to a pile-up. But the traffic is overwhelming.

“After a while, surface streets don’t work either. You have to open the big freeway,” Atkinson says of the vessel with the blood clot. “The sooner you do it, the more brain tissue you save. You hope to save enough to change people from being in a nursing home to being at their own home, independent.”

Atkinson was a co-principal investigator with the National Institutes of Health in the mid-’90s when the FDA approved tPA to treat ischemic stroke patients. Twenty years later, the evolution of this new blood clot removal treatment is revolutionizing the industry. The latest devices can get the blood clot out up to 80 percent of the time, sometimes in as little as 10 to 20 minutes, Atkinson says. And every second counts.

“The sooner, the better,” he says, “but we’re working under short timelines. It’s great to have proof that we can salvage some people up to six hours. That’s particularly helpful in transferring patients. A lot of hospitals in Northern California don’t have the specialists or expertise. Now that this [thrombectomy] is available, we actually have the time to move them.”

BEATING THE CLOT

In addition to tPA, the clot-busting drug that helped save Logue, doctors have used all kinds of tools to try and beat the clot: lasers, vacuum-like tubes, some suture material. Each device has had varying degrees of success, but none of them actually grabbed the clot.

In 2014, the MR CLEAN trial came out of the Netherlands, showing the safety and efficacy of what is called the stent retriever, in removing blood clots to treat acute ischemic strokes. This study was a game-changer.

With this endovascular procedure, a neurointerventionalist first threads a plastic catheter into the groin, up through the aorta and the neck and into the brain where the clot is. Next, the stent retriever, a wire-caged device, goes through the catheter, all the way up to the blocked vessel. The stent springs open on the other side, enmeshing the clot in the wire, allowing the doctors to pull it out.

Act F.A.S.T.

Strokes can strike anytime, and most come in a flash. Some types of strokes can trigger symptoms over a period of days. In any case, timing is everything, and recognizing and responding to the warning signs quickly can save a life. One easy way to remember the symptoms is to think F.A.S.T.

  • F is for Face-Drooping: Is one side of the face sagging or numb? Is the smile uneven?
  • A is form Arm-Weakness:Is one arm weak? Does it drfit downward?
  • S is for Speech Difficulty:Is the speech slurred? Are simple sentences like “the sky is blue” difficult to say?
  • T is for Time to Call 9-1-1:Even if the symptoms go away, you should call an emergency department immediately. Check the time to get a sense of when the symptoms began.

“It’s not a Roto-Rooter kind of thing,” Atkinson says. “But more like if you went in with a lot of tweezers at once.”

If the neurointerventionalist can open up the blood vessel in time, neurological damage will be minimal, says Dr. George Luh, the neurointerventionalist with Dignity Health who performed the thrombectomy on Logue. These patients may experience minor issues (e.g. weakness on one side or slight problems talking), but they will still be able to live independently.

“Previously, when we used our devices, the success rate of being able to remove the clot may have been 50/50,” Luh says. “Now, with these devices, we’ve probably done close to 200 of these procedures at our hospital over the last two years. We have a success rate of 90 percent for opening up the blood vessel.”

But unlike tPA, which most ischemic patients can receive, only one out of six patients is eligible for a mechanical thrombectomy. To qualify, the clot has to be fairly large and in certain locations, determined by a brain scan.

SCANNING IS OF THE ESSENCE

For the longest time, interventionalists had to try and pinpoint when the stroke symptoms began to identify which patients might benefit from blood clot removal. With brain imaging, neurologists and neurointerventionalists can select eligible patients up to 18 hours after symptom onset, according to new research presented at the American Stroke Association’s International Stroke Conference 2016.

Related: Sutter Health Unveils New Machine for Brain Surgery

The findings came from a two-year acute stroke study that ended in 2014. Funded by the NIH, the study focused on 102 patients, 18 and older, who had endovascular therapy up to 18 hours after the stroke began and a CT Perfusion imaging scan before treatment. About 71 percent of the patients treated within six hours and 62 percent treated beyond six hours of stroke onset showed “good recovery,” which means they showed little to no disability.

“Using this image-based selection, we would be able to look at any patient who comes through the door to identify the ones likely to benefit from these therapies [blood clot removal], regardless of what the clock shows,” said author Dr. Jenny Tsai, a neuroimaging and vascular neurology fellow at the Stanford Stroke Center, last February at the conference.

Neurologists determine who is eligible by scanning the brain with a CT scan or MRI to see where brain tissue can be salvaged. This process, called Acute Stroke Imaging, could potentially add a whole new population of stroke patients, who previously might not have reached the hospital fast enough to receive treatment.

“The problem with time windows is they’re very generic,” Luh says. “But everybody is different. We all adapt and react to different situations in different ways. Some people can last longer than other people. ASI allows us to see individual variation and tailor our treatment.”

As for Logue, she’s back home after spending two nights in the hospital, a stroke survivor with no disabilities.

The doctors don’t yet know what caused her stroke. It could’ve been something wrong with her heart, a genetic clotting disease or possibly triggered by medication. In any case, Logue’s getting back to the life she once feared she would lose. She’s cooking dinner one night in February while recounting her whirlwind experience as little Lola plays in the background.

“I’m still a little scatterbrained,” Logue admits. “It’s only been about a month and I’ve had some headaches. It will heal entirely. Other than that, I’m pretty tip top. After the procedure was completed, it was like a switch was turned back on.”

Comments

VisitorWilliam (not verified)May 2, 2016 - 5:25pm

This is my daughter and I thank God that medicine has come this far..

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