Clearing Carotid Arteries
LOS ANGELES, Calif. (Ivanhoe Newswire) - Every year, more than 300,000 people in the U.S. are diagnosed with blockages in their carotid arteries, which can lead to a dangerous stroke. Now, there's a new, safer way to clear these arteries.
Biff Yeager has been an actor for more than 40 years. It's a career he's passionate about.
"I just like to make people feel, I think," Biff told Ivanhoe.
But when Biff recently found out he had a blockage in his carotid arteries, he had a new role to play—informed patient.
"I knew that if an artery was blocked, you could have brain damage or a stroke," Biff said.
Traditionally, doctors repaired the problem with open surgery or a riskier stenting procedure performed through the groin.
"Doing that particular approach for stenting, carries twice the stroke risk as doing the open operation," Wesley Moore, MD, Professor and Chief Emeritus of the Vascular Surgery Division of Vascular Surgery at UCLA, told Ivanhoe.
Now, with the "silk road" technique, surgeons enter directly through the neck to access the carotid arteries. To prevent pieces of debris from traveling to the brain, they temporarily reverse blood flow.
"So, if there are any bits of debris present, instead of going toward the brain, or into the brain, they go through a circuit external to the body, trapped in a filter," Dr. Moore explained.
A stent is placed to keep the artery open. Then, blood flow resumes to its normal direction.
Biff stayed in the hospital just one night after his procedure, and now he can focus on landing that next part.
The new procedure doesn't require general anesthesia like the traditional, open surgery. In clinical trials, results show the procedure is as safe as the standard operation. There are about 19 centers in the United States participating in the clinical trial to test this new method.
BACKGROUND: Carotid artery disease is generally defined as the narrowing of the carotid arteries. This happens when cholesterol deposits and fatty substances, known as plaque, build-up in the arteries causing a narrow pathway. A carotid artery occlusion is when there is a complete blockage of the artery, which may put the patient at risk of a stroke. These arteries are two large blood vessels that supply the oxygenated blood to the front of the brain. This part of the brain controls motor functions, thinking, your personality, and your speech. If you are to place your fingers on each side of your neck below the jaw line, you can feel the pulse in the carotid arteries. (Source: http://www.webmd.com/heart-disease/carotid-artery-disease-causes-symptoms-tests-and-treatment)
SYMPTOMS: Patients are usually unaware they have carotid artery disease until they have a stroke. Signs that you may have carotid artery disease include:
- Dizziness or loss of balance
- Trouble speaking and understanding
- Severe headaches with an unknown cause
- Trouble seeing in one or both eyes
- Numbness or weakness in face or limbs (Source:http://www.mayoclinic.com/health/carotid-artery-disease/DS01030/DSECTION=symptoms)
SILK ROAD PROCEDURE: This new technique was created to protect the brain from stroke risk during carotid artery stenting. It allows doctors to deliver a stent directly from the neck. This is intended to avoid complications associated with starting from the femoral artery in the groin, which is typically used in carotid artery stenting procedures. To provide protection for the patient's brain during the entire procedure, the Silk Road system temporarily reverses blood flow in order to move any debris away from the brain. A worldwide clinical trial called ROADSTER is now underway to evaluate the safety and efficacy of the Silk Road system in patients who are at high surgical risk and have either symptomatic or asymptomatic carotid artery disease. If you have carotid artery disease and your physician has told you that you are at high risk for surgical treatment (carotid endarterectomy), you may be eligible to participate in the ROADSTER trial. Several factors may increase your risk of surgery, including age and other medical conditions you may suffer from. (Source: http://www.silkroadmedical.com/silkroad-procedure/what-it-is/)
Wesley Moore, MD, Professor and Chief Emeritus of the Vascular Surgery Division of Vascular Surgery at UCLA, talks about a new procedure for carotid arteries.
What is your involvement at UCLA's surgery division?
Dr. Moore: My primary area of involvement is in the surgical management of carotid artery disease, but the new approach to carotid stenting that we are using has been appealing to me. Besides performing surgery, I also do what's called endovascular surgery and that includes procedures like stent angioplasty.
Now, this would be very basic the carotid arteries you have four of them?
Dr. Moore: No, there are two carotid (two) arteries in the front of the neck, and in the back of the neck there are two vertebral arteries. There are a total of four arteries that supply blood to the entire brain.
Are you only dealing with the front two?
Dr. Moore: That is correct.
Why is that? Why can't you do it with the back two?
Dr. Moore: We can, and we do operate on the back two on occasion. The carotid artery is a much more frequent location.
Are they very important arteries?
Dr. Moore: Indeed.
Do they supply at all of our blood to the brain?
Dr. Moore: The carotid arteries supply the major portion of blood to the brain.
What happens if one of those gets clogged?
Dr. Moore: If one of the carotid arteries develops plaque in a critical location, bits and pieces of that plaque can break loose, go up to the brain, and cause a stroke.
Traditionally, how would you normally treat that?
Dr. Moore: The traditional approach to treating a plaque in the carotid artery is to actually remove the plaque by a technique called carotid endarterectomy.
Is that a surgery?
Dr. Moore: That is an open operation.
Are there any symptoms when you're carotid arteries are blocked?
Dr. Moore: There are symptoms and there are also patients who have no symptoms until they actually experience a devastating stroke. Symptoms are what are called transit ischemic attacks. They are kind of little or mini strokes, but in which the patient has a total recovery. That's ideal because it warns us when a patient is at risk of a stroke. The more subtle approach is a patient that may have a major blockage in the artery and their first symptom may be a major stroke. Our job is to try to identify those patients, and to intercede before that event occurs.
When you approach this with surgery can you explain to me a little bit the different ways you go about it?
Dr. Moore: The surgical approach involves taking the patient to the operating room either under a general or local anesthesia, making an incision along the front part of the neck over the carotid artery, mobilizing the carotid artery, clamping it below and above the diseased segment of the artery, making length wise incision in the artery, cleaning out the plaque from within the artery, and then closing that incision with a little patch to widen it so that when it heals the scar tissue won't constrict the artery.
From there it went to ballooning and stenting, correct?
Dr. Moore: There have been attempts beginning many years ago to have a less invasive approach to opening the carotid artery. The traditional way of doing that has been to approach it through an artery in the groin area, the so-called femoral artery. A needle is used to puncture the artery and thru the needle guide wires advanced up through the main artery going through the body, the aorta and then extending that guide wire into the branch of the aorta, the so called carotid artery. Then over that guide wire, a stent delivery system is passed to the level of the carotid stenosis. The stent is then deployed in the narrow portion of the artery. A balloon is then passed over the guide wire and balloon expansion of the stent is performed.
Is there a big risk for the patient?
Dr. Moore: There have been a number of clinical trials that have shown that using that particular approach for stenting carries twice the stroke risk as doing the open operation.
Why is that?
Dr. Moore: We believe the reason for that is that plaque either in the aorta on the way to the carotid artery or plaque within the carotid artery itself can be dislodged and travel up through the artery to the brain and producing a stroke before any protective devices can be placed in the artery itself.
What is this new trial called?
Dr. Moore: The new trial is called direct carotid stent angioplasty with flow reversal. That accomplishes two things. Number one, we don't have to traverse long distance to get the device into position because we're going directly to the carotid artery low down in the neck. The second thing we do in order to keep bits and pieces of debris from going up to the brain is to temporarily reverse the direction of blood flow in the carotid artery. If there are any bits of debris present, instead going toward the brain with normal blood flow, flow reversal carries these particles through a circuit external to the body. The debris is trapped in a filter, while blood is being returned to a vein in the leg.
So how many people have you done this to?
Dr. Moore: Here at UCLA, I've done six patients to date, but worldwide there have probably been close to 100 altogether. In the United States, it's probably upwards of 50.
Is this clinical trial is being done in how many centers, do you know?
Dr. Moore: I'm not sure of the number at this point.
We're talking to a patient, John. What was John's artery like?
Dr. Moore: John had almost a total obstruction of his artery. He was not having symptoms, but we identified the narrowing because I had been following him with ultrasound over a period of time. We demonstrated that this had gotten very severely narrowed. It put him at a high risk for blocking the artery completely and I was concerned that he might have a stroke if and when it was to occur.
If his artery was not cleared, is a stroke a sure threat?
Dr. Moore: Not a sure thing, but a highly likely thing.
Since this stent has been placed, how is his artery now?
Dr. Moore: Now, it's completely clear by ultrasound criteria.
Is this something that can come back, if you get a buildup of plaque once we you get it again in a different area?
Dr. Moore: Certainly there is the risk of a recurrence either directly in the area that we stented or above or below. But that risk is quite low.
Is there a downside to this that you are seeing so far?
Dr. Moore: The results to date that have been reported suggest that the risk of this procedure is now quite comparable to the very safe procedure of carotid endarterectomy, and at the same time being less invasive and associated with a quicker recovery for the patient.
When you talk about a major surgery on a major artery and less invasive surgery what's the recovery time?
Dr. Moore: Well, basically using either procedure it's an overnight in the hospital. In the case of carotid endarterectomy there's a longer incision and there is a healing time associated with that. In the case of the direct cervical carotid stent angioplasty there is a very small incision to expose the artery but the patient makes a very rapid recovery, faster than with the carotid endarterectomy.
Do you have any specifics like a two-week recovery to a two day recovery or anything like that?
Dr. Moore: Well, it depends upon how you want to define recovery. Even with the open operation of carotid endarterectomy patients are discharged from the hospital the next day. They can drive an automobile and carry out their normal daily activities. I've had patients get on airplanes and go home in three days. There's not a big recovery time, but there is some discomfort associated with the larger incision. In the case of the stent angioplasty with a very small incision in the neck it's just proportionately less.
Is this something that you're excited about? Is this something that you see as the future?
Dr. Moore: I'm very excited about it. I've been very pessimistic about the femoral approach to carotid stent angioplasty because of the high complication rate, but the direct cervical approach with flow reversal in my opinion is going to be a winner. For that reason I am an enthusiastic participant in the clinical trial.
Is that something that was always on your mind when you're going through the groin snaking your way up? Were you always thinking in the back of your mind, you know, I'm hoping were not doing any damage with the plaque?
Dr. Moore: Well let me clarify as far as the femoral approach is concerned, I have not personally done carotid angioplasty. I've been always very skeptical about that particular approach. My colleagues usually interventional neuroradiologist or interventional cardiologists have been doing it and I've observed them and I've observed their results. In the case of the direct cervical approach I am enthusiastic enough about that approach that I've been willing to do that myself.
When the flow is reversed is there any time that the blood is not actually go to the brain?
Dr. Moore: No, while temporarily there's no blood going to the brain through the artery we are treating, this is compensated for by blood going to the brain through three other arteries. We do monitor these patients if they are awake, by conversation. If they're under anesthesia we have EEG monitoring so we're looking at the electrical activity of the brain to make sure that there is no period of time where the brain is in jeopardy.
So do you do this surgery with the patient awake?
Dr. Moore: We can.
Why would you do that?
Dr. Moore: Some patients may have a preference, that's a good way to monitor brain function because we can converse with them. From a personal perspective I think patients are more comfortable being asleep. I'm certainly more comfortable doing either open operation or angioplasty when I don't have to worry about the comfort of the patient and devote 100% of my attention to the procedure at hand.
FOR MORE INFORMATION, PLEASE CONTACT:
For patients outside the Western U.S.:
Silk Road Medical
For patients in the Western U.S.:
Wesley Moore, MD
Professor and Chief Emeritus, Division of Vascular Surgery
David Geffen School of Medicine at UCLA