MINIMALLY INVASIVE CAROTID ARTERY STENTING PROCEDURE WHICH CAN HELP by zfz19897

VIEWS: 15 PAGES: 17

									 MINIMALLY INVASIVE CAROTID ARTERY STENTING PROCEDURE WHICH CAN
                   HELP PREVENT LIFE-THREATENING STROKES
    MEMORIAL HERMANN HEART AND VASCULAR INSTITUTE – SOUTHWEST
                                   HOUSTON, TEXAS
                            Broadcast date: March 8, 2006
00:00:09
NARRATOR: The carotid arteries carry blood from the aorta to the base of the brain.
Build up of cholesterol, calcium and fibrous tissue can form plaque inside these
vessels, narrowing them and restricting the flow of blood. Traditionally, physicians
treat severe carotid artery disease by making an incision in the neck and surgically
removing plaque and diseased portions of the artery. A newer approach, carotid
stenting, enables treatment from inside the vessels. This minimally invasive
procedure can help prevent life threatening strokes.
00:00:37
Today’s program is part of Memorial Hermann’s ongoing educational efforts to bring
the latest information in health care to physicians and patients. During the program
you may send your questions to the OR surgeons at any time. Just click the
MDirectAccess button on the screen.
00:00:56
ROBERT BALDWIN, M.D: Good afternoon. I’m Dr. Robert Baldwin, a cardiovascular
surgeon at Memorial Southwest Hospital in Houston Texas. I’ll be your co-moderator
today, for tonight’s live video webcast of carotid artery stenting. Co-moderating with
me today will be my colleague, neurologist Dr. William Fleming. Performing today’s
surgery is cardiovascular surgeon Dr. Luis Escheverri from Texas Surgical Associates
in Memorial Southwest Hospital.

During today’s webcast, we will try to take as many e-mail questions from our
audience as possible. You may submit your e-mail question by clicking on your
MDirectAccess button. Dr. Fleming and I will try to answer as many as possible.
00:01:47
Dr. Luis Escheverri has established a successful carotid artery stenting program here
at Memorial Southwest Hospital and will be performing the stenting live in the next
several minutes. Perhaps we can visit Dr. Escheverri in the operating room at this
time.
00:02:08
LUIS ESCHEVERRI, MD: Okay, we’re going to get access on the right femoral artery.
But first let me introduce here is Dr. Walker, our anesthesiologist, who’s going to help
us with handling with any hemodynamic changes that we may have doing the
stenting. Here helping are Diana and Beverly and Evita, and other personnel.

We do this under local anesthetic. We’re trying to obtain access on the right femoral
with a micropuncture device. We use a local.
00:02:58
ROBERT BALDWIN, M.D: Our patient today is a fifty-eight year old woman who’s had
numbness in her left – her right hand and sought evaluation by her family doctor,
which brought about the physical exam findings of a bruit in her left neck. A carotid



Page 1 of 17
duplex scan was then performed, which revealed very high grade stenosis of her left
internal carotid artery. Subsequent angiogram confirmed a very high grade stenosis,
which we’ll visit later on. There’s some substantial findings on it that made it a higher
risk for conventional coronary artery surgery.
00:03:40
Dr. Escheverri’s first steps in this carotid artery stenting will be directed toward
gaining access to the vascular tree. This is typically done through the right common
femoral artery. Dr. Escheverri has accessed this with a fine eighteen gauge
micropuncturing needle. He then will insert a wire through the needle into the
common femoral artery, removing the needle and then directing a sheath, a 6 French
sheath into the common femoral artery, where it will reside there for the duration of
the case. Leaving the sheath in place allows Dr. Escheverri to advance a wire up
through the iliac artery, infrarenal abdominal aorta, descending thoracic aorta and up
into the abdominal arch, as we can see here. Once access is established through this
sheath, it is kept in place and the blood is displaced with systemic heparin. Once, Dr.
Escheverri has traversed the lesion, they will administer systemic heparin.
00:04:54
Some of the challenges that Dr. Escheverri will be managing today is advancing and
positioning his wire through the abdominal aorta, aortic arch and common carotid
artery, up towards his target lesion and from that point across the high grade
stenosis, which can and frequently does present some challenges. What we just saw
was the wire wanting to advance into some of the vessels of the infrarenal abdominal
aorta. Dr. Escheverri was able to direct the wire past that up into the arch. What we
see here is the common femoral artery with the wire and sheath in place. Dr.
Escheverri, are you…
00:05:51
LUIS ESCHEVERRI, MD: We are ready to – We have done a prior angiogram that we
know how the anatomy is. We’re going to try to cantilate the left common carotid and
advance the wire in this position, allowing us to then advance a long sheath that will
give us the access to the manipulation of the area of the stenosis. So we can use
different catheters for this purpose. Today we’re going to use a [bearing?] size – a
[bearing?] catheter, [bearing?] five.
00:06:22
ROBERT BALDWIN, MD: Much of the challenge in carotid arteries – Much of the
challenges in carotid artery stenting is directing your access through the acute angles
of the aortic arch and into the common carotid artery. Dr. Escheverri has done very
many of these and has less trouble than one might if you were just starting out. But,
frequently getting access to the left common carotid artery can be most of the battle
in this. And, indeed, in many patients, particularly elderly patients, is a limiting factor
and can sometimes make carotid artery stenting not possible in some patients.
00:07:18
WILLIAM FLEMING, MD: As Dr. Baldwin said, that this lady has carotid artery disease.
She has carotid artery stenosis, which is a narrowing of the carotid artery, which is the
main artery in the neck that supplies blood to the brain.

Stroke is a tremendous public health problem in this country. A stroke occurs about
every forty-five seconds in this country. Each year, 700,000 to 750,000 strokes
occur. About 500,000 of these are first attacks and about 200,000 are repeat strokes.
Each year about 60,000 more women than men have strokes, and this is primarily due
to an age factor. As age factor is one risk for stroke, we know that women have a
longer lifespan than men, therefore stroke is a little bit more prevalent in women than
men. Stroke is about fifty percent more prevalent in African Americans than whites.
00:08:24


Page 2 of 17
Stroke is the leading cause of disability in this country and the third leading cause of
death in this country, behind cancer and heart disease. It is the second cause of
death worldwide. In 2004, the estimated cost of stroke care in this country
approached about fifty-four billion dollars, so it’s tremendous, tremendous economic
impact upon the population, as well as the social impact upon the population, given
the disability that the stroke patients have.
00:09:03
The mean lifetime cost of ischemic stroke is about $140,000. Stroke deaths occur
about – account for more than one in every fifteen deaths in the U.S. Again, stroke
rates number three in this country among deaths, following heart disease and cancer.
On average, every stroke – On average, every three minutes someone dies of a stroke
in this country, so as you can see it is a tremendous, tremendous public health
problem.

LUIS ESCHEVERRI, MD: Let’s try a different catheter.
00:09:41
What is a stroke? A stroke is basically a brain attack. A stroke occurs when a blood
vessel is blocked, supplying blood to the brain, therefore depriving the brain of oxygen
and nutrients. If the brain cells do not receive oxygen and nutrients, then brain cells
die, therefore producing various neurological deficits in varying degrees.
00:10:15
ROBERT BALDWIN, M.D: Let me briefly review our anatomy of the carotid arteries
and the blood flow to the brain. The blood flow to our brain is supplied by the carotid
arteries. The left and right carotid artery provide the majority of blood to the brain.
The vertebral arteries, left and right, provide a smaller quantity of blood to the brain.
Most cortical strokes are caused by the blockages in the internal carotid arteries. We
see how Dr. Escheverri will direct his catheter up through the arch of the aorta,
through the common carotid artery and subsequently into the internal carotid artery.
00:11:06
How is the diagnosis of carotid artery stenosis performed? Well, there’s several ways
of diagnosing carotid artery stenosis. The first modality will be noninvasive testing,
such as duplex ultrastenography. Limitations of this sort is very dependent upon the
ultrasound technician and – but in experienced hands is a very, very effective way of
separating high grade carotid stenoses from trivial carotid stenoses that might be best
managed medically.
00:11:47
Once a duplex scan is done, frequently confirmation will be necessary by one of
several methods. In Dr. Escheverri’s practice, he will choose either MRA or CT angio.
These more modern tests are preferred because of their low risk of complications;
namely, low to nonexistent risk of intra-procedural stroke. Many times, to get the
information that’s necessary, conventional angiograms are necessary. And, certainly,
in any cases where the diagnosis is in question, conventional carotid angiograms is
still the gold standard. We have our first e-mail that I may direct to our neurology
colleague, Dr. Fleming.
00:12:44
WILLIAM FLEMING, MD: Yes. We have a patient here who’s cardiologist has
diagnosed him with peripheral artery disease, with sixty percent blockage of both legs
and a one hundred percent occluded internal carotid artery. They ask if he may be a
candidate for this procedure. The answer is no. In a one hundred percent occluded
artery, we do not do conventional endarectomy, nor do we do carotid stenting. To
unblock a one hundred percent occluded internal carotid artery would cause a
significant brain hemorrhage. It’s kind of like opening up the dam and letting the
water through. So, the answer is no, you would not be a candidate for this procedure.


Page 3 of 17
00:13:26
ROBERT BALDWIN, M.D: That’s a good question and it’s a very common one. We get
that very frequently. It’s actually not even possible to – As you can see, Dr.
Escheverri would need to get his wire and catheter through. This procedure’s
predicated upon an open artery so that the wire and catheter can pass through it.
00:13:48
You may notice on our fluoroscopy that there is some motion of the patient’s
mandible. These procedures are done under local anesthesia. Our patient is
completely awake and coherent and will occasionally discuss her sensations and
experiences with our cardiovascular anesthesiologist, Dr. David Walker, who will
monitor her throughout. At the point where the stent is deployed, there are some very
classic findings, as it relates to heart rate and hypotension, sometimes very dramatic
changes, and having a skilled cardiovascular anesthesiologist present for this
procedure s absolutely essential. And an experienced team is an essential portion of a
successful outcome in carotid artery stenting.
00:14:55
LUIS ESCHEVERRI, MD: So we have access into the common and we have a stiff wire
advancing to the external, just by the curvature that you observed towards the upper
portion. And now we’re going to advance a really long sheath that is going to
maintain the access where we need to be for the procedure. So, this is a 6 French
destination. We need to go down to the chest, Jackie.
00:15:24
ROBERT BALDWIN, M.D: Dr. Escheverri has just done part of the real challenging
portion of this procedure; that is traversing a high grade stenosis with that wire can
be quite a challenge and one where his experience really pays off. This next portion is
to get a very stiff wire and stiff tube into the orifice, or origin of the common carotid
artery, such that the stent can go up and won’t be abrading the walls of the aorta and
causing damage to the aortic intima or inner layer of the aorta. What he’s doing is
directing this tube directly up to the origin of the carotid artery stenosis. It sounds
like things are going along quite well in this.
00:16:24
LUIS ESCHEVERRI, MD: We’re pulling the wire out. We can see the [unintelligible].
This is all flush. The same. Okay, very good. Okay. Give me suction here.
00:16:52
ROBERT BALDWIN, M.D: Dr. Escheverri, it looks like you’re exactly where you want to
be now.
00:16:52
LUIS ESCHEVERRI, MD: Well, we are going to obtain, actually, an image to see
exactly the anatomy and demonstrate the lesion.
00:17:04
ROBERT BALDWIN, M.D: So how do you perform these angiograms? This will be a
contrast, a conventional contrast angiogram?
00:17:10
LUIS ESCHEVERRI, MD: We’ll use just a, yeah, a regular [VC peg?]. And in this case,
we’re going to do manual injections, since we have a….
00:17:17
ROBERT BALDWIN, M.D: Can you tell our audience where your catheter is located,
which artery and are you….
00:17:22
LUIS ESCHEVERRI, MD: Right in the left common carotid.
00:17:23
ROBERT BALDWIN, M.D: Which is exactly where you’re hoping to be, because you…
00:17:24


Page 4 of 17
LUIS ESCHEVERRI, MD: That’s where I want to be.
00:17:27
ROBERT BALDWIN, M.D: Your lesion –This angiogram will probably reveal the lesion
to be just distal to the end of your catheter, is that correct?
00:17:35
LUIS ESCHEVERRI, MD: Exactly. So, a little bit higher. Just like a centimeter or so,
Jackie. On the x-ray. Table up. We have heparinized the patient with a one and a
half milligrams per kilo. Right there. And, we’re going to see what this – That’s not a
good projection, Jackie. That one. Yeah, right there.
00:18:02
ROBERT BALDWIN, M.D: Dr. Escheverri and Jackie Wright use the boney landmarks
of the cervical spine to know where they are in the soft tissues.
00:18:14
LUIS ESCHEVERRI, MD: So, let me see.
00:18:22
ROBERT BALDWIN, M.D: This is a really good angiogram here and it brings out a
really interesting part about this patient. A conventional carotid surgeon, we may –
Dr. Escheverri, I see the stenosis real well there. I’ll bet you in another projection
you’d be able to show that distal stenosis. One of the really relevant things here is
that this blockage is substantially up closer to the brain stem than most carotid artery
blockages or stenoses are. The angle of the mandible usually is the limit of your
carotid artery exposure. This patient would be extremely high risk to be done open
technique.
00:19:18
LUIS ESCHEVERRI, MD: Okay, hold your breath for one second. Take a deep breath
and hold your breath. So that is the stenosis. That’s going to be our working
position.
00:19:28
ROBERT BALDWIN, M.D: That looks like about a ninety percent….
00:19:30
LUIS ESCHEVERRI, MD: She has a four hundred and something centimeters per
second of velocity across the stenosis that is – Can you freeze the image in the
middle?
00:19:38
ROBERT BALDWIN, M.D: So that’s very consistent with the doplar findings of…
00:19:42
LUIS ESCHEVERRI, MD: And I think the position of the sheath is very adequate. We
have enough landing zone to deploy a protective device. We have measured this and
it’s around ninety-five percent by NASA criteria, and so we’re going to try to deploy a
stent that, as far as the bifurcations, the stenosis is quite high and is quite discreet;
maybe an        8 x 20 will be enough for that. Yeah. Once we get this position,
actually, we’re not even – actually in a working position, we’re going to maintain this
projection and we’re going to – next we’re going to get the Accunet, which is the
protective filter that we’re going to position way up in the carotid. Give me the
Accunet.
00:20:24
ROBERT BALDWIN, M.D: The Accunet filter is one of the very significant advances in
this technology industry has made this procedure advance from its initial stages ten
and fifteen years ago, where stents were placed without these so called distal
protection devices into a much safer procedure. Initial stroke rates varied, but were
frequently above ten percent in the era prior to distal protection devices. Those are
historic figures and really are not relevant at this time.
00:21:04


Page 5 of 17
Maybe we can go in and get a close-up picture of this wire. This is basically what has
changed – This is what has changed the whole field of carotid artery stenting and has
made it much safer. This wire is not only a wire, but will open up into a little nano-
shuttlecock that can entrap any cholesterol debris that might fragment from the
angioplasty that is performed concomitant with the deployed of the stent. The higher
stroke rates that were seen in the early nineties were due to debris from that high
grade stenosis breaking off and embolizing to the brain, killing a portion of the brain.
This shuttlecock will capture that and can be retrieved through that sheath that Dr.
Escheverri had inserted earlier protecting the distal brain and allowing stroke –
expected stroke rates in the area of two to four percent, which is comparable to
traditional open surgery.
00:22:18
In this particular patient, with the distal lesion, we’re not even able to expose that due
to proximity of the skull and base of the skull there. Dr. Escheverri is now – What
appears to be the wire is also the un-deployed distal filtration wire and he’s directing
that – aiming to get that into the internal carotid artery instead of the external carotid
artery. A review of the anatomies at the external carotid artery feeds the skin and
muscles of the face. That has little to no relevance for the development of stroke. Dr.
Escheverri is trying to get this up past the stenosis to make this deployment a safe
deployment.
00:23:21
LUIS ESCHEVERRI, MD: I’m going to make sure that we’re going to go into the
internal here. Now we are crossing this stenosis already with the wire. Still too low
for the deployment of the filter, so we’re going to advance slightly more, and that will
be a good area for deployment. Make the hole here.
00:23:42
ROBERT BALDWIN, M.D: How many centimeters distal to the stenosis do you wish to
be, Dr. Escheverri?
00:23:46
LUIS ESCHEVERRI, MD: Well, at least two and a half, because you don’t want to get
entangled with the device. Well, I think that’s a good position. I don’t want to get in
the curve. We now want to stay into the – Lower…
00:24:03
ROBERT BALDWIN, M.D: The fluoroscopy is really showing this very well.
00:24:08
LUIS ESCHEVERRI, MD: Okay. Pull for me, Jackie, because I’m going to be far from
the pedal. We’re going to deploy the filter at this point. Now we see – Let’s magnify
this a little bit more, Jackie. Up. Yeah. Back. Now right there. Don’t move. Just
mag. That’s right. So, yeah, we’ll see the [four?] point, the [unintelligible] point.
Okay. Lower it back to mag one.
00:24:42
ROBERT BALDWIN, M.D: So at this point, Dr. Escheverri is now getting his balloon
mounted stent and he’s chosen approximately a two centimeter long stent. That
decision is based off of a length of the cholesterol plaque that was observed and is
targeting a opening diameter. Dr. Escheverri, did you say a 5.0 millimeter?
00:25:08
LUIS ESCHEVERRI, MD: Yeah. I’ve got to put a [unintelligible?] with 5.5. Mag one.
00:25:13
ROBERT BALDWIN, M.D: 5.5 reflecting 5.5 millimeters ultimate diameter, which is a
very wide open…
00:25:20




Page 6 of 17
LUIS ESCHEVERRI, MD: The thing is that after a single step we usually go ahead and
– Good. More slack right there – and check that we are in position, that everything is
where we need to be. Hold your breath.
00:25:40
ROBERT BALDWIN, M.D: Another contrast angiogram, revealing that the filter wire is
in appropriate position to prevent any distal cholesterol debris from embolizing into
the brain, delivering this protection to the patient.
00:25:54
LUIS ESCHEVERRI, MD: The bottom of the device is not in any way going to entangle
with the stent. Usually there is a way to do this, so we’re doing our predilitation.
Let’s go ahead and get the stent. It’s already flush. But I think that usually if the
filter device is able to cross properly, you don’t have to do a predilitation. You can
deploy the stent, which is almost the same profile and yet do a postdilitation. That
minimizes the risk of embolism and as well as complications. Very few cases you need
to do a predilitation in a carotid stenting; probably less than ten percent.
00:26:28
This is the stent. We’re going to prepare the stent. I know. We’re going to remove
this [mandril?] that comes with it. So it’s a monorail system. It’s a very – Saline. We
just flush [unintelligible]. One second before you flush. You really won’t see anything
but just a very short yellow portion. That’s where the stent is constrained. It’s a
Nitinol stent, which is an alloy of nickel, titanium that has been predetermined to
expand to a [90?] millimeter size by a heat exchange procedure that sets – around
thirty-two degrees the stent is going to reach it’s maximum diameter. In carotid,
usually you oversize it slightly, the size of the stent. Not too much. Nitinol is a great
material.
00:27:26
ROBERT BALDWIN, M.D: Technology in industry has really moved this field far more
to a safe field than it was in the early nineties. Dr. Escheverri, what would you be
able to offer this patient from an open surgery? Say ten years ago, would this be
approachable through open carotid endarectomy, Dr. Escheverri?
00:27:50
LUIS ESCHEVERRI, MD: It could be approachable, but it would be a quite difficult
approach because, as you see, the stenosis is right behind the mandible.
00:27:56
ROBERT BALDWIN, M.D: So perhaps a higher risk for stroke, [poor for?] nerve?
00:28:01
LUIS ESCHEVERRI, MD: The thing that’s going to be difficult would be what I think
that – because you have to make a very high incision and that’s when the stenting has
come to play a roll. So, our eyes are actually on that little filter. We don’t want the
filter to move, neither up or down, because that may produce damage to the area and
spasm.
00:28:24
Before we proceed, we’re going to have the stent already in place inside the sheath.
We’re going to shoot a gram and be ready to mark the landing zone of the stent.
Okay. Just go ahead and hold your breath. Okay, Jackie, you can make a mark on
the screen right there. Just right in the middle.
00:28:57
ROBERT BALDWIN, M.D: Jackie Wright will now be marking on the screen to show…
00:29:00
LUIS ESCHEVERRI, MD: You know, there is some disease of the bifurcation. I don’t
think that is needing, in her case, to do…
00:29:09




Page 7 of 17
ROBERT BALDWIN, M.D: Some smooth wall irregularity there. About ten to twenty
percent stenosis that you believe probably would have very little clinical relevance.
00:29:19
LUIS ESCHEVERRI, MD: Right in the middle of where we know is the area of her
stenosis. At this time we’re going to deploy the stent, so we open the lock on the
stent here. Hold this and you…
00:29:31
ROBERT BALDWIN, M.D: Dr. Escheverri, are those markers on the stent that we see?
00:29:36
LUIS ESCHEVERRI, MD: Those markers are the beginning of the end of the stent.
00:29:38
ROBERT BALDWIN, M.D: So you would like those markers to be directly above and
below the angiographic stenosis, is that correct?

LUIS ESCHEVERRI, MD: No, wait. Right there. Pull back.
00:29:54
ROBERT BALDWIN, M.D: It looks like your filter wire is in perfect position.
00:29:56
LUIS ESCHEVERRI, MD: The stent is deployed. The filter wire hasn’t moved. Now we
are retreating. The filter wire has not moved at all. Don’t erase my mark. That’s
where I’m going to dilate.
00:30:44
ROBERT BALDWIN, M.D: Dr. Escheverri’s left hand is keeping his filter wire in place
while he removes his delivery device, while monitoring both of these fluoroscopically.
Dr. Fleming, this is a pretty common disease in a neurologist’s practice, is that not
right?
00:31:15
WILLIAM FLEMING, MD: It certainly is. It’s a large part of our practice, carotid artery
disease and stroke.
00:31:23
ROBERT BALDWIN, M.D: As our population gets older, all forms of atherosclerotic
disease will become more common in the next decade as well.
00:31:30
WILLIAM FLEMING, MD: That is correct. Yeah, age is a major factor, a major risk
factor in stroke. We have modifiable risk factors and non-modifiable risk factors.
Modifiable risk factors, such as smoking, obesity, diet, et cetera. We have non-
modifiable factors, such as diabetes, family history and age. Age is a major factor.
And I think as our population ages, we may see a high incidence of stroke.
00:32:06
LUIS ESCHEVERRI, MD: Now we’re going to balloon the area, so we’ll see this change
in diameter.
00:32:10
ROBERT BALDWIN, M.D: So your stent is deployed, Dr. Escheverri?

LUIS ESCHEVERRI, MD: Yes, it’s already deployed.
00:32:14
ROBERT BALDWIN, M.D: And you’re pleased with your location of it?
00:32:16
LUIS ESCHEVERRI, MD: Oh, the location is very good. It’s right in the middle of the
stenosis.
00:32:19
ROBERT BALDWIN, M.D: So at this point, Dr. Escheverri is advancing a balloon that
will break the area of tight stenosis and will leave the patient with a pleasing


Page 8 of 17
angiographic result and we’ll be able to appreciate that after the balloon is up and
subsequent angiograms are performed. Again, the filtration, the filter wire is in the
same place you see up at the top of the screen, right inside the intercavernous carotid
artery and is available to protect and….
00:33:04
LUIS ESCHEVERRI, MD: This is the balloon and it is right inside the stent. Now we’re
going to inflate the balloon exactly inside the stent.
00:33:10
ROBERT BALDWIN, M.D: Dr. Escheverri, are you able to mag in there and show the
stent?

LUIS ESCHEVERRI, MD: Am I able to what?
00:33:23
ROBERT BALDWIN, M.D: Are you able to magnify on the stent?

LUIS ESCHEVERRI, MD: Yeah, it’s in mag one. Now go back to – okay. This is a very
quick inflation. Only to around [unintelligible].
00:33:40
ROBERT BALDWIN, M.D: Dr. Escheverri, is this the stage where the hemodynamic
changes may occur in the patient?
00:33:45
LUIS ESCHEVERRI, MD: And deflation. How are we doing there? Yeah, this is the
stage. But in her case, because of the location there is about a carotid bifurcation.
Maybe better receptors won’t be affected as much as in other cases. So we have done
the dilatation. Now we’re removing the balloon. Come off mag so I can see my
sheath.
00:34:10
ROBERT BALDWIN, M.D: The stage where the balloon is inflated can, in some cases,
cause severe bradycardia or lowering of the heart rate, sometimes completely stop for
several seconds or even a minute, in severe cases. That is treatable with
cardiovascular medications. Dr. Walker is an integral portion of this procedure and is
monitoring that very closely.
00:34:49
Dr. Escheverri is now removing his balloon angioplasty catheter while being very
careful to leave the filtration wire intact. As you can see, the sheath has a very clever
valve on it that does a good job, except does have a little bit of leaking when the
balloon or device is removed and leaves the filter open.
00:35:22
LUIS ESCHEVERRI, MD: Let’s see how it looks after the dilatation. Okay. Just take a
deep breath and hold your breath for a minute. That’s a lot better.
00:35:33
WILLIAM FLEMING, MD: Dr. Baldwin, you may want to answer this question.

LUIS ESCHEVERRI, MD: See the change?
00:35:5:37
WILLIAM FLEMING, MD: We have another question. How frequently do you see re-
stenosis during the first three years?
00:35:42
ROBERT BALDWIN, M.D: Yes. We’ve got an e-mail submission from our audience.
It’s an excellent question, How frequently do you see re-stenosis during the first
three years. I’m going to address that for carotid artery stenting. Although, the same
question could be applied to conventional carotid endarectomy. One of the nice things
about our old fashioned operation is that the re-stenosis rate is quite low. It does


Page 9 of 17
exist. There’s no doubt that some patients will develop a blockage at the area of the
endarectomy. You’ll have variable estimates of that. Typically in men it’s
approximately five percent. In women it may be a little bit more than that.
Frequently, they are candidates for re-operation, if the stenosis is severe. We’re
hoping that carotid artery stenting may be helpful in some of these patients. As a re-
do, carotid endarectomy has a higher degree of difficulty, perhaps some increase risk
of peripheral neuropathies, if not stroke.
00:36:47
In carotid artery stenting, I don’t think we have a really solid answer for this yet. As
this procedure has not been done for – hundreds of thousands of them been followed
for many, many years..
00:37:03
LUIS ESCHEVERRI, MD: Okay, now we’re going to recover the Accunet device.
Unfortunately, the – Okay, now you can’t see well because the [E-display?] right in
the middle of the boney portion of the carotid.
00:37:18
ROBERT BALDWIN, M.D: Dr. Escheverri is retrieving the filtration device now. It’s
important that that be withdrawn into the sheath with any of the cholesterol debris, to
prevent it from embolizing. Dr. Escheverri, is that feeling normal to you?
00:37:36
LUIS ESCHEVERRI, MD: Yeah. It feels okay. And we went through the stented area
and we are coming with everything out through the sheath. We’re going to get a final
angiogram. Don’t move from there.
00:37:46
ROBERT BALDWIN, M.D: Going back to our question about re-stenosis, many people
are aware that one of the shortfalls of stenting is the recurrence rate. It is common…
00:37:56
LUIS ESCHEVERRI, MD: This is the [mesh] that was deployed. Hold it there.
00:38:01
ROBERT BALDWIN, M.D: It is commonly thought that carotid stenting does not have
the same high degree of recurrent instant stenosis as conventional coronary, pre
[unintelligible] coronary angioplasty or peripheral angioplasty. It does occur, probably
at different rates and different patient populations, particularly in the patients that
have an instant stenosis from surgery.
00:38:23
LUIS ESCHEVERRI, MD: Go ahead and hold your breath. Don’t breath, don’t move,
don’t swallow.
00:38:29
ROBERT BALDWIN, M.D: Dr. Escheverri, what is that that you’re seeing on your
filtration wire there?
00:38:33
LUIS ESCHEVERRI, MD: Actually, to look with a microscope it will be better. Usually,
I mean, it changes the amount of captured material between twenty up to sixty
percent in very [specific?] lesions. I mean, right now we see a lot of – I mean, some
blood on it, but if you actually look under a microscopic examination, I mean, the filter
is 140 microns, 120? Yeah, it’s a 100 microns. And the filter cannot be too small, like
80 microns, because that actually induces thrombosis. And not too big, more than
160, because it may allow significant particles to go through.
00:39:13
ROBERT BALDWIN, M.D: Is that pretty soft and flexible?

LUIS ESCHEVERRI, MD: The filter?




Page 10 of 17
ROBERT BALDWIN, M.D: Yes.
00:39:18
LUIS ESCHEVERRI, MD: Yeah, the filter is quite flexible. We can just put it back in
the sheath. You can pull back.

ROBERT BALDWIN, M.D: Is that the Guidant filter?
00:39:25
LUIS ESCHEVERRI, MD: This is the Accunet. Yes, pull back. Pull back on the wire. So
that’s the way it loads. More essentially it does it where we deployed. This is a bigger
catheter with a softer tube, the Accunet tube, that we use to recapture. You may
have a little bit of debris on this side, so the filter has – The patient is doing really
well.
00:39:47
ROBERT BALDWIN, M.D: And ten years ago, perhaps…
00:39:48
LUIS ESCHEVERRI, MD: So we can look at the video. I mean, we have the final
result. Can you go ahead, Jackie, and pull the first with the stenosis?

ROBERT BALDWIN, M.D: How much residual stenosis do you think is…
00:39:59
LUIS ESCHEVERRI, MD: I think this one has none.
00:40:01
ROBERT BALDWIN, M.D: Yeah, that’s zero percent residual stenosis. Dr. Escheverri,
that’s the preoperative film. Excellent.
00:40:13
LUIS ESCHEVERRI, MD: This is the pre-op film. And now let’s pull the post-op film.
They can only get one image. You see the stenosis right there. This is the post-op
film. You don’t see any stenosis.
00:40:23
ROBERT BALDWIN, M.D: That came across real well. I think everybody in the
audience will appreciate that and the risk reduction of stroke with that.
00:40:30
LUIS ESCHEVERRI, MD: And at this point we’re going to proceed to exchanging the
sheath for a 6 French [angio seal?].
00:40:35
ROBERT BALDWIN, M.D: Dr. Escheverri, can I ask you a question from our audience,
a very good question? What is the three year re-stenosis rate for a carotid artery
stenting?
00:40:48
LUIS ESCHEVERRI, MD: Well, the recurring area stenosis is – I mean, really to
perform in this fashion is only around five years out. The three year re-stenosis rate
is probably less than fifteen percent, and it has a lot to do with what kind of stents
we’re using, what kind of disease we’re treating. Let’s go back a little to the [chest?].
In the United States, really the only stent that is being used is the Acculink. That is
the one that has been tested the most. In two randomized trials, that has shown to
be as effective or as good as endarectomy. And I think that what we’re going to see
is very comparable results to the endarectomy.
00:41:28
However, I mean, that said, not every patient is a candidate for stenting. Carotid
artery endarectomy has been a very adequate procedure performed for over thirty-
five years and we should reserve the stent for those patients who have high risk for
endarectomy or that for any other reason because its co-morbidities had a high risk
for surgery. I think that your vascular surgeon is the best person to consult and


Page 11 of 17
decide, because probably only fifty percent of the patients are going to be a real
candidate for stenting, while the other fifty percent will be good candidates for
endarectomy.
00:42:07
ROBERT BALDWIN, M.D: So not all patients should have carotid artery stenting.
00:42:09
LUIS ESCHEVERRI, MD: Not everybody should go for stenting. There are some
stenting procedures that cannot be performed because of [unintelligible], because of
calcific disease. I think that in general, some patients may have a very high risk of
embolism with the stenting and they probably will do better with endarectomy
compared to stenting. So we have to change the wire. Put pressure here.
00:42:29
WILLIAM FLEMING, MD: Dr. Escheverri, in the case of re-stenosis, how could that be
treated?
00:42:36
LUIS ESCHEVERRI, MD: A stent re-stenosis can actually be treated again with a
protective device and a rehabilitation of the old way to deploy a stent, and is quite
effective. It has been done, and even if there is other segments of a stenosis, this can
also be treated with re-stenting proximately or distally the disease appears in a
different area. So there is a lot of possibilities that we can perform with the stenting.
One other thing is that many patients who have undergone surgery and then
presented with re-stenosis, we have a similar case that has operated three times. It
will be probably a better result with a stenting of the [stenosis portion?].
00:43:18
ROBERT BALDWIN, M.D: Any of our audience have any questions they’d like to e-mail
to Dr. Escheverri, Dr. Fleming, you can send those in by your MDirectAccess button.
We welcome and solicit your inquires. We seem to have a pretty sophisticated
audience, judging by these questions. We’re happy to answer any of your questions.
Dr. Escheverri, this patient was symptomatic too. She had been having some [pain?]
symptoms.
00:43:51
LUIS ESCHEVERRI, MD: Yeah, she had very subtle symptoms, and that’s what
prompted the performance of the angiographic evaluation and the ultrasound
evaluation.
00:44:00
WILLIAM FLEMING, MD: Yeah, she was having what we call TIA, the transient
ischemic attacks. TIA symptoms was the same as those of a stroke, except TIA by
definition resolves within twenty-four hours, and it usually occurs when a clot goes
upstream or an artery is clogged. And then TIAs are significant predictors of stroke,
about one third of all TIA cases a person will have a stroke within a year following the
transient ischemic attack. So it’s very important to follow-up on these stroke-like
symptoms or TIAs.
00:44:41
ROBERT BALDWIN, M.D: Dr. Escheverri, what stage are you at now? It looks like
you’re…
00:44:43
LUIS ESCHEVERRI, MD: Well, we are done. We’re essentially closing this with the
Angio-Seal closing device to prevent any complication from the actual site.
00:44:53
ROBERT BALDWIN, M.D: That looks like a sophisticated device you’re using. That
actually plugs the artery?
00:44:59
LUIS ESCHEVERRI, MD: Yeah, it plugs the artery with a little platform. Scissors.


Page 12 of 17
ROBERT BALDWIN, M.D: And allows the patient to not go through the six hours of
bed rest?
00:45:09
LUIS ESCHEVERRI, MD: Yeah. 4 x 4. So it has a little stitch and a little platform that
holds into the artery, and a collagen plug that will deploy through the tract. And once
we’re done with that, we actually have very good hemostasis. We have had very good
results. You can see that it’s not bleeding whatsoever with the use of the Angio-Seal.
We just put a dressing that will hold pressure for a while.
00:45:33
ROBERT BALDWIN, M.D: Dr. Escheverri, you’ve been able to talk with our patient.
She’s awake?
00:45:36
LUIS ESCHEVERRI, MD: Yeah. We’re talking. She had a little discomfort on the
groin, but otherwise no major problems and we didn’t have any hemodine before,
would you say David? It went very well.

ROBERT BALDWIN, M.D: What is your postoperative management for our patient
today.
00:45:49
LUIS ESCHEVERRI, MD: We will maintain this patient with [unintelligible] therapy.
She has been given Plavix and we’ll keep her on Plavix, at least for the next month,
and aspirin will be also maintained as part of the therapy. Besides she will maintain
all the other medications that she needs for her hypertension, coronary disease or
other co-morbidities.
00:46:12
We follow them with an ultrasound in approximately around a month, and usually
when you have deployed a stent, which is a metallic structure, there is going to be
some increase in velocities that are [audifactual?], so that will give us a baseline of, I
mean, what is going to be the post-stent examination. But usually the velocity
shouldn’t be more than 120 to 140 centimeters per second, and if we maintain then
an ultrasound probably in six months and then a year, a little bit after.
00:46:44
If there is any change on symptoms or there is any change on duplex scan
examinations, then is when we probably would proceed to perform either an MRA, CT
angio or an angiogram. But I think that coronary stenting has a place in the therapy.
It is not for every case, and you definitely should consult with your vascular surgeon
to determine which would be the best procedure to perform. The same applies for all
endovascular therapy, and endovascular therapy is very attractive but has to be
tailored and suited to each patient and each anatomic case. Any more questions?
00:47:20
ROBERT BALDWIN, M.D: Dr. Escheverri, Dr. Fleming has a question from our
audience for you.
00:47:23
WILLIAM FLEMING, MD: Yes. Number one, do you get a loaded dose of Plavix
following this procedure, or is it the regular routine dose?
00:47:28
LUIS ESCHEVERRI, MD: Yeah, we give a load. We give 300 milligrams and then we
continue on 75 a day.

WILLIAM FLEMING, MD: Okay. We have a question…
00:47:37




Page 13 of 17
ROBERT BALDWIN, M.D: When is the 300 milligrams given? Is that in preparation?
Is that last night?
00:47:39
LUIS ESCHEVERRI, MD: Yeah. They gave that before, and some of the patients
actually come on Plavix and we actually don’t start the Plavix, we just maintain the
Plavix as part of the therapy. We don’t start the antiplatelet therapy before we do
this. Also, when the heparinization is performed by the – once you are committed
that you know that you have access and we don’t reverse the heparin, and that’s one
of the reasons we use closing devices because it will avoid complications in the actual
site.
00:48:04
ROBERT BALDWIN, M.D: So your patient could go home tomorrow?
00:48:07
LUIS ESCHEVERRI, MD: I think this patient may be able to go home tomorrow. We
have very few hemodynanic disturbances, and even if they do very well we still keep
them in observation at least for twenty-four hours. When the stenosis is more toward
the bifurcation, where there are receptors, you see more hemodynamic changes at the
time of the dilatation. Not the stent deployment, but dilatation, and it usually is
[unintelligible] cardio hypertension, as Dr. Baldwin mentioned, and that’s when the
anesthesiologist needs to jump in and usually asking the patient to cough and bring
[unintelligible]. Eventually we have some cases that have needed a few hours of
dopamine therapy, and some cases actually, initially, may be hypertensive but later
on they may present with hypertension that needs to be treated.
00:48:53
ROBERT BALDWIN, M.D: Dr. Escheverri, we have a really good question from one of
our audience for Dr. Fleming. I’m going to ask him to read it for us.
00:49:59
WILLIAM FLEMING, MD: This is a e-mail question. If one has not had a stroke within
a year of having a TIA event, what is the likelihood thereafter of another stroke,
assuming the patient is taking Plavix and Bayer aspirin? Well, about one-third of all
TIA patients lifetime will develop a stroke some time in their lifetime. There are some
published articles that give a risk at about five percent per year, so there is still a
significant risk of stroke in post-TIA patients. Again, about one-third of the total
patients will develop a stroke somewhere down the line.
00:49:41
We have another question here, Dr. Escheverri. What is the material of the – and I
think that they’re asking what a stent is composed of, I think is what they’re asking.
What is a stent composed of?
00:49:53
LUIS ESCHEVERRI, MD: Well, the stent is a metal structure and, as I mentioned, it’s
called Nitinol. It’s an alloy of nickel and titanium, and it probably is one of the most
widely used stents nowadays. Also, all stents are called [names?]. Stainless steel,
which is a cobalt alloy which is a Boston Scientific Wallstent and the NexStent, but
those are not available for carotid stenting in the United States. So it’s an Nitinol
alloy, nickel and titanium.
00:50:20
ROBERT BALDWIN, M.D: What is your filter wire composed of, Dr. Escheverri.

LUIS ESCHEVERRI, MD: Those are Nitinol, yeah.

ROBERT BALDWIN, M.D: One of our audience wants to know, do you commonly
perform a post-procedural angiogram of the intracranial vessels?
00:50:39


Page 14 of 17
LUIS ESCHEVERRI, MD: Well, that’s – I mean, something that has been done
routinely when you start doing cases, but we have learned that if there are no clinical
symptoms or there’s no clinical evidence that there is any problem with embolization
or occlusion, by assessing the patient and that this is all he has been doing, we
actually don’t do routinely the post-procedure in intercranial angios. We used to, but I
mean, since the visit with the guys in Frankfurt Heart Hospital in Belgium, that they
have hundreds of cases of experience, they have demonstrated that there is no need
to unless you have any evidence of any problem. So we don’t do them routinely.

WILLIAM FLEMING, MD: Do you want to answer that one?
00:51:22
ROBERT BALDWIN, M.D: Yeah. We have one question asks, would we expect this
patient to feel any change in her symptoms? I think that this patient feels normal.
The nature of TIAs or mini-strokes is that you feel totally normal, except for a brief
period, sometimes only one period, sometimes multiple, the TIA nature is always the
same. It’s very stereotyped as the debris from a plaque or platelet thrombi effect the
same portion of the brain. So the patient feels normal 99.9 percent of the time and
would be expected to feel like that tomorrow, after their medication has wore off.
What we do expect is for the TIAs to cease.
00:52:20
And, again, the main goals of this are not control of the TIAs but risk reduction of
stroke, as we know, can be quite devastating, and those are our real goals in
treatment of carotid artery disease, be it carotid artery stenting, conventional carotid
endarectomy or medical therapy. So this patient we would truly expect to have no
more of these TIAs or episodes of tingling in the hand. Should this patient have this,
this would be quite concerning for either recurrent stenosis or looking into other
problems that may have caused that. That’s pretty unlikely.
00:53:05
WILLIAM FLEMING, MD: Here’s an interesting question here a patient e-mailed in.
Two years had an echogram that showed eighty percent blockage in the right side of
the neck. Had a repeat study on February 6th of this year and was told that there was
no blockage at all and that there was one hundred percent blood flow to the brain.
And this patient is asking, did the blockage just go away? My answer to that, Dr.
Baldwin, is that one of these was wrong.
00:53:36
ROBERT BALDWIN, M.D: One of them was wrong. We get this all the time and it can
be very confusing. There’s many different tests that are involved. Sometimes the
tests conflict with one another. All I can say is find somebody who’s willing to work
through the previous tests that you’ve had and try and make sense with them, but
that varies too much and doesn’t seem like the typical variability that one might
except from well performed studies.
00:54:09
I have another good interesting question from one of our audience. Dr. Escheverri,
are you still with us there?

LUIS ESCHEVERRI, MD: Yes, I’m here.
00:54:18
ROBERT BALDWIN, M.D: We have a cardiologist from St. Petersburg in Russia who
wants to know which brand stent have you found to work best in your patients. And I
might just ask you what stents do we have as options in the United States period?
00:54:37
LUIS ESCHEVERRI, MD: Well, that’s a good question. Essentially, I mean, for
seventy-five percent of the cases, or so, and really any stent will really give you what


Page 15 of 17
you need. There are several cases where you need to have availability of different
stents. Essentially the stent, Occulink is the only stent available which is a [nine
hole?] open cell stent, which means the stent has a kind of wider spaces in-between
the frame of the wires. And that stent actually works very well for most stenosis and
also for very tortuous vessels, because it’s very flexible and accommodates really
easily to the tortuosity of the vessels.
00:55:13
In the cases of embologenic plaque, meaning plaque with a lower debris or plaque
with significant calcification, it has been shown that a closed cell stent probably works
better. The only closed cell stent that we had is the Wallstent and probably in the
future the Nexstent. I’ve used them, but in the United States commercially available,
the only ones really we have is Acculink. But it’s true that in calcific lesions, or so,
you may accommodate better with a different kind of a stent, like a stainless steel
Wallstent closed cell.
00:55:45
Also the protective devices mean they are different. This is a consent to protective
device. There is also an [unintelligible] protective device, which is the EasyWire from
Boston Scientific that accommodates only one size fits all and may be also very easy
to use in patients with a lot of tortuosity. So in the future, when more devices get
approved, I think that you are going to be using different devices to accommodate the
patient’s anatomy and needs. But it’s only in around twenty percent of the case that
you need to really make a choice on which stent to use, which is the tortuosity and
calcification on the vessels.

ROBERT BALDWIN, M.D: I have another question.
00:56:23
LUIS ESCHEVERRI, MD: The other option is also the taper stent. When there is a
significant discrepancy in diameter you can also use a taper stent. Acculink has a
taper stent which is in a conical shape. There is another stent not approved in the
United States that is shoulder type, but if I have to use a taper stent I’d probably use
a conical shape like Acculink has.
00:56:41
ROBERT BALDWIN, M.D: We have another question from one of our audience. One of
our patients is to undergo carotid endarectomy tomorrow and is interested in what her
risk of stroke would be during the procedure. And I think we all want to emphasize
that carotid endarectomy is a great operation that is performed frequently here at
Memorial Southwest Hospital. Dr. Escheverri performs a large number of these,
believes in it and that is not going to be replaced by carotid artery stenting. In the
United States, that is an operation that is done so frequently and that is done so well,
typically American stroke risk is around two percent for a stroke, so I would just
encourage you that it is generally a pretty routinely performed and very safe
operation, so would want to give you some confidence as you approach that operation
for tomorrow. Dr. Escheverri, do you have any parting comments for our audience?
00:57:44
LUIS ESCHEVERRI, MD: No. I want to thank you, everybody. Our nursing personnel
and Dr. Walker and you two guys for all your help. I mean, we have a few more cases
this week and I hope it has been instructive and information for everybody who has
been watching these webcasts. Thank you very much.
00:58:01
ROBERT BALDWIN, M.D: Memorial Hermann Southwest Heart and Vascular Institute
has been very pleased and honored to be able to participate in this webcast and we
appreciate our audience who have mailed in for that. We would like to remind our
audience that this video webcast will be archived for a four week period. It can be


Page 16 of 17
accessed with the MDirect button. We will be continuing to answer e-mails over the
next one month, so please feel free to send us any inquiries. We’re interested in
corresponding with you.
00:58:39
On behalf of Dr. Escheverri, Dr. Fleming and myself, we would like to sign out and we
appreciate your participation in today’s live webcast at Memorial Southwest Hospital.
00:58:54
NARRATOR: Thank you for watching the live carotid artery stenting procedure from
Memorial Hermann Heart and Vascular Institute Southwest in Houston. To make an
appointment, make a referral or request more information, please click the buttons
below.
00:59:57
[END OF WEBCAST]




Page 17 of 17

								
To top