00:01
Welcome back.
00:02
Thanks for joining me
on this discussion of carotid stenosis
in the section of vascular surgery.
00:10
Carotid stenosis is a very common disease
and there are some risk factors,
particularly puts you at higher incidence.
00:17
For example, smoking.
00:19
In fact, smoking is a high-risk factor
for most vascular diseases.
00:24
There is some association with
increased alcohol intake
and, of course,
like any peripheral vascular disease,
when one has one peripheral vascular disease,
one is at a higher association for another.
00:38
In this situation,
patients with coronary artery disease
also may have carotid disease.
00:43
This is an important distinction,
because when patients have
coronary artery disease,
also think about working them
up for bilateral carotid diseases.
00:54
Let's discuss the pathophysiology of
carotid diseases and atherosclerotic plaques.
01:01
Here's a depiction of a
common carotid bifurcation.
01:05
It's, of course, situated in your neck.
01:06
You can feel your own carotid pulses.
01:09
Atherosclerotic plaques are dense in lipids
and they usually occur
at the carotid bifurcation.
01:17
This is particularly because,
at the bifurcation,
laminar or straight-line
flow becomes turbulent.
01:24
And as turbulent flow
occurs at the bifurcation,
it perpetuates worsening of
the atherosclerotic plaque.
01:32
At some point,
the plaque becomes so thick
that it actually narrows
the lumen of the vessels.
01:38
That's when you become symptomatic.
01:43
What are some common
findings of carotid stenosis?
One might actually hear a carotid bruit.
01:48
When you listen to a patient
who has a carotid stenosis,
the carotid bruit actually sounds like,
well, turbulent flow,
as I previously described.
01:57
Some patients will also describe
transient ischemic attacks,
also known as TIAs.
02:04
In these select patients,
it's a warning sign.
02:07
Patients may have intermittent stroke
symptoms that are self-contained.
02:12
They may have completely resolved
by the time the patient
even presents to your office
or the emergency room,
but don't lose these patients to follow up.
02:21
They may actually have significant carotid disease.
02:27
This is a depiction of a curtain drawn down
or a shade over a window.
02:32
And that's a classic
description of amaurosis fugax.
02:36
That's the transient monocular blindness
that's associated with plaques.
02:41
And those plaques
may be distributing themselves
into the ophthalmic artery.
02:45
Next.
02:46
Patients may actually
have CVAs or stroke.
02:49
CVA stands for cerebrovascular accidents.
02:54
This is most likely due to
portions of the atherosclerotic plaque
breaking off and being embolic.
03:01
Also, when the channel is so stenotic
that the flow is inadequate,
one may actually have a
broader distribution ischemic stroke.
03:10
Labs are unlikely to be helpful to you,
but it is very important to
screen for carotid disease
when you have high suspicions.
03:18
How do we screen for carotid disease?
I’ll give you a second
to think about it.
03:25
That's right.
03:26
Carotid duplex ultrasonography.
03:29
As with all ultrasounds,
the results and accuracy of these tests
are heavily operator dependent.
03:35
Let's say the clinical scenario is a patient
who presents to your office.
03:39
They describe symptoms consistent
with TIAs or amaurosis fugax.
03:44
The next step of management will be
obtain a carotid duplex ultrasound.
03:50
Duplexes are helpful
not only because they give
you anatomic information,
but more importantly,
for stenotic vessels,
they give you velocity information.
04:00
Recall,
flow through a smaller diameter
is usually at higher velocities.
04:06
That’s simple physics. A certain velocity,
as described as centimeters per second,
is indicative of a
percentage of carotid stenosis.
04:16
This is an approximation of course.
04:19
Angiography.
04:21
For many years,
angiography was the gold standard.
04:24
I'm talking about the
invasive interventional angiography,
of course,
not the spiral CAT scan angiographies.
04:32
In this representative invasive angiography,
the arrow points at an area
that’s most likely
representative of a plaque.
04:39
Note, it's very close
to the bifurcation.