Upper Extremity Venous Ultrasound - SD

Introduction

This is Edward Grant,
and I am the chairman of radiology at the University
of Southern California Medical School,
and today I'm gonna be talking about
upper extremity venous disease.

Good morning. Today I'm going
to be talking about the upper extremity venous
ultrasound examination.
And in particular I'm going
to emphasize its use in the evaluation of both acute
and chronic venous disease.

Venous Disease in General: Differences and Causes

When I think in terms of venous disease in general,
I think it's worth pointing out that there are
definite differences between several of the problems
that we encounter with upper extremity venous disease
that are not the same as those that are encountered
with probably the better known venous disease of the legs.

The vast majority of upper extremity venous disease
has its origin from catheters,
and for this reason probably explains why there seems
to be such an increasing prevalence
of upper extremity venous thrombosis
and associated complications.

Given the fact that in most hospitals, the majority
of patients will have some form of either central
or peripheral lines, obviously,
as you can see from these statistics,
the indwelling central catheters carry a far greater risk
of upper extremity thrombosis than do peripheral IV lines.

Also, other areas that may be problematic for
or associated with upper extremity venous disease are cancer
and hypercoagulable states, which
for the most part are often the same entity,
and that patients with cancer are often hypercoagulable
and may develop thrombosis in unusual places.

Probably the most important other group of patients
with upper extremity venous disease are the so-called
patients with effort thrombosis.
These are basically patients who have a form of
thoracic outlet obstruction
or hypertrophy of the anterior scanline muscle, such
that there is compression of the proximal outflow
of the subclavian vein
and the predilection for diffuse thrombosis distal to that.
Luckily, this is relatively rare.

Clinical Features and Complications

I think another important set of clinical features
of upper extremity venous disease are complications.
And it's interesting
that catheter induced deep venous thrombosis tends
to have a better prognosis than those patients in whom there
is primary or effort thrombosis.
Those patients, again, who develop acute thrombosis
to outflow obstruction proximally from an anterior scaling,
enlargement or possibly hypertrophy.

It's also important to remember at this point,
although the prognosis of the primary
or effort thrombosis may be poorer because probably
because there's such massive thrombosis
and destruction of the valves, that at this point most
of these patients are acutely treated
with thrombolysis, which may in fact
improve the outcome of this group of patients.

Also important to point out
that upper extremity venous thrombosis may be associated
or a cause for pulmonary embolism,
and the literature would tell us that probably around 10%
of patients with pulmonary embolism will actually have
the clot originating in the upper extremity veins.

It's somewhat comforting to think,
however, that these rarely cause death,
and that basically this has been reported as between zero
and 2% in several series.
This is probably secondary to the fact
that the clot burden the size of the clots
that arise in the upper extremity veins are much smaller
than those that arise in the legs and
therefore are much less prone to actually kill the patient
through blockage of the pulmonary vasculature.

It is important to remember that approximately one third
of patients with upper extremity venous disease will develop
post-thrombotic syndrome, which similar to
what is seen in the legs, is probably secondary to
a destruction or fibrosis of the jugular
venous valves and again, result in stasis.

Also important to point out that jugular vein thrombosis,
while it may be a rather spectacular thing
to look at, sono graphically, does not go
or does not cause pulmonary emboli.
And is really a very little clinical import.
Does not lead to post-thrombotic syndrome either.
And for that reason, is probably why so many of our
patients with indwelling catheters,
at least acutely indwelling catheters,
now have them positioned in the internal jugular vein rather
than the subclavian vein, which
of course it does set up the possibility for thrombosis
and result in post-thrombotic syndrome.

Scanning Technique

The technique that we use
for scanning the upper extremity veins may involve any one
of a number of differing transducers, so it's a good idea
to have multiple of them available.
Most typically for general scanning,
we use a linear array with as high a frequency
as will permit good penetration to the vessels,
depending of course on the size of the patient,
and occasional patients with very large shoulders
or very muscular or obese patients.

A curved array may be helpful in scanning the axillary
area as you traverse that region.
And for the identification of lesions
or problems in the area of the internal jugular
or subclavian junction.

Any transducer with a very tiny footprint,
which some people call baby head transducers
with a small footprint that gives you a wide field of view,
may actually help you to intonate this area,
which is typically surrounded by bone
and may even allow you to get some imaging
of the inmate veins.

Typically, I begin the examination by
placing the transducer in a medial fashion,
in the medial upper arm, transversely,
identify the arterial and venous landmarks
and then proceed proximally in a longitudinal orientation
until I'm blocked by the clavicle.
Once you get to that region,
I then jump up over the clavicle, look
for the internal jugular vein
and follow it as proximally as I can.
Again, if there's a question of orientation,
turn the transducer into the orthogonal plane,
and that will also show you the surrounding,
usually the adjacent artery or other veins and,
and help you with your identification of landmarks.

Normal Venous Anatomy

Now, the upper extremity,
normal venous anatomy is nicely shown in
this particular diagram.
I think the thing that is probably most unique about it is
that remember, unlike the arterial tree,
there is a brachiocephalic
or a nominate vein bilaterally, so there is a left
and right innominate or brachiocephalic vein.

This is formed by the junction of the jugular veins
and the proximal subclavian vein following the subclavian
vein out laterally to its junction with the cephalic vein,
which is the large vein
that comes along the lateral side of the arm.
After this point, it ducks through the
pectoral muscles to become the axillary vein
and eventually then emerges in the upper arm
and divides into the basilic, which is a superficial vein,
and the deep brachial veins,
the brachial veins are usually multiple
and closely applied to the brachial artery.

Again, a diagram I think shows this very nicely the
superficial location of the basilic vein,
which is really not paired with an artery,
and the fact that there are usually multiple small brachial
veins which are smaller than the superficial veins
and closely associated with the brachial artery.

Remember, the division of the axillary artery into the
brachial, and then the brachial into the radial
and ulnar arteries and veins is extremely variable
and actually may occur anywhere through the length
of the upper arm.

This is a patient in whom you can see
that there has already been division of the
brachial artery into the ulnar
and radial artery in the mid portion of the upper arm.

Compression and Transducer Use

We do use compression where it's possible.
Obviously, compression is not going to be easy
or possible once you get up underneath of the clavicle,
but in the more peripheral portions
of the upper extremity venous system,
we use compression wherever it is possible.

Again, in some of the larger patients with a lot
of musculature or extremely obese may be a good idea
to actually use a curved array, lower frequency probe
to be able to identify usually the axillary arteries,
the only one that you'd actually
need anything like this for.
And of course, as I mentioned, looking for the junction
of the internal jugular vein with the subclavian vein,
these very small footprint transducers with a
fan shaped array or
visualization of the vessels,
can actually be beneficial
and get us way down into the chest, which would
otherwise be impossible using a linear probe.

Normal Venous Pulsations and Catheters

Always very important in the upper extremity venous system
to identify the normal venous pulsations.
Remember this is a typical
systemic vein which is closely connected
to the right atrium, and
therefore should have this very choppy kind
of sawtooth phasic pattern that is typical
of most central systemic veins.

We also may identify catheters in these veins.
The cephalic vein
or any of the veins in the upper arm may actually be used
for venous access, particularly PICC lines
and other long indwelling catheters.

Literature on Diagnostic Accuracy

Now, going back to the old literature, on some
of the original articles
that were written on using upper extremity Doppler,
you can see the results were fairly good.
I think that probably a more realistic article was won
by Nuen etal, which showed a 78% sensitivity
and 92% specificity for upper extremity venous thrombosis.
But do remember this was a mixed population
and that they did not use the multiple transducers
that we have available today.
So this was done with a linear probe,
and I think that our results should be better than they are.

In this early study, also one by Joe P*****k,
which showed a hundred percent sensitivity and specificity.
Now Joe's really good,
but the reality of it is these were all effort
thrombosis patients.
They had massive thrombosis,
so you really should have a hundred percent sensitivity
and specificity in a population like this.

Diagnostic Criteria for Acute Upper Extremity Venous Thrombosis

Now, the diagnostic criteria
for acute upper extremity venous thrombosis are very similar
to what you would expect to find in the legs.
First, you look for the presence of hyper
or hyperechoic thrombus.
It's very variable, just as we see in the legs.

Absent color
and spectral doppler should be obvious.
You obviously also may see color around a thrombus.
They may not be completely occlusive,
and that really doesn't have a whole lot
of clinical relevance.

As I mentioned, we look for lack
of compression from usually the axillary vein on out.
And for chronic venous thrombosis, we also tend to look
for or central thrombosis that's not visible
on the ultrasound.
Look for loss of that normal phasic spectral signal.
Some people have likened it to a portal vein signature.

Also remember collaterals develop very quickly in
the upper extremity veins
and can actually cause confusion.

Examples in the Brachial Distribution

These are a couple of classic examples
or typical examples of what you see
in the brachial distribution.
You can see the vein on either side
of the brachial artery.
And again, these are the brachial arteries.

This transverse image of the same patient shows you
that the two brachial veins applied very closely to the artery
and the basilic vein, which is actually again, larger,
and more superficial and not paired to an artery.
Therefore, it is a superficial vessel,
even though in this particular case it may harbor more clot
and be larger than the accompanying brachial arteries.

Axillary Vein Thrombosis

The axillary vein can actually get quite large when it's
distended by thrombus, as is the case here.

Just as in the legs, I think we often see echoic
or hypoechoic thrombus.
But as is the case here, this is a large thrombus,
which is expanding the vessel.
It's bigger than the adjacent artery.
This is an acute axillary vein thrombosis.

Replacement of Venography

We have largely come away from performing venography,
unless intervention is being contemplated,
but certainly venography was something
that was quite commonly performed in the old days.
At this point, I think between ultrasound
and MRV, we've largely replaced it.

Catheter-Related Findings

Again, as I mentioned earlier, you may actually find
these vessels are expanded
and are traversed by a catheter, which is probably the root
of the thrombosis itself.

Collaterals and Waveform Changes

If you see collaterals,
or vessels beyond an obvious thrombosis, again,
you will probably lose that nice phasic waveform.
Here you can see we have a collateral dumping into the
subclavian vein,
and an absolutely flat portal vein kind
of flow without the expected phasicity, good idea just
as in the legs to always document the proximal
and distal extent of the thrombosis,
particularly the proximal extent centrally.

If these patients show up again
for a repeat examination, it's a good idea to know
or be able to at least document has this
thrombus propagated.
And you can only really do that if you know
what the proximal extent
of the thrombosis was on a earlier scan.

Comparing Sides for Phasic Signal

As I mentioned, it's very important
to compare the two sides,
and look for that phasic signal.
Here you can see on the right that nice normal phasic signal
that we showed earlier.
Comparing that in the same patient to the signal,
the spectral signal from the opposite subclavian
vein, absolutely flat.
This is good evidence that there is a central thrombosis
or at least occlusion.
If you can't see it,
obviously we don't know which it is,
but certainly this is very good evidence
that there is some form
of central blockage, whether an acute thrombus
or in most cases probably a chronic thrombus,
but always very important
to document at least in the subclavian veins.

A couple of images of the
phasicity of the normal vessel.
If we do a unilateral study, as part of our protocol,
I always insist that we also obtain some images from the
opposite side because again, the normality
of the upper extremity veins is very
variable from one person to the next,
and it helps to actually have
that image from the opposite side so that you can use that
as a baseline for comparison with the other side.
This of course, may fall flat if you've got bilateral
brachiocephalic or superior vena cava disease,
but for the most part, I think it's a very important thing
in the upper extremities to have that comparison
of the spectral patterns.

Partial Thrombosis

You can have partial thrombosis in these cases.
In such cases, you will usually find an area
of elevated velocity.
And it's interesting that in this area,
usually the phasicity will return once you get into the actual
area of narrowing.
As is the case here,
and you can see that there is partially occlusive
echoic thrombus to the one side of the vessel.
You can see an area of color aliasing within
that narrowed region,
and it's confirmed that there is high velocity flow in
this selected region by the spectral tracing itself.

Extrinsic Causes of Narrowing and Thrombosis

Now, do remember that there may be extrinsic reasons
for narrowing
and resultant thrombosis of the upper extremity veins.

This was an elderly man who was sent
to us from a nursing home with swelling of the arm.
And you can see
that there was thrombus identified in the vein itself,
which extended distally,
but that the vein was actually quite narrowed
by a solid mass.

In this particular case, we went back
and reviewed the chest x-rays on this gentleman,
and needless to say, there is a mass in the
apex of the right lung.
You can see there's already a metastatic deposit in the rib
on the left, and this turned out
to be a squamous cell carcinoma of the lung,
an apical tumor, a pancoast tumor,
and that we actually biopsy this under ultrasound guidance.

So do remember everything
that affects the veins may not be intrinsic
to them and to look around.
This is obviously also the basis, for example,
of the effort thrombosis in those patients in whom there is
enlargement of the anterior scaly muscle with entrapment
of the vein leading to outflow obstruction
and resultant massive thrombosis.

Cephalic and Basilic Veins in Routine Examination

Now, as part of our routine examination
of the upper extremity veins, we do not tend
to include the cephalic vein.
This is a large vein that, as I mentioned,
extends along the lateral edge of the lateral side
of the upper arm and then anastomosis with the branches
of the basilic and brachial veins in the anti cubital fossa.

This is really a clinical diagnosis.
The thrombosis of the cephalic vein is really
for the most part, a clinical diagnosis.
If there's a thrombus there, you can probably see it.
And better yet you can even feel it as a ropey area
of thrombosis On the lateral side of the arm, this is
that vessel that you see, um, in well muscle people, um,
along the biceps muscle laterally.
So we don't tend to include that in our normal examination.

As I mentioned, we do tend
to include the basilic vein since it's right in that area,
where the rest of the vessels live.
The brachial veins live the brachial artery.
And this is a relatively large vein,
which can carry a considerable clot burden.

Again, whether it's the cephalic vein
or the basilic vein, these are often used for
venous access lines.
And in this particular case, you can see
that we have a thrombosis around an indwelling catheter.

Chronic Venous Disease and Post-Thrombotic Syndrome

Now, I mentioned that about 33% of patients
with acute venous thrombosis will develop
chronic venous disease post-thrombotic syndrome,
and this is another area where ultrasound may be used
to clinical advantage.

First of all, it's important
to know in these patients, whether you're dealing
with residual clot or
acute clot versus what often happens in these patients,
both in the upper and lower extremity veins,
after a thrombotic episode,
the vessel may simply fibrosis down.
So it's important to know whether you're dealing
with fibrosis or whether you're dealing
with clot from the standpoint of both imaging
and possible er resultant thrombolytic treatment.

Sonographic Features of Chronic Disease

Now as far as the sonographic features
of upper extremity venous thrombosis
or chronic disease, rather, we look for a residual
or recanalize thrombus within the vein, just
as occurs in the lower extremity, the
thrombus will begin to shrink
and fibrosis down as time goes on.
So a small thrombus, again,
probably smaller than the adjacent artery should tip us off
to the probability of chronic venous disease
or chronic venous thrombosis.

You may actually see true recanalization
of the thrombus, look for collaterals.
Remember, there's a very rich collateral bed
around the upper extremity, and shoulder.
And so collaterals will begin to open up very, very quickly
around any deep venous thrombosis.

Just as we had mentioned earlier, we look for a
decrease in the normal spectral ity, again,
as some meat will call it this portal signature,
where you actually have a lack of, um, ity
due to the presence of,
or the absence really of direct contact
between the flow in the upper extremity veins,
and the normal pulsatility of the right atrium.

Also you may actually see consistent,
visible narrowing either on gray scale or color.
And oftentimes in these cases,
you will actually see a focal region
of increased spectral velocity.

Remember that while these narrowed regions may be secondary
to thrombus
and often probably are,
they are not uncommon in patients who have long term
indwelling catheters, whether it's actually cases
of silent thrombosis leading to fibrosis
or actually irritation from the,
indwelling catheter itself is not known,
but certainly it is well known that you may
actually have true stenosis of these vessels.

Now, many patients are able to open up collaterals
around them and, decrease the resultant,
arm swelling, but it is sometimes necessary
to go on and stent these patients.
So this is an important thing to identify.

Remember not to create it by pressing too hard
with your transducer.
If you press too hard with the transducer,
you will actually cause narrowing
and potentially increased spectral velocity.
So make sure that you're very light in your touch,
and don't actually cause transducer induced,
pseudo narrowing.

Differentiating Collaterals from Native Vessels

Also do remember that again,
differentiating collaterals from the native
or the real deep vessels may be quite challenging.
Always look for consistent anatomy.
Look for the adjacent artery so that you know
that you're dealing with the adjacent large vein rather than
a large collateral that is formed.

As I mentioned, there is the potential for the opening
of a very rich collateral bed,
all throughout the upper arm and shoulder area.
Even in the jugular area.
It's remarkable how patients can open up huge collateral
beds across the neck when there is blockage on one side.

Again, always look for
that nice normal spectral waveform choppy phasic waveform.

Examples of Chronic Findings

Here you can see that this vessel looks perfectly normal
by gray scale evaluation,
but there is a definite lack of
that normal phasic pulsatility.

In this particular case, following the vein centrally,
you can see that there's an area of intense aliasing,
which is very nicely defined as a very,
very narrow channel in this proximal subclavian vein.

This is an interesting piece of physiology,
which tells us a lot.
If you look at the color pattern on this particular
patient, you can see
that the subclavian vein is displayed in blue in
that it's going away from the transducer,
but the jugular vein is displayed in red going up
toward the patient's neck.

So in this particular case, with
or without abnormal spectral lack of of ity,
by the physiology here, you can clearly see
that the innominate vein on the left is out,
probably chronically thrombo or scarred,
and that flow comes down through the subclavian vein
and then reverses its course going up into the jugular vein.

And as I mentioned, it's remarkable how a, how rich a bed
of collaterals can open up when the patient needs to get
around a central obstruction on one side or the other.
So the color pattern in this particular case is essentially
diagnostic of a central occlusion.

Here you can see on the venogram that
there is complete blockage of the flow centrally
and that flow is now shunting up
through the jugular system.
And across to the other side to get around this central,
innominate vein occlusion, as I mentioned,
it is extremely important
to compare the Doppler waveforms from one side to the other.

Studies on Central Occlusions

An older study actually claimed
that ultrasound was not particularly good for this,
and it has been stated that about a quarter of patients
who have catheters in their veins
will develop a DVT or stenosis.
And these may be silent, as I mentioned,
and what these are, how,
the reason they're they're discovered is simply
through the inability to catheterize veins when one tries
to insert such things as a PICC line.

So people have actually done pre PICC line scanning.
We don't do an awful lot of that anymore.
And a study done a number of years ago showed
that ultrasound was really only 27% sensitive for
identifying these so-called central occlusions.

I think that this probably does not give justice
to the results that we can achieve
with ultrasound at implying
or identifying these central occlusions.

And another article, published a number of years later,
actually showed very good results.
And this article actually looked specifically
at the waveform rather than actually identifying a stenosis,
which I think most of us would say is going
to be very difficult visually.
In this particular article,
they actually compared the waveforms from one side
to another with an eye toward diagnosing
or implying central occlusions.

As we've discussed earlier,
they took 21 patients in whom there was absolutely no
abnormality seen by gray scale or color doppler imaging.
And they looked at asymmetry in cardiac pulsivity
and respiratory ity.
And they found that
asymmetry in cardiac puls fity
was a hundred percent sensitive and specific.

And that respiratory ity
or a decrease, a unilateral decrease in respiratory ity
yielded a lower sensitivity,
but was still perfect with regards to specificity.

So again, very important when thinking in terms
of these almost silent occlusions, that we compare
with the waveform from the opposite side.

Unusual Entities: Venous Pseudoaneurysm

Now, in closing, an unusual entity
that may be encountered is something known
as a venous pseudo aneurysm.
This is a rare complication of trauma.
I think most commonly these are actually going
to be iatrogenic,
and again, from puncture of the veins,
usually the internal jugular vein is the
most common location.
And this will be seen sono graphically as a ular outpouching
of the vein, which contains puls ital flow.
And you can see that the puls ital flow will actually,
essentially be in sync with the motion.
In the adjacent vein, you can actually see a squirt
of flow going into this sack on either gray scale or color
or power doppler.

Again, it is most commonly going
to be found in the internal jugular, probably
because again, at this point the internal jugular is
probably the most commonly punctured upper
extremity proximal vein.

The important thing about venous pseudo aneurysms
as opposed to those which affect the arteries, is not
to get excited about them.
These are not clinically significant.
There's no reason to intervene and remove them,
or not to thrombosis them as we do with,
various,
arterial pseudo aneurysms.

Again, these can be quite dramatic sono graphically.
Here you can see the jugular vein In this particular
patient, my images,
my mind was originally completely reversed on this.
I actually thought it was the carotid artery next
to the jugular, and then I realized, oh,
it was actually lateral.
So you can see a small neck here
and you can see pulsitile flow extending out
of the jugular vein on this power Doppler image.

Likewise, I think the,
gray scale also shows this kind of swirling flow
with rhythmically moves.
And some of it settles out within this,
internal jugular pseudo aneurysm.

So again, an unusual entity, rather dramatic images.
But the important thing to keep in mind is
that these are clinically of no significance
and really do not require any kind of intervention.

Conclusion

So with that, I think we will close our session.