Lower Extremity Veins: Techniques and Interpretation with How To Demonstration

Introduction

Hi, my name is Annemarie Kapinsky.

I'm from Albany, New York,

and I'll be speaking to you about venous duplex

ultrasound examinations.

This lecture will be on the techniques

and interpretation of lower extremity venous duplex

ultrasound examinations.

Assessment Methods for Venous Disease

There are many ways to assess a patient for venous disease.

We can do a clinical exam,

however, this is not highly sensitive.

In fact, only about 50% of the time will we be correct,

by just evaluating the clinical signs

and symptoms of a patient.

There are other indirect tests involving CW Doppler

or various plethysmography,

but those have pretty much been abandoned for the use

of duplex ultrasound, which is our primary testing modality.

Although some folks will do occasional venography,

venography is still considered the anatomic gold standard.

Patient and Operator Positioning

One thing to pay attention to when you're doing any type

of ultrasound is your position as well

as the patient's position.

Now, sometimes the veins are harder to see.

They're under low pressure, so in order

to make them dilate a little bit,

if you put the leg into a dependent position,

either reverse Trendelenburg is shown here,

or having the patient sit upright

to examine the calf portion of the veins.

Either one will be a good method to

get some more pressure on the veins, have them

stand a little bit more,

but understand that they will be under more pressure.

Therefore, they will need more pressure.

You'll need more pressure to get those veins

to completely compress.

And of note, to pay attention as you're scanning,

you want to pay attention to your posture, how your arm,

elbow, wrist, and everything is aligned,

to avoid any work related injuries.

Starting the Lower Extremity Venous Examination

When we examine the lower extremity veins,

we pretty much start at the top

of the leg in the groin crease,

but we're really below the inguinal ligament.

The inguinal ligament sits just a little bit higher

from where we begin.

So we start at the common femoral vein just

below the inguinal ligament,

and we'll follow that all the way through the femoral vein,

the popliteal, and into the tibial level vessels.

One thing to note, remember,

we call this vein the femoral vein.

We no longer call it the superficial femoral vein,

even though it's the companion vessel

of the superficial femoral artery, we

have gotten away from using the term superficial femoral

vein to avoid any confusion as far

as treatment is concerned for thrombus in that vessel.

Vessels to Assess in Lower Extremity Venous Ultrasound

So what vessels do we need

to assess when we do a lower extremity venous ultrasound?

The documentation that I've put together within

this presentation relies pretty much on the standards

of the Intersocietal Commission for the Accreditation

of Vascular Laboratories.

I-C-A-V-L. These are in compliance

with the I-C-A-V-L standards.

Currently, I'm less familiar with a CR standards,

American College of Radiology,

but they're probably pretty similar.

And in terms of the vessels that need to be documented,

we again do the common femoral vein.

We do the very terminal portion of the deep femoral

or profunda femoral vein, the great saphenous vein,

popliteal vein,

and then down into the calf, we look at the terminal portion

of the small saphenous as well as the gastrocnemius,

posterior tibial, peroneal, and soleal veins.

Now, one vein that's not listed

here is the anterior tibial vein.

The incidence

of isolated anterior tibial thrombus is probably less

than half a percent.

It's very uncommon. I've seen it only three times.

And in each of those patients, they've presented

with symptoms along the anterior compartment.

So in the absence

of symptoms along the anterior compartment,

the anterior tibial veins do not need

to be routinely examined.

Examination Procedure

The procedure is simple.

We use a transverse orientation

and we do compressions every two to three centimeters.

We'll rotate the transducer into a sagittal plane if we're

doing color flow evaluation or spectral analysis.

Here we begin again, we're at the top of the leg just

below the inguinal ligament,

and we see the common femoral vein here,

very large in the center, common femoral artery off

to one side, and the great saphenous vein off to the other.

And we always position this.

So the patient's right is actually on the left

of the screen here, and their left is on the right.

So it's like somebody standing in front of us,

this is their right, and over here is their left.

Some people look at this orientation

and have referred to this orientation as Mickey Mouse sign,

where Mickey's face is, the common femoral vein,

and the great saphenous

and common femoral artery make up his ears.

We go down the leg

and we document the compressibility of the vein.

Most folks will do a split screen image like this displays

where the left side of the screen is non compressed

and the compressed view is on the right side of the screen.

This works very nicely for large vessels.

You can put in indicators, arrows as

shown here, but you don't have to.

And this is the convention of showing compressed

and non compressed views.

We'll continue down.

This slide is labels obviously added in

to show the superficial femoral artery and the femoral vein.

Again, the just femoral, not superficial femoral vein.

And here we can see the walls of the femoral vein collapsed.

One thing as we go down the leg,

we're usually on a medial approach onto the thigh here.

The femoral vein gets deeper and deeper,

and here it's not very deep.

It's only about four centimeters,

but it gets down into the muscle layer coming

through the adductor canal.

And at that point, it is actually hard

to compress from this view here.

So if you actually apply pressure with your free hand from

underneath, you can get that vein to collapse a lot easier.

Calf Veins Evaluation

Here we have also the calf veins can be a little bit troublesome to evaluate.

There is a lot of anatomic variation,

particularly in this region right here off

the popliteal vein.

We usually give rise to a common peroneal

and common tibial trunk, which goes just a centimeter

or two, and then splits again into paired peroneal veins

or posterior tibial veins.

But this can be really very variable.

The length right here of this vein

or the common tibial vein could be fairly non-existent.

You may have the popliteal vein come down

and then just split into four branches being all the named tibial veins.

And here's ultrasound of the popliteal vein,

both non compressed and compressed.

Right here is what's left to the popliteal vein.

Remember, when we scan the popliteal vein,

we're using a posterior approach.

And from that approach,

the vein now sits on top of the artery.

The other thing to remember about the popliteal vein is

that very often it's a paired system.

I think perhaps about a third of the time,

some folks say it's more like 40 to 50% of the time.

The literature is pretty variable.

But be assured that there will be patients that will come

to you with two popliteal veins.

One usually does sit superior to the artery,

but a lot of times the other one is more inferior or

much deeper.

And you may miss it.

So it may be sitting somewhere over

here, and you may miss it.

It may be thrombosed and hard to see.

So just try to look around

and make sure you have fully evaluated that popliteal area.

Anatomy in Ultrasound Images

The other thing is to really get comfortable

with the rest of the anatomy.

Obviously we know the skin is at the top of the picture,

and we've got the subcutaneous tissue just below it.

But this bright white through here, that's fascia,

that's the loose connective tissue part

of the connective tissue, I should say.

That wraps the muscle bundle.

And you see it here and you also see a little

bit of it underneath it.

And when we see vessels sitting inside that muscle bundle,

those are the muscular branches, either the in,

in this view, we're seeing the gastrocnemius veins,

vein, artery vein.

There is a companion artery here.

If we see vessels that are coursing between the muscles,

those are the big veins like the posterior tibial and peroneal.

And that's what this picture shows.

We can just about make out the edge

of this one muscle head right here.

You can kind of see the difference in the tissue

and a little bit of the fascial wrap here.

And here are posterior tibial vessels,

and here are peroneal vessels.

So we have posterior tibial vein, posterior tibial artery,

posterior tibial vein,

and then peroneal vein, peroneal artery, peroneal vein.

Now the peroneal vessels used to be called fibular vessels,

fibular artery, fibular veins, because they sit right here.

Here's the fibula right down here in the corner.

They sit right on top of it.

So that's why they used to be called fibular,

but we call them peroneal

and they'll be a little bit deeper just above the bone,

whereas the posterior tibials will be a little more superficial

and sort of just medial to the tibia.

Evaluation of Superficial Veins

Now it's an examination for a deep vein thrombosis,

but we do include evaluation of the superficial veins.

We've got here a schematic

of the great saphenous vein.

We do want to look at the termination

of the great saphenous vein into the common femoral vein.

Here we see a sagittal orientation,

the great saphenous coming in

and emptying into the common femoral.

We see the superficial epigastric vein in view in this image.

And what we don't want to see is a GSV

that looks like this, where we can see this hyperechoic

material, which is thrombus extending right across the

saphenofemoral junction.

Depending on the circumstances, most physicians would treat this as a DVT

because it does present a risk

for thromboembolism and PE.

Here is another view of the calf.

This is higher up in the calf.

We have the popliteal vein,

popliteal artery down near the bottom.

And again, if we look at the rest of the gray scale image,

we can appreciate the muscle head right here

and our gastrocnemius artery and companion veins.

But what's important in this view is the small saphenous.

The small saphenous, of course, used

to be called the lesser saphenous or short saphenous.

And it sits way right up in like a fascial sandwich.

There's a piece of fascia above it and below it,

and not much tissue next to it.

So often the small saphenous is hard

to distinguish, and it is pretty small.

So we'd probably want

to even increase the transmit frequency in this case

and see if we can maybe decrease the number of focal zones

and move them up closer so we can optimize

that first centimeter or so of tissue depth.

If we're evaluating the small saphenous,

well image is important,

but when we talk vascular, we have

to worry about the Doppler too.

And we do have to take Doppler signals from

basically several major vessels.

You can do it from all the vessels.

I don't think it's really needed below the knee.

There are multiple calf veins, so if you're going

to Doppler, you really have to Doppler all of them

because it's not all that helpful just

to document a Doppler waveform from one of several calf veins.

So we normally record spectral Doppler from the common femoral vein as well

as the popliteal vein.

Many folks also include the what we used

to call the superficial femoral vein.

Now, the femoral vein, so it's common femoral, femoral

and popliteal are kind of standard levels to document.

We record those Doppler spectrums at rest

and also with augmentation maneuvers, either Valsalva

or distal compression.

And there are many reasons why we may examine patients just

for one leg symptoms with one leg.

However, we need

to record a complementary contralateral common femoral

vein Doppler signal.

If we're only doing a unilateral study,

this is a requirement by the I-C-A-V-L,

and it's a requirement

because when we examine these common femoral vein signals bilaterally,

it'll give us a good idea

of what's going on systemically with the patient.

And we might be able to detect things like

systemic venous hypertension or other problems.

Doppler Evaluation

So here's a Doppler spectrum

where we've got our Doppler cursor in the common femoral vein.

And you notice here the angle correction is on,

and it may actually appear on in several of the images,

but it is not necessary to angle correct for venous Doppler.

But you still need to get a good angle in order

to get a good Doppler shift.

So you will want to try to approximate your 60 degree angle

of insonation, but here we see flow

and then no flow flow, and then no flow.

And what happens is when we take a breath in

and inspire the pressure in our abdomen increases,

the pressure in the abdomen increases to a point

where it actually exceeds the pressure in

the common femoral vein.

So we basically shut down flow from the common femoral vein.

When we exhale, the pressure in our abdomen goes down,

it's now lower than the common femoral vein pressure.

So we see flow. Again, we should be able to see that

spontaneity and phasicity in the venous Doppler signal down

through the popliteal vein.

That's pretty common.

You may have a little trouble with some

of the tibial veins if you are going

to do tibial vein Doppler,

but you should see good spontaneous signals at least

down through the popliteal.

If not, take a look at your adjustments.

In fact, this PRF or scale is probably too high for a vein.

You might even want to drop that down a little bit lower.

Color Flow in Venous Ultrasound

Well, when we talk about ultrasound,

it wouldn't be complete if we didn't discuss color.

Now, color isn't essential.

You can get through a venous exam without it,

but it certainly is helpful.

It is still considered to be complimentary and not required.

However, it can aid in the identification

of the extent of thrombus.

We can use color to help locate a vessel,

finding the companion artery and using that as a guide.

And certainly there's areas where we can't compress a vein,

so we can use the color signal

to help confirm vessel patency.

But remember, just

because you don't see color, it doesn't necessarily mean

that the vessel is thrombosed.

And just because you do see color in a vessel doesn't

necessarily mean that the vessel is thrombus free.

That's very important.

It all depends on the settings of the equipment.

Now here we see, again, a femoral vein

and superficial femoral artery kind of getting deep in view,

and we're using the superficial femoral artery as our guide

to help us follow that femoral vein

Down in the calf here again,

we've got the subcutaneous tissue here,

we've got the gastrocnemius muscle on top.

That's the first one. And now underneath that is the soleus.

And this tributary coming out of the soleus muscle

coming into the posterior tibial veins is a soleal vein.

We aren't getting good filling in these

posterior tibial veins.

But remember, venous flow is dynamic,

and we've got a static image here.

And these vessels are perfectly patent.

It's just a matter of timing.

We are transverse to them, so that's a little bit more

of a challenge to create an angle

so we can get good filling.

But certainly color is very beneficial when

we have things like this.

Acute non occlusive thrombus with this tail sort

of swinging in the blood flow

of this common femoral vein.

Color can help here as we see another bit of thrombus,

another patient in the saphenofemoral junction,

we can see while the thrombus does extend,

here's the saphenous out into the saphenofemoral junction.

We are getting flow around it

and a little bit of flow from the great saphenous,

probably from the superficial epigastric vein in fact.

And that'll help define where we see things.

Over here, we've got flow filling the popliteal artery

and one tributary vessel here,

but no flow in that popliteal vein.

Here's just a series of images of the same popliteal artery

and popliteal vein.

Now here is the popliteal vein.

You can see there's echogenicity within the vessel

and a very, very faint amount of color filling here.

In this next view, this is the exact same location.

We still see our popliteal artery,

but we're seeing a little more color filling

in another view, even a little more color filling.

And in this view, almost not really fulfilling,

but a lot more filling than we saw in the first image.

The only thing that was changed in these images was the

color priority.

This is a setting on all ultrasound systems.

They might have different names,

but it basically tells the system how much color

to write over the gray scale.

So if your color priority is high,

you'll get a lot more color filling in,

and it'll fill right in over areas

of non occlusive thrombus.

If your color priority is low, the software

of the ultrasound systems is going

to send much more power into generating the gray scale image

and not overlay very much color.

So you'll see more thrombus and less color.

Interpretation of Venous Ultrasound Images

Now what about interpretation of the images?

Well, normal veins should appear nice, smooth, thin walled.

You may see slight changes with respiration.

You may see some echoes,

but we usually set this up so that the lumen

of the vessels are pretty dark, pretty anechoic.

If we can see the valves, we may see some slight motion within the valves with blood flow

and the valve sinuses may appear elliptical.

And here's a picture.

Actually, this is an arm vein

where we can see the valve leaflets here

and here, a little bit of the insertion ridge,

this thickening here, which is part of the vessel wall.

And we have the valve open and valve closed.

And that's just during normal breathing patterns.

Sometimes though thrombus does happen behind valves.

And here's a valve that sort of stuck out,

frozen out into the lumen with lots of thrombus behind it.

And that thrombus has propagated

and extended into the lumen of the vein,

and certainly represents a risk to the patient

once we find thrombus.

The other thing we need to do is characterize it

as being chronic or acute.

Some people use a third categorization of subacute.

But for the purposes of today's lecture,

we'll just talk about acute and chronic.

Here we have an artery and a vein, artery and a vein,

non compressed and compressed.

And we can see that we're not getting compression on this vessel.

We know that it's thrombosed.

When we take and document these images,

we can certainly do whatever we want.

We can include labels and arrows.

I think cine, small cine loops three seconds

or so are extremely valuable for the tibial level veins

that may be small and difficult to image well

with a still image.

Acute Thrombus Characteristics

When we find acute thrombus, the thrombus is brand new

or relatively new.

There's a lot of liquid plasma still within that clot.

So that thrombus may appear spongy

or deformable with ultrasound transducer pressure.

The thrombus itself may be echoic or hypoechoic,

but you can't rely on the echogenicity alone.

It may be poorly attached. We may see a tip or tail visible.

The thrombus itself will have smooth borders

and the vein will be dilated

because what happens is as the thrombus starts to form,

that creates an increase in venous pressure more

distal to the thrombus.

That vein will dilate

with the increase in venous pressure.

So the vessel will be quite dilated with acute thrombus.

And here's an example of that. Here's an artery up here.

Here's the vein. And you can see

that the vein is very dilated compared

to the companion artery, but relatively anechoic.

And that's consistent with acute thrombus.

This image I showed a few minutes ago of

a thrombus here in this vein.

But let's pay attention a little bit closer to some

of the information here.

We have the artery in this view

where it's being compressed is actually being

slightly compressed itself.

And it's turned from a relatively circular artery into

more elliptical artery.

But the vein has changed as well.

We have a relatively circular vein here,

and the vein has become more elliptical.

That's because it's new and it's what we call spongy.

It's deformable. Of course, when we see images like this,

we know that we're dealing with an acute thrombus.

Again, real smooth on the borders.

And this tail or tip, sort of just extending into the vessel lumen.

Here's another image of an acute thrombus.

And I think if you look at this quickly,

you can again distinguish up here the muscle bed

and these vessels in the muscle.

There's the gastrocnemius artery, there's one vein

and there's the other.

And this is probably a good four

or five times the size of this vein.

So it is dilated.

And if we were even to look a little bit closer,

I think we can see the edge

of the thrombus here a little bit.

There's a little bit of echoic lumen. It's relatively smooth.

So we have something that's dilated, relatively smooth

echoic, all characteristic of an acute thrombus.

Chronic Thrombus Characteristics

Now, when we get chronic thrombus,

chronic thrombus is rigid.

It's firm, it's hard, it's been there for a while.

The liquid, the plasma has been reabsorbed.

When that liquid gets reabsorbed, all we're left

with is fibrin and some dead cells.

But this is all attached to the vessel wall.

So as the clot itself constricts

or contracts because the water's being reabsorbed,

the plasma is being reabsorbed, that

clot actually pulls the walls of the vein with it.

So the vein now looks constricted or contracted,

and is smaller as compared to its companion artery.

The walls of the thrombus, the edges of the thrombus,

I should say itself look irregular.

Maybe hyperechoic the vein walls too.

And we may see collaterals.

And here is a good image of a chronic thrombus.

Here's the artery, here's the vein.

We can see mixed level echoes here,

and a vein that's just about the same size

as its companion artery.

Here's another view of chronic thrombus

where we see this tail.

This just fibrotic material where we have a vein here

that's about the same size as the companion artery,

and again, some chronic residual thrombus.

So to compare and contrast, generally spongy, smooth surface

dilated versus rigid,

irregular surface contracted.

Those are some of the key characteristics between chronic

and acute thrombus.

Venous Doppler Signal Characteristics

In terms of the venous Doppler signals,

venous Doppler signals from the lower extremity should

display these five characteristics.

It should be spontaneous,

it should be phasic with respiration.

It should cease with proximal compression

and augment with distal compression

and should be unidirectional towards the heart.

This is a little bit different in the upper extremity,

but for the lower extremity,

these five things should take place.

Here we have two examples of venous Doppler signals.

On the top, we see nice phasic flow on the bottom,

we see phasic flow as well, but we've got flow

and then no flow flow and then no flow.

But we're seeing a little bit of super

and pulse pulsations here.

This is just transmitted cardiac pulsations.

It does not represent true pulsatility.

As we are getting cessation of flow in

between these breaths, augmentation,

we should see this augment.

When we do a squeeze, when we do a Valsalva,

we should see the flow stop.

And those are all important images

to document when we're doing our Doppler signals.

Well, what if we don't find that in our Doppler signals?

What if the Doppler signals are slightly pulsatile?

Well, if they're pulsatile

and they're pulsatile bilaterally, this is an indication

of systemic venous hypertension.

There's a lot of things

that can cause systemic venous hypertension, right?

Heart failure, tricuspid insufficiency,

pulmonary hypertension, any of those things

can be present

and will create pulsatility within the venous side.

Most folks don't get into things too specifically other than

noting that there's pulsatile signals bilaterally at the common femoral veins.

And you can add in something like it's suggestive

of systemic venous hypertension

or indicative of systemic venous hypertension.

Now, if you only get a pulsatile signal on one leg,

it's probably because there might be some sort of AVF

or arterial venous fistula present could be

congenital traumatic iatrogenic.

Any of those will give you a pulsatile signal.

These two types of pulsatile signals differ just a little

bit, but they are going to be something similar to this.

This is in a patient with systemic venous hypertension

where we're seeing beep beep beep.

And if we were to move into the companion artery,

we'd see the same type of rhythm placed within that artery.

Kind of mimicking the venous rhythm here.

Well, if we get a continuous Doppler signal

that's equally abnormal on one leg, we have

to think what's going on with that one leg.

That would create a continuous Doppler signal.

A continuous Doppler signal comes about

because the pressure in that vein is now increased

and it's increased to a point

where it's exceeding abdominal pressure changes.

So what can increase the pressure in that vein?

What can back it up?

Well, partial DVT or previous DVT

or intrinsic venous compression,

or extrinsic venous compression, will also produce a continuous Doppler signal.

If we see a continuous Doppler signal bilaterally,

then we have to think further centrally

and that the IVC may be involved either with thrombus

or extrinsic compression.

And here we see a common femoral vein

with a continuous Doppler signal.

But we know there's something wrong here.

We see all this thrombus within the vein.

So we have a partial thrombus.

That partial thrombus is not letting all the flow through.

The flow is backing up, it's increasing the pressure,

and it's producing this non phasic Doppler signal.

Case Examples

Now we have a couple of examples here

to illustrate some of these points.

This we have a couple images here from a 63-year-old

female who is presenting with left lower extremity swelling.

She's a hypertensive, non-smoker, non-diabetic,

and all the veins were found to be fully compressible,

but this was the Doppler signal obtained.

So while the Doppler signal is not phasic,

it is in one direction,

the veins are compressible.

But what could be going on with this area here?

Here's another image where, again, fairly straight

and we see some augmentation.

Things don't get any better when we look distally.

Here's the proximal thigh portion of the femoral vein

and the distal thigh portion of the femoral vein, not

what we would expect for venous Doppler signals.

And here's the contralateral leg,

actually almost appearing pulsatile here.

Okay, so what's the best explanation for these signals?

Can we say this is a normal study with no evidence of DVT?

Probably not.

While there's no evidence of DVT,

those Doppler signals are not normal.

So we have to report on them.

Are they consistent with a patient

who might have an arterial venous fistula?

Are they consistent with a patient who might have some sort

of outflow obstruction,

or are they consistent with a patient

who might have systemic venous hypertension?

Well, we've ruled out A, B

and D are almost going to give us the same sort of answer

in terms of what we would expect to see on the image.

And that if we have a fistula

or if we have venous hypertension, we'll expect pulsatility.

We did not see that on the left leg.

So we examined this patient further up,

we went up into the pelvic region,

and sure enough, here's the external iliac vein.

Now it's compressed down. We see this mass.

And sure enough, it was

outflow obstruction due to extrinsic compression.

The left external iliac vein was being compressed

by this pelvic mass,

and the patient went on to get a CT to further

delineate what that pelvic mass was.

But we can see this highly abnormal

external iliac vein Doppler signal.

The only other thing that we should think about when we talk

about Doppler in the venous system is reflux time.

The topic

of venous insufficiency is a whole nother lecture,

but just know that we can look at veins,

we can look at color, we can measure vein diameter.

We also need to measure the reflux time

with the spectral Doppler.

And in this case, we're here at the saphenofemoral junction

and our reflux time is all approaching three seconds here,

2.7 seconds.

Now, here's another case where we have a female, again,

57-year-old who's presenting

with varicose veins along the medial aspect

of her left thigh.

She has really no major history of any kind, non-smoker,

no hormone treatment, no history of DVT.

So we begin the exam at the saphenofemoral junction

And we see that there's flow on color

and we see some flow on Doppler

and we see the flow stop, kind of a little,

this is a little bit of noise.

This is normal valve closure here.

But as we go down the thigh, we can see all

of a sudden here now we've got a different story.

If we look at the color flow, image

flow towards the transducer should be in blue.

Flow away is red. This is color coded in red.

If the heart's up here

and the feet are down here,

this is flowing towards the feet,

so it's flowing in the wrong direction.

And that is displayed here in the spectral Doppler as well.

We see the antegrade flow up towards the heart.

And then this is retrograde flow falling back down several

seconds worth, probably close to three seconds worth

of retrograde flow in this evaluation.

But going further down the thigh,

we see this image.

Now we've got blue, blue is away.

This is angled in this direction.

So flow should be away from the transducer

back up towards the heart.

And what's going on with this patient?

Well, was there incompetence at the saphenofemoral junction?

Sorry, extending all the way through the thigh.

Well, we didn't show really incompetence at

the saphenofemoral junction.

Was it competent there

and then the remainder of the GSV incompetent?

Well, not really,

because in that last view, we saw some degree

of competence in the great saphenous vein.

So it's just the mid portion of the GSV incompetent

and the remainder competent.

Well, if you look very closely,

we actually could find the point at which

the reflux was occurring.

So we had competent vein up here,

but then we had a large tributary coming in.

Could have been fed from a pelvic vein or

some lateral accessory system

creating incompetence through the middle of the thigh,

and then another large lateral accessory

or anterior accessory system that was taking

that pressure gradient out.

So the remainder of the GSV was competent.

This is important because it actually will determine

what kind of procedure a surgeon may

or interventionalist may want to do on a patient like this,

being that we had competent segments,

but large incompetent areas as well.

So yes, for this patient, the mid thigh GSV was incompetent

due to an incompetent accessory system,

but the remainder of the GSV was competent.

Non-Vascular Pathology

Now, not everything that we see on ultrasound is going

to be pathology that is the result

of some abnormality within the veins.

Remember, we can be faced with patients

with arterial aneurysms, cysts, hematomas tumors.

And what will happen if we see these things is that

these large structures can often compress the vein

extrinsically, again, increasing the venous pressure leading

to some edema pain, decrease in flow,

which actually can result in a DVT,

but sometimes we have no DVT

yet we see this non venous pathology

as in this case here we have this large mass that's sort

of tracking down, not too deep on the leg,

but sort of extending down a good portion

over the head of the gastrocnemius muscle.

We can see that whatever it is, it's kind

of pointy at the edges

and we are definitely getting posterior enhancement

of the Doppler signal.

So what could that be?

Well, it actually is a ruptured Baker cyst,

or more correctly a ruptured popliteal cyst.

Not every cystic structure in the popliteal fossa can be

called a Baker cyst.

Baker cysts have a unique configuration where they travel through

the musculoskeletal features

of the popliteal fossa.

But we can appreciate the cyst,

we can appreciate the posterior enhancement

a little bit here in a greater way here.

Sometimes the cysts have this mushroom like appearance

where again, you kind of see the head of the mushroom,

the cap of the mushroom and the little stem

or tail kind of coming down into the popliteal fossa.

When the cyst ruptures, they kind of will take the path

of least resistance, of course.

And what happens with the cyst is they'll kind of,

that fluid will sort of divide

and tear down along that fascial boundary.

So rather than having a more rounded appearance,

you'll have a pointy appearance to the edge here,

very consistent with a ruptured popliteal cyst.

Now, many folks are trained to read vascular ultrasound.

Some are trained to read general ultrasound as well

as vascular, have a good appreciation

of skeletal muscular features and other things.

But if you're not sure about what you're looking at

and you're not really well experienced enough to

read nonvascular pathology,

your documentation should just include the size

of the structure, the heterogeneity of the structure.

Could you compress it at all?

And was there any blood flow present?

Those are all important features to be documented

when we run across some nonvascular pathology.

Here's an example where we've

see this large mass in the popliteal fossa

and we put color on,

and we can clearly see that it's being fed with several

flow channels here.

And this it represents actual tumor.

This patient had metastatic cancer.

Conclusion

So to conclude, ultrasound can easily be used

to determine patency of a vessel

and confirm the patency of the vessel.

It certainly can be used to identify the pathology.

And if we have thrombus, whether it's acute

or chronic, we're going to use our venous Doppler patterns

to help us figure out what's going on within the vessels

that we're looking at directly, as well as

what could be going on remotely, say as up into the IVC

or the pelvic veins.

And we must thoroughly document our findings

as our lab protocols dictate.

But if we can't, then we definitely need

to know any deviations thereof.

Live Demonstration of Lower Extremity Venous Exam

We start with the patient's leg positioned

as you see it here, slightly bent at the knee

and externally rotated at the hip.

One thing to note, some folks with arthritic issues

find this position slightly uncomfortable.

So we'll put a small roll of towel

or pillow behind their knee.

It gives their knee a little bit of support,

so it takes pressure off of their hip here.

I usually begin with a transverse orientation

and we start at the top of the leg just about at the groin crease.

And what I try to do is just sort of get oriented first

to see what's what it,

and at this level here,

what we're seeing is the common femoral vein

and common femoral artery.

There's the common femoral vein, common femoral artery.

We position this always of course,

so the patient's right is on the left

side of the screen here.

If I come down slowly, you can start to see some changing

taking place both with the artery as well

as over here we see the terminus of the great saphenous vein

and we see the common femoral artery branch into the superficial

femoral and deep femoral or profunda femoral.

So basically we begin at this point,

and I'm going to sort of take us through really evaluating this just on gray scale image.

That is the important part

of venous ultrasound is being able to look for thrombus

and make sure that there's nothing going on

in that vein, anything subtle.

So at this point, basically I'll just do a slight

compression and it won't take much pressure

with your patient supine like this.

The pressure at the femoral vein at this point at the top

of the leg is probably between five

and 10 millimeters of mercury.

So it doesn't take much to compress in terms

of documentation.

We can use a split screen feature

where we have the non compressed image on the left

and then we'll switch to the right and then just compress

and freeze and then we can label that as common femoral.

You can do add in more compressed

and non compressed, but most physicians realize

the proper documentation is non compressed over

here and compressed here.

So we'll just come back to the full screen here

and we would probably document at this level here

where it's just common femoral and then come down

and also document right here

to show the terminus of the GSV.

And you can actually see his terminal valve right here.

But everything's nice and fully compressible.

We don't have any pathology

and we would again, either record this as a loop

or as a still image now.

And other than taking a look at those last couple

of centimeters of the GSV, we're pretty much done at

that point unless a patient's presenting with any kind

of symptoms suggestive of superficial thrombophlebitis.

So we'll return back to the deep system here,

the artery branches first, as I said.

And here's the vein and we can see that

the vein is starting to change.

It's moved its position a little bit.

We were basically almost even laterally with the artery.

And as I've moved down the leg, it's come deeper

and underneath it.

And now we can see that it's gone from just a circle

to an oval to now two.

And we're just going to increase our depth here no other way.

There we go. Increase the depth a little bit

so we can visualize.

This is the profunda femoral artery or deep femoral artery

and profunda femoral vein or deep femoral vein.

And again, press and we get everybody to compress.

We know that there's no thrombus there now

because we've got the superficial femoral artery,

femoral vein and profunda femoral vein.

To get this vein down here

to compress fully may take a little bit more pressure

because we're kind of going through

the other couple of vessels.

So we'll want to be able to vary our position a little bit.

And you can kind of see where I am on the thigh.

We're down maybe five

or six centimeters from the groin

and we're seeing those vessels.

So we'll document the terminal area of the profunda femoral,

and we'll also continue now just looking

at the femoral vein.

So here we have the superficial femoral artery

and the companion vein.

And this is probably an adequate point where we would

document again, if we wanted the right

and left side by side showing good compression.

And that would be obviously labeled.

However you prefer.

You could say just proximal femoral vein

or whatever kind of short nomenclature you'd like to use.

Of course, all the systems have preset labels

as well that you can use if you don't like to type.

So it's press and release, press

and release every couple of centimeters.

Now interestingly,

perhaps you've noticed here,

I'm just going to come back up a little bit.

Here's the artery, there's the vein and down a little bit

and we see this other vessel over here.

And obviously with a little bit of a pressure, it's

collapsing away.

Oftentimes there are multiple femoral veins.

Some people say half the time,

a third of the time, it's fairly variable.

Just know that they can occur and look for them.

And you want to just get full pressure

and there's no magic place.

But somewhere when you're about halfway down the thigh

is again where you'd want to document your mid femoral vein

again with a split and then go to the other screen

and compress and freeze and label it accordingly.

So further documentation, we did the common femoral,

we did the great saphenous, we did the termination

of the profunda, we did the upper thigh femoral,

mid thigh femoral.

And we'll continue on down

and we'll look at the distal thigh.

Now you can see the vessels are getting deep

and they're coming on down

and we'll be getting through going

through the adductor canal.

We can see muscle here and muscle here.

And our model today is a pretty easy

subject, so it's pretty easy to compress.

But another thing you can try is with your free hand is

to come up behind the leg

and you can actually press from behind

and do the same thing in terms of collapsing that vein.

So somewhere again, just as far down

as you can see, we'll document that one more time,

compressed and non compressed.

And remember, you know, you're by yourself, you've got your

cin feature, you can scroll back to capture

where the compression is.

Okay, before we turn our attention to the lower part

of the leg, let's look at some Doppler.

That would be the other thing that we'd want to record.

You can record the whole thing and color as well.

I don't think transverse color is all that helpful because it's difficult to get good filling.

So if I want to look at color,

I will use a sagittal view or longitudinal view.

But we'll come back up here at the groin

and we're going to bring up this image again.

So I'm just going to come up here

and get the common femoral vein in view

and drop our Doppler in

and we'll just turn that volume down a little bit

and we'll want to adjust baseline down just a little bit.

There we go.

Oh, I'm sorry.

Can we just move that baseline down? Oh, I see.

It's just a toggle down. There we go.

Sorry, I like to make sure that I can,

and I'll just drop that volume a second.

I like to make sure I can see a little bit on both sides

of the baseline, particularly obviously if we're going to do

reflux study, we're not going to do reflux study in the supine

position because the results are going to be inaccurate.

So let's just bring the Doppler back up

and I'm just going to come

back to my live screen.

Some folks like to be able to have full simultaneous duplex

where we're seeing the live image and live spectral Doppler.

And I think that that is helpful,

particularly if you're following down, to make sure

that you don't fall out of the vessel.

And what we're going to have is we're just going to, again,

with your free hand, take a little and do a little squeeze.

And we just augmented the signal here.

As you can see, when I squeezed,

I augmented the return back up the leg

and that was detected with that increase in the Doppler pattern.

We'll come back here alive

and I'm just going to ask the patient

to take a big deep breath in.

Alright, and relax.

And we can see that we stop the flow.

In fact, we actually get a little bit of reversal of flow,

which is not uncommon in this position.

It does not mean that our patient has reflux.

It is just actually physiologic flow moving retrograde

because we don't have enough pressure to engage the valves.

So this is why we don't do reflux studies supine,

but that's another story.

So we've augmented the flow with Valsalva

and distal compression

and we've documented our venous Doppler pattern

and usually we get just the femoral.

We will always get a contralateral femoral vein

if we're only doing a unilateral study.

So we can compare the symmetry right to left.

The other thing that we'll do, many folks will also grab

a mid thigh portion again just to see we need

to do our Doppler sagittal

cause we need a decent angle of insonation.

So here we are And I'm getting a little bit

of the artery in there just cause I was up a little high.

And you can adjust your controls here

to get a nice clean signal, nice normal phasic flow

with just quiet respiration is exactly what we want to see.

There's really no need to document

and color if we've shown the image

and we've shown the Doppler, but we can just go through

and show you just

to be complete since we do have wonderful color imaging.

See, you know, good color filling on the vessel.

Although color is still considered complimentary.

We'll just steer this back.

Is that right? Oh, sorry.

There we go. Work with the natural angle

of the vessel so we can get good color filling.

And you can see a beautiful picture here.

I'm just going to drop the overall color gain.

You'll want to be adjusting your gain

and your scales a little bit if you've got

some artifact.

And what we see here,

Obviously the artery on top, the artery is aliasing,

the color signal is aliasing.

Because we have our PRF set very low,

our scale is set low so that we can get good venous filling.

And we have the common femoral vein splitting into the

femoral vein and the profunda femoral vein.

So that's a very nice documentation

of the color flow there.

And you can scan all the way down if you prefer

looking at the color signal

and documenting the color signal.

But the interpretive component to this exam is going

to be the illustration

of the full compression of those walls together.

And we can see vessels coming and going.

We've got, again, the companion artery aliasing

because of the low scale or PRF

and we're following this all the way

down very nicely.

One thing to remember, most of the equipment nowadays

have multiple frequencies for color

Doppler and image.

And if we were in a little bit of a jam

and we weren't getting good filling, we could change our

color frequency.

Although this is set pretty low already,

but we have multiple frequencies

that are available on all the most

of the systems nowadays.

So, and you can see we're pretty much down to where we were when we were doing the image.

So you can document the color if

that's part of your protocol.

Now we're going to move down to the lower part of the leg.

So one thing when you're scanning, you don't want to scan

behind the center of your body.

You're going to move yourself back

and move your equipment back.

Maybe

that'll be well good enough.

And from this view we can actually see pretty well,

if you needed to, you could turn the patient over.

But it works pretty well.

And we're going to come up where we left off

and I'm moving up onto his lower thigh

and we're visualizing here the vein and the artery.

And I'm just going to press a little bit,

make sure we still got a nice compressible vein.

Okay. And we're just going to come down

and basically even with the knee joint here

and we would want to record

the same left right compression, non compression

of the popliteal vein.

While I'm also here, I'm just,

because this is the last point that I routinely record a venous Doppler, I'm going to go into a sagittal mode

And obviously fix the Doppler angle

and grab a Doppler,

Do a little augmentation

and record that for our popliteal vein.

So at this point I'm done with the amount of Doppler I need

to record and the rest is based on image.

So we come down here

and we start to see,

I'm just going to zoom up for a second here.

We start to see a lot of vessels.

If I come back up to the popliteal, we see a lot

of branching coming off.

We've got the small saphenous way up at the top.

Yeah, we've got a bunch of veins and arteries right here.

Those are the gastrocnemius.

They're staying within the muscle

and there are paired lateral and medial gastrocnemius.

And other than taking a look here,

I don't really follow them much more.

And let me come back and let up on the leg a little bit

and then compress.

And I like to actually record a little loop

of this data versus a still image.

But you could do the same thing as we've done before.

You could do the right left, still compress

and freeze that and store that.

But with these small veins,

I think loops are pretty helpful.

So we'll just come down.

It's important to look at the calf and look at an area.

If the patient's presenting with a focal pain,

that's important.

Cause a lot of times it is one

of the smaller gastrocnemius veins that are involved with a partial thrombus.

So I'm going to come back up to the popliteal,

which is in the center of you there.

And I'm just going to see how well I can follow it

without changing my view

In terms of my approach onto our patient's leg here.

And you can see it's a little deep, a little hard to follow,

but now we're getting into the point where

the calf is most muscular

and the vessels are starting to branch.

So you're going to try to follow from behind

and kind of swing up forward.

Okay? And now we're over

where we see our tibial vessels.

And from this point on down,

then we can use a much more medial approach

and follow all the tibial vessels.

Remember, there are not under a lot of pressure,

so if we push too much, we will get them

to collapse away.

So let's just point out

what we're looking at here on the image.

I'm using a lot of gel here.

So we can reduce any artifact by any little bits of air

that might be trapped under the

by the skin as a result of hair on the leg.

So we will get them nice and gooped up.

We see some vessels here that are kind of deep

and we see some vessels up here that are more,

a little more superficial.

Okay? The tibia is over here

and actually the fibula is right here.

These guys right here, vein, artery,

vein sitting right on top

of this bone from this medial approach.

Those are the fibular vessels

or what we now call more commonly the peroneal vessels or peroneal if you're from the UK.

But we've got the vein, artery vein

and we can get good compression

and we'll follow them up a little bit.

We lose them a little bit right up and through here

and that's when we're going to vary our approach

and try to come around.

And at this point in

through here on the leg is probably the point

where you're going to have to press the hardest.

You might want to warn your patient

or apologize in advance

because they're so deep, they're deep to the muscle there.

Okay? So we kind of follow them right on up.

Getting good compression,

actually pretty much compressing them away.

If you have very small veins that are difficult

to visualize, you can sit the patient up

and have them fill more.

Now I'm going to look up here

and I'm going to look at these vessels up here.

Here we have a large vein, well large

by tibial level standards,

which is probably a soleal vein.

It looks like it's coming right on in.

Let's see if color will make things any more apparent.

Not too much. That's the hard thing.

I mean we can see the vessels colorized as I compress,

but it's not all that helpful.

I think the better thing is to rely on the ability to

compress those vessels and record that either as a loop.

So these are the posterior tibial vessels.

That's what we're following up here now.

And again, we're going to do the same thing,

follow them back up to

where they connect into the peroneals.

And I've zoomed up our depth a little bit,

but you can see we're coming up and following up.

And then in a minute we're going to be back up to

where we started at the popliteal level.

Now the posterior tibials are right here.

They're very easy, very nice.

We're going to continue to follow them basically all the way

to the level of the ankle.

And I don't like to use a ton

of goo, although I will use a fair amount of gel.

The more gel you put on is that starts to evaporate.

The cooler your patient will get when they get cold,

they vasoconstrict, which also makes your job harder.

So keeping them warm, wrapping their foot in a blanket,

keeping the rest of them covered is very helpful.

So you can see I'm all the way down to the ankle

and I've got very nice visualization of

the posterior tibials and it's the only vessel up here

and I'm just working my way back up.

We see this guy at the top of the screen up here.

That's the great saphenous.

And that was actually a perforator coming down.

Again, topic of another lecture.

But we can see,

and we're kind of getting back up to

where we started in the mid-calf.

Now there's one vessel that we haven't looked at

and that's the anterior tibial vein.

Most folks don't image it. I'll just show you.

I'm going to have you just roll your knee

for me a little bit this way.

The anterior tibial vein is going to course along here,

along the anterior lateral aspect.

They are really small.

It might be very hard to see in this view, but actually, and I didn't even plan this,

but this is them right here.

Here's the tibia.

This is the anterior compartment over here.

And here's our distal anterior tibial artery,

which will turn into the dorsalis pedis

and a few more centimeters distally.

But here are the companion veins right here.

And you see I've kind of taken the image depth up a bit

to see them, but these are the only

vessels that are going to be over here.

And that's where you'll follow them from

the foot from here

and back up this way if there was an issue.

But most labs don't routinely include the anterior tibial,

but that's where I would go to find them.

They're going to continue on up

and then about somewhere in here, dive deep to come back up

and connect into the popliteal.

So we've gone through the B mode imaging

and we've gone through the required Doppler imaging

and how we can use color if we want to help follow.

We've talked about requiring Doppler at the popliteal

and femoral or common femoral levels,

but compression of the veins all the way from

the groin to the ankle.

And that is the basic exam for lower extremity DVT.

Thank you very much.