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.

Methods of Assessment 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.

Positioning for Ultrasound Examination

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.

Overview of 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?

Well, 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.

ICA VL. These are in compliance

with the ICA VL standards.

Currently, I'm less familiar with ACR 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 so 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.

Scanning Procedure and Technique

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.

Groin and Thigh Scanning

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.

Popliteal and Calf Vein Scanning

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 Calf Vein Evaluation

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.