Lower Extremity Veins: Techniques and Interpretation with How To Demonstration

Patient Positioning

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.

Initial Gray Scale Imaging

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.
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 a 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.

Scanning the Deep System

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 gonna 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 wanna be able to vary our position a little bit.
And you can kind of see where I am on the thigh.
We're down a 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 a 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 prox 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.

Multiple Femoral Veins

Now interestingly, perhaps you've noticed here, I'm just gonna 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 to look for 'em.
And you wanna 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 wanna 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, the 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're by yourself, you've got your cine feature, you can scroll back to capture where the compression is.

Doppler Imaging

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 wanna record.
You can record the whole thing in 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 gonna bring up this image again.
So I'm just gonna 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 want to adjust baseline down just a little bit.
There we go.
I like to make sure that I can see a little bit on both sides of the baseline, particularly obviously if we're gonna do reflex study, we're not gonna do reflux study in the supine position because the results are gonna 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 gonna have is we're just gonna 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 gonna 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 he has 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 Val Salva 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 sagal 'cause we need a decent angle of intonation.
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 vasic flow with just quiet respiration is exactly what we wanna see.
There's really no need to document in 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, good color filling on the vessel.
Although color is still considered complimentary.
We'll just steer this back.
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 gonna drop the overall color gain.
You'll wanna 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 an 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.

Imaging the Lower Leg

Now we're gonna 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 gonna move yourself back and move your equipment back maybe.
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.
We're gonna come up where we left off and I'm moving up onto his lower thigh and we're visualizing here the vein in the artery.
And I'm just gonna press a little bit, make sure we still got a nice compressible vein.
Okay. And we're just gonna come down, I'm basically even with the knee joint here and we would wanna 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 gonna go into a sagal 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 gonna 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.
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 gastrocs.
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 it.
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 gonna 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, they're 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 skin as a result of hair on the leg.
So we will get 'em 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 in through here.
And that's when we're gonna 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 gonna have to press the hardest.
You might wanna 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 'em 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 gonna look up here and I'm gonna look at these vessels up here.
Here we have a large vein, well large by tibial level standards, which is probably a so 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.
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 gonna 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 gonna be back up to where we started at the popliteal level.
Now the posterior tibs are right here.
They're very easy, very nice.
We're gonna 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 tibs 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.

Anterior Tibial Vein

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 gonna have you just roll your knee for me, Mike. A little bit this way.
The anterior tibial vein's gonna 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 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 gonna be over here.
And that's where you'll follow 'em from the foot from here and back up this way if there was an issue.
But most labs don't routinely include the anterior tib, but that's where I would go to find them.
They're gonna continue on up and then about somewhere in here, dive deep to come back up and connect into the popliteal.

Conclusion

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.