Lower Extremity Veins: Techniques and Interpretation with How To Demonstration

Illustrative Examples in Venous Ultrasound

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 vasic,
it is in one direction,
the veins are compressible,
but what could be the going on with this,
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.
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.

Reflux Time in Venous Insufficiency

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 reflex 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.

Case of Varicose Veins and Reflux

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 coated in red.
If the, 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 and this evaluation.
But going furtherly 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 superficial fem
or 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 in, competent.
Well, if you look very closely,
we actually could find the point at which
the reflux was occurring.
So we had competent veins appear incompetent vein here,
almost, almost at every valve, area.
And this is a valve right here. There are branches.
And what was going on in this case,
if you look at this little sketch,
is we can see we had competent vein up here,
but then we had a large tributary coming in.
Could have been fed from a pelvic vein or,
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-Venous Pathology in Ultrasound

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 gastric anus 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 faucet 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 these 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 rupture, they kind of will take the path
of least resistance, of course.
And what happens with the cysts 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 pointer appearance to the edge here,
very consistent with a ruptured popliteal cyst.

Documenting Nonvascular Pathology

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, 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 defer, 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 gonna 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, in 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.