0:00

In the last couple of minutes, we're gonna finish up

0:03

with popliteal artery entrapment.

0:05

There are a number of different types

0:07

that have been described.

0:10

I don't memorize these types. You can always look it up.

0:14

The first, uh, four types are, um,

0:19

the ones that have some separation

0:21

between the popliteal artery and the vein.

0:24

So that's why I mentioned earlier, always look

0:26

and make sure that they're traveling, uh, together.

0:29

And these latter types, the artery

0:32

and vein are still, uh, traveling together.

0:34

So I'll show you a few things.

0:35

So this is type one through four, taken from RAD source.

0:40

And in all of these, they're, they all have differences in

0:44

how the medial gastroc anemia inserts.

0:47

But in all of these, there's something

0:50

between the artery and nerve.

0:52

It may be a big chunk of muscle, a smaller chunk of muscle,

0:55

little chunk of muscle, or it may be just tenderness tissue.

0:59

So those would be the type one through four.

1:02

And if you see anything between the artery

1:04

and the vein, then you want to think about this.

1:08

Now, this is a pitfall case.

1:09

Okay, I thought this was gonna be a, an entrapment,

1:12

but this is actually a graft.

1:14

So be careful

1:15

that you're not looking at a popliteal artery graft in

1:18

somebody that's had surgery, because that is going

1:21

to have an anomalous course.

1:23

So let's look at a couple of these.

1:25

The type three is the most common.

1:27

This is what it looks like, arteries here, vein is there,

1:31

and I have tissue in between.

1:33

You should never have tissue in between those two.

1:38

And in the right clinical setting, you know,

1:40

it's a slam dunk diagnosis.

1:43

The problem is sometimes we'll see little thin tenderness

1:45

slips in this area,

1:47

and the patients don't have claudication,

1:49

and you really don't know what to do.

1:51

Uh, in those examples,

1:53

and I'll show you one, uh, in just a second.

1:55

So this particular patient was symptomatic

1:59

and has this interposed muscle.

2:01

Here's another one that was symptomatic,

2:04

underwent CT angiography where the diagnosis of obstruction,

2:08

uh, compression was made,

2:10

but they didn't notice this muscle slip.

2:13

And here on the patient's symptomatic right side, we can see

2:17

that there's tissue interposed between the artery,

2:20

which is a pacified

2:22

and the vein that isn't present on the contralateral side.

2:26

And this is the corresponding MR in this patient showing you

2:30

that muscle slip in between the artery and the vein.

2:34

So that's a, that's straightforward.

2:37

This was a case that Brady saw,

2:39

and, uh, uh, I don't know the clinical story as well

2:42

as he does, but there was this just tiny tendonous strip,

2:46

very subtle between the artery and the vein.

2:49

And I don't know if this patient was symptomatic.

2:52

So sometimes you can get these little, little slips

2:55

that are very, very subtle.

2:57

Uh, so, you know, frankly,

2:58

I don't really look at this super carefully

3:00

unless the patient has a history of claudication

3:04

in the type five, both the artery and vein are displaced.

3:08

Uh, this is usually due to some vascular of some sort

3:11

of muscular anomaly.

3:13

It often has to do with the lateral gastroc anemias.

3:16

Here we have this anomalous insertion

3:18

with a midline, uh, muscle.

3:21

And, uh, and you can see the vessels being,

3:24

uh, being displaced.

3:25

So that would be a type five where they go together.

3:28

These lateral head gastroc anemia variants are really not

3:32

well defined, uh, in the literature.

3:34

This is what I see most frequently, is that one of the heads

3:37

of it goes up high and then swings medially,

3:40

and it draws the artery

3:43

and vein together towards the medial knee.

3:46

And again, uh, I see this not uncommonly

3:49

and most of 'em don't have any symptoms related to it.

3:52

And then the final type, I'm sorry, this is one that had,

3:56

uh, that anomalous head that wound up having an aneurysm.

3:59

But again, most of these patients don't wind up having, uh,

4:02

any symptoms related to this.

4:04

And I honestly don't know if the aneurysm

4:06

and this were related in this case,

4:08

or they just happened to coexist, uh, together,

4:11

didn't have the opposite side.

4:13

And finally, the type six, which is a physiologic one,

4:17

which is that the anatomy's normal.

4:20

But patients who have really bulky muscles when they're

4:23

exercising, they may wind up compressing their popliteal

4:27

artery and getting entrapment.

4:28

So this is more of a functional, uh, type.

4:31

It's a clinical diagnosis.

4:33

Perhaps ultrasound might be helpful, uh, for making this,

4:37

uh, this particular, uh, diagnosis.

4:40

But this one's controversial

4:41

because if you look at asymptomatic individuals, uh,

4:46

and you move the leg up

4:47

and down, you can see

4:48

that they get some vascular, uh, compression.

4:52

This is just an athlete just showing

4:55

how big the muscles can get

4:56

and the potential for, uh, compression, uh, in the, uh,

5:01

in the, uh, area of the knee.

5:03

Okay, so what we did today was to go through normal anatomy,

5:07

look at the various cysts and buri that can exist here,

5:11

and then just a brief word on the lymph nodes, nerves,

5:15

vessels, uh, and veins.

5:17

The, the structures

5:18

that you should be evaluating when you're looking at, uh,

5:21

the po, the teal fossa.

5:22

Thank you very much.