0:00

Right. The next scan in the trauma series is an arteriovenous fistula.

0:05

So starting with this patient here,

0:09

right at that pelvis, we're going to scroll all the way down.

0:11

I think you can see that this is an ultra-high-resolution scan,

0:15

sharper kernels, unprecedented

0:17

detail. The slice thickness here is really

0:21

0.2 millimeters, which really helps us see all that really

0:25

fine muscular branches and fibular perforators much

0:28

better. And so as I'm scrolling down, I think one

0:32

noticeable thing here is that

0:36

on the left side,

0:38

these veins that are next to the superficial femoral artery, they're

0:42

already showing enhancement.

0:45

And it's asymmetrical. You don't really see that degree of enhancement at all

0:49

on that right side. So these veins appear

0:53

larger. If you compare this

0:56

superficial femoral artery on both sides and the vein that's next to them, this one

1:00

is non-opacified, this one's opacified.

1:03

But even so, these veins are larger.

1:05

They're showing an early opacification, and all of those suggest that

1:09

there might be an arteriovenous communication in this limb.

1:13

So as I'm scrolling all the way down,

1:16

this popliteal artery and the popliteal vein, the superficial femoral

1:20

veins in this limb are also more prominent compared to

1:24

the other side.

1:26

So as I'm scrolling down and looking at that patent popliteal artery,

1:30

there really isn't much atherosclerosis.

1:34

The popliteal artery is patent otherwise.

1:38

As I'm scrolling down right here, it's

1:41

bifurcated, so we have the anterior tibial artery and the

1:46

tibial peroneal trunk. Both of these are patent.

1:49

And we talked about one of the pitfalls being venous contamination and

1:53

how assessment of infrapopliteal vessels can be sometimes

1:57

challenging. I think this is a good example to show that.

2:00

So right here is an anterior tibial artery,

2:03

whereas there are two paired veins next to it.

2:06

And you can see just because those are not opacified,

2:10

it kind of makes assessment of this artery more difficult

2:14

compared to the other side where the veins are not opacified.

2:17

So you can really see how well

2:20

and patent this anterior tibial artery is.

2:23

Now, you might wonder that this peroneal artery looks really big and patent.

2:27

The anterior tibial artery looks big and patent as well.

2:29

The posterior tibial artery is quite small and diminutive as it

2:33

is on the other side as well. It's because this patient has hypoplastic posterior

2:37

tibial arteries. And as I'm scrolling down all the way,

2:42

looking at that peroneal artery

2:45

and scrolling all the way down,

2:49

I think right about here, you can see that

2:52

there's actually a communication between this peroneal artery and the paired

2:56

peroneal veins that's suggestive of an arteriovenous fistula.

3:00

And so this is the reason why the veins in this lower

3:04

extremity have enhanced a lot faster than the veins in the

3:08

contralateral extremity. It also explains why these veins are

3:12

larger than the other veins

3:16

on that same

3:18

lower extremity, as well as compared to the veins of the other extremity.

3:22

So

3:24

arteriovenous fistula

3:27

at the distal peroneal artery.

3:30

And this is pretty much kind of at that site of this open

3:34

reduction internal fixation. So

3:38

probably is iatrogenic

3:42

in the setting of a prior surgery at that level.

3:46

So two key findings in this person, a

3:50

hypoplastic posterior tibial arteries bilaterally, as well

3:54

as arteriovenous fistula between the distal peroneal

3:58

artery and veins.