0:00

So the next set of cases are going to be scans obtained post

0:04

an intervention, and we're going to either see normal appearances or

0:08

we're going to see complications. The first one is dissection.

0:13

So this is a 73-year-old male who underwent iliac artery

0:17

stenting recently in both the common iliac, proximal left

0:21

external iliac, and proximal left internal iliac arteries.

0:25

And so as we're scrolling down, we're just going to focus on the

0:29

topic of interest here. We see that there is severe aortic

0:33

atherosclerosis. There's stents in both the common iliac

0:37

arteries right here. We're going to now focus on just the right side

0:41

first. And here we can see that stent has ended in

0:45

that right common iliac artery right here.

0:48

That stent ended

0:50

right here.

0:52

And under that stent, we see a

0:56

hypodensity with calcifications in that proximal

0:59

vessel right here. If I were to make a double oblique

1:03

plane right here, I think that answer is going to be very clear that this

1:07

is a focal dissection flap in this right common iliac artery,

1:11

which has been new since the prior exam.

1:13

And obviously, in the interim, a stent has been placed, so it's probably

1:17

iatrogenic. Dissection flap extends into the external iliac

1:21

artery. We can see that here it's actually obstructive.

1:24

While the lumen was completely patent in the common iliac artery up top, in the

1:28

external iliac artery, as we're scrolling down, it

1:31

causes moderate stenosis in that proximal

1:35

vessel, and then in the more distal vessel,

1:39

it is causing severe stenosis right here, and you can barely see the

1:43

lumen here. There's fats trending in both the inguinal

1:47

regions, which is something that you can see after an intervention.

1:50

Basically, they use these as an access site, and so they can have ill-defined

1:54

hematomas

1:57

in both the groins. Now, one interesting

2:00

thing to note over here is that if you compare-- Now, let's take a look at the

2:05

left side before we talk about that.

2:06

So on the left side, this stent is patent, and you can

2:10

see it extending into the left external iliac artery, and it's patent.

2:14

But if you look at the stent that's extending into the left internal iliac

2:18

artery, it doesn't look as expanded, and that's one of the

2:21

complications of a stent that can happen.

2:24

So there's basically underexpansion of that stent, and this

2:28

stent is occluded, and there's no opacification of this internal

2:32

iliac artery. It is, however, distally reconstituted by

2:36

collaterals.

2:38

Shifting our focus back to the external iliac artery on that left side.

2:42

So here, again, in the external iliac artery, there remains

2:46

stenosis.

2:48

But the focus of our scan in this was just that

2:52

post an intervention, you can have complications.

2:55

You can have ill-defined hematomas, which is not

2:58

significant unless we look at

3:03

active bleeds or if the patient is dropping their hematocrit and are

3:06

hemodynamically unstable.

3:09

But really dissection as being the complication of the intervention.

3:14

Now, one of the dynamic things that can be assessed on the CT is

3:18

that there's actually sluggish flow.

3:19

So if you compare the degree of opacification of the right compared to the

3:23

left side,

3:25

the left-sided vessels are quite bright, but as you're coming to that

3:29

right external iliac artery, it's much less

3:33

dense compared to the right side. So right here, there is much

3:37

lesser degree of opacification of this superficial femoral artery

3:41

compared to this one. And again, this is where the delayed

3:45

is helpful because it helps you in making sure

3:48

in areas where there is sluggish flow.

3:51

So here,

3:52

because a dissection flap is a dynamic structure and it is obstructive at

3:56

certain level, there is sluggish flow to the right lower extremity.

4:00

If I were to put that immediate delay scan, and if we were going to look at that,

4:04

you can see here now that there is much improved opacification of that

4:08

superficial femoral artery. And now that right actually looks brighter.

4:12

It's because there's lesser and slower flow, and it's just taking more time

4:15

for contrast to go into this extremity.