0:01

So here we have a 68-year-old woman.

0:03

She presents to the emergency room four

0:04

days after an uncomplicated catheter

0:06

angiography with left brachial artery access.

0:08

Now she has numbness and

0:09

coldness of her left forearm.

0:11

So what does the ultrasound show?

0:12

It reveals the following findings.

0:14

So what are we seeing here?

0:16

What are you most suspicious of?

0:18

Well, there's an echogenic little

0:20

sort of mass going on here within

0:23

this sort of saccula outpouching.

0:25

You know, and there's no

0:26

flow on the color Doppler.

0:28

Very strange.

0:29

So I would say we're most suspicious of thrombus

0:31

at the affected site causing acute ischemia.

0:35

So, what's arterial thrombosis and occlusion?

0:38

So, basically, thrombus formation

0:39

sort of occurs and results in

0:41

progressive vessel lumen obliteration.

0:44

And it causes focal cessation

0:46

of flow in that vessel.

0:47

Has an incidence of about 3 percent when

0:49

we're looking at transfemoral arterial

0:50

interventions, particularly post angioplasty.

0:53

And the ultrasound image really shows

0:55

thrombus with varying degrees of echogenicity,

0:58

internal complexity, and associated

0:59

reduction in the intraluminal flow.

1:02

Now if you have chronic thrombus, this

1:04

is sort of usually decreased in luminal

1:06

diameter, often now with eccentric wall

1:08

adherent thrombus, which oftentimes remodels.

1:11

And the therapy here is thrombolysis with

1:14

anticoagulation to prevent new clots from forming.

1:17

How does arterial thrombosis actually present?

1:19

Well, we think about sort of the six Ps of

1:21

acute ischemia: the pain, the coolness of the

1:24

extremity, the paleness, the color, the pulses

1:27

that end up being reduced when we sort of put

1:29

our fingers on those sort of strategic pulses

1:31

in that extremity: the ulnar, radial, the DPT.

1:35

46 00:01:36,240 --> 00:01:38,160 We think about the pins and needles

1:38

feeling that results in paresthesias, and

1:40

paralysis, which is usually the last to occur.

1:42

Um, that indicates advanced ischemia.

1:44

Okay, and this all results from

1:45

focal cessation of blood flow.

1:48

So how does arterial thrombosis

1:49

appear on Doppler ultrasounds?

1:50

What we see is spectral broadening with

1:53

a biphasic pattern in the thrombosed artery.

1:55

We sometimes see this monophasic

1:57

low-velocity flow distal

1:59

to that point, okay?

2:01

And that's a particularly important

2:03

thing for us to keep in mind.

2:04

And so what we're seeing here is a

2:06

ultrasound of right

2:09

lower extremity arterial thrombosis.

2:11

We see color flow on either side.

2:15

And there is aliasing.

2:17

This turbulent flow in this region

2:20

is being blocked by this

2:21

occlusion, which is actually a closure device

2:24

that was deployed in the center of the vessel,

2:26

superimposed on a focus of atherosclerosis.

2:32

So one of the things that you want

2:33

to ask yourself is, how can a CT

2:34

scan help diagnose arterial thrombosis?

2:36

Well, contrast-enhanced CT scans

2:38

are particularly good and recommended to

2:40

determine the extent of an

2:42

occluded site and really help us

2:44

understand the underlying disease.

2:46

We have this case, as we talked about before,

2:48

of seeing significant Mockenberg-type

2:50

calcification, or coral reef calcification,

2:53

in the region of the common femoral artery.

2:54

So is that the issue?

2:56

The CT scan is going to give

2:57

us a good little overview.

2:59

So you know, when you have sort of

3:00

heavy arterial calcification, sometimes

3:03

that can give us some artifacts.

3:04

Um, it can confound the diagnosis, but

3:06

a CT scan is as beneficial as a CT

3:08

scan is, but we just want to know

3:10

about some of the pitfalls that exist.

3:12

We have non-contrast enhanced scans.

3:14

When we're looking at sort of femoral artery

3:15

thrombosis, as in the case of that image that

3:17

I showed you of that sonographic evaluation

3:20

that showed sort of the collagen plug from a

3:22

closure device in the center of the vessel,

3:24

what we see here is that big sort of kind of

3:26

almost like, it's almost like a little iceberg

3:29

into the vessel and even on this non-

3:31

contrast scan we can still appreciate that.

3:33

So what's the management?

3:34

Well, of course, you know, we want

3:36

to treat the patient immediately.

3:38

We want to prevent new clots from forming.

3:41

Anticoagulation, unfractionated low

3:43

molecular weight heparin can be administered.

3:45

Intervention subsequent to that is actually

3:47

sort of, you know, determined based on etiology,

3:50

severity, and duration of the ischemia.

3:52

Watchful waiting is an option.

3:54

Thrombolytic therapy is an option.

3:56

And of course, for extremity

3:57

revascularization, with a number of tools,

3:59

including thrombectomy, is also an option.

4:02

So when we think about fluoroscopy before and

4:03

after thrombolytic therapy and anticoagulation,

4:06

you know, here's a case whereby we have

4:09

thrombosis of the brachial and axillary arteries.

4:12

Um, in this case, sort of brachial artery.

4:15

And after thrombolysis, we

4:16

see nice, clean vasculature.

4:18

Um, and this is the benefit of using TPA.

4:21

With a little sort of heparin anticoagulation

4:23

to prevent new clots from forming.