0:01

I do want to keep you up to date with some of the

0:03

literature that has come out of Johns Hopkins about

0:07

traumatic injuries to the blood vessels in the neck.

0:12

This is an article that was written by one

0:16

of my research fellows, Farzan Sherbach.

0:18

And she looked at a multi-institute study that

0:23

included the University of Pennsylvania

0:26

and University of Texas,

0:27

San Antonio and looked at the value of emergent

0:33

neurovascular imaging when the clinical

0:36

indication is seatbelt injury.

0:38

So in those individuals who have motor vehicle

0:40

collision and have to-and-fro back-and-forth injury,

0:46

quite often you'll see discoloration across

0:49

the neck from the seatbelt,

0:51

the lap belt that's coming across and protecting the

0:54

individual in addition to obviously the airbag.

0:58

So we looked at five institutions and we looked at

1:02

the incidence of vascular injury when the only

1:07

etiology, the only indication was seatbelt injury.

1:10

In other words, there were no fractures,

1:11

there was no stroke,

1:13

there wasn't any other findings on the imaging other

1:17

than a clinical history of seatbelt injury.

1:20

And when we looked at 535 adults and

1:23

32 children in this time frame,

1:27

what we found was only 0.5% of the patients who had

1:33

CT scan CTAs done for seatbelt injury actually

1:37

had a vascular injury and of those,

1:41

none of them had any neurological sequelae of it.

1:44

So in the isolated situation where the patient

1:47

doesn't have other imaging findings of fractures

1:51

or hematomas or dissections or whatever,

1:55

in that situation where you only have the

1:58

lap belt demarcation discoloration,

2:01

the value of doing CTA is pretty low.

2:06

This is a case of a patient who did have a motor

2:11

vehicle collision and presented

2:13

with Horner syndrome.

2:15

This is an example of what is a pseudoaneurysm seen

2:20

on MRI scan with variable signal intensity.

2:23

And this is typical of pseudoaneurysms

2:25

being evaluated with an MRI scan.

2:28

You can have all different types of signal intensity

2:31

characteristics because of the different stages

2:34

of hematoma. You can have deoxyhemoglobin,

2:37

which is dark on T2 and dark on T1.

2:41

You can have intracellular methemoglobin,

2:45

which is bright on T1 and dark on T2.

2:47

You can have extracellular methemoglobin,

2:49

which is bright on T1 and bright on T2.

2:52

And very rarely you can have calcification in the

2:55

wall of an old pseudoaneurysm which obviously

2:58

is going to be dark on T1 and dark on T2.

3:00

In this case,

3:01

we were looking at this and saying, well,

3:03

could this be a mass or an enhancing

3:06

tumor schwannoma?

3:09

See that the parapharyngeal fat is displaced

3:12

anteriorly and when you look at

3:14

the conventional arteriogram,

3:16

what you're seeing is that swirling contrast

3:19

within the lumen of the pseudoaneurysm,

3:21

which accounts for the mixed density

3:24

and or intensity on MRI scan.

3:26

So remember that traumatic aneurysm is Biffl stage

3:30

three. And if you also have luminal narrowing,

3:35

which is seen proximally here,

3:37

if it's less than 25%, Biffl stage one,

3:40

greater than 25% Biffl stage two.

3:44

So if you look at these patients who have

3:47

the injury to the intima media,

3:49

that is what is going to lead

3:50

to the pseudoaneurysm.

3:53

And that can lead to subsequent either

3:55

partial thrombosis or narrowing,

3:59

again using the Biffl staging.

4:01

So if it's completely occluded,

4:04

it would be grade four.

4:05

Even with a pseudoaneurysm,

4:07

the risk of stroke with a pseudo

4:09

aneurysm is about ten to 20%.

4:11

Remember that I had said previously that most people

4:14

report five to 30% for strokes associated with

4:20

dissections. 25% of pseudoaneurysms will enlarge,

4:24

25% will resolve on their own

4:27

and 50% will simply persist.

4:30

These are usually found below the skull base.

4:33

And remember that dissections are more

4:36

common in the vertebral arteries,

4:37

but pseudoaneurysms are more common

4:40

in the carotid arteries.