0:01

The final scenario that I'd like to discuss with

0:03

you occurs in general in pediatric patients.

0:07

These are patients who have a ventriculoperitoneal

0:11

shunt and present with new lethargy, maybe a fever.

0:18

Maybe new neurologic symptoms,

0:20

but they're just not themselves.

0:21

And a lot of times, uh, these are young children who

0:25

may not be necessarily very verbal, and the parents

0:29

bring them in, saying, "He's just not acting right.

0:31

I am concerned that we have shunt failure."

0:35

So remember that the ventriculoperitoneal

0:38

shunt is shunting CSF from the ventricular

0:41

system into the peritoneal cavity and allowing

0:45

the patient to have normal-sized ventricles.

0:47

In this scenario, we are utilizing HASTE,

0:51

T2-weighted scans in the sagittal, axial,

0:54

and coronal planes in order to evaluate for

0:58

shunt failure and ventricular enlargement.

1:01

It's a very simple study.

1:02

It takes around two minutes to perform, and this

1:05

is being done instead of doing screening with

1:08

CT scanning, again, because we want to limit

1:11

the amount of radiation to these young patients.

1:15

So here is the typical appearance in this case.

1:18

We have a December 17th patient who has the

1:23

ventriculostomy catheter, which you can see is

1:25

coming in on the right side into the ventricles.

1:28

The ventricles are not enlarged on this single image.

1:31

Here, you can see the ventricular catheter coursing

1:34

from the occipital region into the lateral ventricles.

1:37

And when we compare it to the prior

1:39

examination from December 9th,

1:41

we see that the ventricles have not changed at all.

1:44

So this is what we would be doing—comparing from

1:47

the prior to the current one to see whether the

1:50

ventricles have enlarged because the shunt has failed.

1:53

When the shunt fails, it may fail at the

1:55

tip of the shunt in the ventricular system.

1:58

It may fail at the reservoir in the scalp.

2:03

But most commonly, it fails secondary to

2:06

obstruction in the peritoneal cavity, where it

2:09

may either just have some germs that develop

2:13

there or, because of some inflammatory process

2:16

within the peritoneal cavity, it obstructs.

2:19

Sometimes, you can see discontinuity in the shunt.

2:24

Catheter going from the calvarium

2:26

down into the abdominal cavity.

2:28

And for that, we're usually using plain film

2:31

technology to see whether there's a disconnection

2:34

anywhere along—from the brain part to the reservoir,

2:38

from the reservoir to the portion that's leading

2:40

to the catheter going into the peritoneal cavity.

2:43

And anywhere along that—here, for example,

2:47

is a patient who has shunt failure.

2:49

This is...

2:50

The baseline scan on December 9th,

2:53

where the ventricles are small in size.

2:56

Here is a patient who has the ventricles blowing

3:00

up dramatically with transependymal CSF flow in

3:05

this instance, secondary to shunt failure.

3:08

This is usually manifested as new lethargy, patients

3:13

not eating, failure to thrive, particularly in

3:16

The infancy and the shunt may have been

3:20

inserted because of, for example, a myelomeningocele

3:23

repair or for Chiari malformations,

3:27

Arnold-Chiari malformations, et cetera.

3:29

But this is what we're looking

3:30

at, and this is a simple process.

3:32

This is a HASTE image that takes

3:34

about two minutes per form.

3:35

This is a HASTE image that takes

3:37

about two minutes per perform.

3:38

We look at them, we say, yeah.

3:40

There's a problem with the shunt.

3:42

They'll then get the plain film to look at

3:44

the reservoir and the tubing to see whether

3:46

there's a disconnection or problem with that.

3:49

If not, they will go on to neurosurgical

3:51

evaluation, where they will either pump the shunt

3:55

or do various manipulations to see where the

3:59

disconnection or malfunction is in

4:02

the shunt, and if necessary, replace either the

4:06

reservoir, the tubing, or the shunt itself.

4:10

Now, sometimes you have a patient who presents

4:13

with hydrocephalus, and they have a large mass

4:18

that is causing the ventricular enlargement.

4:21

This is different than status post

4:23

shunting and rule-out shunt failure.

4:26

In this case, you see that the patient has

4:28

a very large posterior fossa mass, which

4:31

was newly diagnosed. It has herniation of the

4:35

cerebellar tonsils through the foramen magnum.

4:38

And crowding at the foramen magnum with obstruction

4:41

of the fourth ventricle and cerebral aqueduct,

4:44

and hydrocephalus of the lateral ventricles.

4:49

CSF shunt malfunction can occur due to obstruction,

4:53

migration, disconnection, or sometimes even overdrainage.

4:57

Or sometimes the patient can get an infection,

4:59

such as meningitis, that, because of the synechiae

5:03

and purulent material, can obstruct the shunt.

5:06

Sometimes you get a CSF collection at the distal

5:08

end in the peritoneum, which we call a CSFoma.

5:12

It's like a mass of CSF secondary to accumulation

5:16

and fibrotic change around the distal end of the

5:20

ventriculostomy catheter.

5:22

These breaks, disconnections, and kinks

5:24

are usually detected on conventional

5:26

radiography, but what we see is the manifestation

5:29

intracranially of a change in ventricular size.