0:00

Before I discuss additional congenital anomalies

0:03

that are associated with the external auditory canal,

0:05

I want to make a quick comment about the treatment

0:08

of external auditory canal atresia from

0:10

the standpoint of the timing.

0:14

So, there is a difference in the approach to a

0:17

patient who has bilateral external auditory

0:19

canal atresia versus unilateral.

0:21

If you have unilateral external

0:23

auditory canal atresia,

0:25

you are likely to be able to hear on the

0:28

contralateral side, and therefore the surgeons,

0:31

by and large, delay reconstruction and correction of

0:35

the external auditory canal on the affected

0:38

side until late childhood.

0:42

Why would that be? Well,

0:45

this is in part a cosmetic deformity as well.

0:48

And the last thing they want is to reconstruct a

0:51

one-year-old's external auditory canal and

0:55

have an ear that is the size of an adult.

0:59

They don't want to have to do

1:00

the cosmetic surgery twice,

1:02

one as a child and then again as an older child

1:06

that has a normal-sized adult external ear.

1:10

And they can wait because you can develop normal

1:15

speech through hearing on the contralateral ear.

1:19

Contrast that with bilateral external

1:22

auditory canal atresia.

1:23

Now you have a child who can't hear,

1:25

there is conductive hearing loss bilaterally, and

1:28

you need to hear speech through your parents

1:30

and whatnot in order to develop speech.

1:33

So for bilateral external auditory canal atresia,

1:37

it usually means that there will ultimately

1:39

be two surgeries, one at early childhood,

1:43

so that way you develop normal conductive hearing

1:47

and you reconstruct externally as a

1:51

childhood-sized ear, if you will,

1:54

and then potentially having to come back at late

1:57

childhood and reconstruct the external ear.

1:59

So it's more appropriately pleasing to the eye,

2:03

if you will, cosmetically,

2:05

so it looks like a normal ear

2:08

as an adult.

2:09

So that's an important difference between the timing

2:12

of and the evaluation of patients with external

2:15

auditory canal atresia, is a unilateral process

2:18

that will not affect the child's ability to

2:20

develop speech, versus a bilateral process which

2:24

leads to bilateral hearing loss and therefore a

2:27

learning disability that has to be

2:29

addressed early in childhood.

2:32

So let's move from external auditory

2:34

canal atresia and the issues,

2:35

both imaging as well as treatment-wise, on what to

2:38

do about that to the other congenital

2:42

anomalies of the external auditory canal.

2:44

The most common of these is first

2:46

branchial cleft cysts.

2:48

So the first branchial cleft cyst is a cystic

2:51

structure which is often seen in close

2:55

approximation to the parotid gland and

2:57

may or may not communicate with

3:00

the external auditory canal via a fistula.

3:03

So it's just below the external auditory

3:06

canal in the region of the parotid.

3:08

And this example that is demonstrated shows a

3:12

cystic structure in a child that is in the parotid

3:17

gland, and it's just below the level

3:19

of the external auditory canal.

3:23

The other abnormalities that can occur

3:26

congenitally in association with the external

3:29

ear are things like Keutel syndrome.

3:32

So this is a rare autosomal recessive condition with

3:35

abnormal calcification of the cartilage

3:39

of the external ear.

3:40

It may also affect the cartilaginous portion

3:42

of the external auditory canal.

3:45

But this increased density you see is not

3:48

something that's been placed to secure the

3:52

brain or the head in the CT scanner.

3:54

This is abnormal calcification

3:57

within the external ear.

4:04

This is an MRI scan showing a cyst which

4:08

is superficial to the parotid gland.

4:11

It's bright on the T2-weighted scan

4:13

identifying it as a cyst.

4:15

This was an additional first branchial cleft cyst

4:20

in association with the parotid gland and

4:22

just below the external auditory canal.

4:25

The external auditory canal fistula that is

4:31

associated with first branchial apparatus cysts

4:36

may be identified via otoscopy as a small dimple

4:41

or opening in the external auditory ear canal

4:44

which subsequently gets explored.

4:46

And through the imaging exploration, they may find

4:49

that cyst below with a tract leading from

4:53

it to the external auditory canal.

4:55

This is the difference between the Arnold Type 1

4:58

and Arnold Type 2 first branchial cleft cysts.

5:02

Another congenital anomaly that may be associated

5:05

with the external ear and may affect the external

5:08

auditory canal is the venous

5:10

vascular malformation.

5:12

You're looking at a sagittal T1-weighted

5:16

scan that is far lateral in its location,

5:21

affecting the external ear and neck structures.

5:25

And you note that there is a large venous

5:28

structure within this vascular malformation

5:32

that is affecting the external ear region.

5:37

And this was indeed a venous

5:39

vascular malformation.