1. Mastoid Exposure

2. Mastoidectomy

Mastoidectomy involves the removal of bone and air cells contained within the mastoid portion of the temporal bone. Common indications for this procedure include acute mastoiditis, chronic mastoiditis, cholesteatoma, and the presence of tympanic retraction pockets. Mastoidectomy may also be performed as part of other otologic procedures (e.g. cochlear implantation, lateral skull base tumors, labyrinthectomy, etc.) in order to gain access to the middle ear cavity, petrous apex, and cerebellopontine angle. The procedure involves dissecting within the confines of the mastoid cavity, which include the tegmen superiorly, the sigmoid sinus posteriorly, the bony ear canal anteriorly, and the labyrinth medially. Mastoidectomy is traditionally classified as: simple (cortical/Schwartze), radical, and modified radical/Bondy’s mastoidectomy. The procedure can also be classified based on the preservation of the posterior canal wall: canal wall up (CWU) or canal wall down (CWD). 

<h4>CHAPTER 1</h4>

<p>I'll release these attachments of the SCM
off the mastoid tip – get a little better
exposure.
Of the whole mastoid tip here.
And there is the ear canal.
And then, I like to make a little relaxing incision right there,
which then allows me to have a little better exposure
to the mass -
to the anterior mastoid here.
The epitympanum-attic area.
All right, so that's the exposure we need.
So now I'll start with the drill.
5 cutter.
Let me have a bipolar first.
If you don't get all these little bleeders
now, they'll bug you the whole case, so
it's important to take the time in the beginning to get everything
ready so you don't have to stop and go back and fix things.</p>

<h4>CHAPTER 2</h4>

<p>All right.
I'll start with a 5 cutter and the...
Okay, water on.
Okay, decrease the water.
Down? Down the irri - yeah, down.
Up.
So you want it so – that's perfect.
So you want it so when it's on, it's flowing,
and when I put my finger on the hole, it stops. Okay.
So that's the perfect amount.
So I start
at the linea - above the linea temporalis -
about 5 mm above the ear canal is where I
expect the tegmen to be,
and I make a - I go all the way from front to back...
Using irrigation to keep my visualization to blow -
wash away the bone dust
and bleeding. It keeps the -
it keeps the specimen cool, so you don't burn the bone.
It also keeps bone
dust out of your burr, which keeps it sharper.
So here I see an air cell, and this is dura right here. So I've -
I've now exposed - that's going to be dura under here -
the tegmen.
I'm going to expose a little better anteriorly.
It's going to be pretty good anterior exposure for this.
And that's going to be dura there. So once I have the tegmen, my
superior limit, I'll come along the anterior canal, along -
along the ear canal
out to the mastoid tip and expose my anterior limit.
And then I can remove the rest of the cortex,
going from known to unknown.
I go superior to inferior, exposing the air cells.
And taking - doing the cortex. Taking the cortex off.
Exposing all the air cells.
Alright, can I have an irrigation? So once you
get all that bone dust out...
Actually, let me have water off for a second.
Let me have a - let me have a freer.
So, can you save all this?
Get a container or something from the...
So I'm going to save this bone pate for later
to use to help plug the hole.
So this is really good stuff.
It can be used for a lot of different things.
Do you want a cup with saline?
Just no - just leave it as it is. Leave it as it is. Okay.
Let me have irrigation.
Drill. You may have to what?
Water on. Turn it up a little bit.
Up?
Decrease it a little. Down.
All right.
It's a little bit low.
Do you want me to adjust the microscope?
Yeah - and it's not going to have to be much.
You're just - you're going to have to just look a little bit lower. That's perfect.
Oh, that's fine with me. Okay. Good.
So,
I'm going to follow the tegmen.
In. And what I think there - here's sigmoid sinus.
It goes up nicely there, so that's as far back as I need to be.
And so,
I'll follow the tegmen in, thin out the ear canal,
and just keep following it medially.
So here I am now getting through into the antrum.
All right, irrigation.
Can you put a 4 cutter on? Yep.
And can I have the bed away, please?
So I'm going to change my
angle a little bit to look more into the antrum.
Can I have the bed away, please? Yes.
Okay,
so here I'm starting to see the lateral canal, but I have all this
bone I can thin out.
So I thin the ear canal out,
and then I expose more of the tegmen, and
then I can go between them. That lets me know I'm safe.
And there's the incus.
So I'm going to want to
expose...
Thinning this.
All right, water off. Can I have a 4 diamond?
I'm going to zoom in a little more.
Gimmick.
So here we see
the incus really well right there.
There.
All right, water on.
Slowly.
Very thin tegmen here, so there's some dura.
All right, let me have a 3 diamond.
Can we have bipolar first?
There's often very thin
bone over the dura.
Often natural dehiscences.
Can I have some bone wax on the back of a freer?
Okay, bed back towards me a little bit, please.
Okay, so here's the lateral canal.
I'm just going to expose this a little better.
I'm going to skeletonize the -
the labyrinth.</p>

Watch this narrated surgical video of a mastoiectomy performed by Dr. David Kaylie at Duke University Medical Center.

DOI
Publication Date	2023/12/15
Article ID	222
Production ID	0222
Volume	2023
Issue	222
https://doi.org/10.24296/jomi/222

Mastoidectomy

Procedure Outline

Table of Contents

1. Mastoid Exposure

2. Mastoidectomy