-
Indications and Techniquein Mastoidectomy
Marc Bennett, MD*, Frank Warren, MD,David Haynes, MD
The Otology Group, Otolaryngology Head & Neck Surgery,
Vanderbilt University,
300 20th Avenue North, Suite 502, Nashville, TN 37203, USA
Approximately 350 years have passed since the rst published
report ofa mastoidectomy by Riolan the Younger. Many changes have
occurredover the subsequent years, especially since the advent of
the operatingmicroscope 50 years ago. This report focuses on
mastoid surgery as it relatesto chronic ear disease as well as
providing access for a variety of other sur-gical procedures. We
reect on the current status and indications of theprocedure as well
as common complications.
History
Chronic and suppurative infections of the mastoid have been
described aslong ago as ancient Greece. However, it was not until
mid 17th centurywhen Riolan the Younger described the rst
trephination procedure ofthe mastoid. The subsequent 200 years did
not produce many signicant ad-vances until Fielitz and Petit
reported multiple cases of mastoid trephina-tions for acute
abscesses in the late 18th century. These procedures fellout of
favor for more than 100 years until Schwartze and Eysell [1]
popular-ized the cortical mastoidectomy in 1873. It was eective for
draining acuteinfections; however, it did little to treat chronic
infections of the ear. In1890, Zaufal [2] described the rst radical
mastoidectomy removing thesuperior and posterior ear canal,
tympanic membrane, and ossicles in an at-
Otolaryngol Clin N Am
39 (2006) 10951113tempt to eliminate infection, externalize
disease, and create a dry ear. Bondyrevised the technique by
leaving the uninvolved middle ear alone and exte-riorizing the
epitympanum [3].
* Corresponding author.
E-mail address: [email protected] (M. Bennett).
0030-6665/06/$ - see front matter 2006 Elsevier Inc. All rights
reserved.doi:10.1016/j.otc.2006.08.012 oto.theclinics.com
-
The introduction of the Zeiss otologic operating scope in
1953made precisedissection possible. Soon thereafter, Wullstein
described the rst attempts atreconstruction of the tympanic
membrane via tympanoplasty [4]. Five yearslater, William House
introduced intact canal wall mastoidectomy [5]. Sincethen, there
have been multiple variations of the mastoidectomy described.
Indications
The goals of any chronic ear surgery are to create a dry, safe
ear and pre-serve or restore hearing as much as possible. Although
there are some abso-lute and relative indications for a
mastoidectomy, the type of mastoidectomyis based on the extent of
disease, preoperative health of the patient, the statusof the
opposite ear, and both the surgeons and patients preference.
Forchronic ear surgery, a mastoidectomy is performed to help
eradicate diseaseand gain access to the antrum, attic, or middle
ear. It also increases the air-containing space in continuity with
the middle ear, allowing the middle earto better accommodate
changes in pressure without tympanic membrane re-traction. Absolute
indications include cholesteatomas or tumors with exten-sion into
the mastoid bone. Relative indications include [6]:
History of profuse otorrhea Previous tympanoplasty failure
Secondary acquired cholesteatoma Tympanic membrane perforations no
correctable without the further ex-posure provided by a
mastoidectomy
Although surgeons remain divided on the utility of the
mastoidectomy inprimary cholesteatoma surgery and tympanic membrane
perforation re-pairs, most agree to its utility in revision cases
after graft failure. Generally,imaging and cholesteatoma size are
not a determinate of what procedure isperformed.
Simple mastoidectomy
A simple or cortical mastoidectomy involves removing the mastoid
cortexand some of the underlying air cells. Dissection may be
supercial or pro-ceed to the mastoid antrum. It is used to unroof
the mastoid cortex anddrain a coalescent mastoiditis with
subperiosteal abscess.
Intact canal wall or complete mastoidectomy
The canal wall up mastoidectomy involves removing the mastoid
air cellslateral to the facial nerve and otic capsule bone while
preserving the poste-rior and superior external auditory canal
walls. This technique aords
1096 BENNETT et alaccess to the epitympanum while maintaining
the natural barrier betweenthe external auditory canal and mastoid
cavity. In pediatric patients, this ap-proach is preferred
generally to avoid the long-term problems associated
-
with canal wall down procedures. This approach can be combined
with a fa-cial recess dissection for:
Removal of disease in the recess Better exposure of the
posterior mesotympanum around the oval andround windows
Better visualization of the tympanic segment of the facial nerve
Better middle ear aeration postoperativelyFor increased exposure,
the facial recess can be extended inferiorly or su-
periorly to gain complete access to the hypotympanum and
epitympanum. Ifcholesteatoma or tumor cannot be resected via this
approach, the surgeryneeds to be converted to a canal wall down
procedure. Occasionally, a mas-toidectomy may be used to identify
and repair an injured facial nerve.
Modied radical mastoidectomy
Although the classic description of a modied radical
mastoidectomy isthe atticotomy described by Bondy, most surgeons
currently use the termto describe a canal wall down mastoidectomy
with tympanic membranegrafting. There are both preoperative and
intraoperative indications to re-move the auditory canal.
Preoperative indications for a modied radicalmastoidectomy include
[5] (1) disease in an only hearing ear, (2) patientswith poor
general health making them an anesthetic risk, and (3) patientsin
whom follow-up is problematic.
Some surgeons advocate a canal wall down after multiple failed
attemptsat canal wall intact surgery [7]. The decision to remove
the canal wall ismade intraoperatively when one of the following is
encountered [8]: (1) un-reconstructible posterior external auditory
canal defect, (2) labyrinthinestula where the matrix cannot be
resected primarily, and (3) obstructinglow-lying middle fossa dura
limiting epitympanic access. Again, cholestea-toma size is not a
determining factor.
Radical mastoidectomy
A radical mastoidectomy is performed in patients with severe
eustachiantube dysfunction, irreversible middle ear disease, or
unresectable cholestea-toma or tumors. The procedure leaves middle
ear and mastoid air cells ex-teriorized as a single cavity with no
attempt at reconstruction. Theeustachian tube is occluded and both
the malleus and incus are removed. Be-cause the middle ear is not
reconstructed, the expectation is that surround-ing squamous
epithelium will overgrow the middle ear and mastoid cavity.
1097MASTOIDECTOMYMastoid obliteration
Mastoid obliteration involves overclosing the external auditory
canal inblind sac fashion and obliterating the cavity with
autologous bone, bone
-
pate, vascularized aps, or abdominal fat. It is used in advanced
cases inwhich the ear continues to drain despite multiple prior
attempts at canalwall down surgery. Obliteration may also be
indicated in cases of chronicsuppurative otitis media in which
there is extensive dural dehiscence withor without cerebrospinal
uid leakage.
Canal wall up versus down
The controversy over canal wall up versus down surgery has been
on-going for nearly half a century. Although there are multiple
indicationsto remove the canal wall, the decision is usually
individualized. Most sur-geons prefer to avoid a cavity if
possible. The primary advantage of a ca-nal wall down procedure is
increased visibility and access to themesotympanum and epitympanum,
which allows disease resection and re-construction to be
accomplished in a single stage. This increased exposureaccounts for
reduced rates of recurrences versus intact canal wall proce-dures
[9]. However, postoperative care is more intense in the canal
walldown surgery both in the immediate postoperative period and
long-term. Serial debridements of the cavity and frequently
antibiotic dropirrigation are often required. In contrast, the
intact canal wall mastoidec-tomy maintains the natural anatomy and
heals more quickly than themodied radical mastoidectomy. Canal wall
intact procedures do not re-quire regular debridements, and hearing
outcomes tend to be slightly im-proved over canal wall down
procedures [10]. However, poorerintraoperative exposure and the
recreation of a middle ear space increasethe potential for
recurrent or residual disease after intact canal
wallprocedures.
Preoperative evaluation
Preoperative planning includes a comprehensive head and neck
exami-nation with an otomicroscopic examination. Active infections
are treatedaggressively with topical antibiotic drops before
surgery. Bilateral full au-diometric evaluation is performed in all
cases. Although computed tomog-raphy scans can help delineate the
bony anatomy of the temporal bone,this evaluation is not necessary
in most patients. They are especially usefulin revision surgery and
in patients with symptoms consistent with a labyrin-thine stula.
All patients should be encouraged to stop smoking because
itincreases recurrence rates over nonsmokers [9]. Sinonasal disease
is treatedaggressively. Adult patients with signicant symptoms are
tested and
1098 BENNETT et altreated for seasonal allergies. In children,
preoperative adenoid assessmentmay be necessary and when
appropriate, adenoidectomy should be per-formed 1 month before ear
surgery.
-
Preparation
Anesthesia is given without paralytic agents. Facial nerve
bipolar elec-trodes are placed into the orbicularis oculi and oris
muscles for monitoringof the facial nerve throughout the case. The
tragus and the area just behindthe postauricular sulcus are
injected with 2% lidocaine with 1:100,000 epi-nephrine about 10
minutes before the start of the case to allow proper he-mostasis.
The periauricular hair is cleansed with a hibiclens shampoo andthe
patients ear is prepped and draped in the usual sterile fashion.
Antibi-otics are routinely given preoperatively to reduce infection
risks [11]. Ste-roids are also often used to reduce postoperative
nausea.
Surgical incisions
Canal incisions
Each case starts with a detailed examination of the tympanic
membrane.With the exception of cochlear implantation, temporal bone
resection, andskull base procedures, transcanal injection of the
posterior ear canal with2% lidocaine and 1:50,000 epinephrine is
performed. The ear is copiouslyirrigated with saline solution
impregnated with antibiotic and desquamateddebris in the external
auditory canal is removed. Fig. 1 shows the vascularstrip
incisions. A radial incision is made in the tympanomastoid and
thentympanosquamous suture lines. The dependent or inferior cut is
always per-formed rst to avoid blood obscuring future incisions.
These incisions arethen connected by a medial incision
approximately 1 to 2 mm lateral tothe annulus. Just medial to the
bony-cartilaginous junction, a radial incisionis made from the
tympanomastoid suture line to the inferior aspect of theexternal
auditory canal.
1099MASTOIDECTOMYFig. 1. Vascular strip incisions. (A)
tympanomastoid suture line, (B) tympanosquamous suture
line, (C) medial incision, (D) radial incision.
-
Mastoid incisions
The standard postauricular incision and the endaural incision
are the twobasic incisions for access to the mastoid.
Postauricular incision
A postauricular incision as shown in Fig. 2 is the method most
widely usedto gain access to the mastoid. The incision spans from
the helical rim to themastoid tip and is well hidden in the
postauricular region. It rarely causes anyvisible scarring. The
incision should be about 1 cm behind the postauricularcrease to
avoid unsightly deepening of the sulcus, which can occur when
in-cisions are placed directly in the crease. The incision is more
posterior inyoung children to avoid a supercial facial nerve near
the mastoid tip.
The incision is made through the skin with a scalpel. An
avascular planeis elevated anteriorly toward the external auditory
canal just below the sub-dermal fat, leaving a layer of loose
areolar tissue on the temporalis fascia.This plane is developed
down to the mastoid tip. The attachments of thesternocleidomastoid
muscle can be separated from the mastoid tip for in-creased
exposure during skull base cases, but usually these attachmentsare
left intact to reduce postoperative discomfort.
A self retaining retractor is spread over the temporalis muscle.
As shown inFig. 3, a large graft is harvested with a scalpel and
scissors. This tissue often isscarce in revision surgery and if not
present, a true temporalis fascial graft canbe harvested. For
proper healing, this graft must be thinned of all muscle andfat
attachments. If the temporalis fascia is unavailable, tragal
perichondriumor periosteum medial to the temporalis muscle may be
harvested for grafting.Autologous veins or alloderm may also be
used for grafting in rare cases [12].
As shown by the dashed lines in Fig. 3, T shaped incisions are
thenmade through the mastoid periosteum with electrocautery. The
horizontalincision is made just below the temporalis muscle in the
linea temporalis.A second incision is made perpendicular to the rst
in the middle of the
1100 BENNETT et alFig. 2. Postauricular incision.
-
mastoid extending from the temporalis muscle to the mastoid tip.
A Lem-pert elevator is then used to elevate the periosteum
posteriorly over the sig-moid sinus, superiorly over the tegmen,
and anteriorly to the suprameatalspine of Henle where the vascular
strip is identied and reected laterally.Two self retaining
retractors are then placed in orthogonal directions asshown in Fig.
4. In revision surgery, careful palpation of the underlyingbone
will often identify a potentially unprotected sigmoid sinus or
dura.The incision is also modied to a C shaped incision at the
posterior aspectof the previously dissected mastoid cavity. In
younger children, elevation in-ferior to the external auditory
canal can potentially injure a lateralized facialnerve near the
stylomastoid foramen.
Lempert incision
Endaural incisions have been used for more than 100 years.
Lempert pop-ularized this approach in the mid 1930s. An incision is
made down to the
Fig. 3. Fascial graft harvest and periosteal incisions.
1101MASTOIDECTOMYFig. 4. Mastoid surface anatomy.
-
mastoid bone in the lateral external auditory canal between the
tragus andthe helical crus. Because exposure can only be obtained
of the anterior su-perior part of the mastoid, these incisions have
fallen out of favor for mas-toidectomies; however, some surgeons
continue to use these incisions tofacilitate exposure of the middle
ear in transcanal surgery.
Techniques
Basics
All drilling is done under the microscope with binocular vision.
Constantirrigation is critical to prevent thermal damage from the
drill bits. A varietyof surgical drills exist for mastoidectomy,
but a high-speed, comfortable,and reliable drill system is crucial.
In the past, air-powered systems werethe norm, but recently the
development of high-speed electrical systems oereasier setup,
eciency, and less noise than the air powered systems.
A variety of burs exist, ranging from those that aggressively
remove boneto those used for ne polishing of structures like the
facial nerve. Larger bitsare always preferred as they oer better
control and easier removal of bone;however, drill bits should not
be so large as to obstruct visualization duringthe dissection.
Initially, cutting burs are used to removed bone and
identifyimportant landmarks. Diamond burrs are then used for more
delicate pro-cedures like removing the last layer of bone over
sigmoid sinus or facialnerve. As dissection continues, smaller
burrs will be required as spacebecomes limited. Periodic irrigation
of the surgical eld with saline solutionreduces bleeding and washes
squamous debris from wound.
Surface anatomy
An understanding of the temporal bone anatomy is important to
avoidinjuring vital structures. The surface landmarks of the
mastoid bone shownin Fig. 4 not only dene the boundaries of the
mastoid bone, but approxi-mate important deep structures. The spine
of Henle is the anterior extentof dissection. This protuberance
extends supercially from the posterior su-perior bony ear canal and
approximates the location of the underlying mas-toid antrum.
Superiorly, the linea temporalis, the inferior border of
thetemporalis muscle, approximates the lowest level of the tegmen
or oor ofthe middle fossa. The mastoid tip is the inferior limit of
dissection.
Complete mastoidectomy
The key to a safe dissection is identifying key structures.
Identifying thetegmen, external auditory canal, sigmoid sinus,
middle ear ossicles, and
1102 BENNETT et alfacial nerve is the easiest and safest way to
ensure their preservation.As indicated by Fig. 5, dissection starts
high in the mastoid cortex, re-
moving bone along the linea temporalis until a thin layer of
tegmen bone
-
is left over the middle fossa dura, remembering that tegmen
height is vari-able depending on mastoid pneumatization. Next, a
cut perpendicular tothe rst and tangential to the external auditory
canal is made from the zy-gomatic root to the mastoid tip. Finally,
a cut is made from the mastoid tipto the sinodural angle.
Dissection is continued along these three planes, sau-cerizing the
lateral surface of the temporal bone from the middle fossa teg-men
to the mastoid tip and from the ear canal to the sigmoid, keeping
thedeepest part of the dissection in the anterior superior mastoid
directlyover the mastoid antrum. There is no attempt to keep the
mastoid small.The next structure visualized deep in the mastoid
cavity is Korners septum,the remnant of the petrosquamous suture
line. Once through Korners sep-tum, the lateral semicircular canal
is visible on the medial side of the antrumas shown in Fig. 6. The
otic capsule bone is easily distinguished from themastoid air cells
by its smooth glistening appearance.
For proper exposure, it is critical at this point to thin the
posterior exter-nal auditory canal. The lateral external auditory
canal is thinned from be-hind to the base of the spine of Henle.
This thickness is carried mediallyto the level of the mastoid
antrum. The superior external auditory canal isthinned similarly,
and the bone between the middle fossa tegmen and supe-rior ear
canal is removed to open the zygomatic root. As dissection is
con-tinued medially, the epitympanum is opened widely and both the
incus andmalleus are visualized. Air cells lateral to the labyrinth
are exenterated downthe mastoid tip where the digastric ridge is
identied. At the completion of
Fig. 5. Drill cuts used in start of mastoidectomy. (A) Thin
layer of tegmen bone is left over the
middle fossa dura, remembering that tegmen height is variable
depending on mastoid pneuma-
tization. Cut (B) perpendicular to the rst and tangential to the
external auditory canal is made
from the zygomatic root to the mastoid tip. Cut (C) is made from
the mastoid tip to the
sinodural angle.
1103MASTOIDECTOMYthe procedure, the middle and posterior fossa
plates, sigmoid sinus, poste-rior external auditory canal, and bony
labyrinth are all skeletonized.
For endolymphatic sac procedures, the sigmoid sinus is
decompressedand the jugular bulb identied. The labyrinth is
skeletonized, and the
-
dura between Donaldsons line, a line drawn as the posterior
extension ofthe lateral semicircular canal, and the jugular bulb is
exposed. The endolym-phatic sac and duct are identied and
decompressed carefully or openedover the underlying dura.
At the completion of the procedure, the mastoid periosteum is
reapproxi-mated with several interrupted 3-0 Vicryl sutures, and
the skin is closed withinterrupted subcuticular 4-0 Vicryl sutures.
The wound is then covered witha piece of telfa, several 4 4s, and a
Glasscock dressing. The mastoid defectrarely causes any aesthetic
concerns, but recently surgeons have attemptedto reconstruct the
mastoid cortex with titanium mesh [13].
Facial recess or posterior tympanotomy
As seen in Fig. 7, the facial recess is an inverted triangle
bounded poste-riomedially by the facial nerve, anterolaterally by
the chorda tympani nerve,and superiorly by the incus buttress. The
rst step in safely performing a fa-cial recess is to ensure that
the posterior external auditory canal is thinnedappropriately at
the end of a complete mastoidectomy. The next step is iden-tication
of the facial nerve using previously found landmarks including
thelateral semicircular canal, short process of the incus, and
digastric ridge. Thefacial nerve is always found inferomedial to
the lateral semicircular canal.As shown in Fig. 7, a line drawn as
the extension of the short process ofthe incus approximates the
facial recess.
Using a large diamond burr and copious amounts of irrigation,
the facialnerve is identied throughout its entire mastoid course,
from the second
Fig. 6. Complete mastoidectomy in cholesteatoma dissection.
Asterisk indicates lateral semicir-
cular canal.
1104 BENNETT et algenu just inferior to the lateral semicircular
canal to the stylomastoid fora-men. Using strokes parallel to the
direction of the nerve, the nerve is tracedout, leaving a thin
layer of the fallopian canal bone intact over the nerve.
-
The surgeon must be wary of a lack of bony covering, or
dehiscent, facialnerve in the mastoid. Invariably, there are
several small vessels aroundthe facial nerve that bleed during
dissection near the nerve that usuallycan be controlled by the
diamond burr or bipolar cautery. Next, the chordatympani nerve is
identied as the anterior branch of the facial nerve 4 to 5mm
proximal to the stylomastoid foramen. Dissection proceeds between
themedial facial nerve and lateral chorda tympani nerve superiorly
where therecess is the widest until the middle ear is entered. A
short bridge of bone,the incus buttress, is left in the superior
part of the facial recess to protectthe incus from the drill and
maintain the support for the incus.
Extended facial recess
The facial recess can be extended after a complete mastoidectomy
witha facial recess both inferiorly and superiorly. Superiorly, the
incus buttresscan be removed with a small diamond burr. After
removal of the incusand head of the malleus, the entire epitympanum
can be accessed. Dissectioncan proceed anteriorly to the
temporomandibular joint.
Inferiorly, an extended facial recess can expose the entire
hypotympanumas shown in Fig. 8. The chorda tympani nerve is
skeletonized and sacricedsharply to avoid retrograde trauma to the
facial nerve. As shown in Fig. 8,dissection proceeds between the
facial nerve and the tympanic membraneannulus as far anteriorly as
the parotid fascia. Identication of the jugularbulb in this
approach often helps avoid inadvertent injury.
Fig. 7. Facial recess. (dashed line) Short process of the incus
helps identify the facial recess.
1105MASTOIDECTOMYModied radical mastoidectomy
The goal in creating a modied radical mastoidectomy is to
createa smooth, self-cleaning cavity with no corners, edges, or
depressions in
-
which debris can accumulate. As shown in Fig. 9, the keys to the
procedureinclude [7]:
Aggressive saucerization of the mastoid Eliminating
irregularities or overhangs in the bone Removing the posterior bony
external auditory canal down to the levelof the facial nerve
Creating a large meatusThe modied radical mastoidectomy
procedure starts after a complete
mastoidectomy and identication of the mastoid segment of the
facial nerve.The incudostapedial joint is separated, and both the
incus and malleus areremoved. The external auditory canal is then
removed completely to thelevel of the fallopian canal, rst with a
large cutting burr and later with a di-amond burr. If the air cells
in the mastoid tip are diseased, they are com-pletely exenterated
to avoid dependent tip infections. If the mastoid is
Fig. 8. Inferior extended facial recess. Asterisks indicate
sacriced chorda tympani nerves.
1106 BENNETT et alFig. 9. Modied radical mastoidectomy. Asterisk
indicates low facial ridge. Arrowheads
indicate smooth junction of ear canal plus mastoid cavity.
-
well aerated, it is often helpful to reduce the size of the
cavity by removingthe lateral aspect of the mastoid tip, allowing
the soft tissue to cave in andauto-obliterate some of the cavity.
As shown by the arrowheads in Fig. 9,both the oor and roof of the
medial ear canal are then drilled ush tothe anterior ear canal.
This creates a smooth transition between the ear ca-nal and tegmen
superiorly and mastoid tip inferiorly. Care must be used
in-feriorly to avoid injury to a high jugular bulb in the
hypotympanum. Theossicular chain may be reconstructed and a large
fascial graft is used to rec-reate the tympanic membrane.
A large meatoplasty is necessary for epithelialization of the
cavity andeasier postoperative care. A postauricular approach is
used to removenearly 30% to 40% of the conchal cartilage as shown
by the trapezoidalwedge of cartilage between lines A and B in Fig.
10. This allows posteriorreection of the Korners ap without
deforming the auricle. Electrocauteryis used to divide the
subcutaneous tissues of the auricle in a half-moonshape until the
conchal cartilage is encountered. The cartilage is then ex-posed
medially to about the bony cartilaginous junction. A curvilinear
in-cision is made through the cartilage as shown in Fig. 11.
Retrogradeelevation of the deep perichondrium with a freer elevator
is then performed,and a crescent-shaped wedge of cartilage is
removed. A small portion of the
1107MASTOIDECTOMYFig. 10. Meatoplasty. (A) Superior canal cut.
(B) Inferior canal cut. Dashed line indicates area
of cartilage removed. The lower image shows Koerners ap reected
posteriorly.
-
cartilage is cut to the appropriate size and thinned for use in
the ossicularchain reconstruction.
A shown by the dashed lines in Fig. 10, meatal incisions A and B
arethen made to enlarge the opening of the external auditory canal.
A 15blade is placed in the ear canal and under direct vision an
incision ismade through skin and subcutaneous tissue at 12 oclock
in the externalauditory canal. As shown by line A, this incision is
made from the bonycartilaginous junction to the incisura notch. An
incision is made in the in-ferior aspect of the ear canal as
depicted by line B. These incisions aremade through the skin and
subcutaneous tissues in continuity with thepostauricular Koerners
ap. As shown in Fig. 12, three subdermal suturesare placed between
the Koerners ap and periosteum to reect the Koern-ers ap
posteriorly. Tension in the sutures is adjusted to optimize the
con-guration of the meatus. Generally, the meatus initially should
be madeabout the size of the mastoid cavity because it will undergo
about 25%contraction over time. A good approximation of this size
is the surgeonsthumb.
The postauricular skin is then closed using several interrupted
subcuticu-lar 4-0 Vicryl sutures. The mastoid and meatus are then
lled with bactro-ban ointment. The wound is then covered with a
telfa, several 4 4s anda Glasscock dressing or formal mastoid
wrap.
Radical mastoidectomy
The radical mastoidectomy is an operation performed to eliminate
all
Fig. 11. Conchal incisions.
1108 BENNETT et almiddle ear and mastoid disease through
complete removal of mucosa, tym-panic membrane, annulus, malleus,
and incus. Dissection is performed ina fashion similar to the
modied radical mastoidectomy, but there is no
-
attempt at reconstruction or tympanic membrane grafting. In
addition, theeustachian tube is occluded with a fascial plug.
Alternative procedures
Recently, several alternative procedures to the standard
mastoidectomyhave been described. Dornhoer [9] has described an
intact canal wall mas-toidectomy in which removal of the posterior
superior external auditory ca-nal provides better epitympanic
exposure. It also allows for dissection ofcholesteatoma sacs in
continuity without the obstruction of the ear canal.The canal
defect is then reconstructed with conchal cartilage to maintainthe
natural barrier between the external auditory canal and mastoid
cavity.The cartilage appears to remain stable over time, and there
is a low rate ofpostoperative complications or recurrences.
A recent variation of the modied radical mastoidectomy has been
pro-posed recently by Gantz and Hansen [14] in which the posterior
ear canal isremoved en bloc. This creates exposure for
cholesteatoma dissection similarto a canal wall down mastoidectomy.
Once dissection is complete, the poste-rior external auditory canal
is replaced, and several large bone chips are usedto seal o the
epitympanum. The mastoid cavity is then obliterated with bonepate,
obviating the need for serial mastoid cavity care. Patients require
hospi-talization for at least 2 days of intravenous antibiotics
postoperatively [14].
Fig. 12. Koerners ap. Suture tension can be varied to optimize
meatus.
1109MASTOIDECTOMYCholesteatoma dissection
For the sake of simplicity, this article will not address
cholesteatoma dis-section in the middle ear. However, cholesteatoma
sacs often extend into the
-
mastoid air cells. Before dissection, bone is removed
circumferentiallyaround the cholesteatoma sac avoiding direct
contact with the sac. Oncefully exposed, the cholesteatoma sac is
opened and the squamous debris re-moved to facilitate
dissection.
Because labyrinthine stulas are dicult to assess preoperatively,
carefulexamination of medial surface of the cholesteatoma sac is
performed, look-ing for attening of the lateral semicircular canal
or defects in the medialwall of the cholesteatoma, which may
indicate an underlying stula. Areasof suspected stula can also be
palpated carefully with blunt instruments.Leaving a small matrix on
the stula preserves labyrinthine function in93% of patients as
opposed to only 80% if the matrix is removed [15]. Ifless than 2 mm
of matrix is left, a canal wall intact procedure can be per-formed
if a second stage is planned. A canal wall down procedure shouldbe
performed if a large cholesteatoma matrix is left in the mastoid
[16].
Postoperative care
Both immediate and long-term care are important in the
mastoidectomypatient. Both nausea and pain are treated aggressively
to make the patientcomfortable. Facial nerve function is tested and
recorded. Patients are dis-charged with their dressings in place
and are allowed to remove the dressingafter 24 hours. Patients are
instructed to change cotton balls in their ear andkeep the
postauricular incision clean. Follow-up is scheduled for 3 weeks
atwhich time their ears are lightly debrided and the patient is
started on anti-biotic drops. Gentian violet is often used on
granulation tissue in liberalfashion in canal wall down cavities.
Water precautions are maintained for2 months or until the ear drum
is noted to be fully healed.
Complications
Facial nerve injury
Other than death, facial nerve injury is the most disturbing
complicationof ear surgery. We monitor all otologic cases to aid in
preservation of thefacial nerve; however, monitoring is not a
substitute for the thoroughknowledge of the anatomy of the nerve.
In primary surgery, surgical land-marks are usually present and
identication of the nerve is easier. In revisionsurgery and
congenital ears, normal landmarks may be absent, making
iden-tication of the nerve more dicult.
If nerve injury is suspected intraoperatively, identication of
the nerve isperformed. It is important to remember that the injury
often extends beyond
1110 BENNETT et althe visible injury several millimeters in both
directions, and 3 to 4mm of nerveshould be exposed both proximal
and distal to the suspected site of injury us-ing a diamond burr.
Injury to the epineurium or nerve sheath usually has no
-
long-term consequences [17]. If less than 40%of the nerve is
injured and facialmuscle contraction can be elicited with small
milliamp (!0.1) stimulation ofthe proximal segment of the nerve, no
further treatment is necessary otherthan the decompression already
performed, postoperative steroids and closefollow-up. If more than
50% of the nerve is injured, superior results may beachieved
through nerve grafting [18]. This is often a dicult decision, anda
consultation from a colleague is useful in prompt evaluation of the
nerve.Primary reanastamosis through simple reapproximation in the
fallopian ca-nal or several 9-0 sutures through the epineurium
should be performed if thereis enough length of nerve present. If
there is a segment of nerve missing, mo-bilization of the nerve may
obtain the extra length needed for anastomosis. Ifmore length is
still needed, a cable graft using the great auricular or sural
nervemay be used.
Immediate facial paralysis in the postoperative period also
requiresprompt evaluation. Several hours may pass to ensure paresis
is not the resultof overzealous use of local anesthetic at the
beginning of the case. If paral-ysis persists beyond 4 hours,
prompt operative exploration of the nerve iswarranted.
Postoperative care depends on intraoperative circumstancesand
common sense; if the nerve was already decompressed in the
operatingroom, observation may be appropriate. If the operative
team has gone homeand an inexperienced team is present, it may be
advisable to observe the pa-tient until the regular team is back in
the morning. Referral may also be thebest option in these dicult
cases depending on the experience and expertiseof the surgeon.
Conservative management with steroids, antibiotics, andantivirals
is warranted in all cases of delayed facial paralysis [19].
Hearing loss
Iatrogenic hearing loss may occur after mastoid surgery.
Sensorineuralhearing loss (SNHL) may be the result of removal of
cholesteatoma overlabyrinthine stulas or inadvertent contact
between the drill and ossicularchain during dissection.
Labyrinthitis may also lead to SNHL as inamma-tory cells enter the
inner ear via the round or oval windows. Drill injuriesusually
result in a high-frequency sensorineural hearing loss.
Conductivehearing losses are usually observed. They can be owing to
multiple etiologiesincluding middle ear adhesions, tympanic
membrane perforation, middleear eusions, ossicular xation, or
failed ossicular chain reconstruction.
Infection
Postoperative infections occur in 2% to 5% of mastoidectomies.
Infec-tion may be the result of wound infection or continued
chronic ear disease.Routine prophylaxis may not necessarily reduce
postoperative infection
1111MASTOIDECTOMYrates [20]. Perichondritis occurs in
approximately 1% of canal wall downprocedures; therefore,
perioperative antibiotics are used routinely in theseprocedures.
Aggressive intervention with debridement and topical
-
antibiotics will limit overall disgurement. Infections in a
mastoid withexposed dura may predispose the patient to meningitis
and brain abscesses.
Vertigo
Labyrinthine stulas and injuries during mastoid surgery may
alter thevestibular responses of an ear. Chronic infection may also
be a source of re-duced vestibular function. Although unilateral
loss of vestibular functionmay occur, chronic disequilibrium is
rare.
Intracranial injury
Exposure of dura generally is avoided but is not of consequence
unlesslarge defects in the tegmen, dural abrasions, or
cerebrospinal uid are en-countered. Repair is generally through
layered closure with soft tissue sup-port including muscle and
fascia grafts with brin glue. Emergence fromanesthesia must be
controlled without bucking or rises in intracranialpressure.
Bleeding
Like any surgery, bleeding is a potential postoperative risk. In
modiedradical and radical mastoidectomies, postoperative bleeding
is greater owingto more soft tissue dissection; however, blood
drains through the meatusand there is little risk for hematoma
formation. Injury to large vascularstructures like the sigmoid
sinus, jugular bulb, or large emissary veins man-dates immediate
assessment. Bleeding often is controlled easily with gelfoamand
gentle pressure. Hematomas may form from uncontrolled bleeding
ormore often from vessels in vasospasm during the procedure, which
startbleeding with coughing or straining in the postoperative
period.
Canal defects
Small defects in the external auditory canal usually require no
interven-tion. Defects greater than 0.5 cm may be xed with bone
pate or cartilagegrafting often with overlying fascial grafts to
prevent canal cholesteatomaformation.
Further readings
Cass S. Mastoid surgery. In: Operative Otolaryngology Head and
Neck Surgery. 1997.
p. 128098.
Glasscock ME. Surgical technique for open mastoid procedures.
Laryngoscope 1982;92:14402.
GlasscockME III, Haynes DS, Storper IS, et al. Surgery for
chronic ear disease. In: Hughes GB,
1112 BENNETT et alPensak ML, editors. Clinical otology. New
York: Thieme Medical Publishers; 1996.
p. 21532.
Haynes DS, Harley DH. Surgical management of chronic otitis
media: beyond tympanostomy
tubes. Otolaryngol Clin N Am 2002;35:82739.
-
Jackson CG, Glasscock ME, Nissen AJ, et al. Open mastoid
procedures: contemporary
indications and surgical technique. Laryngoscope
1985;95:103743.
Kaylie DM, Jackson CG.Revision Chronic Ear Surgery. Otol
HeadNeck Surg 2006;134:44350.
McGrew BM, Glasscock ME. Impact of mastoidectomy on simple
tympanic membrane
perforation repair. Laryngoscope 2004;114:50611.
Pillsbury HC III, Carrasco VN. Revision mastoidectomy. Arch
Otolaryngol Head Neck Surg
1990;116:101922.
Smyth GD, Toner JG. Mastoidectomy: the canal wall down
procedure. In: Otologic surgery.
p. 22639.
Syms MJ, Luxford WM. Management of cholesteatoma: status of the
canal wall. Laryngoscope
2003;113(3):4438.
References
[1] Schwartze HH, Eysell CG. Ueber die Kunstliche eronung des
warzenfortsatzes. Arch
Ohrenheilkd 1873;7:157.
[2] Zaufal E. Technik der Trepanationdes Proc. Mastoid. Nach
Kusterschen Grundsatzen.
Arch Ohrenheilkd 1893;30:291.
[3] Shambaugh GE, Glasscck ME. Surgery of the ear. Philadelphia:
WB Saunders; 1980.
[4] Wullstein HL. Tympanoplasty and its results. Arch Ohren
Nasen Kehlkopfheilkd 1958;171:
8490.
[5] HouseWF.Middle cranial fossa approach to the petrous
pyramid. Report of 50 cases. Arch
Otol 1963;78:4609.
[6] Haynes DS. Surgery for chronic ear disease. Ear Nose Throat
J 2001;80:811.
[7] Jackson CG, Touma B. A Surgical solution for the dicult
chronic ear. Am J Otol 1996;17:
714.
[8] Sheehy JL. Mastoidectomy: the intact canal wall procedure.
In: Otologic surgery. Chapter
18. 21224.
[9] Dornhoer J. Retrogrademastoidectomywith canal wall
reconstruction: a follow-up report.
Otol Neurotol 2004;25:65360.
[10] Dodson EE, Lambert PR. Intact canal wall matoidectomy with
tympanoplasty for choles-
teatoma in children. Laryngoscope 1998;108(7):97783.
[11] Haynes DS. Perioperative antibiotics in chronic suppurative
otitis media. Ear Nose Throat J
2002;81(1):135.
[12] Haynes DS, Vos JD, Labadie RF. Acellular allorgraft dermal
matrix for tympanoplasty.
Curr Opin Otol Head Neck Surg 2005;13(5):2836.
[13] Kim HH, Wilson DF. Titanium mesh for functional
reconstruction of the mastoid cortex
after mastoidectomy. Otol Neurotol 2006;27(1):336.
[14] Gantz BJ, HansenM. Canal wall reconstruction
tympanomatoidectomy with mastoid oblit-
eration. Laryngoscope 2005;115:173440.
[15] Palva T, Ramsay H. Treatment of labyrinthine stula. Arch
Otolaryngol Head Neck Surg
1989;115(7):8046.
[16] Glasscock ME, Poe D. Surgical management of cholesteatoma
in an only hearing ear. Otol
Head Neck Surg 1990;102:24650.
[17] Lambert P. Mastoidectomy. In: Cummings otolaryngology head
and neck surgery. 4th edi-
tion. 2005. p. 307586.
[18] Brackman DE. Tympanoplasty with mastoidectomy: canal wall
up procedures. Am J Otol
1113MASTOIDECTOMY1993;14:380.
[19] Vrabec JT.Delayed facial palsy after tympanomastoid
surgery. Am JOtol 1999;20(1):2630.
[20] Jackson CG. Antimicrobial prophylaxis in ear surgery.
Laryngoscope. 1988 Oct;98(10):
111623.
Indications and Technique in
MastoidectomyHistoryIndicationsSimple mastoidectomyIntact canal
wall or complete mastoidectomyModified radical mastoidectomyRadical
mastoidectomyMastoid obliterationCanal wall up versus down
Preoperative evaluationPreparationSurgical incisionsCanal
incisionsMastoid incisionsPostauricular incisionLempert
incision
TechniquesBasicsSurface anatomyComplete mastoidectomyFacial
recess or posterior tympanotomyExtended facial recessModified
radical mastoidectomyRadical mastoidectomyAlternative
proceduresCholesteatoma dissection
Postoperative careComplicationsFacial nerve injuryHearing
lossInfectionVertigoIntracranial injuryBleedingCanal defects
Further readingsReferences