Phẫu Thuật Tai Mũi Họng Và Phẫu Thuật Đầu Cổ

1142
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
tion should be staged and performed only after the
tympanic membrane is intact.
The ossicular chain must be adequately visualized
and palpated to determine its mobility. Ossicular recon-
struction is undertaken when indicated. Specifi c details
regarding these techniques are discussed in Chapter
114.
After inspection and treatment of the middle ear
and ossicular chain, the posterior fi brous tympanic
membrane and cartilaginous annulus are returned to
their original positions. The areolar tissue or fascia is
harvested and cut to the proper size, typically an 11- by
13-mm oval disc, although smaller grafts can be used if
the perforation is not large. If the posterior annulus is
defi cient or a large amount of bone from the posterior
canal wall has been removed, a longer, more oblong
graft is tailored. The longer portion of the graft is laid
on the posterior canal wall. The graft is positioned on
the annular margin, lateral to the handle of the malleus
(Fig. 113-16).
When the perforation is nearly total and the malleus
is not supported by any remaining fi brous tympanic
membrane, the graft can still be positioned lateral to
the malleus. However, when the malleus is directed
medially, approximating the promontory, the graft
should be positioned medial to the umbo of the malleus
to prevent lateralization. The graft is then cut radially
for a few millimeters from the 12-o’clock position and
placed medial to the umbo and distal handle of the
malleus, with the superior edges of the graft overlap-
ping in the pars fl accida area (Fig. 113-17) (see Video
113-16). The graft must be positioned so that it lies on
the cartilaginous annulus and does not extend onto the
anterior or inferior bony canal walls. A graft that is too
thick, placed beyond the fi brous annulus, and extended
onto the anterior inferior canal wall may result in blunt-
ing of the angle between the tympanic membrane and
the bony canal wall. This problem is avoided by trim-
ming the graft to the appropriate size and shape. When
the graft must be wrapped around the medial surface
of the malleus, the superior margins of the incised graft
are overlapped over each other (see Video 113-17).
The skin that had been harvested from the external
canal is then inspected under the microscope. Scissors
are used to open up the sleeve of skin that was obtained
from the medial external canal. It is thinned and sub-
cutaneous tissue is removed if necessary (see Video 113-
18). The separate pieces are placed on a plastic cutting
block with the epithelial side up and cut into rectangu-
lar shapes. It is necessary to remove extremely thin or
irregular edges of the skin to ensure that all of the epi-
thelial surfaces face the ear canal lumen. Preparation
and trimming of the skin should be done with use of
the microscope to eliminate unfurled edges. An accu-
rately sized graft should be placed so that it is just
overlapping the anterior annulus to avoid blunting (see
Video 113-19).
Each piece of skin is then carefully placed lateral
to the areolar (or fascial) graft with the epithelial
surface toward the auricle. Attention is directed to the
anterior sulcus, where skin is placed on the anterior
canal with the thinner edge positioned lateral to the
areolar or fascial graft. The skin overlying the graft
should be thin. The fi rst piece of skin is placed in this
area, and subsequent grafts are placed over the pars
fl accida area and, when available, posteriorly onto the
bony canal wall (Fig. 113-18) (see Video 113-20). If
there is insuffi cient skin to provide coverage of the bony
canal, a thin split-thickness skin graft (Thiersch graft)
is harvested from the non–hair-bearing postauricular
skin with a no. 10 blade.
Packing of the external ear canal is necessary.
Packing keeps canal fl aps and epithelial grafts in their
Figure 113-16. The areolar graft is routinely placed lateral to the
annulus, and the remaining fi brous tympanic membrane is draped
over the malleus.
Figure 113-17. If the handle of the malleus is directed medially
within the middle ear, the areolar graft is cut vertically at the 12-
o’clock position and positioned medial to the malleus handle and
lateral to the fi brous tympanic membrane and annulus. The edges of
the areolar graft overlap superiorly, lateral to the proximal handle
and the short process of the malleus and pars fl accida area.

Chapter 113
Myringoplasty and Tympanoplasty 1143
proper positions, which greatly aids in the healing
process. The cylindrical channel of the ear canal is
maintained to preclude narrowing from blood products
and granulation tissue. The contour and patency are
preserved until the packing is removed or dissolves. It
is important to prevent blunting of the anterior sulcus
with one of the following techniques: Gelfoam, oint-
ment, Merocel sponges, or a silk rosebud pack. We use
two methods of packing, depending on the preference
of the surgeon. The fi rst consists of Gelfoam soaked in
antibiotic suspension. The initial piece is approximately
5 to 7 mm in length and 4 mm in width, compressed,
and folded on itself. While fi rmly holding the anterior
canal wall skin graft, the Gelfoam is secured anteriorly
to defi ne the anterior tympanomeatal sulcus. The
remainder of the ear canal is fi lled with small to pro-
gressively larger pieces of Gelfoam.
The other packing technique that we use is precise
but tedious. It consists of using strips of silk, 4 × 25 mm,
placed in rosebud fashion into the medial canal (Fig.
113-19) (see Video 113-21). Merocel balls impregnated
with bacitracin ointment are then placed within the
rosebud, and the lateral leaves are folded over one
another to create a mold or cast of the medial canal.
This accurately defi nes the anterior sulcus, which will
minimize the risk of anterior blunting and lateraliza-
tion (Fig. 113-20) (see Video 113-22).
The tracheostomy tape and self-retaining retractors
are then released and the ear is returned to its anatomic
position. The conchal fl ap is thinned if there is too
much subcutaneous tissue and returned into the exter-
nal canal. Lateral rosebud packing consisting of silk
strips 7 to 10 mm × 30 to 35 mm is then placed in a
similar rosebud fashion and secured with larger Merocel
balls (Fig. 113-21) (see Video 113-23). Another method
for stenting the lateral canal is with a small-pore Merocel
sponge (Schindler ear pack) impregnated with antibi-
otic otic suspension. The postauricular wound is closed
with interrupted 4-0 Monocryl suture and running 5-0
fast-absorbing chromic suture and Steri-Strips. A cotton
ball is placed at the external meatus, and a sterile
mastoid or Glasscock dressing is applied. Most patients
undergo surgery as an outpatient and are discharged
the day of the procedure. The mastoid or Glasscock
dressing is maintained overnight and removed by the
Figure 113-18. The skin of the medial bony canal wall and lateral
tympanic membrane was thinned and cut into rectangular pieces.
The thicker part of the skin graft is initially placed on the anterior
bony canal wall. The thinner edges overlie the areolar graft. Depend-
ing on the availability of skin, multiple pieces are placed.
Figure 113-19. Medial rosebud packing consists of strips of silk
that are placed radially to completely cover the areolar graft.
Figure 113-20. Small cotton or Merocel balls are packed within
the rosebud dressing, and the edges are folded over one another.

1144
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
patient or family after 24 hours. The cotton ball placed
in the external meatus is removed and replaced every
few hours as needed.
Medial Grafting Technique
The external canal is injected as described earlier. Once
anesthesia is adequate, the edges of the perforation are
trimmed with a perforating pick or sickle knife (see Fig.
113-4). A graft is then harvested. Small perforations can
be repaired with compressed adipose tissue harvested
from the earlobe or with areolar tissue from the post-
auricular area. For larger defects, an incision posterior
to the superior aspect of the helix is made over the
temporalis area, where areolar tissue or fascia is
obtained. (This is incorporated into the postauricular
approach if greater exposure of the tympanic mem-
brane is necessary.) A tympanomeatal fl ap is elevated
by incising the medial canal skin over the scutum supe-
rior to the lateral process of the malleus. It is extended
posteriorly while keeping a distance of 4 to 5 mm from
the annulus. The incision is then curved inferiorly,
running parallel to the annulus, and is directed toward
the 6-o’clock position. The tympanomeatal fl ap is then
elevated along with the annulus. The ossicular chain is
next inspected and palpated as mentioned earlier. The
graft is then brought into the middle ear, placed up
against the medial aspect of the tympanic membrane
perforation, and supported with Gelfoam placed within
the middle ear space (Fig. 113-22). The fl ap is then
returned to its anatomic position. Packing consists of a
strip of silk supported with cotton balls impregnated
with bacitracin ointment or Gelfoam to fi ll the external
canal.
Figure 113-21. The medial rosebud pack secures the grafted tym-
panic membrane. The lateral pack stents the lateral canal and conchal
fl ap.
Figure 113-22. Medial grafting technique. After the edges of the
tympanic membrane perforation are freshened, a tympanomeatal
fl ap is elevated. A tissue graft (shaded area) is positioned medial to the
perforation and supported by packing Gelfoam into the middle ear.
(Redrawn from Naumann HH: Head and Neck Surgery, vol 3: Ear. Stuttgart,
Germany, Georg Thieme, 1982.)
POSTOPERATIVE MANAGEMENT
After myringoplasty for repair of tympanic membrane
perforation or lacerations, the packing is removed 7 to
10 days after the procedure. Patients in whom a paper
patch has been applied to the lateral surface of the
repair are monitored until the paper patch migrates
onto the skin of the bony canal wall. This process may
take 6 to 12 weeks, during which time the patient is
instructed to avoid getting water into the ear.
With the lateral grafting technique, the Glasscock
or mastoid dressing is removed on the fi rst postopera-
tive day. Patients are instructed to keep the incision dry
for 1 week; they are permitted to shower but should
avoid getting the incision and Steri-Strips soaking wet.
Topical eardrops are used twice daily for repairs packed
with Gelfoam. Lateral packing involving the rosebud
technique can remain dry. Topical eardrops are not
needed during the fi rst postoperative week. The oint-
ment around the Merocel balls keeps the lateral packing
moist. Drainage normally occurs through the external
canal, and the cotton ball is changed frequently. Anal-
gesics are provided. The patient is seen 7 to 10 days
after surgery, and the postauricular Steri-Strips and the
lateral rosebud packing are removed. Antibiotic-steroid
drops are prescribed for use twice a day.
One week later, the medial rosebud pack is removed.
The canal is cleaned with a thin wisp of cotton on an
applicator. The cotton applicator is used to gently wipe
or absorb any residual blood that may collect or pool
in the inferior or anterior sulcus. Cleaning the medial
canal will help avoid the development of granulation
tissue, scarring, and blunting. A 3F suction device or

Chapter 113
Myringoplasty and Tympanoplasty 1145
cotton on an applicator can be used to remove excessive
blood or serum, but caution is needed to avoid acciden-
tal removal of the replaced skin. The ear canal may
attempt to heal with cicatricial midcanal soft tissue ste-
nosis. If not recognized, it can progress to complete
stenosis and give the appearance of a lateralized tym-
panic membrane. In the immediate postoperative
period, most patients have a relatively insensate ear
canal that permits offi ce débridement and stenting.
Occasionally, the patient must be returned to the oper-
ating room for aggressive débridement and repacking.
Granulation tissue, if present, is cauterized with silver
nitrate. Excessive granulation tissue can be removed
with a curette. Topical 5-fl uorouracil can also be used.
It may be necessary to place a wick with antibiotic drops
for another week to ensure smooth healing of the ear
canal.
The tympanic membrane should be intact and
mobile. Tuning fork testing is performed and the results
compared with those obtained preoperatively. If the
middle ear space is incompletely aerated, positive nasal
pressure (Valsalva maneuver) is occasionally used to
aerate the middle ear space. No additional drops are
used if the canal and tympanic membrane are well epi-
thelialized. Otherwise, drops are continued for approxi-
mately 2 to 3 weeks. The patient is instructed to continue
avoiding getting water in the ear when showering until
healing is complete (usually 1 month). Patients are
instructed to use Vaseline on a cotton ball for protec-
tion from water.
Postoperative care of medial grafts is similar to that
for myringoplasty. The lateral packing is removed 7 to
10 days later. Drops are used twice a day, and the patient
is instructed to keep the ear dry. For all techniques, the
patient returns in approximately 3 to 4 weeks or at a
total of 5 to 6 weeks after surgery. If healing is adequate,
audiometric testing is performed at that time.
References
1. Zollner F: The principles of plastic surgery of the sound-conduct-
ing apparatus. J Laryngol Otol 69:637-652, 1955.
2. Wullstein H: Theory and practice of tympanoplasty. Laryngoscope
66:1076-1093, 1956.
3. McGrew BM, Jackson CG, Glasscock ME 3rd: Impact of mastoid-
ectomy on simple tympanic membrane perforation repair.
Laryngoscope 114:506-511, 2004.
4. Collins WO, Telischi FF, Balkany TJ, Buchman CA: Pediatric tym-
panoplasty: Effect of contralateral ear status on outcomes. Arch
Otolaryngol Head Neck Surg 129:646-651, 2003.
5. Dornhoffer J: Cartilage tympanoplasty: Indications, techniques,
and outcomes in a 1,000-patient series. Laryngoscope 113:1844-
1856, 2003.
6. Tarabichi M: Endoscopic management of limited attic cholestea-
toma. Laryngoscope 114:1157-1162, 2004.
PEARLS
• Anticipate and inform patients who may not achieve
successful tympanoplasty repair, including those
who have failed multiple previous procedures;
patients with severe contralateral atelectasis, middle
ear effusion, or otorrhea; and those with obvious
sources of eustachian tube dysfunction, such as
abnormalities of the soft palate.
• Preparation and trimming of the skin should be
done under the microscope to ensure that no
unfurled edges are present.
PITFALLS
• Incision into and exposure of the cartilage of the
external canal may result in pain and possibly
chondritis.
• Leaving remnants of epithelium from the tympanic
membrane or on the anterior inferior sulcus when
elevating the external canal skin from the medial
canal can result in residual drum or canal
cholesteatoma.
• Injury to the chorda tympani nerve results in
sensation disturbances of the tongue, especially
taste.
• The ear canal may attempt to heal with cicatricial
midcanal soft tissue stenosis.
• Failure to recognized signifi cant mucosal disease or
compromised eustachian tube function will probably
result in graft failure.
• If there is insuffi cient skin to provide coverage of
the bony canal, a thin split-thickness skin graft
(Thiersch graft) from the non–hair-bearing
postauricular skin is used.
• Place an accurately sized graft that just overlaps the
anterior annulus to avoid blunting.
• Once the medial packing is removed from the ear
canal, diligent local care of the external canal is
necessary to avoid midcanal stenosis.

Chapter 114
Ossicular Chain Reconstruction
Barry E. Hirsch
Conductive hearing loss results from restriction of
sound wave energy in displacing the basilar membrane
of the organ of Corti. Conductive hearing loss not of
middle ear or tympanic membrane origin can result
from obstruction in the external auditory canal and
possibly from fl uid distention within the inner ear, such
as that seen in early Meniere’s disease. Inner ear con-
ductive hearing loss also occurs when a “third window”
exists in the otic capsule. Dehiscence of the superior
semicircular canal provides a site for expansion of inner
ear fl uid, which prevents the fl uid wave from providing
full stimulation to the basilar membrane of the cochlea.
This may result in conductive hearing loss even though
acoustic refl exes will still be present.
Conductive hearing loss of middle ear origin may
be congenital or acquired and results from ossicular
chain fi xation, erosion, dislocation, or fracture. Ossicu-
lar chain reconstruction (OCR) re-establishes the
sound-transforming mechanism to provide a mobile
connection from the tympanic membrane through an
aerated middle ear space to the perilymph. This chapter
focuses on the surgical techniques for OCR. Tympanic
membrane grafting, surgery for stapes fi xation second-
ary to otosclerosis, and chronic otitis media with
cholesteatoma are addressed in other chapters.
The term tympanoplasty describes procedures that
address the status of the middle ear from the tympanic
membrane to the vestibule. OCR is frequently per-
formed in conjunction with tympanic membrane graft-
ing for eliminating middle ear and mastoid disease.
Zollner and Wullstein were early pioneers in the con-
cepts of middle ear reconstructive surgery.1,2 Wullstein
provided a classifi cation system consisting of fi ve types
(I to V) of tympanoplasty that focus on reconstruction
with the remaining ossicular chain. Each type refers to
the most lateral intact structure that remains connected
to the inner ear on which the tympanic membrane is
grafted or the ossicular chain reconstructed. Type I
tympanoplasty indicates that all three ossicles are
present and mobile. Thus, OCR is not needed. In type
II tympanoplasty, the tympanic membrane is grafted to
an intact incus and stapes. In practice, the need for type
II tympanoplasty is rarely encountered. According to
Wullstein, a type III tympanoplasty exists when an intact
mobile stapes superstructure is present and the tym-
panic membrane or graft remains directly on the stapes
superstructure. Type IV tympanoplasty describes an
absent or eroded superstructure with the graft or tym-
panic membrane overlying a mobile stapes footplate.
Type V tympanoplasty refers to a fenestration created
in the horizontal semicircular canal (Fig. 114-1).
Use of this classifi cation system was subsequently
encouraged by Farrior,3 who clarifi ed the terminology
by basing the type of OCR on the pathologic anatomy
at the completion of surgery rather than the method of
reconstruction used. According to Farrior, type III tym-
panoplasty refers to establishing continuity of the stapes
to the more lateral tympanic membrane or malleus by
interposing a sculpted ossicle, bone, or other alloplastic
material. A type IV tympanoplasty denotes reconstruc-
tion of the ossicular chain from a mobile stapes foot-
plate to the malleus, tympanic membrane, graft, or
rarely, the incus. Type V tympanoplasty has been sub-
divided into types Va and Vb. Type Va designates a true
fenestration procedure into the horizontal canal,
whereas type Vb implies that the footplate is fi xed or
absent. After the vestibule is sealed with a tissue graft,
continuity is restored from the oval window to the incus,
malleus, tympanic membrane, or graft. Technically, sta-
pedectomy would be characterized as a type Vb tympa-
noplasty, but this terminology is not proposed for
otosclerosis surgery.
This classifi cation system is supplemented by
describing the method of reconstruction used for each
case. This is applied particularly to type III tympano-
plasty. The most common type III tympanoplasty per-
formed is an incus interposition with the patient’s own
incus (autograft). We had used homograft (cadaver)
1147

1148
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
ossicles in the past, but concern regarding possible
infection or contamination with viral or prion particles
has eliminated their use. A type III tympanoplasty with
stapes augmentation entails increasing the height of the
stapes above the fallopian canal when a canal wall–down
mastoidectomy is performed and the malleus is absent.
This technique frequently uses the body of the incus,
the head of the malleus, or a cortical bone graft. We
use the term partial ossicular replacement prosthesis (PORP)
when a synthetic biocompatible prosthesis is positioned
from the stapes superstructure to the tympanic mem-
brane, graft, or malleus. Types IV and Vb tympanoplasty
are performed with either a total ossicular replacement
prosthesis (TORP) or the patient’s own incus from the
footplate or grafted oval window to the malleus, tym-
panic membrane, or graft.
PATIENT SELECTION
OCR is performed for conductive hearing loss or when
the ossicular chain must be disarticulated for access
to other middle ear pathology. A chief complaint of
hearing loss may result from trauma, chronic eusta-
chian tube dysfunction, congenital anomalies, chronic
otitis media, tumors of the middle ear space, or ossicu-
lar chain fi xation resulting from tympanosclerosis.
Physical examination may demonstrate an intact or
perforated tympanic membrane. It is important to
examine the contralateral ear, which provides a means
of predicting the likelihood of successful tympano -
plasty and OCR when eustachian tube function is
compromised.
Patients sustaining head trauma with fractures
involving the temporal bone may present with a con-
ductive, sensorineural, or mixed hearing loss. Hemo-
tympanum often occurs but is usually resorbed in 4 to
6 weeks. This time frame is necessary to determine the
type and degree of residual hearing loss after return of
middle ear aeration. The anatomy of the external canal
should be examined along with the integrity of the
tympanic membrane. Pneumatic otoscopy is useful for
confi rming a small tympanic membrane perforation by
demonstrating lack of mobility. Myringosclerosis can
also restrict movement of the tympanic membrane. In
contrast, hypermobility suggests a fl accid membrane or
possible fracture of the malleus handle. Tuning forks
are used to both confi rm the presence and estimate the
magnitude of a conductive hearing loss.
Pure-tone audiometry is performed to determine
the degree of conductive hearing loss and the quality
of cochlear function. A persistent conductive hearing
loss typically indicates ossicular chain disruption. This
may be repaired electively or rehabilitated by aural
amplifi cation. Patients demonstrating a large mixed
hearing loss should be considered surgical candidates
for OCR (Fig. 114-2). In patients with signifi cant mixed
hearing loss, bone-windowed thin-cut computed tomog-
raphy (CT) helps defi ne the status of the cochlea, ossi-
cles, and middle ear space. Disruption of the ossicular
chain can be demonstrated in these scans (Fig. 114-3).
Patients with severe to profound mixed hearing loss
may have hearing aid tolerance problems. Closing the
air-bone gap restores hearing thresholds to levels at
which routine hearing aid amplifi cation is more feasi-
Type I
Type IV
Type V
Type II
Type III
Figure 114-1. The Wullstein
classifi cation of types of tympano-
plasty. (From Kley W: Surgical treat-
ment of chronic otitis media and its
immediate consequences. In Naumann
HH [ed]: Head and Neck Surgery, vol
3: Ear. Stuttgart, Germany, Georg
Thieme, 1982, p 221.)

Chapter 114
Ossicular Chain Reconstruction 1149
ble. OCR may not be warranted in patients with cochlear
concussion and poor speech discrimination.
Patients undergoing tympanoplasty with or without
mastoidectomy and are found to have signifi cant middle
ear mucosal disease may not be ideal candidates for
immediate reconstruction. On occasion, the procedure
is staged in anticipation of achieving an aerated middle
ear space with healthier mucosa. Our philosophy on
staging the procedure has evolved over the past 2
decades. It was our routine approach to remove patho-
logic disease, reconstruct the ossicular chain, and graft
the tympanic membrane in one procedure. We believed
that recurrent or persistent disease would become
evident by the fi ndings of subsequent progressive con-
ductive hearing loss, recurrent otorrhea, or evidence of
cholesteatoma in an ear with cholesteatoma as the origi-
nal pathology. Our approach has been modifi ed slightly
based on the fi ndings in the middle ear and the age of
the patient. In initial procedures or operations per-
formed on young people in whom taking the canal wall
down would minimize the likelihood of persistent
disease, we would attempt total removal of the disease
and keep the canal wall intact but plan to re-explore
the ear in 6 to 12 months.
A staged procedure is performed when cholestea-
toma is mixed within granulation tissue around the
stapes footplate and superstructure and cannot be com-
pletely removed. Another situation follows removal of
thickened hyperplastic infl amed mucosa from the
promontory and eustachian tube orifi ce when a large
graft to the tympanic membrane is necessary. If the
incus or head of the malleus is available and free of
disease (cholesteatoma), it is removed and banked for
planned subsequent reconstruction. A piece of sculpted
Silastic sheeting (0.02 to 0.04 inch) with a rounded tip
extending into epitympanum is place over the promon-
tory. The video shows a disc of reinforced Silastic sheet-
ing being placed on the promontory and medial to the
malleus (see Video 114-1). A fascia graft is positioned
lateral to the Silastic and rests on the bony annulus (see
Video 114-2). Placement of the Silastic block over a
mobile stapes superstructure occasionally provides an
effective columellar connection between the stapes and
the tympanic membrane and results in near closure of
the air-bone gap. If good hearing has been achieved
with the initial procedure, re-exploration is not manda-
tory unless concern exists about residual or recurrent
disease.
On rare occasion, reconstruction at a subsequent
staged procedure may not require access through the
external auditory canal and tympanic membrane. If the
original tympanomastoidectomy procedure entailed
opening the facial recess, it is possible to reconstruct
the ossicular chain from the postauricular approach.
Endoscopes may be necessary to fully evaluate the attic
and mesotympanum. This technique allows improve-
ment in hearing and avoids canal incisions, middle ear
packing, and restrictions from water exposure.4
Figure 114-2. The audiogram
shows a left moderate to severe
mixed hearing loss with fair word
recognition. Options for rehabilita-
tion include amplifi cation or ossicu-
lar chain reconstruction. ANSI,
American National Standards Insti-
tute; LE, left ear; MCL, most com-
fortable loudness level; PB, phonetic
balance; PTA, pure-tone average;
RE, right ear; SRT, speech reception
threshold;
UCL,
uncomfortable
loudness level.
Figure 114-3. Computed tomography scan demonstrating tempo-
ral bone trauma with disruption of the ossicular chain. The normal
incudomalleus complex is indicated with the open arrow. The solid
arrows identify the separated malleus and incus.

1150
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
In keeping with otologic principles, the surgeon is
cautioned about operating on the better-hearing ear.
As with all rules, there are exceptions. Surgical interven-
tion could be considered in a better-hearing ear if other
pathologic fi ndings are present, such as cholesteatoma
in the involved ear. However, the status of the contra-
lateral ear is most important to consider.
Age does not impose a limitation for tympanoplasty
and OCR. In children who do not have a recent history
of recurrent episodes of otitis media and demonstrate
a dry ipsilateral perforation and normal contralateral
ear on physical examination, it can be assumed that
eustachian tube function is competent and they are
candidates for tympanoplasty. Similarly, elderly patients
in good health have the option of amplifi cation or
middle ear reconstruction.
The decision regarding elective reconstruction for
conductive hearing loss remains with the patient. If
there is no evidence of active infection, potential tumor,
or cholesteatoma, the option of hearing aid amplifi ca-
tion should be discussed. If a patient has chronic otitis
media with perforation and it is believed that a hearing
aid would exacerbate the underlying disease and
promote drainage, appropriate counseling should be
given.
Patients with a large conductive loss in the involved
ear and normal hearing in the contralateral ear require
further counseling. Despite a technically successful
operation, complete closure of the air-bone gap is fre-
quently not achieved in some type III and more com-
plicated reconstructive procedures. Although hearing
can be improved substantially, a residual difference
between the two ears may be perceived by the patient
as being an unsuccessful result. Realistic expectations
must be conveyed when discussing anticipated goals of
the procedure.
It may be diffi cult to decide what to recommend to
patients with residual conductive hearing loss who have
undergone previous attempts at OCR. Although previ-
ous operative dictations are occasionally unreliable, in
this situation it is often helpful to review them. Nearly
complete closure of the air-bone gap should be antici-
pated with a type I tympanoplasty. Patients with a type
III or IV tympanoplasty and residual conductive hearing
loss of 15 to 20 dB with normal hearing on the contra-
lateral side may desire further improvement. Surgeons
must have an appreciation of the hearing results before
contemplating revision surgery.
PREOPERATIVE PLANNING
Physical examination of the external auditory canal and
tympanic membrane is important in determining the
status of the ear. Primary infl ammation of the skin of
the external canal or infl ammation secondary to disease
from the middle ear requires medical management to
optimize postoperative healing. A few weeks of topical
and systemic antibiotics may be necessary. The integrity
of the tympanic membrane and middle ear space is
noted. Tuning fork testing with 256-, 512-, and 1024-Hz
forks is performed to determine whether a conductive
hearing loss is present and to estimate the degree of
loss. The most commonly used frequency is 512 Hz.
Obtaining an audiogram is mandatory to establish the
nature and degree of the conductive hearing loss and
cochlear function. Patients with an intact tympanic
membrane, no history of chronic ear disease, and pro-
gressive conductive hearing loss most likely have oto-
sclerosis. Fixation of the lateral ossicular chain is
relatively uncommon. An astute clinician may detect
decreased mobility of the malleus during pneumatic
otoscopy. It is typically diagnosed at the time of explor-
atory tympanotomy. The cause may be congenital.
Delayed lateral chain fi xation is probably due to tympa-
nosclerosis secondary to chronic infl ammation of the
middle ear. Acoustic refl exes should be absent in the
setting of conductive hearing loss caused by pathology
within the middle ear. Dehiscence of the superior semi-
circular canal may give fi ndings of conductive hearing
loss of inner ear origin. Acoustic refl exes are character-
istically present in this form of conductive hearing loss.
We now request acoustic refl ex testing of patients with
conductive hearing loss and an intact tympanic
membrane.
CT is not routinely performed unless symptoms or
signs of complications of chronic otitis media and cho-
lesteatoma are present, including asymmetrical cochlear
function, dizziness, severe headaches, facial paresis, or
cerebrospinal fl uid otorrhea. Repair of congenital
atresia also requires CT scanning to defi ne the otic
capsule, middle ear space, ossicular chain, bony plate,
and course of the facial nerve. This topic is covered
more thoroughly in Chapter 111.
The method for providing anesthesia is dictated by
the status of the tympanic membrane, the presumed
status of the ossicular chain, the presence or absence of
infl ammatory middle ear disease, the anticipated
approach, the patient’s tolerance for a procedure under
sedation, and the experience of the surgeon. Patients
with an intact tympanic membrane and conductive
hearing loss can undergo an endaural approach under
local anesthesia and intravenous sedation. General
anesthesia is recommended for children and patients
with a tympanic membrane perforation who require a
postauricular approach. Facial nerve monitoring is not
used for routine tympanoplasty procedures; however,
monitoring is indicated for patients with evidence of
facial nerve signs of weakness, fasciculations, or spasm
and during procedures for repair of congenital aural
atresia. Antibiotics are not given perioperatively. As
with all procedures, the patient is informed of the risks,
benefi ts, and alternative treatments.
PROSTHESIS OPTIONS AND ADJUNCTIVE
TECHNIQUES
Over the past 60 years there have been signifi cant
advances in the development and application of new
materials available for reconstruction of the ossicular
chain. In a poll of members of the American Otologic
Society published in 2001, hydroxyapatite was the pre-
ferred alloplastic material because it provided biocom-

Chapter 114
Ossicular Chain Reconstruction 1151
patibility, rigidity for sound transmission, durability,
longevity, ease of use, and good hearing results.5 Plasti-
pore prostheses, which had been widely used in the
latter part of the past century, were reported to have
the lowest satisfaction rate, of all prostheses.
The newest material currently available is titanium,
which is lightweight, has great tensile strength, and is
rigid yet slightly malleable. It requires a cartilage inter-
face between the prosthesis and the tympanic mem-
brane. The design for partial prostheses incorporated
a bell-shaped confi guration that fi ts over the stapes
superstructure (Fig. 114-4). Jackson and colleagues
compared titanium with synthetic non–titanium-based
prostheses and showed improved hearing outcomes
with titanium prostheses but thought that there was a
minimal learning curve needed to successfully achieve
closure of the air-bone gap.6 A consortium of otologists
from different regions of the United States were simi-
larly in favor of titanium prostheses given their good
hearing results and low rate of extrusion.7 Our only
reservation with using this material is the requirement
for a cartilage graft under the tympanic membrane.
This inhibits visual monitoring of the middle ear
for recurrent cholesteatoma after surgery for that
pathology.
The use of bone cement in skull base surgery and
cranioplasty has led to applications in otology and
reconstruction of the ossicular chain. The chemical
composition of these products includes hydroxyapatite,
cyanoacrylates, polymethyl methacrylates, and glass
ionomers. Great care must be taken with the latter
product to avoid contact with any neural tissue because
of the severe neurologic complications that can occur
from aluminum being leached from the product. A
study using SerenoCem (Corinthian Laboratory, Not-
tingham, UK) for repair of an eroded incus confi rmed
that the product was not exothermic when reconsti-
tuted but required at least 20 minutes to harden in a
dry operative fi eld.8
Hydroxyapatite bone cement is available from
numerous manufacturers. It too is minimally exother-
mic, is malleable for a few minutes, sets in 4 to 6 minutes,
and undergoes osteointegration over time. It can
provide an adjunct or alternative to ossiculoplasty with
preformed prostheses. Goebel and Jacob reported suc-
cessful use of hydroxyapatite bone cement in challeng-
ing cases with diffi cult ossicular reconstruction.9 The
products currently available include Mimix (Walter
Lorenz Surgical, Jacksonville, FL), BoneSource (Stryker
Leibinger, Portage, MI), and Norian (Synthes USA,
Paoli, PA).
SURGICAL TECHNIQUES
The approaches to and methods for tympanic mem-
brane grafting are reviewed in Chapter 113. Frequently,
the preoperative status of the ossicular chain is unknown
when correction of conductive hearing loss is attempted.
The surgeon must be prepared to have access to the
entire ossicular chain. When elevating a tympanome-
atal fl ap, the superior limb of the incision should be
superior to the pars fl accida and approximately 4 to
5 mm from the posterosuperior annulus (Fig. 114-5).
This longer fl ap permits removal of bone from this area
to provide exposure of the malleus neck and the entire
stapes footplate and to gain access for removal of the
body of the incus, if necessary.
Reconstruction of the tympanic membrane and
ossicular chain demands a precise and stable connec-
tion between the drum and the stapes or footplate. The
reconstructed ossicle or prosthesis should not make
direct contact with the surrounding tympanic ring,
which would restrict transmission of sound to the
cochlea. A prosthesis that is too short will have a ten-
dency to fall or become displaced. On the other hand,
excessive length and poor eustachian tube dysfunction
Figure 114-4. Titanium partial ossicular replacement prosthesis
with a cage or bell that fi ts over the stapes superstructure.
4-5 mm
Figure 114-5. The tympanomeatal incision for exploratory tympa-
notomy should be 4 to 5 mm away from the posterosuperior
annulus.

1152
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
set the stage for extrusion of the prosthesis. The pros-
thesis should not only touch the tympanic membrane
but should also be under slight tension to create minimal
tenting of the tympanic membrane over the prosthesis
(Fig. 114-6). The following text focuses on isolated
problems encountered in OCR and the methods and
techniques for reconstruction.
Problems with the Incus
The most commonly encountered abnormality in the
ossicular chain involves the incus. Rarely, it is mani-
fested as incudomalleal fusion or fi xation. More com-
monly, the long process and lenticular process of the
incus are eroded or connected by a fi brous union (Fig.
114-7). In patients with an intact mobile malleus and
stapes, incus interposition is the most commonly used
method for OCR. This technique has been used for the
past 50 years. A variety of techniques are available for
modifi cation of the incus to provide a mobile yet fi rm
connection from the stapes superstructure to the
malleus. The surgeon should note the status of the
middle ear mucosa and the relationship of the malleus
to the stapes.
The stapes may be located directly medial to the
handle of the malleus. The other anatomic variation
occurs when the malleus is located anterior to the verti-
cal plane of the stapes. This relationship is important
in determining how the incus will be sculpted so that it
can be interposed between the stapes and the malleus
(Fig. 114-8). In addition, the height of the stapes rela-
tive to the promontory and facial nerve is noted. This
is more of an issue when disease in the middle ear and
mastoid requires a canal wall–down mastoidectomy.
The patient’s incus (autograft) is usually available for
Figure 114-6. Hydroxyapatite partial ossicular replacement pros-
thesis making direct contact with the tympanic membrane. Note the
very slight tenting over the prosthesis.
Fibrous
incudostapedial
joint
A
B
Figure 114-7. A, Erosion of the lenticular process with a residual
fi brous joint. B, Erosion of the long process of the incus.

Chapter 114
Ossicular Chain Reconstruction 1153
reconstruction, but it may be necessary to remove addi-
tional bone from the posterosuperior canal to extract
the incus. A right-angled hook or curved needle is used
to disarticulate any remaining attachments of the incus
body to the malleus head. Cup forceps are used to grasp
the proximal long process of the incus. With a rotating
downward maneuver the surgeon extracts the incus
from the epitympanum entering into the middle ear
(Fig. 114-9) (see Video 114-3). Care is taken to avoid
displacement of the stapes superstructure and injury to
the chorda tympani nerve.
Various designs for sculpting an incus for interpo-
sitioning between the stapes and the malleus are dem-
onstrated in Figure 114-10. The incus should be held
with an instrument such as a fi ne hemostat or forceps
designed for holding ossicles (Fig. 114-11). Should the
incus be inadequate because of signifi cant erosion or
infi ltration by cholesteatoma, we had used a homograft
incus in the past but now use a synthetic PORP prosthe-
sis. If a mastoidectomy had been performed, the same
variable high-speed drill is used for incus sculpting.
Otherwise, a battery-powered microdrill is used (see
Video 114-4).
When the stapes and malleus are in a nearly vertical
plane, height is needed to connect the two ossicles. The
acetabulum for the stapes head is drilled into the short
process of the incus. A groove for the malleus handle
is created in the articulating surface of the incus body.
This is initially positioned underneath the malleus
handle, and the malleus-incus complex is lifted and
rolled onto the stapes (Fig. 114-12). A very common
confi guration is one used to gain some height and hori-
zontal span. The acetabulum for the stapes is created
in the body of the incus near its junction with the long
process (Fig. 114-13A). A more oval aperture is drilled
to accommodate the shoulder of the crura (see Fig.
114-13B). Care must be taken to ensure that the under-
surface of the short process of the incus is not resting
on the promontory of the cochlea. With all interposi-
tioning techniques, placement of the incus superior
or inferior to the chorda tympani nerve can pro -
vide further support to the sculpted ossicle (see Fig.
114-13C). When considerable height is needed to be
bridged, the incus is confi gured as shown in Figure 114-
14A. This relationship can be appreciated when the
tympanic membrane is atrophic and translucent (see
Fig. 114-14B).
Occasionally, the incus is eroded just at the incudo-
stapedial joint (see Fig. 114-7). Rather than removing
Figure 114-8. The position of the
malleus relative to the stapes deter-
mines how the incus will be sculpted
to perform an interposition. Left, The
malleus is located lateral to the stapes.
Right, Reconstruction requires aug-
menting the vertical height of the
stapes and its anterior span to the
malleus.
Figure 114-9. The incus body is disarticulated from the malleus
head and extracted with cup forceps.

Figure 114-10. The incus body
can be sculpted in a variety of forms
to accommodate each particular rela-
tionship between the malleus and
stapes. A, Gains vertical height. B,
Gains some vertical height and mostly
horizontal span. C, Gains mostly ver-
tical height and some horizontal
span.
Figure 114-11. Ossicle holder fi rmly grasping a sculpted incus.
Figure 114-12. Incus interposition to
gain height from the stapes to the
malleus.
A
B
C
1154

Chapter 114
Ossicular Chain Reconstruction 1155
the incus, an alternative method for reconstructing this
joint is to use an Applebaum hydroxyapatite prosthesis.
This prosthesis fi ts on the stapes superstructure and
supports the remaining long process of the incus (Fig.
114-15) (see Video 114-5).
Type III tympanoplasty is also performed with syn-
thetic prostheses. Products containing hydroxyapatite
are well tolerated. A cartilage interface between the
dense hydroxyapatite prosthetic head and the tympanic
membrane or graft is not needed. The shafts are made
of a combination of hydroxyapatite and polyethylene or
fl uoroplastic. In a technique similar to that used for
incus interpositioning, a PORP can be positioned from
the stapes to the mobile membrane (Fig. 114-16). It can
easily be shortened to provide the appropriate distance
from the stapes to the malleus handle and tympanic
membrane (see Video 114-6). We do not strictly apply
the terms PORP and TORP to indicate ossicular recon-
struction directly to the tympanic membrane or its
graft. We use the terms PORP and TORP synonymously
with incus replacement prosthesis and incus-stapes replace-
ment prosthesis, respectively. The malleus may be present
and can provide further support for the prosthesis.
Reconstruction of the ossicular chain in patients
undergoing a canal wall–down mastoidectomy may also
require a type III tympanoplasty. After the head of the
malleus is removed, a connection from the stapes to the
malleus handle is necessary. This can be accomplished
with incus interposition techniques or with a synthetic
prosthesis. When the level of the tympanic membrane
is displaced medially because of an absent malleus,
minimal height is needed for the stapes to reach the
tympanic membrane. The membrane could be grafted
directly onto the stapes superstructure as described by
A
C
B
Figure 114-13. A, Incus interpositioning to gain some height and
mostly horizontal span. B, The sculpted incus has an oval aperture that
fi ts snugly on the stapes (arrow). C, In a left ear, the incus has been
positioned superior to the stapes and medial to the malleus handle.
The chorda tympani nerve provides additional support (arrow).

1156
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
B
Figure 114-14. A, Incus interposi-
tion to gain mostly vertical height and
some horizontal span. B, Postopera-
tive photograph of a right ear with a
translucent tympanic membrane. A
groove was drilled into the short
process of the incus so that it can rest
against the neck of the malleus.
Figure 114-15. Intraoperative photograph of an Applebaum pros-
thesis placed between the stapes and an eroded long process of the
incus.
Wullstein. However, greater surface contact is achieved
when an ossicular graft is placed on the stapes. The
body of the incus, the head of the malleus, or a small
cortical bone graft harvested from the root of the
zygoma or the outer table of the squamosa portion of
the temporal bone can be drilled to form a dome for
the stapes superstructure (Fig. 114-17).
Under high magnifi cation, the relationship of the
facial nerve and horizontal semicircular canal to the
height of the stapes can be appreciated. When the tym-
panic membrane or graft is returned to cover the
middle ear, it is supported laterally by the horizontal
semicircular canal and the facial ridge. The height of
the stapes must be augmented to make better contact
with the tympanic membrane (Fig. 114-18). The vertical
height of a PORP is too great in this situation. It cannot

Chapter 114
Ossicular Chain Reconstruction 1157
tensor tympani tendon can be divided and the malleus
rotated posteriorly and placed on top of the stapes.
Problems with the Stapes
If the stapes superstructure is partially eroded, interpos-
ing an ossicle or prosthesis from the stapes arch or one
of its crura will probably fail. Reconstruction from
the undersurface of the malleus to the mobile stapes
footplate provides a more secure connection of the
ossicular chain.
An autograft incus occasionally provides adequate
length to meet these requirements. The distance should
be measured before sculpting the incus. The size of the
incus from the short process to its articulating surface
often satisfi es the length needed from the footplate to
the undersurface of the malleus.
The incus is sculpted by fl attening the short process
to rest on the stapes footplate. A groove in the articulat-
ing surface of the incus is further defi ned to secure the
incus to the medial surface of the malleus (Fig.
114-19A). Additional length is available when the long
process of the incus remains. The lenticular process is
removed, and the groove for the malleus is drilled on
the superior surface of the incus (see Fig. 114-19B) (see
Video 114-7). The sculpted ossicle is placed on the
footplate between the remaining crura. While the
malleus handle is lifted, the incus is rotated into posi-
tion (Fig. 114-20). The chorda tympani nerve can be
positioned to further secure the ossicular assembly.
When the oval window niche is narrow and deep, a
wide incus body may have to be thinned to fi t between
the promontory and the facial nerve. More often, a
synthetic prosthesis is necessary. The principle for
reconstruction is connection of the malleus to the foot-
plate. Any columella-type prosthesis can be used. In the
past, a stainless steel wire incus replacement prosthesis
was fashioned from the neck of the malleus to the foot-
plate. However, placement of this prosthesis was techni-
cally diffi cult and occasionally resulted in extrusion.
Figure 114-16. A partial ossicular replacement prosthesis is posi-
tioned between the stapes and the malleus handle. It can be placed
directly onto the medial surface of the tympanic membrane or graft
without intervening cartilage when the dome of the prosthesis is
made of hydroxyapatite.
Figure 114-17. Ossicular chain recon-
struction in a canal wall–down cavity.
The stapes has a greater area of contact
with the tympanic membrane or graft.
This is a type III tympanoplasty with
stapes augmentation.
be trimmed suffi ciently to provide the necessary height
of 2 to 3 mm.
On rare occasion, the malleus can be directly
attached to the stapes superstructure. This situation
occurs in a canal wall–down procedure when the incus
is absent and the stapes superstructure is intact. If the
malleus remains attached to the tympanic membrane
along the distal handle and umbo, its attachment to the

1158
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
polytetrafl uoroethylene (Tefl on). It is readily trimma-
ble and does not osteointegrate when there is direct
contact with the promontory.
Titanium prostheses are available in fi xed lengths
or with a trimmable shaft. A sizing set is used to deter-
mine the proper length needed. The video demon-
strates use of a 5-mm sizing prosthesis to verify the
appropriate length needed for the prosthesis implanted
(see Video 114-8).
Type IV tympanoplasty often requires temporary
support of the prosthesis. Wet Gelfoam is placed around
the shaft base up to the level of the facial nerve if the
malleus handle is present. When the prosthesis is in
direct contact with the tympanic membrane, as will be
described, Gelfoam is positioned around the entire
prosthesis to the level of the tympanic membrane (see
Video 114-9).
Problems with the Malleus
A relatively uncommon source of conductive hearing
loss is fi xation of the malleus and incus, also known as
A
B
Figure 114-18. A, Left ear, canal wall–down mastoidectomy in preparation for ossicular chain reconstruction. Note that the stapes head (long
arrow) is at the level of the tympanic segment of the facial nerve (short arrow). The tympanic membrane (curved white arrow) will rest on the facial
ridge and the horizontal semicircular canal (open arrow). The cochleariform process is identifi ed (curved black arrow). B, A sculpted cortical bone
graft is placed as a dome over the stapes. This augments the height of the stapes and provides greater surface contact with the tympanic
membrane.
A
B
Figure
114-19. Techniques
for
sculpting the incus for a type IV tym-
panoplasty. A, The short process of the
incus is fl attened. The long process is
removed and a groove drilled for the
malleus handle. B, The long process
is fl attened, and the notch for the
malleus handle is on the superior
surface of the incus.
Materials such as polytetrafl uoroethylene, titanium,
Polycel with wire, and prefabricated prostheses of
hydroxyapatite are currently available.
We currently use either a titanium prosthesis or
one with a dense hydroxyapatite dome attached to a
shaft that can be trimmed easily. This is the same com-
position as the PORPs previously described. The TORP
is secured from the stapes footplate to the malleus in a
manner similar to that for a type IV tympanoplasty with
an incus (Fig. 114-21). A straight strut of hydroxyapatite
from the stapes footplate to the malleus neck has also
been used. The length must be shortened appropriately
to permit placement of this prosthesis. We have experi-
enced problems when the shaft was made of dense
hydroxyapatite. This ceramic material had a tendency
to shatter or crack when the length was shortened. This
problem can be remedied by holding the prosthesis
fi rmly between one’s thumb and forefi nger. The shaft
can then be shortened with a fi ne diamond burr drill
and drip irrigation. The shaft of the prostheses that we
currently use is a combination of hydroxyapatite and

Chapter 114
Ossicular Chain Reconstruction 1159
lateral chain fi xation. This may entail ankylosis of the
head of the malleus and body of the incus to the scutum,
immobility of the incudomalleal joint, or calcifi-
cation of the anterior malleus ligament restricting its
movement.
A recently described technique for liberating the
lateral ossicular chain addressed both the head of the
malleus and the body of the incus in the epitympanum.
A tympanomeatal fl ap is elevated beginning anterior to
the malleus and extended more superiorly to provide
access to the scutum. A laser was used to release the
areas of bony fi xation anterior to the malleus head and
the superior body of the incus. A small drill provided
greater space between the ossicles and surrounding
bone, and a small piece of thin Silastic sheeting was
placed to prevent refi xation.10 A problem with this tech-
nique is the possibility of contacting the ossicular chain
with the drill and causing sensorineural hearing loss.
Exposure of the epitympanum by removal of the scutum
may also result in retraction of the pars fl accida and
acquired cholesteatoma.
Our method for handling lateral chain fi xation
does not require as much exposure of the epitympa-
num, but the tympanomeatal fl ap must be designed to
be superior to the pars fl accida. The fl ap is elevated
anterior to the neck of the malleus. Palpation of the
malleus confi rms immobility of the lateral chain. It is
necessary to separate the incudostapedial joint to ensure
that limitation of movement is not being caused by
otosclerosis. The joint between the malleus and incus
is disarticulated with a curved pick to allow the entire
incus to be removed (see Video 114-10).
A
B
C
Figure 114-20. Type IV tympanoplasty with incus. A, The sculpted
short process of the incus is placed on the stapes footplate. Note the
small groove created for the chorda tympani nerve (shown in red).
The malleus is lifted laterally to permit the incus to be rotated into
position. B, The incus is secured between the footplate and the proxi-
mal malleus handle. The chorda tympani nerve provides additional
support. C, Intraoperative photograph of a type IV tympanoplasty
using the incus.
Figure 114-21. Type IV tympanoplasty from the footplate to the
malleus with an incus-stapes replacement prosthesis (total ossicular
replacement prosthesis).

1160
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Typically, fi xation of the malleus persists. A 1-mm
microdrill is used to divide the head of the malleus from
its handle at the neck of the malleus. Care must be
taken to avoid injury to the chorda tympani nerve,
which runs just medial to the neck of the malleus. This
technique creates a malleus handle that is mobile and
supported by its attachment to the tympanic membrane
and tensor tympani tendon. At this point the incus is
sculpted and interposed between the head of the stapes
and the handle of the malleus.
On rare occasion, the malleus handle alone may be
absent or defi cient. Diffi culty arises in situations in
which the malleus handle is shortened and the surgeon
must decide whether its length is adequate to use for
reconstruction. As a general rule, shortening beyond a
third of its length will probably preclude satisfactory
closure of the air-bone gap. This is a more diffi cult deci-
sion and a problem for reconstruction. Again, an incus
interposition can be performed. However, the incus
should be sculpted to maintain suffi cient height for
connecting the stapes superstructure to the grafted tym-
panic membrane. Improved transmission of tympanic
membrane vibration is achieved by directing the posi-
tion of the short process of the incus toward the center
of the membrane.
When the malleus handle is absent, we more fre-
quently use a synthetic prosthesis. In canal wall–up pro-
cedures, the remaining malleus head can be ignored.
If the stapes superstructure is present, a PORP is used
(Fig. 114-22). If the stapes superstructure is absent but
the footplate is present and mobile, a TORP is placed
(Fig. 114-23).
A unique situation arises when there is a total or
near-total perforation of the tympanic membrane and
all the ossicles are gone except for a mobile footplate.
The options for reconstruction are grafting the tym-
panic membrane and placing a TORP from the foot-
plate to the graft or placing a thick piece of Silastic
sheeting (0.04 inch) in the middle ear, grafting the
Figure 114-22. Type III tympanoplasty with a partial ossicular
replacement prosthesis when the malleus is absent (stapes to the
tympanic membrane or graft).
tympanic membrane, and staging the procedure. A
problem with the fi rst method is that the fi nal position
of the grafted tympanic membrane is not known. It may
heal in a more lateral or, more likely, a more medial
position. This creates potential uncertainty about how
to choose the appropriate length when placing the
prosthesis. The second method of staging will circum-
vent this problem, but the patient is committed to two
procedures. Unless there is minimal disease in the
middle ear and the ossicular reconstruction can achieve
the appropriate connection to the grafted tympanic
membrane, we opt for performing the grafting and
reconstruction in two stages.
On rare occasion, the malleus handle may be frac-
tured. Preoperative physical examination with pneu-
matic otoscopy can show hypermobility of the tympanic
membrane and malleus. If exploration and palpation
of the malleus can verify this pathologic condition,
reconstruction is performed either by incus interposi-
tion or with a PORP (see Video 114-11).
Problems with the Footplate
The most common cause of stapes footplate fi xation is
otosclerosis. If a fi xed footplate is identifi ed while
repairing a perforation of the tympanic membrane, it
is best to stage the reconstruction to avoid opening the
vestibule to a potentially contaminated middle ear
space. The same philosophy applies to extensive tympa-
nosclerosis of the footplate when a tympanic membrane
perforation or chronic otitis media is present. Tympa-
nosclerosis describes deposition of sclerotic plaque
after recurrent acute or chronic otitis media. This brittle
calcifi cation can restrict the tympanic membrane and
ossicular chain. Movement of the stapes footplate can
also be restricted by tympanosclerosis, which can be
confi rmed by gentle palpation of the stapes while
observing for a round window refl ex. If the tympanic
membrane is perforated, it should be repaired and the
operation staged for a subsequent procedure. Healing
is typically complete within 4 to 6 months, at which time
Figure 114-23. Type IV tympanoplasty with a total ossicular
replacement prosthesis when the malleus handle is absent (stapes
footplate to the tympanic membrane or graft).

Chapter 114
Ossicular Chain Reconstruction 1161
the footplate can be safely addressed. There is contro-
versy about how to best manage the stapes when it
becomes fi xed by this process. Options include not
intervening surgically and providing amplifi cation, per-
forming stapes mobilization, or removing the footplate
(stapedectomy) and placing a prosthesis. The concern
for mobilization is based on the possibility of refi xation
of the stapes by new plaque formation. If the status of
the ear disease is stable, both short- and long-term
hearing results are similar, thus indicating that refi x-
ation is unlikely to occur after mobilization. It has also
been shown when tympanosclerosis affects the foot-
plate, stapedectomy in a sterile middle ear is a safe and
effective procedure.11
In cases of chronic otitis media with cholesteatoma,
the stapes footplate may be eroded. If the vestibule is
opened inadvertently or by disease, OCR is warranted
at that time. It is rare to have such extensive disease yet
still have an intact incus. Therefore, reconstruction is
frequently done from the vestibule to the malleus, tym-
panic membrane, or graft (type Vb tympanoplasty).
The vestibule is covered with a thin but strong graft that
will support a prosthesis. The grafted tympanic mem-
brane may heal in a more medial position when exposed
to the negative pressure of the middle ear space. This
puts further demand on the support needed from the
oval window graft. If there is concern that the prosthesis
may sublux into the vestibule, a perichondrial graft is
harvested from the posterior conchal cartilage or the
tragus. Otherwise, true fascia is obtained from the tem-
poralis muscle. The graft is air-dried, cut to approxi-
mately 3 × 4 mm, and placed over the vestibule. The
shaft of the prosthesis is placed in the center of the graft
and the cap or dome is positioned under the malleus
handle or directly to the grafted tympanic membrane
(Fig. 114-24).
POSTOPERATIVE MANAGEMENT
The principles of care and instructions given to patients
postoperatively are similar to those after tympanoplasty.
Patients are instructed to keep the ear free of water and
avoid blowing the nose or other forms of Valsalva maneu-
vers. It is also recommended that signifi cant changes in
barometric pressure, such as during an air fl ight, be
avoided for several weeks postoperatively. Although dif-
fi cult to enforce, attempts are made to minimize vigor-
ous head movement in the postoperative period. Parents
are encouraged to restrict pediatric patients from engag-
ing in gymnastic or other excessive physical activities.
Less caution is needed for patients undergoing
OCR with an intact tympanic membrane. In this situa-
tion, signifi cantly compromised eustachian tube dys-
function is less likely to be present, so middle ear
aeration is more predictable. Patients with tympanic
membrane perforations more likely have compromised
eustachian tube function or middle ear disease that
must also be taken into consideration.
Patients with an intact tympanic membrane who
are undergoing OCR have silk packing placed sup-
ported by small cotton balls or Gelfoam. The packing
is removed 7 to 10 days postoperatively. If infl ammation
exists, topical ear drops are used for 1 week. The patient
is seen again in 4 weeks for examination of the ear and
audiometry testing. Patients requiring lateral graft
tympanoplasty (tympanic membrane reconstruction)
usually have double–silk rosebud packing in place. The
outer pack is removed in 1 week and topical eardrops
are prescribed. Postauricular Steri-Strips are removed
from the tympanic membrane graft donor site. The
second medial pack is removed 1 week later. Topical
drops are continued twice daily for 2 weeks. Patients are
seen a few weeks later to assess healing of the canal and
tympanic membrane. When the tympanic membrane
infl ammation has resolved and the membrane is thin
and mobile, audiometric testing is performed (see
Chapter 113).
Figure 114-24. Type Vb tympanoplasty with a total ossicular
replacement prosthesis. A graft covers the vestibule on which the shaft
of the prosthesis is embedded. The dome of the prosthesis tents the
grafted tympanic membrane. The malleus handle is absent.
PEARLS
• The surgeon should be prepared to manage all
reconstructive problems within the middle ear by
being familiar with the various techniques for OCR
should unanticipated problems arise.
• Careful palpation plus inspection of the tympanic
membrane and all ossicles is critical to decide
whether myringosclerosis and tympanosclerosis,
separately or in combination, have caused the
conductive hearing loss.
• To avoid restriction of movement, an interposed
ossicle or prosthesis should not be placed so that it
makes direct contact with the surrounding tympanic
ring or rests on the cochlear promontory.
• Reconstruction of the tympanic membrane and
ossicular chain demands a precise connection
between the drum and the stapes or footplate.
• In the postoperative period, should signifi cant
retraction of a tympanic membrane cause to it
drape over a prosthesis, placement of a
myringotomy tube may prevent extrusion.

1162
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
References
1. Zollner F: The principles of plastic surgery of the sound-conduct-
ing apparatus. J Laryngol Otol 69:637-652, 1955.
2. Wullstein H: Theory and practice of tympanoplasty. Laryngo-
scope 66:1076-1093, 1956.
3. Farrior JB: Classifi cation of tympanoplasty. Arch Otolaryngol
93:548-550, 1971.
4. Blevins NH: Transfacial recess ossicular reconstruction: Tech-
nique and early results. Otol Neurotol 25:236-241, 2004.
5. Goldenberg RA, Emmet JR: Current use of implants in middle
ear surgery. Otol Neurotol 22:145-152, 2001.
6. Gardner EK, Jackson CG, Kaylie DM: Results with titanium ossicu-
lar reconstruction prostheses. Laryngoscope 114:65-70, 2004.
7. Krueger WW, Feghali JG, Shelton C, et al: Preliminary ossiculo-
plasty results using the Kurz titanium prostheses. Otol Neurotol
23:836-839, 2002.
8. Chen DA, Arriaga MA: Technical refi nements and precautions
during ionomeric cement reconstruction of incus erosion during
revision stapedectomy. Laryngoscope 113:848-852, 2003.
9. Goebel JA, Jacob A: Use of Mimix hydroxyapatite bone cement
for diffi cult ossicular reconstruction. Otolaryngol Head Neck
Surg 132:727-734, 2005.
10. Seidman MD, Babu S: A new approach for malleus/incus fi xa-
tion: No prosthesis necessary. Otol Neurotol 25:669-673, 2004.
11. Teufert KB, De La Cruz A: Tympanosclerosis: Long-term hearing
results after ossicular reconstruction. Otolaryngol Head Neck
Surg 126:264-272, 2002.
PITFALLS
• Normal mobility must be confi rmed by palpation of
the malleus and incus because lateral ossicular chain
fi xation may be missed by an inexperienced surgeon.
• Reconstruction with a partially eroded stapes (type
III tympanoplasty) may not provide adequate
support of a partial ossicular replacement
prosthesis, and the reconstruction may need
to be taken medially to the footplate.
• Excessive manipulation of the stapes when
tympanosclerosis is present on the footplate may
result in fracture or unanticipated removal of the
stapes.
• A prosthesis will become displaced unless there is
adequate tension between its medial site of contact
(footplate or stapes) and the tympanic membrane
or intervening cartilage.
• Excessive removal of the scutum without the support
of a block of cartilage may result in retraction of the
attic and cholesteatoma.

Chapter 115
Mastoid Surgery
Michele St. Martin and Yael Raz
Mastoidectomy is one of the most common otologic
operations performed today. Indications for mastoidec-
tomy range from eradication of chronic infection or
cholesteatoma to approaches for various neurotologic
procedures. Mastoidectomy was fi rst described by Louis
Petit in the 1700s, although the concept did not gain
wider acceptance until espoused by von Troltsch and
Schwartze.1,2 Modifi cations of the original radical pro-
cedure followed. Bondy described a technique in 1910
in which mastoidectomy was performed and the poste-
rior canal wall removed while leaving the pars tensa and
ossicular chain intact.3 This procedure represents the
origin of today’s modifi ed radical mastoidectomy.
Although the terms canal wall down (CWD) mas-
toidectomy and modifi ed radical mastoidectomy are
sometimes used interchangeably, there are in fact dis-
tinctions between these various procedures. In modi-
fi ed radical mastoidectomy, usually reserved for attic
cholesteatomas, the mesotympanum is not entered.4
Removal of the canal wall externalizes the cholestea-
toma, and there is no need to elevate a tympanomeatal
fl ap to address disease in the mesotympanum or explore
the ossicular chain. When the middle ear is entered,
the procedure is referred to as tympanoplasty with CWD
mastoidectomy.
In 1958, the canal wall up (CWU) mastoidectomy
was popularized by William House.5 This procedure
attempted to avoid the common problems with radical
mastoidectomy, such as the lifelong requirement for
cleaning, a propensity toward caloric stimulation by
cold water or air, and restrictions on water exposure
while bathing or swimming. In addition, hearing results
improved with this procedure when compared with the
standard modifi ed radical mastoidectomy. CWU mas-
toidectomy has the advantage of preserving the normal
anatomy of the ear. Generally, there is no need for
maintenance of dry ear precautions. However, the
exposure granted by this approach is more restricted,
and it is technically more diffi cult to fully eradicate
cholesteatomas. Frequently, a second-look procedure is
required to rule out recurrent or residual disease, and
recurrent disease is more likely.
Removal of the posterior ear canal affords better
exposure that usually allows the cholesteatoma to be
addressed at a single stage. It is technically easier to fully
eradicate a cholesteatoma and the recurrence rate is
lower. Disadvantages of CWD procedures include a
more protracted postoperative healing period, the need
for indefi nite mastoid bowl care, a higher possibility of
recurrent otorrhea, poorer hearing results, and a need
for restricting water exposure.
The technique of removing and reconstructing the
posterior bony canal wall has been espoused by numer-
ous authors over the years.6-8 This technique theoreti-
cally provides the advantage of improved surgical
exposure with recurrence rates similar to those with
CWD procedures yet avoiding the disadvantages of an
open mastoid cavity. McElveen and Chung8 described
en bloc removal of the posterior bony canal wall with
an oscillating microsaw. In certain cases this technique
allows the surgeon to leave the ossicular chain intact,
thereby improving hearing results in comparison with
the use of partial or total ossicular reconstruction pros-
theses. The canal wall is then replaced and secured with
bone cement. Dornhoffer7 advocates removal of the
upper one third of the canal wall and reconstructs the
defect with cymba cartilage. Gantz and colleagues6 have
further modifi ed the technique to involve obliteration
of the mastoid with bone pâté and creation of an attic
block with bone chips to isolate the mesotympanum
from the attic and mastoid. This is done to reduce the
amount of nitrogen-absorbing epithelium to discour-
1163

1164
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
B
Figure 115-1. A, Erythema and
fl uctuance overlying the right
mastoid secondary to a subperios-
teal abscess. The patient had a
history of having undergone mas-
toidectomy
for
chronic
otitis
media. B, Incision and drainage
revealed extensive purulent debris.
Treatment included antibiotics
and revision mastoidectomy.
age the formation of a retraction pocket. Both authors
advocate second-look procedures when the canal wall
is reconstructed.
PATIENT SELECTION
Cortical mastoidectomy may be used for the treatment
of complicated acute otitis media, chronic otitis media
unresponsive to medical management, cholesteatoma,
neoplasm of the temporal bone, repair of cerebrospinal
fl uid (CSF) leaks, and decompression of the facial
nerve, as well as for exposure of deeper structures in
the temporal bone or posterior fossa (Fig. 115-1). The
decision to perform a CWU or CWD procedure must
be individualized to each patient. Important factors
include the location and extent of cholesteatoma, the
presence of defects in the bone of the posterior canal
wall, patient compliance, the presence of complications
of otitis media or cholesteatoma, the presence of malig-
nancy, the patient’s hearing status, and the general
medical condition of the patient.
Removal of the canal wall is indicated when it has
already been destroyed to a signifi cant degree by disease.
Although small dehiscences can be repaired, a large
erosion of the posterior canal wall by cholesteatoma is
often best dealt with by removing the remaining canal
wall. A fi stula in the horizontal semicircular canal (HSC)
(Fig. 115-2) is often best managed by leaving the skin
in situ and externalizing the matrix into a CWD mastoid
cavity. However, successful preservation of hearing has
been reported with complete removal of the matrix
overlying the dehiscence via a CWU technique.9 Scle-
rotic mastoids may necessitate the use of a CWD
approach (Fig. 115-3). When there is extensive choles-
teatoma that would require a second stage in a patient
with signifi cant comorbid disease, removal of the canal
wall can allow single-stage eradication of the disease.
Recurrent cholesteatoma despite multiple attempts at
CWU procedures is another indication for CWD mas-
toidectomy. Some authors would argue that cholestea-
toma in an only-hearing ear constitutes an indication
for a CWD procedure; however, this depends on the
extent of the cholesteatoma and the surgeon’s experi-
ence. Finally, poor compliance has frequently been
cited as an indication for CWD surgery.
Figure 115-2. Cholesteatoma in the left mastoid with dehiscence
of the horizontal semicircular canal (arrow). Matrix was left over
the dehiscent area and exteriorized with a canal wall down
mastoidectomy.
PREOPERATIVE EVALUATION
Before surgery, patients should undergo routine audi-
ometry, in addition to imaging studies as indicated. It
is never advisable to operate on an ear in which hearing
status is unknown. Preoperative audiometry will also
allow the surgeon to determine whether the better- or
worse-hearing ear is being operated on, which can
affect the operative strategy. Additionally, the surgeon
should note the presence and degree of any conductive
hearing loss, whose source should be sought at the time
of surgery.

Chapter 115
Mastoid Surgery 1165
Imaging studies are not mandatory before simple
mastoidectomy, but high-resolution computed tomog-
raphy (CT) allows assessment of the size and degree of
pneumatization of the mastoid cavity, as well as the
position of the tegmen mastoideum and sigmoid sinus.
In addition, one should evaluate for dehiscence of the
tegmen, facial nerve, or HSC. CT of the temporal bone
is usually performed before cochlear implantation to
assess the cochlea for congenital abnormality or
ossifi cation.
Barring extenuating circumstances such as severe
comorbid conditions, mastoidectomy is performed
under general anesthesia. Long-acting muscle relaxants
should be avoided to allow monitoring or electrical
stimulation of the facial nerve. Nerve monitoring is not
essential for initial mastoidectomy, and disposable
nerve stimulator units can be used if an unanticipated
need arises. Formal nerve monitoring should be avail-
able for patients undergoing mastoidectomy in the
setting of congenital ear anomalies, cochlear implanta-
tion, and revision mastoid surgery. Although electro-
physiologic nerve monitoring is not a substitute for
solid understanding of the course of the facial nerve
through the temporal bone, it is a useful tool, particu-
larly when an unanticipated anomaly is encountered. It
is our practice to monitor the facial nerve for all mas-
toidectomies. Even though this may not represent the
current standard of care, regular use of the nerve moni-
toring unit ensures familiarity with the equipment when
the need arises and makes sense from a medicolegal
standpoint as well.
Although evidence supporting the perioperative
administration of antibiotics to patients undergoing
mastoidectomy is limited, we routinely administer one
dose preoperatively (generally 2 g of cefazolin). This
may serve to reduce the incidence of postoperative
wound infection in a contaminated ear inasmuch as
most chronically draining ears harbor polymicrobial
infections. A special note should also be made regard-
ing preparation for revision mastoidectomy. Regardless
of whether the patient has previously been operated on
by the same or another surgeon, the operative report
should be reviewed to allow the surgeon to anticipate
potential pitfalls such as a dehiscent tegmen or facial
nerve. It is generally advisable to use facial nerve moni-
toring in all revision surgery because the potential for
dehiscence is greater in this group of patients. A pre-
operative CT scan is also recommended to delineate
changes related to the previous surgery. The revision
ear must be approached with caution because of the
obliteration of normal landmarks.
SURGICAL APPROACH
The patient is positioned supine on the operating
table, usually with the head at the foot of the bed to
allow the surgeon’s knees to fi t under the table. The
head is turned toward the side away from the operated
ear, while taking care to ensure that the contralateral
auricle is not being compressed. A small amount of
hair in the postauricular region is shaved to keep
the operating fi eld free of hair. The patient’s remain -
ing hair is then secured with tape to keep it out of
the fi eld. The postauricular crease is cleaned with
alcohol and injected with lidocaine with epinephrine.
If a facial nerve monitor is to be used, the electrodes
are placed at this time. The patient should be secured
to the table with straps because rotating the bed will
be necessary during the procedure. Bed controls
may be retained by the anesthesiologist or may be
wrapped in sterile plastic and placed on the bed for
the surgeon to control. The operating table is turned
either 90 or 180 degrees, depending on the surgeon’s
preference.
The operative fi eld is then prepared with povidone-
iodine (Betadine) and the ear canal is fl ooded with
preparative solution. Drapes are applied as the individ-
ual surgeon prefers; it is common to use a drape with
a plastic bag attached to collect irrigation fl uid and
prevent it from running onto the fl oor or the surgeon’s
lap. Suction and irrigation tubing is set up, the drill is
connected to the motor and foot pedal, and the instru-
ment table and operating microscope are brought into
position. Before the start of the procedure, the surgeon
should ensure that the microscope is properly balanced
and that the correct lens (usually 225 to 300 mm) is
attached.
The external auditory canal (EAC) and tympanic
membrane (TM) are examined under the operating
microscope. Cerumen or debris in the EAC is removed
while taking care to not cause bleeding.
Figure 115-3. Cholesteatoma (arrow) in a right contracted mastoid
cavity. A canal wall down mastoidectomy was planned from the
outset.

1166
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Four-Quadrant Injection
If a tympanomeatal fl ap is to be elevated in conjunction
with the mastoidectomy, injection of lidocaine with epi-
nephrine is performed at the bony-cartilaginous junc-
tion. The location of this junction can be estimated by
the medial-most aspect of the hair-bearing canal skin.
A 1.5-inch, 25-gauge needle with the bevel aimed toward
the bone is used to inject the four quadrants of the
canal. Light pressure is applied with the speculum to
create a cushion into which the local anesthetic is
injected and to direct the anesthetic medially. The
correct plane for injection offers a moderate amount of
resistance. The bony canal should be monitored to
ensure that the skin of the EAC has blanched down to
the TM without blebs.
Establishing a Vascular Strip
If a tympanomeatal fl ap is to be elevated in conjunction
with the mastoidectomy, a vascular strip is established
via an endaural approach at this point. The canal inci-
sion can be fashioned in an H shape (Fig. 115-4). Alter-
natively, the vascular strip (the lateral aspect of the “H”)
can be defi ned at this point and the tympanomeatal
fl ap (medial aspect of the “H”) deferred until exposure
of the canal is established via the postauricular incision.
The superior (12 o’clock) incision is placed in line with
the lateral process of the malleus. The superior and
inferior incisions are established with a fl ap knife or
Beaver blade. They are connected approximately
halfway between the annulus and the bony-cartilagi-
nous junction with an angled Beaver blade or a round
knife. A cotton ball soaked in topical adrenaline may
be inserted into the EAC for additional hemostasis if
necessary. Alternatively, the canal incisions can be fash-
ioned via the postauricular incision. In this case it is
useful to have cotton or Gelfoam in the medial ear
canal to provide resistance and protect the anterior
canal. A no. 11 blade is useful for this approach.
Planning the Postauricular Incision
The microscope is moved aside and a postauricular
incision is made with a no. 15 blade. The incision
extends from just superior and posterior to the root of
the helix down to the mastoid tip (Fig. 115-5). The inci-
sion should be placed several millimeters behind the
postauricular sulcus. When the mastoidectomy is per-
formed for access to deeper structures, a more poste-
rior incision is made to provide better exposure of the
sigmoid sinus and posterior fossa (Fig. 115-6). In young
children without a well-developed mastoid tip, the infe-
rior aspect of the incision is more posterior and is not
carried down as far to avoid injuring the facial nerve
(Fig. 115-7). The incision is carried down to the level
of the loose areolar tissue overlying the temporalis
fascia (Fig. 115-8). Identifi cation of this plane is facili-
tated by pulling laterally on the auricle as the incision
is made. Once the correct plane has been entered, the
knife blade is turned fl at and dissection is carried ante-
riorly toward the posterior EAC while taking care to not
Figure 115-4. Skin fl aps within the external auditory canal. An H-
shaped skin incision creates a laterally based vascular strip-type fl ap
and a medially based tympanomeatal fl ap.
Figure 115-5. Postauricular skin incision used in adults.
Figure 115-6. Skin incision used for transmastoid neurotologic
surgery.

Chapter 115
Mastoid Surgery 1167
enter the EAC at this point. Temporalis fascia may now
be harvested if TM grafting is anticipated. The inferior-
most aspect of the fascia harvest site should be placed
at least one centimeter above the linea temporalis. Pre-
serving the fascia at the linea temporalis allows more
solid closure of the superior periosteal incision.
The mastoid cortex is exposed by incising the peri-
osteum along the linea temporalis. A vertical limb is
extended from the posterior aspect of the periosteal
incision toward the mastoid tip. This can be performed
in a T fashion (Fig. 115-9) or in a “7” shape with the
apex positioned posterosuperiorly. A heavy Lempert or
Fisch periosteal elevator is used to free the cortex of
soft tissue. A large duckbill or Joseph elevator is used
to expose the posterior aspect of the EAC. If a vascular
strip was fashioned, it can now be elevated from bone
with a round knife. Tracheostomy tape or a 1/4-inch
Penrose drain can be placed through the canal and
brought out through the postauricular incision to
retract the ear anteriorly. Self-retaining retractors are
positioned and the surface landmarks of the mastoid
are identifi ed, including the spine of Henle, the cribri-
form area, and the linea temporalis (Fig. 115-10).
MacEwen’s (suprameatal) triangle provides an approxi-
mation of the location of the antrum (Fig. 115-11).
Intact Canal Wall Mastoidectomy
During the course of training in otologic surgery it is
imperative that the surgeon fi rst gain exposure to tem-
poral bone drilling in the laboratory. This invaluable
experience will allow familiarity with the anatomy and
equipment and facilitate safe and speedy mastoidec-
tomy in the operating room. Adequate irrigation is
essential for safe drilling. Constant fl ow prevents accu-
mulation of bone dust and thereby allows underlying
structures such as the tegmen to be identifi ed through
intact bone. Irrigation also prevents thermal injury to
underlying structures, such as the facial nerve. Either
suction irrigators or a self-irrigating drill can be used.
Generally, the drill is used in the forward direction and
drilling performed in a clockwise direction. Counter-
clockwise drilling in the “forward” setting can result in
“skipping” of the burr and potentially damage underly-
ing structures. The use of long smooth strokes parallel
to the underlying structures is safer and more effective
and provides better visualization. Larger burrs are safer
because they are less likely to plunge into critical struc-
tures, and the general rule is to use the largest burr that
can safely be used in that particular region. Drilling
typically starts with a large (6 mm) cutting burr that is
downsized to a 4-mm cutting burr more medially, after
entry into the antrum. A diamond burr should be used
for the fi nal thinning of bone overlying structures such
as the middle fossa tegmen or sigmoid sinus or when
drilling near the facial nerve. Drilling with a diamond
burr in the “reverse” direction can also control small
bleeders in the bone. The drilling trajectory should
parallel the underlying structure to be identifi ed to
reduce the chance of unintentional injury. During
the procedure it is important to “saucerize” the edges
Figure 115-7. Postauricular skin incision used in children.
Figure 115-8. Dissection of subcutaneous tissue to expose the tem-
poralis fascia and musculoperiosteal tissue overlying the mastoid
cortex.
Figure 115-9. Incisions used to expose the mastoid cortex.

1168
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
of the mastoid cavity to provide excellent visualization
of structures as they are identifi ed and help prevent
inadvertent injury. The exception to such saucerization
occurs in cochlear implant surgery, where a ledge of
bone laterally may help retain the coiled wire within the
mastoid cavity. In general, injury is best avoided by
clearly identifying vital structures such as the tegmen,
facial nerve, sigmoid sinus, horizontal canal, and incus.
In this manner, structures may be followed throughout
their course in the mastoid rather than risking injury
by haphazard identifi cation.
The initial drilling is often performed more readily
without use of the operating microscope. If the surgeon
prefers to use the microscope, a low-power view should
be used so that the entire mastoid cortex is in view. A
large cutting burr is used to begin drilling. The fi rst cuts
are made parallel to the linea temporalis and then pos-
terior to the EAC to create a 90-degree angle. The third
side of the triangle roughly approximates the course of
the sigmoid sinus posteriorly (Fig. 115-12). The mastoid
cortex is removed and the air cell system is exposed
(Fig. 115-13). Drilling proceeds with identifi cation of
the tegmen mastoideum through bone. The tegmen
will be visible as a pink color change in the bone supe-
riorly in the mastoid cavity; small vessels signal that dis-
section is close to the dura. The sound of the drill may
become higher pitched as the bone becomes thin. The
tegmen should remain covered with a thin layer of bone
to avoid injury to the dura or the future development
of an encephalocele. The posterior canal wall is thinned
while taking care to not enter the canal. Drilling pro-
ceeds along a wide plane to avoid drilling in a hole, and
the edges are saucerized so that one does not have to
drill unseen under a ledge. The deepest point of the
dissection should always be centered over the antrum,
approximated by MacEwen’s triangle. This will ensure
that the antrum with its critical landmarks will be
entered before reaching the plane of the facial nerve.
The sigmoid sinus will come into view posteriorly in the
mastoid cavity as the air cells are removed. Care must
be taken to remove disease present in the sinodural
B
Figure 115-10. A, Surgical landmarks on the lateral surface of the
temporal bone. B, Intraoperative view. The mastoid periosteum has
been incised and refl ected anteriorly to expose the linea temporalis
(white arrow), spine of Henle (arrowhead), and posterior aspect of the
external auditory canal (arrow).
MacEwen’s
triangle
Figure 115-11. MacEwen’s triangle (suprameatal triangle).
Figure 115-12. Location and direction of the initial bone cuts on
the mastoid cortex.

Chapter 115
Mastoid Surgery 1169
fi lling the antral air cell before being visible through
air because of the refractive properties of water. Care
must be taken to not touch the incus with the drill or
high-frequency sensorineural hearing loss may result.
The completed intact canal wall mastoidectomy should
be bounded by a thin but intact middle fossa plate, the
sigmoid sinus should be visible through intact bone, the
posterior wall of the EAC should be thinned yet intact,
the short process of the incus should be visible via the
aditus ad antrum, and the horizontal SCC should be
clearly identifi able (Fig. 115-15). Additional work may
be undertaken to clean Trautmann’s triangle, the
mastoid tip, and the retrofacial air cell tracts as neces-
sary. If cholesteatoma is present in the aditus ad antrum,
it may be necessary to disarticulate the incudostapedial
A
B
Figure 115-13. A, Removal of the mastoid cortex exposes the
mastoid air cell system. B, Intraoperative view.
angle, as well as in the mastoid tip. The digastric ridge
can be identifi ed posteroinferiorly; the cephalic edge
of this ridge provides an important landmark for the
course of the vertical portion of the facial nerve.
Körner’s septum will be present to a varying degree
just lateral to the mastoid antrum. Using the tegmen as
the superior landmark and the posterior canal wall as
the anterior landmark, Koerner’s septum is removed
and the antrum is entered (Fig. 115-14). This step high-
lights the importance of identifying the tegmen and
following it toward the antrum. Failure to identify the
tegmen may result in entering the antrum too low and
risking injury to the HSC and facial nerve. Drilling
through the septum will allow visualization of the HSC.
Once the antrum has been entered, cholesteatoma
matrix or mucosal disease should be removed so that
the HSC may be identifi ed. Once the HSC and tegmen
are clearly visible, the short process of the incus may be
identifi ed. The burr is downsized at this time and drill-
ing continues toward the root of the zygoma until the
incus is seen in the fossa incudis. It is helpful to tilt the
bed away from the surgeon to visualize the incus. Fre-
quently, the incus is visible through the irrigation fl uid
B
Figure 115-14. A, Körner’s septum. The lateral semicircular canal
and mastoid antrum lie under Körner’s septum. B, Exposure of the
mastoid air cells will vary depending on the nature of the surgery. For
this right-sided cochlear implantation, the posterior and superior
margins of the mastoidectomy have not been saucerized. The dome
of the horizontal semicircular canal (arrow) is identifi ed, and the short
process of the incus (arrowhead) is just visible in the fossa incudis.

1170
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
joint and remove the incus to facilitate more complete
resection of cholesteatoma medial to the canal wall by
working from both the mastoid cavity and the middle
ear. Umbilical tape may then be used in a “fl ossing”
technique to further remove squamous epithelium
from the antrum. This is done by passing the tape from
the mastoid cavity through the antrum to the middle
ear and out of the ear canal and then moving it back
and forth over the medial surface of the canal wall (see
Video 115-1). For certain procedures such as endolym-
phatic sac decompression or labyrinthectomy, it may be
desirable to identify the posterior semicircular canal by
removing the retrolabyrinthine air cells.
Drilling the Facial Recess
The facial recess is a triangle defi ned by the incus but-
tress, the facial nerve, and the chorda tympani. Opening
the facial recess allows access to the posterior mesotym-
panum, through which infl ammatory tissue or choles-
teatoma may be removed. This technique is also referred
to as a posterior tympanotomy and is used to create
access to the round window niche for drilling of the
cochleostomy during cochlear implantation. Safely
entering the recess relies on identifi cation of landmarks
for the facial nerve, including the incus, HSC, posterior
EAC, and digastric ridge (Fig 115-16). The posterior
EAC should be thinned laterally to medially to improve
visualization of the chorda tympani and facial recess; air
cells lateral to the plane of the incus should be removed.
The short process of the incus points to the second
genu of the facial nerve. Because it lies in the same
plane, the incus provides a very useful landmark for
identifi cation of the facial nerve. The HSC is another
critical landmark, and the second genu of the facial
nerve is just anterior and medial to the HSC. The digas-
tric ridge may also be useful; the cephalic edge of the
digastric ridge leads to the stylomastoid foramen and is
a good inferior landmark for the vertical portion of the
facial nerve.
A 2- or 3-mm diamond burr should be used for
drilling medial to the plane of the incus. Drilling should
commence just inferior to the short process of the
incus. The bridge of bone between the incus and the
recess is termed the incus buttress. Removal of bone
between the chorda tympani nerve and the vertical
facial nerve proceeds just below the incus buttress by
drilling parallel to the course of the facial nerve. Copious
irrigation prevents thermal injury and enhances visual-
ization through bone. Because the facial recess is larger
superiorly than inferiorly, it is safest to enter the recess
at its superior aspect (Fig. 115-17). Once the recess has
been entered, drilling can proceed medial to the chorda
tympani with caution to expand the view toward the
round window niche. Bone is thinned over the facial
nerve as necessary to provide a suffi cient view of the
middle ear (Fig. 115-18). A thin shell of bone is main-
tained over the nerve. Care must be taken to not allow
the shaft of the burr to contact the facial nerve because
such contact may cause thermal injury to the nerve.
After the middle ear has been entered, the recess can
be expanded to allow visualization of the incudostape-
dial joint, round window niche, promontory, and other
middle ear structures (Fig. 115-19).
Once drilling has been completed, the mastoid and
middle ear are irrigated thoroughly to remove bone
dust and debris. To close the postauricular wound in a
Figure 115-15. Completed intact canal wall mastoidectomy.
Figure 115-16. Landmarks for identifi cation of the facial nerve.
Figure 115-17. Anatomy of the facial recess.

Chapter 115
Mastoid Surgery 1171
CWU procedure, the mastoid periosteum should be
reapproximated to avoid unsightly retraction of postau-
ricular skin into the bony defect. We use 3-0 Vicryl
interrupted sutures for closure of periosteum. The deep
layer of skin is then closed with interrupted 3-0 or 4-0
Vicryl, depending on skin thickness. If a vascular strip
was elevated, a rolled Telfa strip coated with bacitracin
Figure 115-18. Removal of air cells to open the facial recess.
B
*
Figure 115-19. A, Exposure of middle ear structures through the
completed facial recess. B, Using the short process of the incus (aster-
isk), horizontal semicircular canal, and thinned posterior wall of the
external auditory canal as landmarks, the facial recess has been
entered. The cochlear promontory and the round window niche
(arrow) are visible.
ointment is used to stent the meatus. The superfi cial
layer of skin is then closed with running 5-0 fast-absorb-
ing plain gut suture. The incision is then dressed with
bacitracin ointment, Xeroform, Telfa, and a Glasscock
cup. The dressing may be removed 24 hours postopera-
tively; the patient is instructed to keep the operated ear
dry.
Again, special care must be taken in the case of
revision surgery. When making periosteal incisions and
entering the previously drilled mastoid cavity, bony
dehiscences may be encountered over the tegmen,
sigmoid sinus, or facial nerve. The surgeon must use
caution to prevent inadvertent injury to these struc-
tures. Often, cortical bone has regrown to some extent
in a previously drilled cavity. This must be removed to
provide adequate identifi cation of landmarks via the
same principles as described earlier.
Canal Wall Down Mastoidectomy
A problem-free mastoid bowl begins with a complete
cortical mastoidectomy to identify the tegmen mastoi-
deum, the short process of the incus if present, and the
HSC. Successful CWD mastoidectomy entails more than
simply drilling down the posterior wall of the EAC. It is
especially critical to saucerize the bony edges of the
mastoidectomy superiorly and posteriorly to allow the
surrounding soft tissue to collapse into the mastoidec-
tomy defect and ultimately create a smaller cavity.
Trouble spots that can result in a wet cavity include the
sinodural angle and the mastoid tip. Removal of the
mastoid tip is accomplished by identifying the digastric
ridge posteroinferiorly and following its cephalic edge
toward the stylomastoid foramen. Once this has been
completed, the bone lateral to the ridge can be removed
safely with the drill.
The posterior wall of the EAC is thinned and main-
tained as a useful landmark until the facial recess has
been opened. Sequentially smaller diamond burrs are
used to remove the bone between the chorda tympani
and the facial nerve. It is important to establish the
location of the facial nerve and maintain a thin layer of
bone over it. Identifi cation of the facial nerve is critical
for two reasons. First, the best way to protect the nerve
is to positively establish its location. Second, attempts at
protecting the nerve by leaving excess bone over it
result in a bony ledge, referred to as a “high facial
ridge,” which makes subsequent mastoid bowl care chal-
lenging and may ultimately require revision surgery
(Fig. 115-20).
Once the level of the nerve is identifi ed, the EAC
wall can be removed. The area to be drilled can be
conceived of as an anterior buttress (involving the tym-
panosquamous suture and lateral wall of the epitympa-
num or scutum), a posterior buttress (involving the
facial ridge), and the intervening bridge of bone (Fig.
115-21). Removal can be accomplished with a 4-mm
cutting burr (Fig 115-22). Frequently, disease that
necessitates CWD surgery also requires removal of the
incus, in which case it is preferable to proceed with
separation of the incudostapedial joint and removal of

1172
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
ing bone overlying the short process of the incus can
then removed with a pick or curette (Fig 115-23). Once
the canal wall has been removed, a smooth transition
must be established between the roof of the EAC and
the tegmen mastoideum at the anterior buttress. Simi-
larly, inferiorly the fl oor of the ear canal must be con-
toured such that there is a smooth transition to the
facial ridge at the posterior buttress. With an anteriorly
positioned sigmoid or low tegmen in the setting of a
contracted mastoid cavity, the canal wall must some-
Figure 115-20. High facial ridge. Excess bone has been left in
place lateral to the fallopian canal (arrow). This results in excess
buildup of cerumen and squamous debris, which is diffi cult to clear
in the offi ce.
Bridge
Anterior
buttress
Posterior
buttress
Figure 115-21. Buttresses and bridge of the posterior canal wall.
the incus before removing the canal wall. However, if
the ossicular chain is mobile and the ear pathology is
such that the incus can be kept in situ, a small bridge
of bone thinned to an eggshell thickness can be main-
tained over the short process of the incus. The remain-
Figure 115-22. Technique of removing the canal wall.
Figure 115-23. The last bridge of the posterior canal wall is
removed while using a curette to protect the ossicles and facial
nerve.

Chapter 115
Mastoid Surgery 1173
times be removed to permit safe identifi cation of deeper
structures. The mastoid cavity should then be inspected
to ensure that all diseased cells have been exenterated
with a smoothly contoured appearance (Fig 115-24).
Once the middle ear disease, if present, has been
addressed, the middle ear is packed with Gelfoam. The
previously harvested, pressed, and dried fascia can then
be used in an underlay fashion by draping the graft
onto the horizontal facial nerve superiorly and onto the
facial ridge posteriorly, followed by further packing
lateral to the drum and graft.
Bondy-Modifi ed Radical Mastoidectomy
A Bondy mastoidectomy refers to removal of the poste-
rior canal wall for attic disease without entering the
middle ear space. This technique may be used for attic
cholesteatoma in the setting of an intact ossicular chain
and normal or nearly normal hearing. The pars tensa
is not disrupted and the mesotympanum is not entered.
The epitympanic cholesteatoma is exteriorized through
an endaural approach. The anterior buttress is removed
and the canal wall is lowered to the level of the incus.
In this instance, the cholesteatoma matrix is left in situ
as the epithelial lining to the now exteriorized epitym-
panum (Fig. 115-25). A meatoplasty is necessary to
facilitate cleaning of the Bondy mastoid cavity.
Radical Mastoidectomy
When middle ear disease cannot be fully or safely
addressed during a CWD procedure, the surgeon may
elect to proceed with grafting of the TM with plans to
return for a second look. For example, when signifi cant
squamous debris is present in the oval window and the
surgeon believes that it cannot be removed adequately,
sometimes a second look 6 to 9 months later allows the
epithelium to form a pearl, which is more readily dis-
sected. However, in some instances when it is believed
that the middle ear disease is irreversible, radical mas-
toidectomy is performed. Drilling proceeds as for a
CWD mastoidectomy. The malleus, incus, and TM are
removed and hearing restoration is not attempted. The
middle ear mucosa is removed, including the lining of
the eustachian tube orifi ce. The eustachian tube is then
obliterated with muscle and bone. The epitympanum,
mesotympanum, and hypotympanum are thus all exte-
riorized into the EAC (Fig 115-26). A meatoplasty is
then performed.
Meatoplasty
A meatoplasty should always be performed when the
canal wall has been removed. This step is critical in
allowing access for mastoid bowl care in the offi ce. An
inadequate meatoplasty results in accumulation of
squamous debris or cerumen and contributes to chronic
otorrhea. To enlarge the meatus, the skin of the exter-
nal auditory meatus must be incised and cartilage
removed. On the other hand, excessive enlargement of
the meatus results in an unsightly cosmetic defect. The
meatoplasty should be sized so that it matches the cavity
and allows access to the most superior, posterior, and
inferior aspects of the mastoid bowl for cleaning. Some
contraction will occur in the postoperative period.
The meatoplasty begins with removal of a crescent
of conchal cartilage. A Senn retractor or double-
pronged skin hook is used to retract the auricle. The
Figure 115-24. Completed canal wall down mastoidectomy with
tympanoplasty.
Figure 115-25. Completed Bondy-modifi ed radical mastoid -
ectomy.

1174
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
middle or ring fi nger of the retracting hand, when
placed within the concha laterally, can provide resis-
tance as the subcutaneous tissue overlying the concha
is incised via the postauricular approach. The underly-
ing cartilage is exposed to its medial rim (Fig 115-27).
The conchal cartilage is then incised with a no. 15
blade. A round knife or Freer elevator can be used to
elevate the cartilage from the conchal skin, and this
segment of cartilage is removed (Fig. 115-28). A no. 15
blade is then placed in the auditory canal, and 12- and
6-o’clock incisions are made through the canal skin and
Figure 115-26. Completed radical mastoidectomy.
Figure 115-27. The conchal cartilage is exposed up to the medial
edge of the cartilage at the bone-cartilage junction of the external
auditory canal.
subcutaneous tissue (Fig. 115-29). Two or three 3-0
Vicryl sutures are placed in the subdermal tissue and
used to anchor the posterior meatal skin to the deep
periosteal tissue posterior to the mastoidectomy. When
tied, these sutures should establish an open meatus that
matches the size of the mastoid cavity (Fig 115-30). The
attached vascular strip is pulled posteriorly by the stay
sutures to line the lateral and posterior aspects of the
mastoid cavity. The meatoplasty is stented for 10 to 14
days with a roll of bacitracin-coated Telfa. The mastoid
periosteum is not reapproximated. Closure of the post-
auricular skin incision then proceeds as for intact canal
wall procedures.
Postoperative Management
The patient is instructed to wear a Glasscock ear dress-
ing for 2 days postoperatively. After removal of the
dressing, the patient may shower but is instructed to
keep the ear dry. Bacitracin is applied to the postauricu-
lar incision twice a day for 1 week. The fi rst postopera-
Figure 115-28. A Freer elevator is used to elevate the conchal car-
tilage from the overlying skin.
Figure 115-29. A superior canal incision is made and connected
to the postauricular exposure to create a long Koerner fl ap.

Chapter 115
Mastoid Surgery 1175
tive visit occurs in 7 to 10 days, at which time the incision
is checked and any packing in the EAC is removed. If
a meatoplasty has been performed, the stent is left in
place for 10 to 14 days. The second follow-up visit takes
place 3 to 4 weeks later. Frequently, the TM will be
healed suffi ciently to allow an early postoperative audio-
gram at this time. Thereafter, the patient may be moni-
tored routinely per the surgeon’s usual practice. CWD
mastoidectomies require more frequent follow-up for
the fi rst few months after surgery until the bowl is lined
with healthy epithelium. During this healing period,
silver nitrate cautery may be necessary to address granu-
lation tissue.
COMPLICATIONS
Potential complications of tympanomastoidectomy
include TM perforation, altered taste, vertigo, sensori-
neural hearing loss, facial paralysis, injury to the tegmen
or underlying dura, iatrogenic injury to the ossicular
chain, hemorrhage from injury to the sigmoid sinus,
and inadvertent entry into the EAC. An intact TM may
be perforated during elevation of the tympanomeatal
fl ap in a tympanomastoidectomy, particularly if the TM
is atrophic or tethered to middle ear structures. If per-
foration should occur, the torn TM should be grafted
at the end of the procedure. Stretching or cutting the
chorda tympani nerve can lead to dysgeusia; symptoms
of altered taste often resolve within several months if it
does occur.
Vertigo or sensorineural hearing loss (or both) may
result from inadvertently dislocating the stapes or
from entering the HSC. Touching the incus with the
drill during the mastoidectomy may also result in high-
frequency sensorineural loss. If the patient shows evi-
dence of severe vertigo on awakening, inpatient
admission may be required for control of nausea and
vomiting and supportive care. Consideration should be
given to high-dose corticosteroids if sensorineural
hearing loss has occurred. Tuning fork testing per-
formed in the postoperative care unit will help diagnose
sensorineural loss, and an urgent audiogram may be
obtained in cases with signifi cant concern.
The facial nerve may be injured by direct trauma,
either from the burr or from instrumentation of a
dehiscent nerve, or by thermal injury if the rotating
shaft of the burr comes in contact with a thin layer of
bone overlying the nerve. The patient’s facial nerve
function should always be evaluated in the postopera-
tive care unit. If facial weakness is discovered that did
not exist preoperatively, the surgeon should observe
the patient until any local anesthesia has worn off to
ensure that the palsy is not due to infi ltration of the
nerve by local injection. In addition, if a compressive
dressing or ear packing has been used, it should be
loosened immediately. If the weakness persists, the
surgeon should note whether it is partial or complete
paralysis. If partial, the patient should be treated with
high-dose corticosteroids and monitored closely for the
development of complete paralysis. In the case of imme-
diate complete paralysis, the appropriate response
depends on whether the surgeon is confi dent that the
nerve has been visualized during surgery and left intact.
If so, the patient should be treated with steroids and
observed. If the nerve was not visualized, the patient
should undergo electroneuronography and temporal
bone CT. If indicated by CT or electrical testing, re-
exploration of the ear should be undertaken for decom-
pression or anastomosis. Strong consideration should
be given to consultation with another surgeon because
anxiety can run high when faced with this signifi cant
complication and affect one’s ability to best deal with
the situation.
Bony defects in the tegmen result from overly
aggressive drilling along the roof of the mastoid cavity;
on occasion, the dura is violated and a CSF leak results.
If the bony defect is small (<1 cm) and the surgeon is
certain that the dura has not been injured, the defect
need not be repaired because the risk of encephalocele
is low. Alternatively, larger bony defects or injury to
dura necessitate repair, which may be accomplished at
the time of surgery by using fascia or muscle to graft
over the defect from below. Temporalis muscle may
also be rotated into the cavity to cover the defect.
Any of the ossicles may be dislocated during surgery
on the attic or mesotympanum, although the incus and
stapes are more at risk. When dissecting cholesteatoma
or infl ammatory tissue off the ossicles, care must be
taken to not use undue force. Dissection on the stapes
should proceed in a posterior-to-anterior direction to
take advantage of the countertraction provided by the
stapedius tendon.
If signifi cant bleeding is encountered because of a
large emissary vein or injury to the sigmoid sinus, hemo-
stasis can often be achieved by applying pressure over
the bleeding site with Gelfoam soaked in epinephrine.
Alternatively, Surgicel may be placed over the injury
and held in place until the bleeding is controlled.
Finally, during a CWU mastoidectomy, the EAC
may inadvertently be violated as the posterior canal
wall is thinned. To prevent retraction of skin into the
mastoid cavity and subsequent EAC cholesteatoma, the
Figure 115-30. Stay sutures are used to properly match the size of
the meatus to the size of the mastoid cavity.

1176
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
surrounding skin should be elevated and the defect
covered with fascia in an underlay technique. Larger
bony defects should be repaired with conchal or tragal
cartilage as well to reinforce the skin.
References
1. Von Troltsch AF: Lehrbuch der Ohrenheilkunde mit Einschluss
der Anatomie des Ohres. Leipzig, Germany, Foegel, 1873.
2. Milstein S: The history of mastoid surgery. Am J Otol 1:174-178,
1980.
3. Bondy G: Totalaufmeisselung mit Erhaltung von Trommelfell und
Gehorknockelchen. Monatsschr Ohrenheilk 44:15, 1910.
4. Sheehy JL: Surgery for chronic otitis media. In English GL (ed):
Otolaryngology. Philadelphia, JB Lippincott, 1989.
5. Sheehy JL, Patterson ME: Intact canal wall tympanoplasty with
mastoidectomy. A review of eight years’ experience. Laryngoscope
77:1502-1542, 1967.
6. Gantz BJ, Wilkinson EP, Hansen MR: Canal wall reconstruction
tympanomastoidectomy with mastoid obliteration. Laryngoscope
115:1734-1740, 2005.
7. Dornhoffer JL: Retrograde mastoidectomy with canal wall recon-
struction: A follow-up report. Otol Neurotol 25:653-660, 2004.
8. McElveen JT Jr, Chung AT: Reversible canal wall down mastoidec-
tomy for acquired cholesteatomas: Preliminary results. Laryngo-
scope 113:1027-1033, 2003.
9. Copeland BJ, Buchman CA: Management of labyrinthine fi stulae
in chronic ear surgery. Am J Otolaryngol 24:51-60, 2003.
PEARLS
• The use of long drilling strokes in a direction
parallel to important structures such as the facial
nerve, tegmen, and sigmoid sinus facilitates
identifi cation and minimizes injury to these
structures.
• Constant irrigation prevents bone dust from
obscuring underlying structures and prevents
thermal injury, particularly to the facial nerve.
• Important structures should always be positively
identifi ed rather than relying on avoidance to
prevent injury.
• Removal of the mastoid tip, lowering of the facial
ridge, removal of air cells at the sinodural angle,
and an adequate meatoplasty can prevent the need
for revision surgery in CWD mastoidectomy.
• When performing CWD procedures, the canal wall
should be left intact until all the landmarks have
been identifi ed—the thinned canal wall serves as an
additional landmark that can be followed medially
to identify the chorda tympani nerve and enter the
facial recess.
PITFALLS
• Touching the ossicles with the high-speed drill may
result in sensorineural hearing loss.
• Facial nerve injury may occur through failure to
positively identify the nerve or as a result of bony
dehiscence.
• Inadvertent injury to the tegmen and underlying dura
may result in CSF leak or encephalocele, or both.
• Breaches of the posterior EAC wall during CWU
procedures should be repaired by elevating the canal
skin and covering the defect with fascia; cartilage
may be added for larger defects.
• Inadequate meatoplasty is probably the most
common reason for diffi culties in CWD surgery—a
large meatoplasty should be created and stented for
at least 10 days postoperatively.

Chapter 116
Congenital Malformations
of the Middle Ear
Arpita I. Mehta and Yael Raz
The various manifestations of middle ear malforma-
tions provide an interesting clinical challenge for physi-
cians. In the adult population undergoing exploratory
tympanotomy for presumed otosclerosis, such anoma-
lies may be unexpected. The otologic surgeon must be
prepared to deal with unanticipated fi ndings such as
partial or complete absence of components of the ossic-
ular chain, lateral chain fi xation, a persistent stapedial
artery, abnormal course of the facial nerve, or absence
of the oval window. Knowledge of the embryologic
origins of middle ear structures is useful in understand-
ing the various anomalies that arise and anticipating
associated defects. For example, branchial arch anoma-
lies may accompany defects of the ossicular chain, which
is derived in part from the fi rst two arches. Additionally,
the stapes and facial nerve develop simultaneously.1 An
inferiorly displaced facial nerve may prevent contact
between the developing stapes and the inner ear,
thereby inhibiting further development of the stapes
and preventing proper induction of the oval window.2
Thus, an abnormal course of the facial nerve should be
suspected when anomalies of the stapes or oval window
are encountered.
Middle ear malformations should always be con-
sidered in the differential diagnosis for children with
conductive hearing loss. Congenital ear deformities are
estimated to occur in 1 in 11,000 to 15,000 individu-
als.3,4 Isolated anomalies of the middle ear with a normal
auricle and external auditory canal account for only a
small percentage of these deformities.5 Approximately
one quarter of congenital middle ear anomalies occur
in the setting of a disorder such as Treacher Collins,
Klippel-Feil, or branchio-oto-renal syndrome.6 In an
adult patient, congenital middle ear anomalies should
be suspected when hearing loss has been present since
childhood, thus making otosclerosis unlikely, and the
history is negative for otitis media.
This chapter focuses on the operative management
of isolated middle ear malformations. Management of
aural atresia is addressed in Chapter 111, and microtia
repair is discussed in Chapter 85.
PATIENT SELECTION
Depending on the nature of the middle ear anomaly,
the resultant hearing loss can be purely conductive or
mixed, unilateral or bilateral, and range from mild to
profound. Whereas bilateral middle ear anomalies are
often recognized in early childhood, in the past, unilat-
eral middle ear abnormalities were frequently not iden-
tifi ed until a school-aged child received a screening
hearing test. However, with the recent adoption of uni-
versal newborn hearing screening tests by most states,
the age at identifi cation of children with developmental
middle ear abnormalities can be expected to decrease
signifi cantly. Non–otitis-related unilateral conductive
hearing loss should be managed conservatively until the
child is at least 5 to 7 years of age. The age at which
surgery is appropriate must be tailored to each patient
and depends on eustachian tube function and the reli-
ability of the results of behavioral audiometric testing.
In the setting of signifi cant bilateral hearing loss, ampli-
fi cation should be pursued as soon as possible. Given
the signifi cant possibility that stapedial fi xation will be
encountered, it is not advisable to proceed with surgery
while there is a signifi cant risk of otitis media. Stapes
surgery at an early age presents an unnecessary risk of
perioperative labyrinthitis with resultant sensorineural
hearing loss. Surgery is not warranted unless the hearing
loss is in the moderate to severe range, with a speech
1177

1178
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
reception threshold greater than 35 and a pure-tone
average greater than 30 dB.7 Once the child reaches an
age when hearing can be reliably tested and is beyond
the time period of increased vulnerability to otitis
media, stapes surgery can be performed quite safely.8,9
Conductive hearing loss should always be confi rmed
with tuning fork testing before proceeding with surgical
intervention. Children who are unable to respond reli-
ably to tuning fork testing will probably not prove reli-
able for behavioral air and bone conduction testing. It
is safer to provide amplifi cation until the audiometric
test results are reliable. Surgery for conductive hearing
loss in the setting of a normally formed ear canal is an
elective procedure. The hearing loss can be effectively
managed with hearing aids, and it is imperative that
parents understand the alternatives to surgery before
proceeding with exploration in a pediatric patient, par-
ticularly for anomalies that are associated with signifi -
cant risk to the facial nerve or inner ear (i.e., congenital
stapedial fi xation or absence of the oval window). Some
authors argue that it is not appropriate to proceed with
surgical management of unilateral conductive hearing
loss not attributable to otitis media until the child can
participate in the informed consent process.
When stable conductive hearing loss has been doc-
umented in children, the possibility of congenital fi xa-
tion of the stapes must be entertained. This disorder is
caused by failure of differentiation of the lamina stape-
dialis into the annular ligament, which results in anky-
losis of the stapes footplate. The chief risk associated
with fenestration of the footplate in such cases is the
occurrence of a perilymphatic gusher. Although the
true incidence of a perilymphatic gusher is unknown,
it has been reported to be signifi cantly higher than the
incidence seen in otosclerosis (<1%).10 Congenital sta-
pedial footplate fi xation can occur in the setting of an
X-linked familial disorder characterized by progressive
mixed hearing loss associated with inner ear anomalies,
including Mondini’s malformations and dilatation of
the internal auditory canal (Fig. 116-1). The excessive
fl ow of perilymph that follows opening of the footplate
in these children is believed to be due to either a patent
cochlear aqueduct or a defect in the lateral end of a
dilated internal auditory canal. Mutations in the gene
encoding the POU3f4 transcription factor have been
implicated in at least one form of X-linked progres -
sive mixed hearing loss.11,12 The presence of mixed
loss, particularly in males, should alert the surgeon
to a potential gusher. Although some surgeons have
obtained successful hearing results, it is generally con-
ceded that computed tomography (CT) evidence of a
widened cochlear aqueduct or internal auditory canal
should be considered a relative contraindication to
surgery.
Superior canal dehiscence syndrome, in which the
bone overlying the superior semicircular canal is absent,
can be manifested as conductive hearing loss and
probably accounts for a fraction of the patients whose
air-bone gap fails to close after stapes surgery.13 The
conductive hearing loss persists postoperatively because
it is not secondary to stapes fi xation. Rather, the con-
ductive loss is due to bony defi ciency in the otic capsule
and the resultant “mobile third window.” This problem
can be avoided by confi rming the absence of a middle
ear refl ex before proceeding with middle ear explora-
tion. Ossicular fi xation should result in an elevated or
absent stapedial refl ex, whereas in superior canal dehis-
cence syndrome, this refl ex will be preserved. Another
situation in which caution is advised is an adult patient
with conductive hearing loss and a history suggestive of
Meniere’s disease. Stapes surgery in the setting of endo-
lymphatic hydrops is associated with a higher risk of
sensorineural hearing loss and dizziness, which may be
related to the proximity of the distended saccular epi-
thelium to the stapes footplate.
PREOPERATIVE EVALUATION
History and Physical Examination
A thorough history should be elicited from the patient
or caregivers, or both. In children it is important to
note the onset of symptoms to help differentiate a con-
genital disorder from the juvenile onset of an acquired
disorder. Prenatal history, school performance, social
interactions, and language development should be
assessed. Previous otologic history, particularly the fre-
quency of otitis media and requirement for pressure
equalization tubes, should be assessed. The history will
often be limited in a pediatric patient, but when possi-
ble, it should address otologic symptoms such as otalgia,
otorrhea, tinnitus, or vertigo. A careful review of symp-
toms may reveal associated cardiac, renal, or other
medical problems suggestive of a syndromic diagnosis.
A family history of hearing loss is important to
address.
Figure 116-1. Computed tomography scan of a dysplastic inner ear
showing a dilated and tortuous internal auditory canal (small arrow,
internal auditory canal; large arrow, Mondini’s deformity).

Chapter 116
Congenital Malformations of the Middle Ear 1179
Physical examination should include inspection
for other developmental anomalies, particularly those
originating in the fi rst and second branchial arches.
Children with disorders affecting the mandibular arch
(i.e., Treacher Collins syndrome) are at risk for airway
compromise, so appropriate precautions must be taken
in the operating room. Identifi cation of even minor
fl aws in the pinna or surrounding area, such as preau-
ricular tags and pits, should alert the surgeon to a
higher probability of an anomaly. Conductive hearing
loss in a normal-appearing ear in a patient with contra-
lateral atresia or microtia should be assumed to repre-
sent an abnormality of the middle ear. Occasionally,
ossicular anomalies, especially those involving the
malleus, may be visible on otomicroscopy. However,
most often the otoscopic examination is unremarkable.
Weber and Rinne tests must always be included and the
results should be consistent with the audiometric
fi ndings.
Audiologic Testing
Identifi cation and treatment of signifi cant hearing loss
in the pediatric population are critical for appropriate
development of speech and language. Assessment of
hearing loss can be challenging in this population
because of the limitations inherent in patient histories
and the questionable reliability of audiologic testing.
Because conductive hearing loss is so commonly associ-
ated with otitis media, hearing loss caused by an ossi-
cular malformation is occasionally inappropriately
attributed to recurrent infection and eustachian tube
dysfunction. It is important to confi rm closure of the
air-bone gap once a child’s middle ear has been venti-
lated to avoid overlooking a congenital anomaly.7
Audiologic testing is performed in an age-appropriate
fashion. Children as young as 2 years old can be trained,
with repeated testing, to respond reliably to masked air
and bone conduction tests.7 Tympanometry should be
included as well because even the most astute clinician
can sometimes miss a middle ear effusion, particularly
in a poorly cooperative child. When appropriate, acous-
tic refl exes should be determined as well.
Progressive versus Stable Hearing Loss
An important determination in children is the distinc-
tion between progressive and stable hearing loss. Pro-
gressive conductive loss in the absence of signifi cant
otoscopic fi ndings is most often compatible with a diag-
nosis of childhood otosclerosis. Alhough unusual, espe-
cially before the age of 12 years, this condition may be
handled with the same surgical techniques as those
used to perform stapes surgery in adults (see Chapter
117). Several authors have attested to the safety of stapes
surgery in children.14 Congenital fi xation of the stapes,
in contrast, carries some increased risk for sensorineu-
ral deafness and requires additional preparation.
Otosclerosis may be diagnosed by documentation of
progressive impairment in hearing, whereas congenital
stapedial fi xation is stable. The family history may
provide an important clue in establishing this diagnosis,
and CT may identify characteristic radiolucency of the
otic capsule.
Imaging
Developments in radiologic evaluation of the temporal
bone have facilitated the management of middle ear
malformations. Careful evaluation of radiographic
information will allow the surgeon to assess the chance
of successful hearing restoration and provide specifi c
details for informed patient consent. Dilatation of the
internal auditory canal or enlargement of the cochlear
aqueduct can be identifi ed preoperatively and may lead
the surgeon to recommend conservative management
(Fig. 116-1). All pediatric patients with conductive
hearing loss not attributable to otitis media merit high-
resolution temporal bone CT. Radiologic imaging is
not indicated in an adult patient undergoing explora-
tion for conductive hearing loss unless there is strong
suspicion of a congenital middle ear malformation or
neoplasm.
SURGICAL APPROACH
Most of the operative techniques used to correct middle
ear malformations are similar to or modifi cations of
tympanoplasty methods. Procedures that are successful
in middle ear reconstruction after eradication of
chronic disease are highly adaptable in dealing with a
great variety of congenital ossicular problems. Various
approaches to reconstruction of the conductive appa-
ratus can be used, with technical details varying accord-
ing to surgeon preference and the individual patient’s
anatomy. Thus, a “cookbook” approach to surgical cor-
rection of middle ear abnormalities can be diffi cult,
and surgeons will ultimately develop their individual
preferences for materials and reconstructive approaches.
Materials must be available in the operating room to
adequately replace or reconstruct any ossicular abnor-
mality. Incus sculpting is often a viable option in these
cases. An assortment of partial and total ossicular
replacements, as well as stapes prostheses, should also
be kept on hand. The Skeeter drill should be available
for incus sculpting, as well as possible drill outs for
thickened stapes footplates. Depending on surgeon
preference for stapes procedures, CO2, argon, or other
otologic lasers can provide less traumatic access to the
vestibule.
Regardless of the material chosen for reconstruc-
tion, the basic principles for reconstructing the middle
ear conductive apparatus include the use of appropri-
ately sized material in an adequately aerated middle ear
and a stable, columnar mechanism for conduction of
sound from the most lateral mobile structure (capitu-
lum or footplate) to the malleus or tympanic mem-
brane. Appropriate sizing of the reconstruction requires
patience and experience—short prostheses are prone
to slippage, whereas prostheses that are excessive in
length may sublux into the vestibule. The more angled
the reconstruction, the higher the chance for slippage.
Some prosthetic materials (i.e., titanium) require place-
ment of a small cartilage graft between the prosthesis

1180
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
and the tympanic membrane to prevent extrusion. Car-
tilage can be harvested from the tragus or concha via a
small incision. With a postauricular incision, often a
necessity in a pediatric patient, conchal cartilage is pre-
ferred because it can be harvested without a second
incision.
Anesthesia
In an adult it is preferable to perform exploratory
surgery under local anesthesia with intravenous seda-
tion whenever possible. Local anesthesia results in the
advantages of less bleeding, cost-effectiveness, postop-
erative analgesia, quicker patient mobilization, reduced
risk for aspiration, the ability to test hearing during
surgery, and immediate feedback regarding potential
vestibular injury.15 Young children require general
anesthesia. The surgeon must balance the increased
latitude provided by deeper anesthesia with the loss of
feedback information from the patient. If the course of
the facial nerve is found to be signifi cantly aberrant on
preoperative CT, general anesthesia with the use of a
facial nerve monitor may prove safer than local anes-
thesia with sedation.
Elevation of a Tympanomeatal Flap and
Exploration of the Middle Ear
Regardless of the mode of anesthesia, four-quadrant
injection of a local anesthetic in combination with
epinephrine is useful in minimizing bleeding during
elevation of the tympanomeatal fl ap. When planning
the tympanomeatal fl ap, one must always ensure that
the superior limb of the tympanomeatal fl ap extends
far enough superiorly to allow considerable removal of
the scutum in the case of a lateral ossicular chain pro-
cedure (Fig. 116-2). In adults a transcanal approach
typically provides adequate exposure. Younger children
may require a postauricular approach. Once the middle
ear is entered, each component of the ossicular chain
is palpated independently. It is important to recognize
that multiple defects may coexist—as highlighted by the
increased incidence of lateral ossicular chain fi xation
identifi ed on re-exploration after unsuccessful stapes
surgery.14
Anticipating an Aberrant Facial Nerve
In approaching a malformed ear, identifi cation of the
facial nerve is critical. The preoperative CT scan should
be reviewed carefully and the course of the nerve delin-
eated. The surgeon must be familiar not only with the
usual landmarks for the tympanic segment of the facial
nerve but also with the most common aberrant courses.
Dehiscence of the horizontal portion of the facial nerve
is such a common fi nding that it may be considered a
normal variant. Usually, the surgeon need only recog-
nize the condition and avoid trauma to the nerve. Over-
hanging of the nerve may, on the other hand, present
some diffi culty in accessing the oval window (Fig.
116-3). The facial overhang can be managed by gentle
retraction of the nerve while working in the oval window
area. A stapes prosthesis may be placed in close contact
with the nerve and may occasionally even cause a small
indentation in the epineurium. When this abnormality
is combined with shortening of the long process of the
incus, the situation is more diffi cult. It can usually be
solved by bending a crimp-on prosthesis to fi t around
the facial nerve (Fig. 116-4).
The facial nerve may subdivide into several branches
and in some cases may not traverse the bony fallopian
canal. Occasionally, its course across the oval window
prevents surgical access to the vestibule; to avoid injury
to the facial nerve, these cases should be abandoned in
favor of amplifi cation. Anterior deviation of the vertical
portion of the facial nerve is usually associated with
congenital aural atresia, but it may exist alone; it is
identifi ed as it courses across the hypotympanum. In a
Figure 116-2. Correct incision for middle ear exploration to evalu-
ate for conductive hearing loss.
Facial nerve
Figure 116-3. Dehiscent and overhanging facial nerve.

Chapter 116
Congenital Malformations of the Middle Ear 1181
series of 94 patients with congenital malformations of
the ear (50 of whom had anomalies confi ned to the
middle ear), Jahrsdoerfer reported an aberrant course
of the facial nerve in 12 cases.16 Most commonly, the
tympanic segment of the nerve was displaced inferiorly
and obscured the oval window. The nerve was often
dehiscent in the middle ear. The free-fl oating facial
nerve was mistaken for fi brous tissue in two cases previ-
ously operated on elsewhere and resulted in injury to
the nerve.
Modifi cations in the anatomy of the chorda tympani
nerve are common. This nerve may be larger or smaller
in diameter than normal and may be displaced inferi-
orly or superiorly relative to the posterosuperior canal
wall. On occasion, the chorda tympani may enter the
middle ear from a position lateral to the annulus of the
tympanic membrane. In this situation, the nerve travels
beneath the skin of the posterior canal wall for a short
distance and may be injured on elevation of the tympa-
nomeatal fl ap.
In cases in which a middle ear malformation is sus-
pected, intraoperative facial nerve monitoring provides
a defi nite advantage. Unfortunately, these defects are
often not suspected preoperatively. When unexpected
questions arise regarding the location of the facial
nerve, disposable stimulators can be used. If the intra-
operative fi ndings suggest that facial function may be
jeopardized, the procedure should be terminated,
appropriate imaging studies obtained, and formal nerve
monitoring used in a subsequent procedure.
The following discussion reviews middle ear anom-
alies in accordance with the likelihood of their appear-
ance. Congenital anomalies of the incus or malleus in
the setting of a mobile stapes (i.e., epitympanic fi xation
or ossicular discontinuity) are quite amenable to recon-
struction, as is congenital fi xation of the stapes foot-
plate in the setting of a normal incudomalleolar
complex. However, when stapedial fi xation occurs in
the context of an abnormal lateral chain, the chance
for closure of the air-bone gap drops signifi cantly.14,17,18
Aplasia or severe dysplasia of the oval or round window
carries an even worse prognosis for restoration of
hearing, and controversy exists regarding whether
reconstruction should be attempted at all in this situa-
tion. However, some authors have reported successful
reconstruction of even these severe malformations.16
Defects of the Stapes
Although abnormalities of the stapes are the most fre-
quently encountered of all ossicular defects, the varia-
tions seen are most often minor and inconsequential.
Differences in the tilt and shape of the superstructure
of the stapes are common. Hough has comprehensively
reviewed these many variations.19 The size of the obtura-
tor foramen and the shape of the crura often vary. Even
defects as signifi cant as a monopedal stapes are clini-
cally unimportant unless hearing loss is present (Fig.
116-5).
Abnormalities requiring surgical correction are
related to stapes fi xation and incomplete articulation
of the stapes with the incus. Bony bridges may connect
the superstructure to the promontory (Fig. 116-6) or
the facial nerve, or the stapes tendon may be ossifi ed.
These bony bridges probably represent failure of
detachment of the developing stapes from Reichert’s
cartilage (second branchial arch).20 These bridges may
be separated by fracturing them or dividing them with
a CO2 laser. Occasionally, the superstructure of the
stapes is separated from the footplate (Fig. 116-7). The
defective arch should be removed and replaced with a
prosthesis. Reconstruction can proceed with a total
ossicular prosthesis or a stapes prosthesis, depending
on the mobility of the footplate.
Footplate thickness varies but is important only
relative to fi xation. Congenital fi xation is recognized as
Figure 116-4. Use of a fashioned crimp-on piston prosthesis to
circumvent an overhanging facial nerve.
Figure 116-5. Monopedal stapes superstructure.

1182
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
plexes as opposed to only 12.5% of those with anoma-
lies involving the lateral chain.14 The drop in hearing
results can be attributed to the decreased stability of the
reconstruction when the prosthesis must extend from
the footplate to the malleus or tympanic membrane.
The thickness of the footplate may necessitate a drill-
out procedure. This is performed in much the same
manner as for obliterative otosclerosis. The oval window
is gradually saucerized with a microdrill until the foot-
plate is “blue-lined.” At this point, fenestration is carried
out in the usual manner, followed by stapes replace-
ment with an appropriate prosthesis. Total absence of
the stapes is rare, as is true of the other ossicles.
Handling a Perilymphatic Gusher
Excessive fl ow of perilymph on accessing the vestibule
is more common in the setting of congenital stapedial
fi xation than otosclerosis.10 Perilymph fl ow may be ter-
minated by elevating the head of the table and packing
the oval window with connective tissue. This situation
must be handled with extreme patience. It is critical to
avoid suctioning the vestibule. On occasion, a lumbar
drain is necessary for controlling the fl ow of fl uid at the
oval window; however, it should be performed only if
conservative measures fail. The patient may experience
a spinal headache postoperatively. The preoperative CT
scan should be reviewed carefully for the presence of a
dilated internal auditory canal with inadequate defi ni-
tion of the habenula perforata, enlargement of the
cochlear aqueduct, or the presence of a Mondini mal-
formation, all of which suggest a risk for a perilym-
phatic gusher and may warrant management with
amplifi cation in lieu of surgical reconstruction.
Defects of the Incus
Hypoplasia or fi brous replacement of the long or len-
ticular process is the most common defect of the incus
Bony bridge
fixing stapes
to the promontory
Figure 116-6. Bony attachment fi xing the stapes to the pro -
montory.
Figure 116-7. Congenital failure of the stapedial superstructure to
articulate with the footplate.
a blending of the bone of the footplate with the sur-
rounding otic capsule and the absence of a visible
annular ligament (Fig. 116-8). Congenital fi xation of
the stapes may occur as a sporadic abnormality or in
the setting of various syndromes. The fi xed stapes is
often deformed. In one series, one half the cases of
stapedial footplate fi xation were accompanied by associ-
ated anomalies of the incudomalleolar complex.18
Although the reported results of stapes surgery in the
setting of isolated stapedial fi xation are quite good, the
presence of associated abnormalities of the lateral ossic-
ular chain suggests a less favorable chance for a satisfac-
tory hearing result. In a series from De la Cruz and
associates, the air-bone gap was closed to within 10 dB
in 71% of patients with normal incudomalleolar com-
Figure 116-8. Congenital footplate fi xation with absence of the
annular ligament.

Chapter 116
Congenital Malformations of the Middle Ear 1183
(Fig. 116-9). The appearance is much the same as with
incus erosion after chronic otitis media with drum
retraction. Complete lack of an incudostapedial joint is
rare. These defects are most easily remedied by incus
interposition, provided that mobility of the malleus and
stapes is normal. This time-tested technique is associ-
ated with little risk of extrusion or absorption. There
are many variations in modeling the incus for use, and
surgeons have their own preferences. Figure 116-10
illustrates two options for fashioning and positioning
the incus, depending on the anteroposterior distance
between the malleus and stapes. Another option in
dealing with this problem is a partial ossicular recon-
structive/replacement prosthesis (PORP).
Fixation of the incus may occur secondary to bony
attachments within the attic or from the horizontal
semicircular canal. Failure of complete development of
the incudomalleal joint (fusion) is common in aural
atresia, but it may also occur as an isolated fi nding (Fig.
116-11). Minor spurs or projections sometimes emanate
from the long process of the incus, and rarely, a bony
bridge may connect the long process to the malleus
handle. The latter problem is easily solved by separation
of the bony ridge from the malleus with a malleus
nipper. Fixation occurring in the epitympanum,
however, should be corrected by separation of the incu-
dostapedial joint, removal of the incus, and interposi-
tion of the incus between the stapes and the handle of
the malleus. In this instance, mobilization procedures
are associated with a signifi cant risk of refi xation.
Variations in angulation and size of the distal
portion of the long process are common in the setting
of a congenital malformation. These aberrations may
affect the use of certain stapedial prostheses, particu-
larly the bucket-handle variety. A prosthesis with a large
well may be necessary, and failure to engage the bucket
handle may result.
Fibrous
incudostapedial
joint
Figure 116-9. Fibrous incudostapedial joint.
A
B
C
Long
anteroposterior
relationship
Short
anteroposterior
relationship
Figure 116-10. A, Variation in the anteroposterior (AP) dimen-
sions between the malleus and the stapes head. B, Method of inter-
positioning the incus when the AP distance is long. C, Method of
interpositioning the incus when the AP distance is short.
Defects of the Malleus
Developmental anomalies of the malleus are the most
uncommon of the ossicular defects. Complete absence
of this structure is extremely rare and has been described
only in the presence of multiple abnormalities. Separa-
tion of the manubrium from the neck and head of
the malleus has occasionally been reported,21 and the
manubrium is also sometimes twisted or rotated anteri-
orly or posteriorly from its normal position. Absence or
discontinuity of the malleus handle (Fig. 116-12) con-
stitutes a major conductive hearing loss that is most
easily handled by removing the incus and placing a
PORP from the stapes to the tympanic membrane. Pres-
ervation of the incus in these cases makes reconstruc-

1184
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
Fusion of malleus
and incus
B
Absence of
malleus handle
PORP
B
A
Figure 116-11. A, Fusion of the malleus and the incus. B, Radio-
graphic appearance of malleoincudal fusion.
Figure 116-12. A, Absence of the malleus handle. B, Repair with
a partial ossicular replacement prosthesis (PORP).
D
Figure 116-10, cont’d. D, Post operative photograph of a left
tympanic membrane after incus interposition.
tion diffi cult. Use of a PORP ensures that the center of
the tympanic membrane is used to provide the maximal
driving force to the ossicular chain. The authors’ choice
of prosthesis is a hydroxyapatite PORP with a fl exible
shaft. Another rare defect is absence of contact between
the malleus handle and the tympanic membrane (Fig.
116-13). This defect can be addressed by a lateral tym-
panoplasty with placement of the graft medial to the
malleus handle. Alternatively, the incus can be removed
and a PORP used to bridge between the stapes and the
tympanic membrane.
Fixation of the head of the malleus occurs in about
1 in every 100 ears explored for conductive hearing loss
(Fig. 116-14).21 Bony attachments to the scutum may be
present superiorly or laterally; fusion to the incus was
described earlier. Early attempts at correction by merely
fracturing these attachments were met with a relatively
high incidence of refi xation. For this reason, the head
should be separated from the malleus with malleus
nippers or a microdrill after separation of the incudo-
stapedial joint. The incus is then removed, sculpted,

Chapter 116
Congenital Malformations of the Middle Ear 1185
and interposed between the stapes and malleus. Thus,
lateral fi xation of the ossicular chain is actually managed
in the same fashion regardless of whether the malleus
or the incus is involved.
Vascular Abnormalities
Small remnants of the stapedial artery are frequently
noticed in the course of middle ear exploration. These
tiny vessels usually present no problem, and the small
amount of bleeding that they engender will cease spon-
taneously. Large remnants of the stapedial artery require
more careful attention (Fig. 116-15). Access to the foot-
plate and even its removal can usually be accomplished
by working anterior or posterior to these vessels. Liga-
tion of large vessels with clips or laser hemostasis should
be avoided because of potential injury to the facial
nerve. The persistent stapedial artery substitutes for the
middle meningeal artery, and the foramen spinosum is
congenitally absent.22
The presence of a high jugular bulb is relatively
common and may be associated with dehiscence into
the middle ear. The jugular bulb is most often defi ned
as high riding when the most cephalad portion of the
bulb reaches beyond the level of the fl oor of the inter-
nal auditory canal.23 Occasionally, a high-riding bulb
may contain a diverticulum, which projects even further
cephalad (Fig. 116-16). This anomaly is usually asymp-
tomatic and does not require intervention. If the high-
riding bulb is symptomatic (pulsatile tinnitus, conductive
hearing loss), it may be skeletonized and held inferior
to the round window by a graft of tragal cartilage or
cortical bone.
The rarest of vascular abnormalities is an aberrant
carotid artery. The normal petrous carotid turns from
its vertical course to a horizontal and medial trajectory.
Figure 116-13. The long process of the malleus has failed to attach
to the tympanic membrane.
Figure 116-14. Computed tomography scan revealing fi xation of
the left malleus head.
Stapedial
artery
Figure 116-15. Stapedial artery remnant coursing through the
obturator foramen of the stapes.
Figure 116-16. Contrast-enhanced coronally reconstructed com-
puted tomography scan demonstrating a high-riding jugular bulb
with a small diverticulum arising from the superior surface (arrow).

1186
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
72 hours. Strenuous activity is forbidden for 2 to 3
weeks. The usual precautions against blowing the nose
and avoidance of water in the ear are given.
Packing in the external canal consists of a small silk
sleeve held in place over the tympanomeatal fl ap and
supported with several small cotton balls or Merocel
spheres moistened with antibiotic ointment. This mate-
rial is removed 1 week after surgery, but water is avoided
until the canal is completely healed. Audiometry is per-
formed when it can be determined that the fl ap is
completely healed and there is no longer fl uid or blood
Lateralized
dehiscent
carotid artery
A
B
Figure 116-17. A, Aberrant carotid artery as seen through the
tympanic membrane. B, Computed tomography scan demonstrating
an aberrant internal carotid artery.
This genu is normally anteromedial to the cochlea. An
aberrant carotid artery results from inadequate devel-
opment of the cervical internal carotid artery. Blood
fl ow is redirected through the normally very small infe-
rior tympanic branch of the ascending pharyngeal
artery and to the caroticotympanic artery.24 The aber-
rant vessel courses through the middle ear and appears
on CT as a tubular soft tissue mass along the promon-
tory that enters the horizontal carotid canal through a
dehiscence in the lateral carotid plate (Fig. 116-17). An
aberrant carotid artery is not amenable to surgical
therapy. The chief danger with this entity is failing to
recognize its true identity or mistaking it for a glomus
tumor. Misdiagnosis with puncture or biopsy of the
vessel can result in signifi cant hemorrhage and possibly
neurologic sequelae.25
Round Window
Complete absence of the round window is perhaps the
rarest of middle ear defects. As the otic capsule ossifi es
during development, a cartilaginous ring prevents bony
deposition at the site of the nascent round window
membrane.26 Absence of the round window is presumed
to be secondary to improper formation of this cartilagi-
nous ring. Jahrdoerfer reported successful hearing out-
comes in three patients with congenital oval window
aplasia who had no apparent round window, so this
fi nding does not necessarily represent a contraindica-
tion to ossicular reconstruction.16 Fenestration of the
promontory to create a round window is not advisable
because of a signifi cant risk of sensorineural hearing
loss.
Other Lesions
Congenital cholesteatomas are discussed in Chapter
126. These lesions are usually seen transtympanically or
occasionally discovered at the time of myringotomy, but
they are rarely encountered unexpectedly in the course
of middle ear exploration. Choristomas are unusual
lesions consisting of heterotopic tissue and may be
found in the middle ear as well. In both instances, treat-
ment requires complete surgical ablation followed by
reconstructive measures common with tympanoplasty.
Other soft tissue lesions, such as hemangiomas and
adenomas, are rare.
POSTOPERATIVE MANAGEMENT
Postoperative management of patients undergoing
surgery for congenital middle ear abnormalities is gen-
erally the same as that after tympanoplasty with recon-
struction. The exception is a perilymph gusher. In these
cases the head is maintained at an elevation of at least
30 degrees for 48 hours. When perilymphatic drainage
continues postoperatively, a lumbar subarachnoid cath-
eter is inserted, and 50 mL of cerebrospinal fl uid is
removed every 8 hours in adults and older children.
Correspondingly, younger children require withdrawal
of lesser amounts. Minimal hydration is maintained,
and the catheter can usually be removed within 48 to

Chapter 116
Congenital Malformations of the Middle Ear 1187
within the middle ear, typically within 3 to 4 weeks
postoperatively. Antibiotics are not routinely adminis-
tered after middle ear surgery, and analgesics are neces-
sary for several days only.
COMPLICATIONS
Complications after surgical correction of middle ear
anomalies include hearing loss, vertigo, perilymphatic
drainage, and facial paralysis. Treatment of perilym-
phatic drainage has been addressed.
In the early postoperative period, hearing loss may
usually be assessed with a tuning fork. Conductive loss
is common because of packing in the canal and middle
ear effusion, but sensorineural loss may follow a drill-
out procedure or one associated with a perilymph
gusher. Stopping the fl uid leakage is the most effective
way to prevent permanent hearing loss. Steroids have
no proven value in these cases but are often adminis-
tered in divided doses of 60 to 80 mg of prednisone
daily in adults.
Mild to moderate vertigo can follow any middle ear
procedure but is most common after opening of the
oval window. Severe vertigo, especially when not present
intraoperatively under local anesthesia, is unexpected
and may signal a serious problem. The surgeon should
consider a fi stula, subluxation of the footplate, or a
prosthesis that extends too far into the vestibule. Sen-
sorineural hearing loss often accompanies this compli-
cation. If one of the listed causes is believed to be
possible, surgical exploration should be carried out
immediately to correct the problem.
Temporary facial paralysis may result from diffu-
sion of local anesthetic toward the stylomastoid foramen
or, less commonly, from the use of topical anesthesia
in the middle ear in the presence of dehiscence in the
fallopian canal. An appropriate period of observation
will soon delineate these cases. When facial weakness
persists, the surgeon must question whether the nerve
was exposed and injury may have occurred. This situa-
tion is unusual after middle ear surgery but is more
common after mastoidectomy or procedures for aural
atresia. When paralysis is unexpected and without
explanation, re-exploration is mandatory to rule out
disruption of the nerve.
Acknowledgments
The authors would like to acknowledge Dr. Donald B.
Kamerer for his major contribution to the fi rst edition
of this chapter and Dr. Barton Branstetter for gener-
ously sharing radiologic images of congenital temporal
bone malformations.
• Preoperative CT should be obtained in all pediatric
patients with conductive hearing loss not
attributable to otitis media to fully assess the
middle ear for an aberrant course of the facial nerve
and abnormalities of the ossicular chain.
• A variety of materials should be available so that the
otologic surgeon is equipped to deal with any
unexpected fi nding in the course of middle ear
exploration for conductive hearing loss.
• If a perilymph gusher is encountered, avoid
suctioning at the fenestra, elevate the head of the
bed until the fl ow stops, and pack the oval window
with connective tissue.
PITFALLS
• Middle ear anomalies are accompanied by a higher
risk of an aberrant facial nerve and require vigilance.
• Stapes surgery should not be performed when there
is radiologic evidence of a widened internal auditory
or cochlear aqueduct.
• Failure to recognize vascular anomalies such as an
aberrant carotid and attempted myringotomy or
biopsy may result in signifi cant complications—
temporal bone CT allows this entity to be recognized
readily.
• Inappropriate exploratory tympanotomy can be
avoided by confi rmation of the absence of stapedial
refl ex before surgery.
• Unexpected postoperative vertigo should raise
concern for a possible fi stula, subluxation of the
footplate, or a prosthesis that extends too far into
the vestibule.
References
1. Gulya AJ, Schuknecht HF: Phylogeny and Embryology. In
Anatomy of the Temporal Bone with Surgical Implications. New
York, Parthenon, 1994, pp 235-273.
2. Lambert PR: Congenital absence of the oval window. Laryngo-
scope 100:37-40, 1990.
3. Farrior JB: Surgical management of congenital conductive deaf-
ness. South Med J 80:450-453, 1987.
4. Nager GT, Levin LS: Congenital aural atresia: Embryology,
pathology, classifi cation, genetics, and surgical management. In
Paparella M, Shumrick D (eds); Otolaryngology. Philadelphia,
WB Saunders, 1980, pp 1303-1344.
5. Stewart JM, Downs MP: Congenital conductive hearing loss: The
need for early identifi cation and intervention. Pediatrics 91:355-
359, 1993.
6. Cremers CW, Teunissen E: The impact of a syndromal diagnosis
on surgery for congenital minor ear anomalies. Int J Pediatr
Otorhinolaryngol 22:59-74, 1991.
7. Briggs RJ, Luxford WM: Correction of conductive hearing loss in
children. Otolaryngol Clin North Am 27:607-620, 1994.
8. House JW, Sheehy JL, Antunez JC: Stapedectomy in children.
Laryngoscope 90:1804-1809, 1980.
9. Cole JM: Surgery for otosclerosis in children. Laryngoscope
92:859-862, 1982.
PEARLS
• A chance encounter with a middle ear abnormality
is a probability for every otologic surgeon.
• Middle ear malformations should always be
considered in the differential diagnosis of children
with conductive or mixed hearing loss.

1188
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
10. Dornhoffer JL, Helms J, Hoehmann DH: Stapedectomy for con-
genital fi xation of the stapes. Am J Otol 16:382-386, 1995.
11. Vore AP, Chang EH, Hoppe JE, et al: Deletion of and novel mis-
sense mutation in POU3F4 in 2 families segregating X-linked
nonsyndromic deafness. Arch Otolaryngol Head Neck Surg
131:1057-1063, 2005.
12. de Kok YJ, van der Maarel SM, Bitner-Glindzicz M, et al: Associa-
tion between X-linked mixed deafness and mutations in the POU
domain gene POU3F4. Science 267:685-688, 1995.
13. Minor LB, Carey JP, Cremer PD, et al: Dehiscence of bone overly-
ing the superior canal as a cause of apparent conductive hearing
loss. Otol Neurotol 24:270-278, 2003.
14. De la Cruz A, Angeli S, Slattery WH: Stapedectomy in children.
Otolaryngol Head Neck Surg 120:487-492, 1999.
15. Caner G, Olgun L, Gultekin G, et al: Local anesthesia for middle
ear surgery. Otolaryngol Head Neck Surg 133:295-297, 2005.
16. Jahrsdoerfer R: Congenital malformations of the ear. Analysis of
94 operations. Ann Otol Rhinol Laryngol 89:348-352, 1980.
17. Teunissen B, Cremers CW: Surgery for congenital stapes ankylo-
sis with an associated congenital ossicular chain anomaly. Int J
Pediatr Otorhinolaryngol 21:217-226, 1991.
18. Teunissen EB, Cremers WR: Classifi cation of congenital middle
ear anomalies. Report on 144 ears. Ann Otol Rhinol Laryngol
102:606-612, 1993.
19. Hough J: Malformations and anatomical variations seen in the
middle ear during the operation for mobilization of the stapes.
Laryngoscope 68:1337-1338, 1958.
20. Tos M: Embryology of Stapes Ankylosis. Surgical Solutions for
Conductive Hearing Loss. Stuttgart, Germany, Thieme, 2000, pp
240-246.
21. Bergstrom L: Anomalies of the ear. Otolaryngology 1:24-28,
1994.
22. Silbergleit R, Quint DJ, Mehta BA, et al: The persistent stapedial
artery. AJNR Am J Neuroradiol 21:572-577, 2000.
23. Swartz JH, Harnsberger HR: Temporal Bone Vascular Anatomy,
Anomalies, and Diseases, Emphasizing the Clinical-Radiological
Problem of Pulsatile Tinnitus. In Imaging of the Temporal Bone.
New York, Thieme, 1998, pp 170-239.
24. Fisher NA, Curtin HD: Radiology of congenital hearing loss.
Otolaryngol Clin North Am 27:511-531, 1994.
25. Sauvaget E, Paris J, Kici S, et al: Aberrant internal carotid artery
in the temporal bone: Imaging fi ndings and management. Arch
Otolaryngol Head Neck Surg 132:86-91, 2006.
26. Martin C, Tringali S, Bertholon P, et al: Isolated congenital round
window absence. Ann Otol Rhinol Laryngol 111:799-801, 2002.

Chapter 117
Otosclerosis
Barry E. Hirsch
Otosclerosis is a two-stage, metabolic bone-remodeling
process of the otic capsule characterized by bone resorp-
tion (otospongiosis) and recalcifi cation (otosclerosis).
The term otosclerosis was ascribed to Politzer in 1894.1
The etiology is believed to be familial, with inheritance
occurring by autosomal dominant transmission with
varying penetrance. Konigsmark and Gorlin2 reported
the incidence of clinical otosclerosis to be 3 per 1000
in whites and much less in blacks, although histologic
evidence of disease has been reported in as many as 8%
of temporal bones.
Investigations over the past few years have focused
on other causes of stapes fi xation, including viral infec-
tions. It is postulated that a systemic viral infection may
cause an infl ammatory vascular reaction with the sub-
sequent development of otosclerosis. Reverse transcrip-
tase–polymerase chain reaction (RT-PCR) has provided
evidence suggesting that a paramyxovirus respon -
sible for measles may be the cause of otosclerosis. An
excellent summary of the association of viruses as the
cause of otosclerosis was published by Ferlito and
colleagues.3
Among adults, otosclerosis is the chief cause of con-
ductive hearing loss, which occurs in several well-known
patterns. It most frequently begins in young adulthood
but may occur from adolescence to old age. Otosclero-
sis is more common in females by a ratio of 2:1 or
3:1, and the family history is positive in 50% of
patients, which implies that the disease develops spon-
taneously in the remaining 50% of people affected by
otosclerosis.
Although conductive hearing loss secondary to
stapedial fi xation is the classic manifestation, mixed
hearing loss and even pure sensorineural hearing
impairment can result from disease in the otic capsule.
In addition, it is not uncommon for hearing loss to
change in type over time. A sensorineural component
may develop in people with conductive loss, and those
who start with sensorineural hearing loss can acquire
conductive loss as well.
Surgeons have recognized the mechanical impedi-
ment to sound transmission caused by otosclerosis since
the late 19th century. Since then, surgical procedures
for correction of otosclerosis have been modifi ed, aban-
doned, and then re-established to provide one of oto-
laryngology’s most fascinating stories. Today, a properly
selected patient in the hands of an experienced oto-
logic surgeon has a better than 95% chance of hearing
restoration, with a low incidence of complications by
closure of the air-bone gap. Certainly, these expecta-
tions rival those of any surgical procedure and have
resulted in stapes surgery for otosclerosis being an
extremely successful method of restoring hearing.
PATIENT EVALUATION AND SELECTION
Patients typically have a complaint of slowly progressive
hearing loss in one or both ears identifi ed by them-
selves or others such as coworkers, friends, and family.
Associated complaints may include tinnitus that is occa-
sionally described as “hearing one’s heartbeat” in one
or both ears. This form of pulsatile tinnitus can occur
with otosclerosis, especially when otospongiosis is active.
Patients with active disease may describe mild dizziness
or motion intolerance. This complaint can be troubling
because stapes surgery should be avoided if there are
other sources of vestibular dysfunction. Dehiscence of
the superior semicircular canal can be manifested as
pressure-induced dizziness and conductive hearing loss.
This is discussed later in this chapter. If the disequilib-
rium, lightheadedness, or motion intolerance can be
ascribed to otosclerosis, surgery will probably resolve
the problem. Patients may have a varied degree of
hearing loss once confi rmed on audiometric testing.
Some people are acutely aware of 10 to 15 dB of hearing
difference between the two ears. Others may need to
1189

1190
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
incur greater loss to bring the impairment to their
attention. Individual tolerance to hearing impairment
varies greatly. For this reason it is not unusual for
hearing loss to progress to moderate levels, especially
when the patient’s hearing needs have not been
complex. The patient’s subjective assessment of the
hearing loss does not always match the physician’s
objective evaluation.
Physical examination of the ears should identify a
healthy ear canal and tympanic membrane with no evi-
dence of middle ear pathology. Tuning fork testing
remains an essential factor in helping determine the
type and degree of hearing loss. Positive results on the
Rinne test (air conduction greater than bone conduc-
tion) with 256- and 512-Hz tuning forks suggest that if
an air-bone gap is identifi ed on audiometric testing, it
is probably less than 15 dB. Such patients are not usually
considered candidates for surgical intervention at that
time. They are apprised of their hearing levels and
advised to be seen again in 6 months to monitor their
audiometric and tuning fork results. An audiogram is
mandatory in evaluating candidacy for otosclerosis
surgery. There should be evidence of a 25-dB air-bone
gap in the involved ear to consider offering surgery for
correction of the hearing loss. Conductive hearing loss
on audiometric testing should always be confi rmed by
the tuning fork examination. Mixed hearing loss should
prompt the surgeon to consider the phenomenon of
Carhart’s notch (Fig. 117-1). This will allow as much as
15 dB of “overclosure” at 2000 Hz, 10 dB at 1000 and
3000 Hz, and 5 dB at 500 Hz.
Ideally, successful surgery will restore hearing to
normal levels, but many patients are happy with
modest improvement that lessens their dependency
on amplifi cation. Each patient requires a thoughtful
discussion of the realistic expectations for hearing
improvement, in addition to counseling about alterna-
tive methods. For persons who are not certain about
their treatment preference, a trial of amplifi cation
should be suggested.
Some clinical situations can present a signifi cant
challenge to obtaining accurate audiometric data. First
is the presence of a large air-bone gap, particularly
when asymmetrical. Correct use of adequate masking
in this case is mandatory to avoid errors related to cross-
over to the other ear. Likewise, unilateral sensorineural
impairment can create a “shadow curve” that mimics
conductive loss. Tuning fork confi rmation of audiomet-
ric data will save the physician from being misled.
Profound mixed hearing loss will challenge audiol-
ogists and otolaryngologists alike. In this situation, the
bone conduction thresholds may exceed the maximum
output of the audiometer, and the amount of air-bone
gap is diffi cult to ascertain. Several clues, however, will
help make the diagnosis of otosclerosis, including a
positive family history of otosclerosis, documentation of
progressive loss of hearing, evidence of conductive loss
on previous audiograms, and success with amplifi cation
beyond that expected from examination of the audio-
metric thresholds. Reasonable word recognition scores
in association with severe to profound sensorineural
hearing loss should also heighten the clinician’s suspi-
cion of a conductive component. In these patients, sur-
gical restoration of even 20 dB produces a grateful
patient. They are in a much better position to success-
fully use a hearing aid at lower levels of amplifi cation
and avoid problems with acoustic feedback.
There are only two relatively hard-and-fast rules in
surgery for otosclerosis: the fi rst is never to operate on
an only-hearing ear, and the second is always to operate
on the poorer-hearing ear. These simple principles
have been proved to serve the best interest of the
patient. As with any rules, there are rare exceptions. If
a person has profound mixed hearing loss in one ear,
is anacoustic in the other, and is unable to successfully
use a hearing aid, the option of attempting partial
hearing restoration is reasonable. The only remaining
option would be a cochlear implant. In a similar
approach, if a patient who successfully underwent stapes
surgery should lose hearing in the contralateral ear and
serious complications develop in the operated ear, such
as a perilymphatic fi stula, surgical intervention is
warranted.
Differential Diagnosis and Concomitant
Otologic Disease
Conductive hearing loss does not always guarantee the
diagnosis of otosclerosis, especially when only one ear
is involved. This is an important principle to be remem-
bered when counseling patients for surgery. The
surgeon must always look for and be prepared to
manage problems other than stapes fi xation when
exploring the impaired ear. Congenital middle ear
anomalies, tympanosclerosis, and lateral fi xation of the
ossicular chain are among the other causes of conduc-
tive loss.
A new clinical entity has recently been described
that provides an explanation for “inner ear conductive
hearing loss.” Minor noted that patients with dehis-
cence of the superior semicircular canal present with
Figure 117-1. Audiogram showing right mixed hearing loss and a
sensorineural dip at 2000 Hz indicative of Carhart’s notch.

Chapter 117
Otosclerosis 1191
signs and symptoms indicative of having a third window
in the otic capsule, including a positive Tullio phenom-
enon (sound-induced vertigo); dizziness with a Valsalva
maneuver, coughing, belching, or sneezing; pulsatile or
thumping tinnitus; and occasionally, conductive hearing
loss. Tuning fork testing can still show a negative Rinne
test (bone conduction greater than air conduction).
Conductive hearing loss coming from the middle ear
routinely exhibits absence of elicited acoustic refl exes.
In contrast, acoustic refl exes are typically present when
the conductive hearing loss is due to dehiscence of
the superior semicircular canal.4 Patients suspected of
having otosclerosis should undergo testing for acoustic
refl exes preoperatively to help avoid performing middle
ear surgery when an alternative source of conductive
hearing loss may exist.
Concomitant disease must be considered in several
instances. Meniere’s disease in the involved ear is gener-
ally considered to be a contraindication to surgery
because of a higher incidence of postoperative cochlear
impairment. Active Meniere’s disease in the contralat-
eral ear is also a relative contraindication because the
fi nal hearing status of that ear is unknown. Tympanic
perforations should be repaired before stapes surgery
because of the risk of contamination of the middle ear
and vestibule by organisms from the external auditory
canal. The same strategy is maintained when a ventila-
tion tube is in place. The tube needs to be removed and
the tympanic membrane repaired. If needed, a ventila-
tion tube can be placed later in the postoperative
period. Osteogenesis imperfecta (van der Hoeve’s syn-
drome) is often associated with conductive hearing loss,
but more often it is secondary to erosion of the incus
or crura of the stapes. Likewise, patients with Paget’s
disease may have fi xation of the stapes, but long-term
results are unfavorable because of the development of
sensorineural loss.
Otosclerosis in the Pediatric Age Group
Children with conductive hearing loss are less likely to
have otosclerosis than other problems with the ossicular
chain. Fixation of the stapes can be present from birth
as a result of congenital fi xation or can be acquired
from tympanosclerosis or otosclerosis. The outcome
after surgery can vary for each condition and may differ
from surgeon to surgeon. Welling and coauthors
reviewed the literature and reported their experience
with pediatric stapes surgery. In general, similar results
should be expected after stapes surgery for otosclerosis
in children and adults. This implies hearing loss that
develops late in the fi rst decade or early teen years and
is not associated with a history of recurrent otitis media.
Surgical treatment of stapes fi xation secondary to tym-
panosclerosis does not achieve as good or lasting results
as treatment of fi xation secondary to otosclerosis.5 Com-
puted tomography scanning must be performed in all
pediatric patients with conductive hearing loss when
surgical exploration is planned. The ear is examined
for anomalies of the otic capsule such as a large vestibu-
lar aqueduct, cochlear dysplasia such as Mondini’s
deformity, or a wide internal auditory canal. These fi nd-
ings can be associated with a perilymphatic gusher,
which may have disastrous effects on postoperative
hearing. We would also recommend directing attention
to the course of the facial nerve within the temporal
bone to ensure that no anatomic anomalies are present.
Such anomalies should temper the surgeon’s judgment
in favor of the use of amplifi cation.
Selection of the correct ear for surgery is usually
straightforward because the ear with the worse hearing
is chosen. Word recognition scores are seldom a con-
sideration in otosclerosis, but rarely these and other
defi cits in cochlear reserve must be factored in when
presenting the options and risks to the patient. When
hearing thresholds are similar in each ear, it is helpful
to ask patients which side is most impaired in their
judgment. Again, the worse ear is chosen for initial
exploration. If the candidate cannot make a choice, it
is useful to consider the side on which the telephone is
usually held. Finally, if there is neither suffi cient infor-
mation nor patient preference to pick which side should
be done fi rst, the surgeon then has the option. It is
easier for a right-handed surgeon to operate on a
patient’s left ear, especially if the patient has a large
chest and short neck. The opposite holds for a left-
handed surgeon.
In the past, some physicians have maintained that
after successful surgery, the second ear should not
undergo surgery. Today, most experienced surgeons
believe that elective surgery in the second ear is desir-
able and carries the same risks as surgery on the fi rst
side. The advantages of binaural hearing in eliminating
noise and providing sound localization are believed to
outweigh the small risk of sensorineural loss. There is
no correct period before which the second ear may
undergo surgery, but most surgeons prefer to wait at
least 6 months. Certainly, during that period hearing in
the operated ear should improve with no signs of
complications.
Counseling of a patient considering surgery must
always be based on the tenet that these procedures are
elective. Some patients will choose no treatment despite
what the surgeon and family believe is an obvious need
for amelioration. Each individual has the right to make
an informed choice, whether seemingly wise or not.
No surgeon wishes to be in the position of defending
an unfavorable result in a patient who was reluctant to
undergo surgery in the fi rst place. This is why unhur-
ried and careful preoperative counseling is so impor-
tant. A frank discussion of the results expected and
potential risks necessarily includes the experience of
the surgeon and not merely statistics quoted from the
literature.
Although every potential complication cannot be
anticipated, it is imperative to discuss those that present
the greatest dangers and those that occur with the
greatest frequency. Among the specifi c risks to be
addressed are worsening or total hearing loss, possible
infection, vertigo, disturbances in taste, perforation of
the tympanic membrane, and facial weakness. It is also
important to address postoperative restrictions so that