Phẫu Thuật Tai Mũi Họng Và Phẫu Thuật Đầu Cổ

Chapter 117
Otosclerosis 1193
the jaws can be delivered with excessive force, thereby
crimping the hooked portion too tightly. Similarly,
insuffi cient closure will probably result in the patient
complaining of sound distortion and a sense of vibra-
tion. If the prosthesis is too loose, erosion of the incus
will eventually occur, with return of the conductive
hearing loss (Fig. 117-2).
Numerous investigators have researched outcomes
based on the material used for stapes piston prostheses.
Massey and coworkers conducted a study to compare
the effectiveness of titanium and Tefl on wire prostheses
for hearing improvement in patients undergoing stapes
surgery for otosclerosis. Closure of the air-bone gap to
less than 10 dB was achieved in 86% of patients with a
Tefl on prosthesis versus 71% of those receiving tita-
nium prostheses.7 A smaller number of patients received
the titanium prosthesis, which at the time was used
when the diameter of the incus was smaller. The design
of the prosthesis allows a more circumferential crimp
around the incus. A similar study comparing gold and
titanium prostheses was reported by Tange and coau-
thors.8 They found that the heavier gold piston gave
more overclosure (gain) than the lighter titanium pros-
thesis did; however, they thought that the lighter but
stiffer titanium piston provided a higher air-bone gap
closure within 10 dB.8
Developments in metallurgy over the past few
decades have brought new alloys into medicine with
applications in otology. Nitinol is a shaped memory
alloy composed of nickel and titanium. To remove the
forceps from the crimping process, Nitinol is now avail-
able in stapes prostheses. The application of heat acti-
vates a phase transformation in the metal that causes it
to revert to its closed position around the incus. Heat
is typically delivered with a laser on low energy settings.
The use of this material and technique precludes over-
crimping at the attachment to the incus. The piston
portion of the device is made of Tefl on (Gyrus Corp.,
Jacksonville, FL). Knox and Reitan published an excel-
lent review of the history, chemical and mechanical
properties, and in vitro and in vivo testing of Nitinol
stapes prostheses.9
There have been minimal changes in the surgical
method of treating otosclerosis. In the early years, stapes
mobilization was initially successful but routinely suc-
cumbed to refi xation. Over the past 50 years, postopera-
tive results have consistently demonstrated that removal
of a portion or the entire stapes footplate (stapedec-
tomy) or bypass of the obstruction with a fenestration
piston (stapedotomy) successfully resolves the source of
conductive impairment. Silverstein introduced a novel
technique for overcoming otosclerosis limited to the
anterior portion of the footplate (fi ssula ante fenes-
tram) when the remainder of the footplate is blue, thin,
and without fi xation. He described a minimally invasive
stapes procedure termed stapedotomy minus prosthesis
(STAMP). The anterior crus is vaporized with a hand-
held argon laser. The anterior footplate is then vapor-
ized linearly in a superior-to-inferior direction to allow
the posterior footplate to be mobile and still be attached
by the stapes tendon. The decision whether this proce-
dure could be performed was made during exploration
of the middle ear. The preoperative audiogram was not
predictive of the degree and location of otosclerosis.
Statistical analysis suggested that there was improve-
ment in high-frequency hearing results as compared
with conventional laser stapedotomy procedures. The
rate of refi xation was 9%, but revision surgery was not
precluded.10
Positioning of the Patient
Positioning of the patient on the operating table must
be optimal to facilitate proper exposure for the surgeon.
The patient should be as close to the surgeon as the
table comfortably permits. Elevation of the head should
be minimized; in persons with a short neck or a large
chest, it may even be helpful to slightly lower the head
of the table relative to the horizontal plane of the body.
Comfort should be achieved by padding the arms, ele-
vating the knees, or placing support under the lumbar
area as necessary. It is not necessary to remove any hair,
but it must be secured to allow easy and unobstructed
access to the ear canal. The arm opposite the ear under-
going surgery is positioned on an arm board, and an
appropriate vein on the dorsum of the hand is identi-
fi ed for use as a tissue graft in the oval window. Prepara-
tion is carried out with either alcohol or povidone-iodine
(Betadine) solution as the surgeon chooses. After con-
ventional draping for a transcanal procedure, the solu-
tion is gently suctioned from the ear canal, and cerumen
is removed as necessary.
Anesthesia
Anesthetic block is achieved with a 27-gauge needle
and dental carpules containing 2% lidocaine with a
1:100,000 solution of epinephrine. Injection is begun
at the 6-o’clock position in the canal and carried out
slowly because of resistance of the skin, which is adher-
ent to cartilage or bone. Gradual blanching of the canal
Figure 117-2. Left ear showing a crimp-on prosthesis that had
eroded the long process of the incus.

1194
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
skin signals successful injection. Too rapid an injection
may also cause ballooning of the canal skin with a sub-
cutaneous collection of fl uid. When this occurs, the
ballooned area should be punctured immediately with
a needle tip. Gradual progression of the injections then
proceeds from the 6-o’clock position in both directions
until circumferential anesthesia is complete. Slow injec-
tion in this manner usually results in patients feeling
only the fi rst injection if they are awake. Care must be
taken to inject only a minimum of solution because
overzealous injection results in reduction of the size
of the meatus and canal. When general anesthesia
is administered, the same local agents are injected to
provide a bloodless fi eld because of the vasoconstrictive
effect of the epinephrine.
Exposure
Creation of an incision to maximize exposure is impor-
tant in every operation. When exploring an ear with
conductive hearing loss, however, it is wise to anticipate
other situations. Discovery of lateral ossicular chain fi x-
ation, for example, may necessitate greater removal of
bone from the scutum and potentially cause a defect
impossible to close with a short tympanomeatal fl ap.
Correct canal incisions are three dimensional and
extend from the posteroinferior annulus to a point well
superior to Shrapnell’s area (Fig. 117-3). The length of
the canal fl ap is 5 to 7 mm, and it is dissected gently to
avoid tearing the edges. The fl ap is elevated until the
fi brous annulus is well exposed inferiorly and the notch
of Rivinus is seen superiorly (Fig. 117-4). The tympanic
membrane is then elevated anteriorly by sharp dissec-
tion. Sectioning of the posterior plica (mallear fold)
will allow complete refl ection of the tympanic mem-
brane. When this does not suffi ce, the superior incision
has generally not been developed far enough
anteriorly.
The amount of bone that must be removed from
the posterior canal wall for adequate visualization varies
considerably. When bone must be removed, curettage
should begin at the notch of Rivinus and proceed infe-
riorly as care is taken to preserve the chorda tympani
nerve (Fig. 117-5). When exploring the middle ear for
otosclerosis or any conductive hearing impairment, the
following landmarks should be visible to the surgeon to
ensure adequate exposure (Fig. 117-6):
• Anteriorly—the neck and handle of the malleus
• Inferiorly—the round window
• Posteriorly—the pyramidal process
• Superiorly—the horizontal portion of the facial
nerve
Good visualization of these structures will allow sur-
gical correction of any conductive pathology encoun-
tered. Bone removal is generally performed with
microcurettes but may also be achieved with a small
cutting burr. The latter method usually presents a
greater risk to the chorda tympani.
The chorda tympani can be preserved in more than
90% of cases. In the event of partial sectioning, the
fi bers should be reapproximated because good func-
tion will typically be restored. Some authors advise com-
plete sectioning of the nerve when partial damage has
occurred, but this is not justifi ed in our experience.
Even when complete sectioning is necessary, patients
rarely complain of taste disturbance for more than a
few months.
Determining Pathology
After adequate exposure, the entire ossicular chain and
middle ear should be examined. Foci of otosclerosis
may be immediately recognized as chalky white. There
may be increased vascularity on the promontory, but
recognition of the disease can sometimes be diffi cult.
The ossicular chain is palpated gently with a slightly
angled pick. Palpation should begin with the handle of
the malleus and proceed medially to the long process
of the incus and fi nally to the superstructure of the
stapes. Extreme fi xation sometimes precludes determi-
nation of the location of pathology. In this situation,
the incudostapedial joint should be separated with a
right-angled hook or a joint knife. This maneuver will
allow separate palpation of the lateral chain and stapes.
The site of fi xation can then be determined.
In addition to confi rming the pathology to be
located at the footplate of the stapes, the degree of
otosclerotic involvement must be observed. The surgeon
must determine whether the footplate is thin enough
for easy penetration or whether obliteration is present.
Anatomic diffi culties such as a dehiscent or overhang-
ing facial nerve should also be noted at this time. It is
always better to recognize potential diffi culties before
beginning disassembly of the ossicular chain. Failure to
see any “blue area” within the central footplate may
signal partial or complete obliterative disease. In this
situation, the surgeon must judge whether adequate
management of all problems that may ensue is possible,
such as a fl oating footplate or the necessity for a drill-
out procedure.
Figure 117-3. Correct incision in the canal allows adequate removal
of bone and exposure of the ossicular chain.

Chapter 117
Otosclerosis 1195
Notch of
Rivinus
A
B
Figure 117-4. A, Elevation of the
tympanomeatal fl ap. B, Exposure
of the middle ear is enhanced by
ensuring adequate anterior devel-
opment of the fl ap.
Chorda
tympani
nerve
Figure 117-5. Curetting the posterosuperior bony canal wall with
preservation of the chorda tympani nerve.
Pyramidal process
Round
window
niche
Facial
nerve
Malleus
handle
Figure 117-6. Demonstrating adequate middle ear exposure for
management of any conductive problem encountered.

1196
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Philosophy of Footplate Removal
Beginning with the revival of stapes surgery by Dr. John
Shea, Jr., in the 1950s, complete removal of the stapes
footplate was considered the norm and resulted in sat-
isfactory hearing results in a high percentage of cases.
In recent years, the “small fenestra” technique has had
a number of proponents because of the perception of
improved results, particularly in the higher frequencies
of 4 kHz and above. Careful review of the many articles’
pros and cons reveals signifi cant fl aws in case study
conclusions. In almost all the studies, the cases of more
than one surgeon or more than one prosthesis were
combined to arrive at conclusions regarding hearing
results. A signifi cant article on methodology was
authored by Rizer and Lippy,11 who compared results
in three groups of patients, all of whom underwent
surgery by Lippy. The three groups consisted of total
removal of the footplate, partial removal of the foot-
plate, and small fenestra stapedotomy. The Robinson
prosthesis and identical tissue grafts were used in
all cases. Although not statistically signifi cant, the best
hearing results in all frequencies actually occurred
in the group with total removal of the footplate.
Accordingly, it is safe to conclude that the amount
of footplate removal is insignifi cant in comparison
with the skill of the surgeon. With these facts in mind,
two techniques for stapes surgery will be described. The
fi rst is the standard procedure without use of the laser,
and the second embraces the newer laser technology
available for otologic surgeons. Both techniques are
used by our group, and hearing results have been
equivalent.
Several general comments can be made. Conven-
tional stapes surgery avoids the risk of high-energy
lasers within the middle and inner ear. Laser tech-
niques, on the other hand, better handle bleeding
and avoid the potential complication of a fl oating
footplate. Laser surgery is not applicable to obliterative
disease.
Conventional Stapedectomy
After careful assessment of the degree and location of
the otosclerosis, the incudostapedial joint is separated
(Fig. 117-7). At this time, connective tissue is harvested
for use in the oval window. When harvesting tissue, the
surgeon may use the tragal perichondrium, areolar
tissue, or temporalis fascia because of their proximity
to the operative fi eld. An alternative strategy is for an
assistant to harvest a vein graft from the dorsum of the
hand opposite the ear undergoing surgery (Fig. 117-8)
while the otologic surgeon proceeds uninterrupted
with the middle ear surgery. The type of connective
tissue used for sealing the oval window is unimportant,
provided that it is thin. When using vein, either the
adventitial or the intimal surface may seal the oval
window. Brief drying of the vein graft, as would be done
for temporalis fascia, will make the graft easier to
handle, thereby facilitating introduction and placement
in the oval window. As the tissue graft comes in contact
with perilymphatic fl uid, it becomes soft and pliable
once again. Preparation of the tissue graft should
precede opening of the footplate so that the period of
exposure of the vestibule is shortened.
Next, the footplate is fenestrated with a fi ne, sharp
needle (Fig. 117-9). Although fenestration should
ideally be performed in the center of the footplate, it
may be done wherever the blue color indicates the bone
to be thinnest. The stapedius tendon should be kept
intact through this step to supply resistance against
which to push during the fenestration. If gentle pres-
sure does not perforate the bone, slow to-and-fro rota-
tion of the needle point will generally complete the
procedure. Successful fenestration is recognized when
the needle point gives way slightly. Perilymph will be
seen at the point of entry. Successful creation of the
fenestra accomplishes two important purposes. First,
the vestibule is already decompressed in the unlikely
event of total footplate avulsion on fracture of the
superstructure. Second, an area of purchase is now
available for instrumentation in the case of footplate
fl otation. The stapedial tendon is sectioned (Fig.
117-10), and fracture of the stapedial superstructure is
next accomplished by quick downward pressure toward
the promontory (Fig. 117-11) (see Video 117-1). Occa-
sionally, fi xation of the superstructure to the promon-
tory necessitates careful superior fracturing toward the
horizontal facial nerve. In either case, the entire stape-
dial arch is then removed.
Small angled footplate hooks are next used to
remove a suffi cient amount of the central area of the
footplate for placement of the graft and insertion of
the prosthesis (Fig. 117-12). The amount of footplate
removed is the portion that can easily be taken out,
which usually amounts to approximately one fourth of
the surface area of the footplate. Occasionally, larger
portions of the footplate become elevated when enlarg-
ing the fenestra; in such cases, they may be removed
with no fear of complications.
The appropriate length for the prosthesis is mea-
sured, although 4 mm is almost always the correct size
for a bucket-handle prosthesis of the Robinson type
Figure 117-7. Separation of the incudostapedial joint while being
careful to preserve the lenticular process of the incus.

Chapter 117
Otosclerosis 1197
A
B
C
Figure 117-8. A, A 2-cm transverse incision is made on the dorsum of the hand for harvesting the vein graft. B, Removal of connective tissue
from the vein graft. C, Opening the vein graft.
Figure 117-9. Fenestration of the central area of the stapes foot-
plate with a fi ne needle.
Figure 117-10. Sectioning of the stapedial tendon.

1198
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
B
Facial
nerve
Promontory
Figure 117-11. A and B, Down-fracturing of the stapes superstruc-
ture toward the promontory.
Figure 117-12. Removal of the central area of the footplate.
(Fig. 117-13). The Robinson prosthesis is favored for
several reasons:
1. It is self-centering within the fenestration.
2. Its weight favors good hearing results.
3. Because it is not a “crimped-on” prosthesis, the
chance of ischemic pressure necrosis of the incus is
negligible.
4. It can be used with minimal footplate removal.
The vein graft is placed over the oval window and
gently depressed into the fenestra to identify the loca-
tion of placement for the medial end of the prosthesis
(Fig. 117-14) (see Video 117-2). Next, the prosthesis is
placed by inserting the device into the fenestra and
leaning it against the posterior surface of the incus,
where it will remain standing by capillary attraction (see
Video 117-3). A right-angled pick is then used in one
hand to lift the long process of the incus while a second
pick slides the bucket forward and under the lenticular
process (Fig. 117-15). The entire shaft is rotated until
the bale or bucket handle becomes aligned with the axis
of the incus. The bucket handle is then lifted over the
incus and into place (Fig. 117-16). Routine positioning
Figure 117-13. Measurement from the vestibule to the undersur-
face of the incus for the Robinson prosthesis.
of the prosthesis and swinging the bucket handle over
the incus are demonstrated in Video 117-4. A few minor
maneuvers may be necessary to place the well of the
prosthesis beneath the lenticular process of the incus
(see Video 117-5). If the lenticular process is missing
from the incus, a Bailey modifi cation of the Robinson
prosthesis is used. This modifi cation consists of an ellip-
tical notch in the bucket, which allows one to slide the
prosthesis along with its handle superiorly onto the
long process until it is well stabilized. If the bucket
handle is deemed to be too loose as it rests over the
incus, a small piece of tissue graft (residual vein) can
be placed to cover it and the distal incus. This provides
a “band-aid” to secure the handle in position (see Video
117-6).
Next, the ossicular chain is palpated at the malleus
handle to ensure continuity of the chain; gentle pres-

Chapter 117
Otosclerosis 1199
window prosthesis. Likewise, lateral chain fi xation may
necessitate incus interpositioning or the use of a partial
ossicular reconstructive/replacement prosthesis.
CO2 Laser–Assisted Stapedotomy
The laser should be set up with safe energy parameters
and test-fi red to confi rm accuracy of the aiming beam.
The HeNe aiming beam can be set on auto-HeNe so
that when the foot pedal is depressed, the aiming beam
remains off, thereby allowing an undistorted view of the
last laser strike. Alcohol should not be used as a pre-
parative solution when the laser is used.
With the CO2 laser set at a continuous-mode 200-
µm spot size, 0.1-second duration, and 1.25 W, a fenes-
tration is made in the superior central area of the
Figure 117-14. Placement of the vein graft over the fenestrated
footplate.
Figure 117-15. Placement of the Robinson prosthesis via a two-
handed technique.
Figure 117-16. The prosthesis in place with the handle over the
incus.
Figure 117-17. Packing of the tympanomeatal fl ap with a silk
sleeve to maintain its position.
sure is placed on the incus to ensure good “bounce” of
the prosthesis. This maneuver helps center the prosthe-
sis. If this bounce is absent, the medial portion of the
strut may not be within the fenestra. Finally, the tympa-
nomeatal fl ap is refl ected to its original position, and
the fl ap is packed with a single silk strip and several
small cotton balls impregnated with antibiotic ointment
(Fig. 117-17).
Surgeons should have more than one technique at
their disposal when performing stapes surgery because
of occasional unanticipated fi ndings. Shortening or
absence of the long process of the incus may require a
wire-piston device or even the use of a malleus-to–oval

1200
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
footplate. If the oval window niche is narrow or too tight
to gain access to the footplate, one should proceed with
removing the superstructure by fi rst vaporizing the sta-
pedial tendon. The video shows initial laser vaporiza-
tion of the stapedial tendon and the posterior crus and
then fenestration of the footplate (see Video 117-7).
Suction should be used to evacuate the laser plume.
The posterior crus is vaporized as close to the footplate
as possible (Fig. 117-18). The bone char that forms
along the posterior crus should be removed with a fi ne
pick or suction as it forms. It is not useful to fi re the
laser into previously carbonized tissue. When dividing
the posterior crus, it is important to note that the crus
has a horseshoe-arch shape. That is, the superior and
inferior aspects of the crus will be much thicker than
the midportion of the crus.
Next, the incudostapedial joint is separated with a
joint knife, and the stapes superstructure is down-frac-
tured. It has not been necessary to directly divide the
anterior crus with the laser because the anterior crus is
normally thinner than the posterior crus and otosclero-
sis usually fi rmly fi xes the anterior footplate. The laser
is then focused on the footplate. It is useful to confi rm
proper depth of focus by using high-power magnifi ca-
tion (25 × ) temporarily to focus on the footplate and
then return to a comfortable working magnifi cation.
Laser strikes are made on the footplate in a rosette
pattern (Fig. 117-19) (see Video 117-8). Six to eight
laser strikes are usually required to form a fenestra
about 0.8 mm in diameter. The proper size of the fenes-
tra may be confi rmed by using a no. 26 suction device
that has a 0.6-mm diameter at its tip or estimated by the
200-µm size of the laser strikes. It is easier to form a
fenestra that is slightly on the larger side than to increase
the size of the fenestra once the vestibule is open. If the
stapedotomy is not adequate, it can be enlarged with
the laser and footplate instruments (see Video 117-9).
It is important to not fi re the laser into an open vesti-
bule. Next, a Farrior stapes rasp or a fi ne 45-degree pick
is used to remove the char. The rasp has the shape of
a disc (per style) so that small fragments of char may
be removed in any direction, which avoids turning or
twisting of the instrument as must be done when using
angled picks. This instrument comes in two sizes, 0.5
and 0.6 mm, and is manufactured by Gyrus ENT.
(Memphis, TN). Once the char is removed, a small
fenestra stapedotomy is completed. If the opening in
the footplate is irregular, a 6-mm drill set on low speed
can be used to optimize the stapedotomy.
Alternatively, the author still prefers using a Robin-
son bucket-handle prosthesis over a vein graft for all
routine stapedectomy procedures as described earlier.
If the surgeon prefers a wire-piston prosthesis, it is
placed in the oval window and carefully crimped to the
incus (Figs. 117-20 and 117-21). The newer prosthesis
does not have to be manually crimped around the incus
(Smart; Gyrus ENT). After placing the wire-Tefl on pros-
thesis, the laser is used to heat the hook portion of the
prosthesis to secure it around the incus (see Videos
117-10 and 117-11).
An alternative to using multiple 200-µm laser strikes
to form the fenestra is to use one 0.6-mm laser strike in
the middle of the footplate. The oval window may be
sealed with clotted blood or tissue. The tympanic mem-
brane is then returned to its normal position and
secured as described earlier. As mentioned, the laser is
not only useful when there is a narrow oval window
niche but can also help avoid a fl oating footplate.
Revision Stapes Surgery
Revision surgery after stapedectomy or stapedotomy is
performed for two reasons. The fi rst indication is for
Figure 117-18. CO2 laser vaporization of the posterior crus.
Figure 117-19. Rosette pattern of laser strikes on the central
footplate.

Chapter 117
Otosclerosis 1201
development of a granuloma was ascribed to a compli-
cation related to the use of Gelfoam as sealant for the
oval window. Synthetic materials are no longer used to
cover the vestibule when a stapedectomy is performed.
Various autogenous tissues, such as vein, fascia, areolar
tissue, perichondrium, periosteum, fat, and blood,
are used to seal the opening to the vestibule. Other
possible sources include infl ammatory tissue formed as
a result of reaction to talcum powder on the surgeon’s
operating room gloves. On rare occasion, people may
be allergic to an element included in the metal compo-
sition of the prosthesis.
The other urgent indication for surgical interven-
tion is the possibility of a perilymphatic fi stula. Similar
to the signs and symptoms mentioned earlier, patients
can have complaints related to hearing or balance (or
both). Hearing loss may be sudden or rapidly progres-
sive and is characteristically sensorineural. Fistula testing
(pneumatic otoscopy with recording or observation of
eye movements) is not reliable because it can be falsely
positive in patients undergoing stapedectomy.
The second indication for revision surgery occurs
when conductive hearing loss persists or develops over
time. It must be emphasized, similar to the discussion
regarding the initial procedure, that this is an elective
procedure to restore hearing. The other alternative is
amplifi cation with a hearing aid. The hearing status of
the contralateral ear must be defi ned to determine how
best to advise a patient. Given the small but real risk of
total hearing loss after revision stapes surgery, absent
hearing in the contralateral ear is a contraindication to
an elective revision procedure. Possible exceptions to
A
B
Figure 117-20. A, Method of grasp-
ing the piston with alligator forceps for
insertion onto the incus. B, Tightening
of the piston onto the long process of
the incus.
Figure 117-21. Piston in place with insertion into the fenestrated
footplate.
correction of postoperative complications. Such prob-
lems typically occur during the fi rst few weeks after the
initial procedure. Patients complain of decreased
hearing or dizziness, or both. Other complaints may
include increased tinnitus, distortion of sound, motion
intolerance, and vertigo associated with coughing,
straining, sneezing, acute alteration in barometric or
middle ear pressure, or change in body position. In the
immediate postoperative period this could occur as a
result of the formation of a granuloma. In the past,

1202
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
operating on an only-hearing ear are severe complica-
tions from the fi rst procedure (progressive hearing loss
and dizziness) or a severe to profound mixed hearing
loss in which amplifi cation is insuffi cient and cannot
provide adequate gain.
Revisions of this type should be reserved for sur-
geons with considerable experience because hearing
results, even in the best of hands, do not approach
those of primary cases. Lesinksi reviewed his series of
279 cases of revision stapes surgery performed with a
laser. Sources of failure included unrecognized fi xation
of the lateral ossicular chain, erosion of the incus, dis-
placement of the prosthesis from the oval window, and
regrowth of otosclerosis. The most common fi nding was
a displaced or malfunctioning prosthesis (81%), fol-
lowed by erosion of the incus (30%). It was believed
that erosion of the incus was caused by continued vibra-
tion of the incus bone against a prosthesis that was
immobile at the interface with the otic capsule. Resid-
ual fi xed stapes footplate was found in the center of the
oval window in 14% of patients, and 4% had complete
fi xation of the malleus.12
Correction of prosthetic slippage and problems
with the incus is statistically more successful than
reopening of a bony window closure. The laser has a
defi nite advantage in the presence of middle ear fi bro-
sis or scarring and is invaluable in minimizing trauma
to the inner ear associated with removing soft tissue in
the oval window niche. The benefi ts of using the laser
for revision stapes procedures were emphasized by
Lippy and colleagues. The success rate increased to
80% for closure of the air-bone gap within 10 dB with
the use of an argon laser. Hearing results were least
successful when the incus could not be used for
reconstruction.13
Obliterative Disease
Replacement of normal footplate anatomy by oblitera-
tive otosclerosis presents a greater, but not insurmount-
able challenge to the surgeon. Forewarning may occur
in the form of a positive Schwartze sign, a pinkish blush
behind the tympanic membrane indicative of enhanced
vascularity. Unfortunately, no typical audiometric
pattern suggests this occurrence. Experience in using a
microdrill is mandatory for this procedure, and lack
thereof requires abandonment of the operation (Fig.
117-22). Visible superstructure is fractured and removed
without fear of footplate fl otation. A small microdrill
with an angled handpiece is used to saucerize the oval
window area (Fig. 117-23). Cutting burrs are used ini-
tially, and then small diamond burrs are used to remove
the remaining focus of bone until the blue line of peri-
lymph is visualized through the thinned footplate area
(see Video 117-12). It is important to keep the saucer-
ization at the same depth throughout the circumfer-
ence of the drilled-out area. When the site has been
suffi ciently thinned, fenestration is performed in the
usual manner, and surgery proceeds as described
earlier. Although drill-out procedures have been associ-
ated with a greater risk of sensorineural hearing loss,
Figure 117-22. Micro–ear drills can fi t through the ear speculum
and still provide good visualization.
Figure 117-23. Use of a microdrill to saucerize obliterative
disease.
the risk is small in the hands of an experienced
operator.
Expected Results
There is no otologic procedure (save perhaps myrin-
gotomy) in which hearing improvement will exceed
that of stapes surgery. Conservative estimates of at least
90% success in restoration of conductive loss to air-
bone gaps of less than 10 dB are realistic and seen in
nearly all series reported. Results that differ signifi cantly
from these bear investigation for faulty patient selection
or surgical technique. Occasional reduction or cata-
strophic loss of hearing is known to even the most
experienced surgeons, but the incidence should be 1%
or less. These statistics make surgery an acceptable risk
for most patients seeking improvement in hearing.
Although otolaryngologists must decide about their
own qualifi cations as stapes surgeons, experience clearly
leads to superior hearing results.

Chapter 117
Otosclerosis 1203
POSTOPERATIVE MANAGEMENT
The demands of third-party insurers over the past
decade have greatly reduced the length of hospital stay.
Today, surgery for otosclerosis is performed as an out-
patient procedure regardless of the type of anesthesia
provided. Fortunately, most surgeons have discovered
that reduction of stay has not altered the outcome in
otosclerosis surgery. Nevertheless, each physician must
maintain the ability to determine which patients require
overnight observation for any of numerous reasons,
including age, general health, complicating medical
problems, and distance from the hospital. Complica-
tions encountered during surgery or symptoms suffered
postoperatively should also be suffi cient reason for
extension of hospital stay.
Patients are allowed to ambulate soon after surgery,
but they are advised to not lie on the ear that has under-
gone surgery for 24 hours. Precautions are given about
sudden head movements to avoid dizziness, and prohi-
bitions are also outlined against nose blowing, straining
or lifting, or getting water into the ear that has been
repaired. Clean cotton is kept in the external meatus as
necessary until the packing is removed in approximately
1 week. Patients are encouraged to report any occur-
rence of worsening of vertigo, as well as any diminution
in hearing. Sedentary work is permitted within 48 hours,
but more strenuous occupations are banned for at least
3 weeks. Air travel is discouraged until the middle ear
is seen to be well aerated, although this restriction may
be impractical for some patients living at great dis-
tances. Antibiotics are not prescribed routinely. Analge-
sics with codeine are given when necessary.
COMPLICATIONS
Complications encountered during surgery range from
the insignifi cant to those that may require abandon-
ment of the procedure. Even when completion of
surgery is not possible, it is of primary importance to
preserve auditory nerve function whenever possible.
Reliance on a hearing aid as a fall-back position is infi -
nitely preferable to severe loss of cochlear reserve.
Complications are considered individually in the follow-
ing sections.
Tympanic Membrane Perforations
A tear in the tympanic membrane is most often due to
failure to elevate the fl ap throughout its entire width
before separation of the fi brous annulus from its sulcus
(Fig. 117-24). A small tear may easily be repaired with
tiny pledgets of Gelfoam inserted through the perfora-
tion. Larger defects should be reinforced with any
remaining harvested tissue as an underlay graft. Occa-
sionally, an extremely atrophic and thinned tympanic
membrane is recognized preoperatively, and myringo-
plasty should be anticipated at the time of surgery. Tym-
panic membrane problems rarely have an impact on
the outcome of surgery.
Injuries to the Chorda Tympani Nerve
Careful removal of bone from the posterior canal wall
allows preservation of the chorda tympani nerve in
approximately 90% of cases. Stretching of the nerve or
partial sectioning of less than one half its diameter
should prompt preservation with reapproximation of
A
C
B
Tympanic
membrane
defect
Gelfoam
pledget
Underlay
tissue graft
Figure 117-24. A, Postoperative
defect in the tympanic membrane.
B, A moist Gelfoam pledget is
inserted through the defect to
support it from the medial side. C,
Use of an underlay tissue graft for
repair of the defect.

1204
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
the fi bers as well as possible. Complete or nearly com-
plete sectioning of the nerve is inevitable in a small
percentage of cases. Even complete sectioning of the
nerve most often results in only temporary dysgeusia.
Most patients seem to compensate for taste disturbances
within 6 months, although a small number may com-
plain indefi nitely. When taste is of utmost importance
to the patient and when taste disturbance has resulted
from surgery in the opposite ear, amplifi cation for the
second ear should be advised.
Ossicular Dislocation
This unusual complication involves incudomalleal dis-
location. It results from inadvertent lateral displace-
ment of the long process of the incus. Careful placement
of the incus in its original position will usually give a
good hearing result despite somewhat greater diffi culty
in placing the prosthesis because of instability of the
incus.
Floating Stapedial Footplate
A fl oating footplate occurs when the superstructure is
down-fractured and the entire footplate becomes loos-
ened from the surrounding annular attachment at the
oval window. This event is relatively rare and occurs in
less than 1% of cases. It is best avoided by awareness of
the factors that lead to it. Fracture of the stapedial
superstructure before gaining a fenestration or control
hole in the footplate may lead to this problem. Exces-
sive pressure exerted on a thickened footplate may also
result in circumferential dislodgement of it. It is neces-
sary to get a purchase of the footplate when it is mobi-
lized and fl oating. If a fenestration was initially
performed, a footplate hook can be used to engage the
footplate and extract it laterally. When this is not possi-
ble, the undersurface of the footplate is best accessed
by drilling or curetting a small opening in the promon-
tory side of the footplate until a fi ne right-angled pick
can be inserted under the footplate and turned to com -
plete extraction of it (Fig. 117-25). Another method
for removing a large fl oating fragment is to place a
few drops of blood over the window and remove
the coapted fragments once a clot has formed. If the
footplate becomes subluxated too far medially within
the vestibule, attempts at retrieval should not be under-
taken to avoid traumatic injury to the inner ear. A wire
or bucket-handle prosthesis should be placed over a
tissue graft.14 Slight displacement of small fragments
should be left alone because they rarely cause hearing
loss. Larger fragments may induce persistent postural
vertigo.
Perilymph Gushers
Preoperative computed tomography should be per-
formed in children to identify anomalies of the otic
capsule and potential gushers. On occasion, perilymph
gushers are encountered in adults. The problem con-
sists of excessive perilymphatic fl ow into the middle ear
because of enlargement of the cochlear aqueduct or
communication between the medial internal auditory
A
B
Figure 117-25. A, Creation of a small “rescue hole” in the vestibule
for removal of a fl oating footplate. B, Insertion of a fi ne right-angled
pick through the rescue hole for retrieval of the footplate.
canal (fundus) and the inner ear (Fig. 117-26). Control
is best achieved by elevating the head of the table and
continuing to suction the perilymph until the reservoir
of the cerebellar pontine cistern is exhausted. Fat is
harvested from the ear lobule and placed snugly in the
oval window after removal of the footplate. The fat is
held in place with the stapes prosthesis. Elevation of the
head is continued postoperatively and may be supple-
mented by insertion of a spinal drain. This condition
increases the incidence of sensorineural hearing loss.
Round Window Otosclerosis
Complete obliteration of the round window niche as a
result of otosclerosis is rare, although partial narrowing
occurs occasionally. The procedure should be aban-
doned in the case of complete obliteration because
drill-out of the round window has been associated with
a high rate of sensorineural loss. Surgery may proceed
as usual with partial closure.

Chapter 117
Otosclerosis 1205
Persistent Stapedial Artery
Small remnants of this second branchial arch vessel
often course across the stapedial footplate (Fig.
117-27). In a few cases, the artery may be large enough
to create potential bleeding problems when disrupted.
Even the larger arteries can most often be worked
around by fenestration of the footplate and placement
of the prosthesis anterior or posterior to the intact
vessel. If the obturator foramen is obliterated by the
artery, wise judgment may dictate termination of the
procedure and the use of amplifi cation with a hearing
aid.
Dehiscence and Displacement of the
Facial Nerve
Partial or total dehiscence of the horizontal portion
of the facial nerve is a fairly common fi nding during
A
B
C
middle ear surgery. Recognition of this anomaly is
usually only important in that it encourages one to
avoid instrumentation that could damage the nerve.
Much less commonly, the facial nerve may overhang the
oval window and, in rare cases, even travel directly
across its surface (Fig. 117-28). Stapes surgery can
usually be successfully completed in the presence of
moderate overhang of the facial nerve, although visual-
ization of the oval window is somewhat more diffi cult.
Gentle retraction of the nerve with the side of a suction
tip will ordinarily allow fenestration of the footplate and
placement of the prosthesis. When the overhang is
more pronounced, a crimp-on prosthesis of tantalum
or platinum may be bent to curve around the dehis-
cence. Nitinol prostheses are also available, but great
caution must be taken to ensure that tightening of the
metal alloy with the laser does not injure the exposed
nerve. The oval window may also be compromised by
Figure 117-26. A, A gusher of
perilymph through the footplate
fenestra. B, Reverse Trendelenburg
position for relief of the perilym-
phatic gusher. C, Use of a piston
prosthesis with an adipose tissue graft
to seal the perilymphatic gusher.

1206
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Figure 117-27. Persistent stapedial artery.
Dehiscent
facial nerve
Figure 117-28. Dehiscent and overhanging facial nerve.
A
B
Figure 117-29. A, Promontory
focus of otosclerosis. B, Use of a
microdrill to remove the promon-
tory overhang.
an overhang of bone from the promontory. This situa-
tion may be corrected with a microdrill until visualiza-
tion is adequate (Fig. 117-29). Extreme situations of
nerve displacement with coverage of the footplate
dictate abandonment of the surgery.
Intraoperative Vertigo
The onset of vertigo during surgery is related to stimula-
tion of the labyrinthine receptors, which may occur
because of excessive manipulation of the stapes or emp-
tying of the fl uid compartment of the vestibule. Local
anesthesia permits the surgeon to rely on this symptom
as a sign of impending damage to the inner ear. General
anesthesia obviates this important signal. Vertigo is
often transient or mild, but when it persists, it may
imperil the completion of surgery because of associated
nausea and vomiting. In this situation, rapid measures
must be instituted to relieve symptoms and permit com-
pletion of the procedure. Droperidol is the most expe-
ditious drug in this emergency; 1.25 mg is given slowly

Chapter 117
Otosclerosis 1207
as a direct intravenous push, and larger doses can be
used if necessary. Relief of symptoms is rapid and
permits completion of the operation with patient
comfort. Intraoperative monitoring is necessary when
using this drug because of potential cardiac complica-
tions and hypotension. Intravenous ondansetron (4 mg)
is also effective in this regard.
The use of general anesthesia does not permit
the surgeon to monitor inner ear complications.
However, under general anesthesia the patient will not
move or become intolerant of minor middle ear stimu-
lation. It is our preference to use general anesthesia
rather than local or intravenous sedation for stapes
surgery.
Reparative Granuloma
The formation of reactive granulation tissue in and
around the oval window is a catastrophic complication
of stapes surgery that is seen less and less commonly
today. Some have attributed it to particulate foreign
matter from the prosthesis or possibly from the sur-
geon’s gloves, but this hypothesis remains unproved.
Possibly, washing of powder from surgical gloves, use of
powderless gloves, and rinsing of prosthetics before
introduction have reduced the incidence of granuloma.
A granuloma typically develops approximately 1 week
after surgery. Patients complain of diminished hearing
and dizziness after initially exhibiting no signifi cant
problems. Examination reveals a violaceous fullness in
the posterosuperior quadrant of the tympanic mem-
brane. Audiometric testing confi rms sensorineural
impairment, which is usually accompanied by reduction
in word recognition.
Although some authors have advocated systemic
therapy with high-dose steroids, the generally accepted
treatment is immediate surgical intervention with
removal of the granuloma. This entails removal of the
prosthesis and tissue graft and insertion of new mate-
rial. Rapid recognition of the condition and surgical
correction may reverse the hearing loss, but a perma-
nent sensorineural defi cit is more likely. In extreme
cases or when recognition is delayed, granulomatous
tissue has been shown to invade the oval window and
fi ll the vestibule.
Perilymphatic Fistula
In addition to reparative granuloma, postoperative
perilymphatic fi stula is the other chief cause of poor
hearing results. Although each patient has a temporary
fi stula after footplate fenestration, the usual manner of
healing seals the fl uid leak within a short time. Persis-
tence or redevelopment of the fi stula after healing may
be the result of imperfect tissue graft placement,
dislodgment of the prosthesis, or sudden expulsion
of fl uid because of coughing or sneezing. Symptoms
related to perilymphatic leakage are typically fl uctuant
hearing loss and dizziness. Although physical examina-
tion of the ear is unremarkable, audiograms confi rm
deterioration of cochlear function. When this complica-
tion is suspected, immediate exploration is indicated if
hearing is to be salvaged. If a fi stula is confi rmed, tissue
grafting and prosthetic placement are repeated.
Preoperative Problems with the
Tympanic Membrane
When the tympanic membrane is extremely thin or
atrophic, plans for grafting should be included in the
preoperative counseling. Even if such grafting is unnec-
essary during surgery, it is better to have forewarned the
patient. A larger piece of fascia, vein, or perichondrium
can be harvested if a tissue graft is used for closure of
the oval window. Severe atrophy and atelectasis can be
supported with cartilage harvested from the tragus (see
Video 117-13).
Magnetic Resonance Imaging
With few exceptions, almost all middle ear prosthetics
in use today are nonferromagnetic. The Robinson pros-
thesis is included in the group of devices that can be
safely subjected to MRI. Patients are instructed in this
regard to arm them for future questions about their
eligibility for scanning. It is anticipated that magnet
strength will increase in the future. The Robinson pros-
thesis is available in titanium, as well as the original
stainless steel confi guration. Titanium is a safe metal in
a magnetic fi eld. Prostheses made of nitinol are also
safe during MRI.
PEARLS
• An appropriate candidate for middle ear exploration
to diagnosis otosclerosis is a patient with a normal
ear examination, negative Rinne test, conductive
hearing loss of 25 dB, absent acoustic refl exes, and
an understanding of the risks and benefi ts of the
procedure.
• Offer surgery to the worse-hearing ear and do not
undertake elective surgery on an only-hearing ear
unless maximum amplifi cation has been tried and
deemed unsuccessful.
• Ensure that adequate surgical exposure has been
achieved before addressing the status of the stapes.
• Palpate the lateral ossicular chain after the
incudostapedial joint has been separated, confi rm
that the lateral chain is not fi xed, and then check
the mobility of the stapes.
• Do not apply suction directly to the stapedotomy
and vestibule.
• If a fl oating footplate develops and it sinks into the
vestibule, place a tissue graft over the oval window
and reconstruct with a wire or bucket-handle
prosthesis.

1208
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
2. Konigsmark BW, Gorlin RJ: Genetic and Metabolic Deafness.
Philadelphia, WB Saunders, 1976.
3. Ferlito A, Arnold W, Rinaldo A, et al: Viruses and otosclerosis:
Chance association or true causal link? Acta Otolaryngol 123:741-
746, 2003.
4. Minor LB: Clinical manifestations of superior semicircular canal
dehiscence. Laryngoscope 115:1717-1727, 2005.
5. Welling DB, Merrell JA, Merz M, Dodson EE: Predictive factors
in pediatric stapedectomy. Laryngoscope 113:1515-1519, 2003.
6. Sakai O, Curtin HD, Fujita A, et al: Otosclerosis: Computed
tomography and magnetic resonance fi ndings. Am J Otolaryngol
21:116-118, 2000.
7. Massey BL, Kennedy RJ, Shelton C: Stapedectomy outcomes: Tita-
nium versus Tefl on wire prosthesis. Laryngoscope 115:249-252,
2005.
8. Tange RA, Grolman W, Dreschler WA: Gold and titanium in the
oval window: A comparison of two metal stapes prostheses. Otol
Neurotol 25:102-105, 2004.
9. Knox GW, Reitan H: Shape-memory stapes prosthesis for otoscle-
rosis surgery. Laryngoscope 115:1340-1346, 2005.
10. Silverstein H, Hoffmann KK, Thompson JH Jr, et al: Hearing
outcome of laser stapedotomy minus prosthesis (STAMP) versus
conventional laser stapedotomy. Otol Neurotol 25:106-111,
2004.
11. Rizer FM, Lippy WH: Evolution of techniques of stapedectomy
from the total stapedectomy to the small fenestra stapedectomy.
Otolaryngol Clin North Am 26:443-451, 1993.
12. Lesinski SG: Revision stapedectomy. Curr Opin Otolaryngol
Head Neck Surg 11:347-354, 2003.
13. Lippy WH, Battista RA, Berenholz L, et al: Twenty-year review of
revision stapedectomy. Otol Neurotol 24:560-566, 2003.
14. Jaisinghani VJ, Schachern PA, Paparella MM: Stapes mobilization
in otosclerosis. Ear Nose Throat J 80:586-590, 2001.
PITFALLS
• Proceeding with footplate work before optimizing
exposure of the oval window niche may result in
prolongation of the procedure and untoward results.
• Attempts at recovering segments of the footplate
that fall into the vestibule may result in iatrogenic
sensorineural hearing loss.
• Failure to close the air-bone gap after surgery for
presumed otosclerosis may be due to fi xation of the
lateral ossicular chain or dehiscence of the superior
semicircular canal.
• Despite closure of the air-bone gap, residual
sensorineural hearing greater than a 35-dB speech
reception threshold may still require hearing aid
amplifi cation.
• In unilateral otosclerosis, the patient’s perception of
complete success is having the operated ear improve
to air conduction scores within 15 dB of the better
ear.
References
1. Politzer A: Über primäre Erkrankung der knöcheren Labyrinth-
kapsel. J Ohrenheilk 25:309-327, 1894.

Chapter 118
Bone-Anchored Hearing Devices
Yael Raz
Conductive and mixed hearing loss can often be treated
surgically or with conventional hearing aids. However,
certain patients are not candidates for standard surgical
approaches or traditional amplifi cation—for example,
those whose external auditory meatus has been closed
off during lateral temporal bone resection, mastoid
cavities that continue to drain despite surgical treat-
ment, or congenital aural atresia not favorable for
repair. Bone-anchored hearing devices conduct sound
via bone vibration, thereby effectively bypassing the
middle ear conductive apparatus, and represent a viable
alternative for this subset of patients. Although conven-
tional bone-conducting hearing aids can also provide
amplifi cation in such cases, these devices can cause
discomfort and possible skin erosion as a result of pres-
sure from the headband. Bone-anchored devices are
osseointegrated and thus do not place pressure on the
surrounding skin. Bone-anchored hearing devices are
also an appealing alternative to the CROS (contralat-
eral routing of offside signal) aid in the treatment of
single-sided deafness. Sound from the deafened side is
transmitted to the intact contralateral cochlea with little
attenuation. Multiple studies suggest that the Baha is
better accepted than amplifi cation with the CROS
aid.1,2
Coupling of a bone vibrator to an osseointegrated
implant was initiated in Sweden in the early 1970s.3
Several companies have marketed bone-anchored
hearing aids in the past; however, at present there is
one dominant device in the marketplace, the Baha
(manufactured by Cochlear Corporation, which recently
acquired Entifi c Corporation). The Baha consists of
three parts: an implanted titanium fl ange fi xture, a
sound processor, and an external abutment that couples
the titanium fi xture to the sound processor (Fig. 118-1).
Successful placement of the Baha depends on the cre-
ation of a healthy, permanent percutaneous connec-
tion. Osseointegration of the fl ange fi xture is a critical
factor. The implant is made of titanium, a metal that is
highly biocompatible and corrosion free. The micro-
structure of the implant has been designed with a rough
surface containing micropits that enhance interaction
between osteocytes and the implant, thus maximizing
osseointegration.4 The fi xture is threaded to maximize
contact with the surrounding bone and enhance stabil-
ity. The implant is inserted with a high-torque drill at
slow speed to avoid thermal damage to the surrounding
osteocytes. Disposable drill bits ensure a sharp bit for
each step, and irrigation prevents thermal damage.
Another critical factor in ensuring the health of the
percutaneous connection is avoidance of infection or
infl ammation. Modeled after the natural interface
between fi ngernails, talons, or teeth and the surround-
ing skin or gingival bed, the skin at the fi xture penetra-
tion site must be free of hair and immobile.5 Movement
of skin at the implant-skin interface or the presence of
hair follicles can provide an entry point for bacterial
infection or infl ammation. Meticulous attention to
technique in the soft tissue work is critical for stabiliza-
tion of the surrounding skin. Insertion of the titanium
device requires a specialized handpiece that is fi tted
with multiple adaptors to elevate the skin graft, estab-
lish a guide hole, and countersink and insert the fi xture.
Attention to detail such as handling the titanium com-
ponents with titanium forceps, using appropriate drill
speeds, and irrigation can be critical in ensuring osseo-
integration of the device and a healthy percutaneous
connection. Complications with the Baha consist pri-
marily of adverse soft tissue reaction surrounding the
fi xture and failure of osseointegration.6,7
1209

1210
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
PATIENT SELECTION
When the Baha is being considered for mixed or con-
ductive hearing loss, the bone line should be better
than 45-dB pure-tone average (PTA; 0.5, 1, 2, 3 kHz) in
the affected ear, and word recognition should be greater
than 60%. When bone conduction is worse than 45 dB,
a body-level sound processor is more suitable. For
single-sided deafness, the contralateral ear should have
a PTA air conduction threshold better than 20 dB.
Insertion of the titanium fl ange fi xture is a relatively
safe and quick procedure that can be performed under
local anesthesia, and there are relatively few contrain-
dications. The patient must be comfortable with the
concept of having a device protruding from the scalp.
Certain patients actually prefer the aesthetic appear-
ance of the Baha as opposed to a conventional hearing
aid because it can be hidden with certain hairstyles. It
is important to communicate to patients that it is neces-
sary to permanently remove the hair follicles surround-
ing the abutment and that the scalp will be concave at
the site of the implant to immobilize the surrounding
skin. Extensive preoperative counseling with photo-
graphs enhances patient satisfaction. A test band
coupled to the sound processor can provide a simula-
tion of the sound input achieved with the Baha; however,
sound fi delity is not as high as with the actual implanted
device because of soft tissue attenuation.
The patient’s ability to care for the implant site
must be taken into consideration in selection for this
procedure. Patients with certain psychiatric or other
disorders that impair the ability to maintain proper
hygiene may not be able to perform the appropriate
local skin care required to keep the implant site healthy.
Patients with a history of external beam irradiation to
the scalp, diabetes, or dermatologic conditions such as
psoriasis may be more prone to adverse skin reactions
and need to be monitored closely, but these conditions
have not been found to increase the risk of implant
loss.8 Before surgery, the patient meets with an audiolo-
gist to select the sound processor.
PREOPERATIVE EVALUATION
In children, a computed tomography (CT) scan of the
temporal bone can be helpful, particularly in the pres-
ence of developmental abnormalities that affect the
thickness of the skull. In adults, there is no indication
for imaging studies. One potentially frustrating aspect
of the preoperative evaluation is the preauthorization
process. The Baha device falls in the gray zone between
cochlear implants, which are routinely covered by insur-
ance, and hearing aids, which are not generally covered.
Insurance policies regarding the Baha seem to vary from
state to state and among various companies. It is critical
to address this issue before surgery and to clarify whether
the insurance company will cover the cost of the sound
processor in addition to placement of the fl ange fi xture.
On occasion, coverage can be obtained with physician
advocacy on the patient’s behalf in the form of a letter
indicating that the patient is not a candidate for conven-
tional amplifi cation and explaining how the device
differs from a conventional hearing aid.
SURGICAL APPROACH
We prefer to insert the titanium fl ange fi xture under
general anesthesia. However, when there are concerns
regarding a patient’s ability to withstand general anes-
thesia, the procedure can be performed under intrave-
nous sedation with local anesthesia or even with local
anesthesia alone. In adults, insertion of the device is
performed in a single-stage procedure in which the
fl ange fi xture is inserted with the abutment preattached.
Once the site has healed and osseointegration has
occurred, the sound processor is attached to the abut-
ment. In children or in adults with irradiated skin or
poor bone quality, the fl ange fi xture is inserted at the
fi rst stage and the abutment is placed at a second stage
once osseointegration has occurred.
Planning the Flap
We typically use an inferiorly based skin fl ap. A mock
device is useful in outlining the size of the skin fl ap.
However, We have found that the fi xture is ideally placed
at the center of the skin fl ap and not at its superior
aspect, as marked in the present generation of mock
devices. If the fi xture site is marked too superiorly within
the outline of the mock device, gravity often results in a
superior overhang of tissue that makes contact with the
sound processor. The implant site should be 5 to 5.5 cm
away from the ear canal to prevent the sound processor
from contacting the pinna (Fig. 118-2). Placing the
fi xture in the region of the temporal line will make it
most likely that adequately thick cortical bone will be
encountered. It is our preference to use the dermatome
because it is rapid and consistently results in an even,
thin skin fl ap (0.6-mm thickness, 24-mm width).
However, equally thin fl aps can also be achieved manu-
ally. When two-stage surgery is performed, if the cover
screw projects from the skin surface, the dermatome can
tear at this site and therefore manual elevation plus thin-
ning of the fl ap is recommended.
The postauricular region is shaved and topical
anesthetic is infi ltrated at the planned fl ap site. If using
the dermatome, the local anesthetic should be mas-
saged into the skin so that the skin surface is smooth
before harvesting the graft. A superfi cial skin incision
at the superior aspect of the planned fl ap is helpful in
Figure 118-1. The Baha system includes a fl ange fi xture, an exter-
nal abutment, and a sound processor that snaps on to the external
abutment. In adults undergoing a single-stage procedure, the fl ange
fi xture is preattached to the external abutment, and both pieces are
inserted as a unit. (Permission granted from Cochlear Corporation.)

Chapter 118
Bone-Anchored Hearing Devices 1211
allowing the dermatome to engage the skin. Use of
mineral oil and application of pressure with a tongue
depressor in advance of the dermatome is helpful in
developing the skin graft. Steady downward pressure
and slow, even progress ensure an intact graft that
remains attached to the scalp inferiorly. If constant
downward pressure is not maintained until the derma-
tome has been stopped, the skin graft may be severed
at the base. The graft can still be used; it should be
maintained in moist gauze and sutured as a free graft
over the implant site. Once the fl ap has been elevated,
its undersurface is freed of hair follicles with a horizon-
tal sweeping motion of the scalpel (Fig. 118-2). Even for
thin fl aps elevated with the dermatome, this step is
helpful in keeping the percutaneous connection clean
and infection free. The skin graft is then refl ected infe-
riorly and covered with moist gauze.
Drilling the Fixture Site
The soft tissue is incised superiorly, anteriorly, and
posteriorly; elevated off the underlying periosteum;
and refl ected inferiorly. The inferior attachment is not
divided until adequate cortical thickness has been
established by drilling the guide hole. Thus, if the drill
site needs to be altered signifi cantly, the soft tissue
can be replaced while avoiding unnecessarily large and
unsightly defects. This area of the mastoid cortex is
denuded of periosteum in an amount suffi cient to
accept the countersink. Once the initial drilling steps
(guide hole and countersinking) establish adequate
cortical depth, more extensive removal of soft tissue can
be performed.
Drilling of the guide hole is performed at high
speed with irrigation and use of the guide drill and a
plastic spacer to ensure that depth of drilling is not
greater than 3 mm (Fig. 118-3). It is critical that this
step and all subsequent drilling steps be carried out
precisely perpendicular to the mastoid cortex. Acute
angles during the early drilling steps will result in
angling of the fl ange fi xture, which will lead to contact
between the sound processor and the surrounding
tissue and may result in discomfort or acoustic feed-
back. A drill indicator attachment is available to facili-
tate visualization of the drill’s trajectory (see Fig. 118-3).
The guide hole is examined to ensure that the sigmoid
sinus, dura, and mastoid air cells have not been vio-
lated. The plastic spacer is then removed and drilling
continues to a depth of 4 mm, again using copious irri-
gation. Some authors have recommended proceeding
with implantation in the event of violation of the dura
or sigmoid sinus because the fl ange fi xture effectively
stops leakage of cerebrospinal fl uid or bleeding.
However, a cerebral abscess has been reported with the
Baha system.9 Additionally, osseointegration may be
impaired by the absence of bone at the deep surface of
the fi xture. If multiple attempts do not reveal bone
A
B
C
D
Figure 118-2. A, A mock device is used to plan the size of the skin fl ap. The implant should be placed 5.0 to 5.5 cm from the ear canal to
ensure that the sound processor will not contact the auricle. B, The skin is incised superfi cially to allow the dermatome to engage the skin.
C, The Baha dermatome is used to elevate an inferiorly based skin fl ap. D, Hair follicles are removed from the undersurface of the skin fl ap.

1212
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
B
C
D
F
E
Figure 118-3. A, Drilling commences with use of the guide drill and
a plastic spacer to ensure a depth no greater than 3 mm. B, The spacer
is then removed and the guide hole is drilled to a depth of 4 mm if corti-
cal bone thickness is suffi cient. C, The appropriately sized countersink
is then used. Drilling of the guide hole and countersink is performed
under high speed (≈2000 rpm) with copious irrigation. D, The drill
indicator facilitates visualization of the drill’s trajectory. E, If the coun-
tersink has been drilled precisely perpendicular to the cortex, a concen-
tric ring should be visible surrounding the guide hole. F, A 4-mm biopsy
punch is used to remove skin directly overlying the drill site.

Chapter 118
Bone-Anchored Hearing Devices 1213
depth suffi cient to handle a 4-mm fi xture, the surgeon
may elect to proceed with a 3-mm fi xture, although it
is somewhat more prone to failure of osseointegration.10
In a young child with a thin skull, exposure of the dura
is often unavoidable, thus frequently necessitating use
of the 3-mm fi xture.11
Once the guide hole has been established, the
appropriately sized countersink drill bit is attached to
the handpiece (3 or 4 mm, depending on the depth of
the guide hole). The drilling motion for making the
countersink and the guide hole should be up and down
rather than plunging the drill in a single downward
trajectory. This allows irrigation fl uid to enter the
drilled area and protects against thermal damage. The
countersink drill widens the guide hole to an appropri-
ate diameter and creates an even surface for the fl ange,
thereby enhancing contact between the fi xture and the
surrounding bone. Care should be taken to remove
bone from the threads of the drill. If drilling has been
performed directly perpendicular to the cortex, a con-
centric countersink should be visible surrounding the
drill hole. A cruciate incision is then made in the skin
graft overlying the drill site. Alternatively, a 4-mm biopsy
punch can be used (see Fig. 118-3).
Soft Tissue Removal
After drilling of the guide hole and countersink, the
inferior attachment of the soft tissue underlying the
skin fl ap is divided. The periosteum is left intact except
for the area of the countersink. Absence of soft tissue
between the skin graft and the periosteum is essential
to ensure fi xation of the skin surrounding the fl ange
fi xture and prevent infection and infl ammation. The
margins surrounding the graft site are then retracted
with double skin hooks, and the soft tissue surrounding
the graft site is removed anteriorly, posteriorly, and
superiorly (Fig. 118-4). The result is a beveled, gentle
A
B
C
Figure 118-4. A, The bone underneath the skin graft site is covered
only by periosteum. Note the absence of soft tissue. B and C, The tissue
surrounding the graft site is also thinned aggressively to allow the skin
margins surrounding the graft to slope gently toward the graft site.

1214
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
B
C
Figure 118-5. A, The abutment adaptor is placed on the
drill and used to pick up the fl ange fi xture with the preat-
tached abutment. B, The fi xture is inserted at slow speed.
C, The fl ange fi xture is self tapping, and the drill stops
automatically once complete insertion has been achieved.
slope onto the skin fl ap and implant site. Individuals
who are obese or have a particularly thick scalp are
more prone to the development of this superior soft
tissue overhang. Beveling of the margins is particularly
important in this population to avoid contact between
this superior shelf of skin and the sound processor.
Insertion of the Device
For adults undergoing a planned single-stage insertion,
the abutment is packaged preattached to the titanium
fi xture (Fig. 118-5). An abutment inserter attachment
is used to pick up the implant, which is inserted at low
speed. The fi xture is self tapping. Irrigation should be
avoided until the fi rst threads have engaged so that
fl uid is not trapped between the screw and bone. No
pressure is necessary at this stage, and the fi xture should
be allowed to fi nd its own way. The fi nal turns can be
performed manually to ensure a tight fi t; however, care
must be taken to not tighten the screw excessively and
damage the surrounding bone. The implant must be
stable once inserted or connective tissue will form at
the bone-screw interface and prevent osseointegration
of the fi xture. If a biopsy punch was used previously, a
small incision may be necessary to enlarge the opening
suffi ciently to accept the abutment. Alternatively, a
small cruciate incision can be made in the skin overly-
ing the abutment and the abutment delivered through
the skin.
Shrinkage of the skin graft, as well as the added
surface area created by beveling of the margins, some-
times makes the closure tight. Tension can be dimin-
ished by tacking the margins surrounding the skin fl ap
to the periosteum, particularly at the corners. It is better
to leave some of the beveled margin to granulate than
to approximate the graft under tension. The incision
is closed with interrupted chromic suture. Alternate
sutures
incorporate
the
underlying
periosteum
(Fig. 118-6). Tacking sutures, particularly at the base of
the fl ap, and small incisions in the center of the graft
prevent hematoma formation and subsequent separa-

Chapter 118
Bone-Anchored Hearing Devices 1215
tion of the skin graft from the periosteum. A healing
cap is snapped onto the abutment. An inverted Y-shaped
incision is made at one edge of a folded Xeroform
sheet, which is placed under the healing cap. A mastoid
dressing is applied and left in place for 1 to 2 days.
Special Considerations in the
Pediatric Population
The Baha has been approved by the U.S. Food and
Drug Administration for children 5 years of age and
older, although reports from outside the United States
suggest that the fi rst stage can be performed success-
fully in younger children.12 The optimal age for Baha
insertion depends on the thickness of the skull, which
correlates with height more than with age. The proce-
dure should be staged in young children, particularly if
the calvaria is less than 3 mm thick. A longer period—
between 6 and 12 months—should be allotted for
osseointegration. The procedure can be performed in
a single stage between 9 and 12 years of age. If a staged
procedure is planned, a cover screw is threaded into the
inner threads of the fi xture to maintain its patency for
later attachment of the abutment. At the second stage
this screw is removed and the abutment is attached and
externalized. The sound processor may be coupled to
the abutment 4 weeks after the second stage. In chil-
dren, the thickness of the skull may limit the fi xture to
3 mm instead of the 4-mm implant typically used in
adults.
Children with craniofacial anomalies, such as
Treacher Collins syndrome or microcephaly, are more
likely to have thin cortical bone or a low-hanging middle
fossa tegmen. In this population, preoperative CT scan-
ning can be useful for assessing the thickness of the
skull and determining the position of the middle fossa
relative to the mastoid. Techniques have been described
for building up the bone surrounding the fi xture with
the use of a Gore-Tex membrane.13
Children who are too young for insertion of the
Baha may be fi tted with a Baha soft band, which main-
tains the sound processor over the mastoid with light
pressure. Infants with unilateral hearing loss often do
not allow the band to remain in place for long; however,
children with bilateral conductive hearing loss enjoy
the sound and thus tolerate the soft band quite well.
When the hearing loss is due to microtia or anotia,
insertion of the Baha must be coordinated with recon-
structive efforts. Special planning and perhaps more
posterior placement of the device might be required to
keep the device from contacting the anticipated helical
rim of the reconstructed auricle and avoid disruption
A
B
C
Figure 118-6. A, The abutment is delivered through the skin fl ap and
draped over the underlying periosteum. The skin margins surrounding
the graft site have been tacked to the periosteum at the two superior
corners and inferiorly. For closure, simple sutures are alternated with
sutures incorporating the underlying periosteum. B, The completed
closure is free of tension. C, A healing cap is snapped onto the external
abutment, and a large sheet of folded Xeroform with an inverted Y inci-
sion at one edge is tucked under the healing cap. The Xeroform keeps
the skin graft secure against the underlying periosteum.

1216
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
of the vascular supply to the temporoparietal skin fl ap
used for its coverage. Alternatively, osseointegrated
fl ange fi xtures can be used to affi x a prosthetic auricle.
The location of these fi xtures must be coordinated with
an experienced prosthetist. In children, consideration
should be given to the insertion of a “sleeper” fi xture.
This additional fi xture is maintained under the skin
fl ap with an internal cover screw and serves as a backup
in case of failure of osseointegration or secondary
trauma with loss of the initial fi xture.
POSTOPERATIVE MANAGEMENT
One week postoperatively, the folded Xeroform is
replaced. Two weeks after surgery, if the site has healed
satisfactorily, the healing cap can be removed. The
patient is instructed to clean the site with soap and
water. The sound processor is coupled to the abutment
after allowing 3 months for osseointegration to take
place (Fig. 118-7). Premature loading of the abutment
can result in failure of osseointegration. The patient is
then monitored at 6-month intervals to ensure stability
of the abutment.
A
B
C
D
Figure 118-7. A, The graft site with external abutment 3 months postoperatively. Note the absence of hair follicles, a key factor in preventing
infection at the percutaneous connection. B, The graft site 1 year postoperatively. C, The sound processor has been coupled to the external
abutment. D, With certain hairstyles, the BAHA can be quite inconspicuous.
PEARLS
• The planned fi xture site should be marked at the
center of the skin fl ap rather than superiorly, as
indicated by the marker hole in the present
generation of mock devices.
• Successful osseointegration depends on copious
irrigation and maintenance of the appropriate drill
speed when establishing the guide hole and
countersink, as well as insertion of the fl ange fi xture.
• Removal of surrounding hair follicles, a thin skin
graft, and excision of soft tissue underlying the skin
graft will ensure a reaction-free penetration site.
• The mastoid cortex is thickest at the temporal line,
thus making it an optimal site for the fl ange fi xture.
• Extra care must be taken to ensure that all drilling
steps are performed perpendicular to the mastoid
cortex.
• Maintenance of the periosteum surrounding the drill
site is vital for ensuring a satisfactory blood supply
to the skin fl ap.

Chapter 118
Bone-Anchored Hearing Devices 1217
References
1. Wazen JJ, Spitzer JB, Ghossaini SN, et al: Transcranial contralat-
eral cochlear stimulation in unilateral deafness. Otolaryngol
Head Neck Surg 129:248-254, 2003.
2. Niparko JK, Co KM, Lustig LR: Comparison of the bone anchored
hearing aid implantable hearing device with contralateral routing
of offside signal amplifi cation in the rehabilitation of unilateral
deafness. Otol Neurotol 24:73-78, 2003.
3. Tjellstrom A, Lindstrom J, Hallen O, et al: Osseointegrated tita-
nium implants in the temporal bone. A clinical study on bone-
anchored hearing aids. Am J Otol 2:304-410, 1981.
4. Eriksson E, Branemark PI: Osseointegration from the perspective
of the plastic surgeon. Plast Reconstr Surg 93:626-637, 1994.
5. Branemark PI, Albrektsson T: Titanium implants permanently
penetrating human skin. Scand J Plast Reconstr Surg 16:17-21,
1982.
6. Tjellstrom A, Hakansson B: The bone-anchored hearing aid.
Design principles, indications, and long-term clinical results.
Otolaryngol Clin North Am 28:53-72, 1995.
7. Lustig LR, Arts HA, Brackmann DE, et al: Hearing rehabilitation
using the BAHA bone-anchored hearing aid: Results in 40
patients. Otol Neurotol 22:328-334, 2001.
8. Tjellstrom A, Hakansson B, Granstrom G: Bone-anchored hearing
aids: Current status in adults and children. Otolaryngol Clin
North Am 34:337-364, 2001.
9. Scholz M, Eufi nger H, Anders A, et al: Intracerebral abscess after
abutment change of a bone anchored hearing aid (BAHA). Otol
Neurotol 24:896-899, 2003.
10. Tjellstrom A, Granstrom G: One-stage procedure to establish
osseointegration: A zero to fi ve years follow-up report. J Laryngol
Otol 109:593-598, 1995.
11. Papsin BC, Sirimanna TK, Albert DM, et al: Surgical experience
with bone-anchored hearing aids in children. Laryngoscope
107:801-806, 1997.
12. Seemann R, Liu R, Di Toppa J: Results of pediatric bone-anchored
hearing aid implantation. J Otolaryngol 33:71-74, 2004.
13. Granstrom G, Tjellstrom A: Guided tissue generation in the tem-
poral bone. Ann Otol Rhinol Laryngol 108:349-354, 1999.
PITFALLS
• A skin graft that has inadvertently been severed at
the base can still be used; it should be maintained
in moist gauze and sutured as a free graft over the
implant site.
• Inadequate removal of tissue at the margins of the
skin graft, particularly superiorly, can result in a soft
tissue overhang that makes contact with the sound
processor.
• Skin growth over the external abutment can usually
be managed by excision of the skin in the offi ce,
followed by silver nitrate cautery, injection of
triamcinolone (Kenalog), and application of the
healing cap.
• When the Baha is selected for patients with
microtia, the fi xture must not violate the blood
supply to the skin fl aps used for construction of the
auricle.
• Tension on the suture line can be diminished by
tacking the margins surrounding the skin fl ap to the
underlying periosteum.
• In children with thin skin undergoing a second-stage
procedure, consideration should be given to raising
the skin fl ap manually because the internal
hexagonal screw may catch on the dermatome and
cause a tear in the fl ap.

Chapter 119
Perilymphatic Fistulas
Barry E. Hirsch
Perilymphatic fi stulas (PLFs) defi ne a communication
from the inner ear to the middle ear that occurs as a
result of disruption of the natural bony or soft tissue
barrier between the perilymphatic and middle ear
spaces. It can be through the round or oval windows,
fractures, neoplastic erosion, microfi ssures of the otic
capsule, or disruption of the endosteal membrane after
a fenestration procedure. Despite this clear defi nition,
the existence of PLF as a spontaneous event remains a
controversial issue in otology.
The clinical features of PLF became evident as
experienced otolaryngologists correlated patients’
symptoms with operative fi ndings during middle ear
surgery. Three different types of otologic fi ndings have
brought PLF into the differential diagnosis when acute
auditory or vestibular dysfunction occurs. One form of
PLF became recognized in the early era of otosclerosis
surgery. On rare occasion, sudden onset of rapidly pro-
gressive hearing loss and dizziness would develop after
stapedectomy. Middle ear exploration in these patients
often revealed an opening in the oval window. A greater
incidence of oval window PLFs was observed when a
wire-Gelfoam prosthesis had been used. Likewise, poly-
ethylene prostheses were found to erode through the
oval window membrane and create a PLF. After repair
of the PLF, the symptoms were frequently controlled.
A second clinical entity described was erosion of the
otic capsule by tumors of the middle ear or cholestea-
toma and creation of a PLF, also eliciting symptoms of
hearing loss or vertigo. A third clinical situation in
which PLF was identifi ed occurred with implosive or
explosive injury to the inner and middle ear. Fee pro-
posed this concept in 1968.1 Patients subjected to sig-
nifi cant barotrauma followed by hearing loss or dizziness
were found to have a tear in the round window mem-
brane or disruption of the stapes footplate.
PLFs may be categorized as spontaneous (idiopathic)
or post-traumatic. A spontaneous PLF, by defi nition, has
no predisposing events or factors that would induce a
leak. It is often associated with congenital anomalies of
the inner ear.2 The incidence of spontaneous PLFs
without an inner ear anomaly is apparently quite low.
Post-traumatic PLFs include those that occur as a result
of erosive tumors or cholesteatomas, secondary to iat-
rogenic leaks after otologic surgery, or subsequent to
head trauma, barotrauma, or acoustic injuries.
The differential diagnosis should include a PLF
when patients have hearing loss and vertigo, as well as
a recent history of otologic surgery, head trauma, or
barotrauma or evidence of middle ear pathology. Skep-
ticism regarding the incidence of spontaneous PLF
abounds because of isolated reports of large series of
patients undergoing middle ear exploration for this
diagnosis. We do not believe that spontaneous PLF is a
cause of constant disequilibrium, tinnitus, aural full-
ness, and cognitive defects. Thus, PLFs in most adult
patients can typically be categorized as post-traumatic
in origin. In contrast, children and adolescents would
be more likely to have spontaneous PLFs. It was shown
that pediatric patients evaluated for hearing loss or
vertigo had a higher incidence of congenital inner and
middle ear anomalies. This group of patients had a sig-
nifi cantly higher incidence of β2-transferrin present in
fl uid samples collected at the time of exploratory tym-
panotomy.2 Symptoms related to congenital anomalies
of the temporal bone should become apparent in the
earlier years rather than after the third decade of life.
An astute physician must have a high index of sus-
picion in rendering a diagnosis of PLF. The patient’s
immediate history is critical in linking the onset and
activities with the symptoms of hearing loss, tinnitus,
and vertigo. It is also imperative to know the patient’s
past history of otologic diseases and surgery, any con-
genital malformations that may be present, previous ear
or head trauma or barotrauma, or a history of recurrent
meningitis.
1219

1220
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Trauma is the leading cause of PLF. It may be in
the form of barotrauma, head trauma, or a penetrating
injury. The latter is often associated with vertigo and
routinely requires surgical repair. We have had clinical
experiences with unusual forms of ear trauma. One
involved a metal choker necklace and the other a
branch of a tree entering the middle ear and extracting
and subluxating the stapes, respectively. A similar report
described a patient with severe itching; penetration of
the ear with a paint brush resulted in perforation of the
tympanic membrane, anacusis, and severe vertigo. The
vestibular symptoms are often relieved once the fi stula
is sealed.3
It may be diffi cult to differentiate the symptom
complex of Meniere’s disease (fl uctuating hearing loss,
vertigo, tinnitus, and aural fullness) from those of a
PLF. Loss of perilymph may result in a relative increase
in endolymph with resultant secondary endolymphatic
hydrops. Fitzgerald proposed a diagnostic strategy to
manage surgical intervention. Simultaneous repair of a
PLF and performance of an endolymphatic sac proce-
dure may incur an unnecessary operation. A positive
fi stula test or immediate onset of Meniere’s disease
symptom complex after head or ear trauma points
toward the pathology being a PLF, and surgery should
be directed to the middle ear alone.4
There are other rare causes of PLF. An unusual
form of trauma is from a lightning strike. Perforation
of tympanic membrane is a known complication in this
setting. If otorrhea should occur, the discharge, espe-
cially if watery and clear, should be assayed for β2-trans-
ferrin. Exploration for a PLF should be considered
when mixed hearing loss is identifi ed.5
A formidable problem inherent in making the diag-
nosis of PLF is that there are no specifi c tests diagnostic
of PLF, including both preoperative assessment and
intraoperative determination. The current “gold stan-
dard” method of diagnosing a PLF is based on subjec-
tive interpretation of the surgeon’s observations at the
time of exploratory tympanotomy. The surgeon looks
for reaccumulation of clear fl uid in the round or oval
window niche, especially after suction aspiration, or for
a microfi ssure of the otic capsule. Identifi cation of clear
fl uid can be falsely interpreted as perilymph in that a
serous transudate or injected lidocaine may also pool
in niches in the middle ear. Unless a unique marker for
perilymph is identifi ed, PLF at the time of exploration
may be overdiagnosed.
In summary, based on our experience with explora-
tion of the middle ear, we do acknowledge that PLFs
exist but the incidence is low. It is important to consider
a PLF in the differential diagnosis of sudden or rapidly
progressive hearing loss or disequilibrium. However,
one’s criteria for exploring an ear must be defi ned and
understood.
PATIENT SELECTION
Given that most cases of presumed PLF in adults can
be categorized as post-traumatic, a critical feature nec-
essary to entertain a diagnosis of PLF is the history given
by the patient. In contrast, progressive hearing loss in
children cannot be assumed to be hereditary in origin.
The physician must extract and synthesize a complete
otologic history. Complaints of aural fullness, hearing
loss or dizziness, vertigo, or disequilibrium suggest the
need for further information. The present history must
clarify the onset of symptoms along with predisposing
factors or associated physical activities. The duration
and frequency of symptoms are the most important to
ascertain. A history of episodic hearing loss with aural
fullness, tinnitus, and vertigo lasting a few hours is more
suggestive of Meniere’s disease than PLF. Sudden
hearing loss after an upper respiratory infection is prob-
ably a postviral loss unless violent sneezing or coughing
preceded the acute event. Consideration of the diagno-
sis of PLF requires that if hearing loss is present, its
onset be sudden, fl uctuating, or rapidly progressive.
Vestibular complaints may range from symptoms as
vague as episodic lightheadedness or mild disequilib-
rium to unsteadiness, vertigo with nausea and vomiting,
or ataxia.
Sudden auditory or vestibular symptoms may
develop after abrupt changes in middle ear or sub-
arachnoid space pressure. Injury to membranes of the
scala tympani, media, or vestibuli (intracochlear fi stula)
or to the round or oval windows may occur as a result
of severe barotrauma, acoustic trauma, or extreme
physical exertion. Patients would be considered at risk
for having a PLF if symptoms developed within a day or
two after barotrauma from a poorly pressurized air
fl ight; swimming pool or scuba diving; closed compres-
sive ear trauma (hand slap to the ear); violent sneezing;
forceful straining from constipation, labor and delivery,
or weightlifting; or a blast injury.
Patients are questioned about whether they have
recently or previously undergone any otologic surgery.
Attempts are made to extract information regarding
the precise nature of any procedure and whether any
untoward complications occurred. In particular, it is
helpful to determine whether the surgery was for oto-
sclerosis, cholesteatoma, or other tumor of the middle
ear and mastoid. The differential diagnosis for patients
describing episodic dizziness or fl uctuating progressive
hearing loss after stapedectomy includes serous labyrin-
thitis, reparative granuloma (in the early postoperative
period), or PLF (see Chapter 117).
Patients complaining of unrelenting vertigo should
be examined for nystagmus. A spontaneous vestibular
(horizontal) nystagmus may be identifi ed. It can be
observed on gross eye examination or by limiting visual
fi xation by having the patient wear Frenzel’s lenses or
infrared video goggles with display on a monitor.
Another method for identifying nystagmus is via oph-
thalmoscopy. One looks for rhythmic retinal movement
when examining the fundus. Assessment of hearing
status is essential. Interpretation of tuning fork testing
in the immediate postoperative period after otologic
surgery may be diffi cult, depending on the hearing
status of the contralateral ear. Complete closure of the
air-bone gap may not be evident because of canal packing
or middle ear fl uid. Tuning fork lateralization to the

Chapter 119
Perilymphatic Fistulas 1221
operative ear confi rms that cochlear function is pre-
served. Lateralization to the contralateral ear may indi-
cate contralateral conductive hearing loss (bilateral
otosclerosis) or signifi cant ipsilateral sensorineural loss.
The packing should be removed from the ear canal, and
the tympanic membrane should be carefully inspected.
The integrity of the tympanic membrane and the pres-
ence of middle ear fl uid should be confi rmed.
A fi stula test with a pneumatic otoscope is per-
formed to look for pneumatic-induced nystagmus
(Hennebert’s sign) or pneumatic-induced vertigo
(Hennebert’s symptom). Gentle pneumatic otoscopy
may elicit horizontal nystagmus with positive or nega-
tive pressure. However, these fi ndings must be inter-
preted cautiously in the immediate postoperative
setting. The presence or absence of nystagmus does not
confi rm that a fi stula does or does not exist. An audio-
gram will provide helpful information by identifying
the type and degree of hearing loss present. Erythema
of the tympanic membrane with a mild conductive
hearing loss may be treated medically with antibiotics,
steroids, and close observation. Another possibility is
that this manifestation of hearing loss or disequilibrium
may be a result of serous labyrinthitis. Signifi cant pro-
gressive change in sensorineural hearing levels or
speech discrimination scores in the face of new-onset
dizziness is strongly suggestive of a PLF or possible
reparative granuloma. Despite the surgeon’s reluctance
to re-explore a recently operated ear, the history and
fi ndings warrant intervention.
Indirect injuries to the tympanic membrane by an
open hand slap to the ear often result in rupture of the
tympanic membrane. A similar injury could occur with
signifi cant acoustic trauma, such as a blast injury. Blunt
trauma to the tympanic membrane may also result in
direct damage to the ossicular chain. In all three types
of injuries, the compressive energy could be transmit-
ted through the ossicular chain with subluxation of the
stapes footplate into the oval window or explosive
rupture of the round window. Progressive hearing loss
or persistent disequilibrium in these settings is strongly
suggestive of a traumatic PLF. Complete examination
of the ear is necessary in patients experiencing these
types of injuries. The integrity of the tympanic mem-
brane is established. A pneumatic fi stula test is per-
formed to look for nystagmus. In this setting, observing
nystagmus with pneumatic compression is suggestive
of a PLF. Positional testing (Hallpike’s maneuver) is
also useful in patients complaining of position-induced
vertigo. Vestibular tests entail electronystagmography
(ENG) and an ENG fi stula test. The ENG fi stula test is
monitored by recording electrodes placed horizontally
near the lateral canthus of the eyes. Eye movements are
recorded while positive and negative pneumatic tym-
panic membrane massage is applied with a Siegle oto-
scope or tympanometry bridge. The tracing is examined
for nystagmus that is timed to manipulation of ear canal
pressure (Fig. 119-1). Movement of the eyes can also be
assessed with infrared video goggles placed over the
eyes. This eliminates visual fi xation and allows direct
observation of eye deviation.
Unfortunately, the results of preoperative auditory
and vestibular tests are variable and not specifi c to PLF.
A positive pneumatic or ENG fi stula test is certainly
helpful in diagnosing a PLF, but negative explorations
have been reported despite demonstrated affi rmative
preoperative fi ndings. Conversely, PLFs have been
identifi ed in some patients despite normal preoperative
test results.
Identifi cation of the protein β2-transferrin in peri-
lymph has been offered as a diagnostic marker of PLF.
Obtaining an adequate liquid sample of the middle ear
fl uid in question can be diffi cult. The volume may not
be suffi cient to aspirate and collect. Gelfoam has been
used as an absorbent material from which the protein
may be eluted. However, in a study of 20 samples of
known perilymph collected at the time of cochlear
implantation or labyrinthectomy, only 1 tested positive
for β2-transferrin. None of the control specimens dem-
onstrated the protein.6 This adds to the dilemma of
confi rming that a perilymph leak is truly present during
middle ear exploration.
It was anticipated that communication between the
scala tympani (perilymph) and cerebrospinal fl uid
(CSF) from the subarachnoid space through the
cochlear aqueduct may provide a means to detect
whether an active fi stula is present. Fluorescein was
injected by lumbar puncture in the CSF of 28 patients
with suspected traumatic, idiopathic, iatrogenic, or
infl ammatory PLF. A few hours later the oval and round
window niches were microscopically and endoscopically
examined with white and blue light. Only two patients
(7%) demonstrated fl uorescence behind the round
window membrane with blue light. Direct observation
of perilymph in the setting of stapedectomy and semi-
circular canal fi stulas revealed no staining. Despite the
lack of reported neurologic complications from intra-
thecal fl uorescein, this method for evaluating PLF was
not recommended.7
Figure 119-1. Electronystagmographic tracing of a positive fi stula
test. The top row shows that positive pneumatic pressure induces right-
beating nystagmus at 200 and 300 mm H2O. The bottom row demon-
strates that negative pressure in the same ear reverses the direction
of the nystagmus to left beating. Note the increase in beat frequency
with greater pressure.

1222
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
There has been evidence that spontaneous PLFs
may be associated with other congenital anomalies of
the temporal bone.2 Patients with abnormalities such as
Mondini’s dysplasia have a higher incidence of middle
ear abnormalities and PLFs. Whether fi nding plus
repairing a PLF halts the progressive nature of these
anomalies or the PLF simply represents an epiphenom-
enon is unclear. In pediatric and young adult patients
with progressive hearing loss and vestibular symptoms,
radiographic imaging of the temporal bone is war-
ranted. Demonstration of bilateral changes in hearing
implies either metabolic, structural, or neural pathol-
ogy. Although a demyelinating process is more effec-
tively detected with magnetic resonance imaging,
computed tomography (CT) better identifi es anoma-
lies of the otic capsule (Fig. 119-2). Because PLFs have
been identifi ed with congenital anomalies of the inner
or middle ear, a patient with progressive hearing loss
and an abnormal CT scan of the temporal bone may be
a candidate for PLF exploration.
Physicians have varied opinions regarding the
source of sudden, progressive, or fl uctuating hearing
loss in children. There is controversy as to whether PLF
can be a possible cause. A retrospective study investi-
gated hearing and vestibular outcomes in 160 ears of
pediatric patients undergoing middle ear fi stula surgery
for sudden, progressive, or fl uctuating hearing loss of
great than 20 dB in three frequencies. Of the 103 ears
with a fi stula confi rmed by visual inspection of leaking
or reaccumulating fl uid, 92% demonstrated stabiliza-
tion or improvement of hearing after surgical repair of
the leak. In the 57 ears in which a fi stula was not identi-
fi ed but the oval and round windows were packed with
muscle or connective tissue, 95% had stabilized or
improved hearing. Based on observations from their
parents, 70% of children with a positive fi stula explora-
tion for vertigo and disequilibrium had improvement
in their symptoms after surgical repair.8
It is diffi cult to reach a meaningful conclusion
about the potential role that a congenital PLF may have
in causing sensorineural hearing loss in children. Why
hearing levels may stabilize in ears in which a fi stula is
not identifi ed yet still treated surgically is unclear. A
plausible explanation is that at the time of exploration
the leak is intermittent or not evident because the oper-
ative ear is facing up and thus perilymph is required to
drain against gravity. It is reasonable to conclude that
surgical repair (packing of tissue in the round and oval
windows) does not result in a signifi cant risk for post-
operative hearing loss.
Our understanding of the etiology of hearing loss
or vestibular problems, or both, has signifi cantly
expanded since the fi rst edition of this textbook. Lloyd
Minor is credited with characterizing the auditory and
vestibular signs and symptoms associated with dehis-
cence of the superior semicircular canal (SCC).9 Many
of the symptoms, such as noise-induced dizziness,
hearing loss, and disequilibrium precipitated by heavy
lifting, belching, coughing, sneezing, or straining, are
common to both PLF and dehiscence of the SCC. Simi-
larly, a positive fi stula test (nystagmus seen with pneu-
matic otoscopy) can occur in both clinical entities. An
audiogram may show conductive hearing loss, but
acoustic refl exes should still be present in SCC dehis-
cence. Vestibular evoked myogenic potentials are typi-
cally elicited at lower thresholds and can show enhanced
amplitude responses. CT showing dehiscence of the
SSC is critical in making the diagnosis. By using a mul-
tirow CT scanner, images of the temporal bone can
be reconstructed parallel and perpendicular to the
superior canal. We have shown that coronal images
usually suffi ce in identifying the dehiscent canal (Fig.
119-3).10
PREOPERATIVE PLANNING
Patients in whom a PLF is suspected should undergo
preoperative audiography to determine whether there
has been a change from previous levels or to establish
Figure 119-2. Bone-windowed computed tomography scan of a
patient with progressive and fl uctuating sensorineural hearing loss.
Note the otic capsule abnormalities, including the bulbous vestibular
aqueduct (arrow) and the dilated vestibule and internal auditory canal
(arrowhead).
Figure 119-3. Coronal bone-windowed computed tomography
scan showing dehiscence of the left superior semicircular canal
(arrow).

Chapter 119
Perilymphatic Fistulas 1223
the baseline of hearing. Vestibular testing may be
helpful if a unilateral paresis is identifi ed or a positive
PLF test (pneumatic otoscopy) is obtained. Imaging
of the temporal bone may be informative after blunt
or penetrating head trauma but provides limited addi-
tional information in cases of barotrauma or acoustic
trauma. Imaging may be helpful after recent otologic
surgery if a displaced prosthesis is of concern.
The choice of anesthesia is dependent on the age
of the patient and the cause of the suspected PLF.
Having the patient awake provides two benefi ts to the
surgeon. First, the patient is able to follow commands,
such as performing a Valsalva maneuver (breath holding
with forceful straining against a closed glottis). It can
be argued that similar results can be achieved with the
patient under general anesthesia by having the anesthe-
tist deliver sustained positive end-expiratory pressure
(PEEP). Maintaining PEEP increases venous resistance,
which causes increased intracranial pressure. Just as
with a Valsalva maneuver, increased intracranial pres-
sure may enhance transmission of fl uid pressure to the
inner ear perilymph fl uid compartment and augment
visualization of a latent PLF. However, iatrogenic injury
to the inner ear cannot be readily ascertained under
general anesthesia. The second benefi t of having an
awake patient is that it provides immediate feedback
regarding the patient’s subjective sensation of vertigo
and dizziness. This is particularly benefi cial in cases of
recent otologic surgery or limited temporal bone
trauma. Injudicious manipulation of a footplate that is
subluxated or an oval window graft with fi brous adhe-
sions to the saccule or utricle is detrimental to inner
ear function. An awake, although sedated patient can
directly communicate any feelings of disequilibrium to
the surgeon.
Despite the cause of the suspected PLF, it is very
diffi cult to perform exploratory ear surgery on children
under local anesthesia. A young teenager or mature
adolescent may tolerate this procedure with sedation.
The surgeon, along with the parents, must decide which
method of anesthesia is best for the patient and the
surgeon. General anesthesia is generally necessary for
exploratory tympanotomy performed on a child.
SURGICAL TECHNIQUES
The patient is positioned supine on the table with the
involved ear up. A small area of postauricular hair may
need to be shaved to provide access to suitable material
for grafting or obliteration. Surgeons who routinely use
a vein graft for stapedectomy would prepare and drape
the dorsum of the hand if the integrity of the stapes
footplate is in question. After adequate preoperative
sedation or narcoleptic anesthesia is obtained, the oper-
ating microscope is positioned over the ear. Local anes-
thetic (2% lidocaine with 1:100,000 epinephrine) is
infi ltrated into the external meatus in four-quadrant
fashion after inspection of the ear canal and tympanic
membrane (Fig. 119-4). Local anesthesia with con-
trolled vasoconstriction is necessary when exploring an
ear for a PLF. Hemostasis is mandatory to minimize any
confusion that may occur as a result of serum leaking
into the middle ear. It is recognized that some of the
infi ltrated local anesthetic may diffuse into the middle
ear and appear as clear fl uid welling up in the oval or
round window niches.11 The observer could falsely call
this a PLF. Nonetheless, local injection is necessary to
both anesthetize the ear canal and curtail bleeding. A
tympanomeatal fl ap is elevated to enter the middle ear
(Fig. 119-5). It is usually necessary to remove bone from
the posterosuperior canal wall to achieve complete
exposure of the oval window niche. Depending on the
vascularity of the bone and middle ear, bleeding into
the middle ear space may occur. Methods of controlling
bleeding include placement of small Gelfoam pledgets
impregnated with a topical vasoconstrictive solution
from the local anesthetic, small pieces of Surgicel, or
Figure 119-4. Local anesthetic solution is injected into the exter-
nal auditory canal in four-quadrant fashion.
Round
window
niche
Facial
nerve
Malleus
handle
Pyramidal process
Figure 119-5. A tympanomeatal fl ap has been elevated. Bone from
the posterosuperior canal wall has been removed by curette to maxi-
mize exposure of the oval and round window niches.

1224
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
rarely, bipolar electrocautery. Once complete exposure
is obtained, management, which is described later in
this chapter, is dictated by the fi ndings during surgery.
The status of the middle ear mucosa and ossicular chain
is examined.
Usually, the round window niche can be visualized
by repositioning the microscope or the operating table
without having to curette the posterior bony canal wall.
The round and oval window niches are examined to
look for reaccumulation of clear fl uid despite repeated
suctioning. A PLF may also be identifi ed by recognizing
a shifting light refl ex from the operating microscope.
Identifying a perilymph leak is facilitated by increasing
intracranial pressure. If clear fl uid is not noted, the
patient is asked to perform a Valsalva maneuver. Other
techniques used to enhance identifi cation of a latent
PLF include compression of the ipsilateral jugular vein,
palpation of the ossicular chain to facilitate leakage,
or placement of the patient in the Trendelenburg
position.
At present, the diagnosis of a PLF is based on seeing
reaccumulation of clear fl uid or a change in the light
refl ex from the operating microscope. A more objective
laboratory assay of the identifi ed fl uid would certainly
help in understanding PLFs. There is ongoing investiga-
tion of the use of β2-transferrin as a marker for peri-
lymph fl uid. Pieces of Gelfoam or Merocel are placed
in each niche, and separately labeled samples are
absorbed and collected. Electrophoresis with Western
blot staining can identify isoforms of β-transferrin.
Results of the assay are currently available in a minimum
of 3 hours. Unfortunately, this information is not imme-
diately available at the time of surgery to infl uence
operative management. In addition, the true sensitiv -
ity and specifi city of the assay have yet to be
determined.12
Patients being explored for sudden or progressive
hearing loss or vestibular symptoms after stapedectomy
require specifi c management. Surgeons using tissue
graft or vein graft for routine stapedectomy should be
prepared to harvest a new graft before re-exploring an
ear that has previously undergone otosclerosis surgery.
The oval window niche is examined for a reparative
granuloma in patients with rapidly progressive hearing
loss and recent stapes surgery. If a granuloma is present,
the prosthesis is removed and a new tissue seal is placed.
If a granuloma is not present, the position of the
prosthesis is inspected. If a tissue seal was used, its
integrity and the covering of the vestibule are
confi rmed. Appropriate placement of the prosthesis is
verifi ed by palpation of the ossicular chain. Careful
inspection to search for incomplete oval window
coverage is undertaken (Fig. 119-6). The oval window
niche is carefully examined for clear fl uid. If concern
exists regarding the integrity of the tissue seal, the
prosthesis is removed and the tissue graft is replaced.
Likewise, if a stapedotomy piston was used, displace-
ment of the prosthesis from the fenestration site should
be determined.
Patients subjected to blunt or penetrating trauma
to the ear with ongoing dizziness and hearing loss
are managed similarly. The integrity of the ossicular
chain is assessed. The incudostapedial joint may be
compromised and the stapes footplate fractured,
depressed, or subluxated into the vestibule. If this is
determined, the incudostapedial joint is disarticulated.
The dependent portion of the footplate is carefully
elevated out of the vestibule. Should the patient com-
plain of excessive vertigo or nausea, manipulation
of the footplate is terminated. Potential tissue grafts
that can be harvested include a vein from the hand,
temporalis fascia, or tragal perichondrium. Our prefer-
ence is areolar tissue or fascia overlying the temporalis
muscle. After the mucosa is elevated from the margins
of the oval window, the vestibule is sealed with the graft
(Fig. 119-7).
Spontaneous PLFs are handled in a similar manner.
The oval and round windows are inspected for clear
fl uid. If clear fl uid is found, the mucosa near the stapes
footplate is elevated (Fig. 119-8). The round window
may have an overhang that should be removed with a
curette or middle ear microdrill for better visualization.
The mucosa is also elevated if a PLF is found in this
area. The preferred material for sealing PLFs is fi bro-
fascial tissue harvested from the postauricular area.
Perichondrium from the tragus may also be used.
Adipose tissue is purposely avoided because of its inher-
ent properties of atrophy and resorption. Small pieces
of fi brofascial tissue are placed in the oval or round
windows and between the crura of the stapes (Fig.
119-9). Similarly, the round window niche is sealed after
Figure 119-6. A cause of a perilymphatic fi stula is a dehiscence in
the tissue graft sealing the oval window after stapedectomy. The graft
incompletely covers the posterior aspect of the oval window niche.

Chapter 119
Perilymphatic Fistulas 1225
the surrounding bone is denuded of mucosa. Methods
to fi x the tissue in place and promote scarring include
the use of Avitene, Surgicel, or fi brin glue placed lateral
to the tissue graft.
Another method of sealing the annular margin of
the footplate is with a contoured graft. Fascia or peri-
chondrium cut in the shape of a pair of pants or narrow
U can be positioned around the anterior crux of the
stapes with the limbs extending along the superior and
inferior footplates. This provides a good seal of the
anterior footplate and fi stula ante fenestram (Fig.
119-10).
Along with the oval and round window niches,
other areas should be inspected, including the area
anterior to the footplate at the fi stula ante fenestram
and the area inferior to the round window niche, where
microfi ssures have been reported.13
One of the more diffi cult decisions that one faces
is what to do in the event that no PLF is identifi ed. If
clear fl uid is not observed, it can certainly be argued
that a PLF does not exist and that packing the niches
is not warranted. There are anecdotal reports of hearing
returning to normal in patients with negative explora-
tions in which packing was not performed. Proponents
of this philosophy argue that if routine packing is per-
formed, one will never know whether the treatment was
justifi ed. On the other hand, one could argue that PLFs
may be intermittent or diffi cult to identify when the
involved ear is facing up at the time of surgery. The
effects of gravity and minimal inner ear fl uid pressure
may hamper leakage of perilymph. In fact, authorities
Figure 119-7. A portion of the anterior stapes footplate remains
subluxated within the vestibule after trauma. A vein graft will be
placed to completely cover the oval window niche.
Figure 119-8. Using a fi ne pick, the mucosa surrounding the oval
window niche is elevated to promote scarifi cation with fi brous tissue
grafts. (From Bluestone CD, Stool SE: Atlas of Pediatric Otolaryngology.
Philadelphia, WB Saunders, 1995, p 115.)
Figure 119-9. Small pieces of fi brofascial tissue are placed around
the oval window niche to promote closure of a perilymphatic
fi stula.

1226
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
A
B
Figure 119-10. A, A fascia graft cut
like a pair of pants has been prepared
for the footplate area. B, The graft is
placed around the stapes crura.
remain divided about what direction to take in the situ-
ation of negative exploration. Some surgeons pack rou-
tinely; others pack only if a PLF is identifi ed. We
recommend placing fascia (packing) at the time of
exploration.
Management of a subluxated footplate can be dif-
fi cult. Recent injuries, which limit the time for fi brous
adhesions to develop, permit attempts at elevating the
stapes from the vestibule. Should the patient complain
of increasing vestibular symptoms during operative
manipulation, further efforts are aborted. A similar
approach is taken for an ear that is re-explored after
stapes surgery. If a PLF is strongly suspected and none
is obviously seen, the surgeon must decide whether the
prosthesis should be replaced and the oval window
regrafted or the symptoms should be ascribed to serous
labyrinthitis. If surgery is being performed for unresolv-
ing vestibular problems in the presence of severe
hearing loss, more aggressive intervention is warranted.
Along with attempting to alleviate the vestibular symp-
toms, repairing communicating pathways from the
middle ear to the perilymph and CSF may prevent
potential otic meningitis. This approach is particularly
applicable to younger patients with congenital otic
capsule anomalies.
Recurrent symptoms after PLF repair are diffi cult
to interpret and manage. Review of the patient’s history
and physical fi ndings is necessary. A higher incidence
of recurrent PLF has been reported when adipose tissue
is used for grafting, presumably because of progressive
atrophy of the adipose tissue graft. It is for this reason
that we advocate fi brofascial tissue, muscle, or peri-
chondrium for PLF repair.
Once the middle ear procedure is completed,
the tympanomeatal fl ap is returned to its original
position. The fl ap is secured with ointment, antibiotic-
impregnated Gelfoam, or a silk sleeve compressed with
small cotton balls and ointment. The tissue donor site
is closed with 5-0 fast-absorbing suture and covered with
a Steri-Strip.
POSTOPERATIVE MANAGEMENT
Patients can usually be discharged the same day unless
severe nausea or vertigo is experienced. Oral narcotic
analgesics are provided if needed. It is rarely necessary
to provide wound care to the tissue donor site. A cotton
ball in the external auditory meatus is changed as
needed. Some serosanguineous drainage should be
anticipated. Exposure of the ear to water, bending with
heavy lifting, and sneezing with the nares occluded are
to be avoided. The patient is seen 7 to 10 days postop-
eratively for removal of the Steri-Strips and packing.
Restriction from water exposure is maintained for 3
more weeks. An audiogram is obtained 4 to 6 weeks
after surgery to assess and document the status of audi-
tory function.
COMPLICATIONS
The operative morbidity associated with surgical explo-
ration of the middle ear for a PLF is minimal, especially
in patients with signifi cant preoperative hearing loss.
Careful elevation of the tympanomeatal fl ap avoids
potential tears in the tympanic membrane. The chorda
tympani nerve is dissected carefully to minimize stretch
and desiccation. Theoretically, packing of the round or
oval windows should produce a conductive hearing loss.
In reality, however, such packing does not lead to a
signifi cant clinical or audiometric defi cit.
Packing of the round and oval windows should
effectively prevent fl uid from both exiting and entering
the inner ear. As mentioned, symptoms, signs, and the
diagnosis of PLF and Meniere’s disease may overlap.
Should intratympanic therapy with either an aminogly-
coside (gentamicin) or steroid be necessary for subse-
quent intervention, access to the inner ear by injection
into the middle ear may effectively be obstructed by the
tissue graft. The subsequent treating physician should
be aware of the patient’s past medical history and details
of the previous surgical procedures.

Chapter 119
Perilymphatic Fistulas 1227
References
1. Fee GA: Traumatic perilymphatic fi stulas. Arch Otolaryngol
88:477-480, 1968.
2. Weber PC, Perez BA, Bluestone CD: Congenital perilymphatic
fi stula and associated middle ear abnormalities. Laryngoscope
103:160-164, 1993.
3. Gunesh RP, Huber AM: Traumatic perilymphatic fi stula. Ann
Otol Rhinol Laryngol 112:221-222, 2003.
4. Fitzgerald DC: Perilymphatic fi stula and Meniere’s disease. Clini-
cal series and literature review. Ann Otol Rhinol Laryngol
110:430-436, 2001.
5. Sun GH, Simons JP, Mandell DL: Bilateral perilymphatic fi stulas
from a lightning strike: A case report. Laryngoscope 116:1039-
1042, 2006.
6. Buchman CA, Luxford WM, Hirsch BE, et al: Beta-2 transferrin
assay in the identifi cation of perilymph. Am J Otol 20:174-178,
1999.
7. Gehrking E, Wisst F, Remmert S, et al: Intraoperative assessment
of perilymphatic fi stulas with intrathecal administration of fl uo-
rescein. Laryngoscope 112:1614-1618, 2002.
8. Weber PC, Bluestone CD, Perez B: Outcome of hearing and
vertigo after surgery for congenital perilymphatic fi stula in chil-
dren. Am J Otolaryngol 24:138-142, 2003.
9. Minor LB: Clinical manifestations of superior semicircular canal
dehiscence. Laryngoscope 115:1717-1727, 2005.
10. Branstetter BF, Harrigal C, Escott EJ, et al: Superior semicircular
canal dehiscence: Oblique reformatted CT images for diagnosis.
Radiology 238:938-942, 2006.
11. Wilson DF, Hodgson RS: Lidocaine in the middle ear. Laryngo-
scope 100:1059-1061, 1990.
12. Bassiouny M, Hirsch BE, Kelly RH, et al: Beta 2 transferrin appli-
cation in otology. Am J Otol 13:552-555, 1992.
13. Kamerer DB, Sando I, Hirsch BE, et al: Perilymph fi stula resulting
from microfi ssures. Am J Otol 8:489-494, 1987.
PEARLS
• Patients with sudden hearing loss or dizziness who
have a history of recent barotrauma, physical ear
injury, or otologic surgery should be suspected of
having a PLF.
• Exploration of the middle ear should be carried out
in patients in the pediatric age group who have
sudden or fl uctuating hearing loss and dizziness and
middle or inner ear anomalies confi rmed by CT.
• Identifi cation of nystagmus elicited by pneumatic
otoscopy may be enhanced by using infrared video
goggles instead of directly observing the eyes for
movement.
• Observation of a PLF is enhanced by having the
patient perform a Valsalva maneuver if awake or
having the anesthetist apply positive pressure
ventilation if under general anesthesia.
• Because a fi stula may be intermittent or diffi cult to
elicit with the involved ear facing up at the time of
middle ear exploration, both the oval and round
windows should be packed with a tissue graft.
PITFALLS
• The symptoms and signs of pressure-induced vertigo
and nystagmus are similar with acute endolymphatic
hydrops, a stapes prosthesis located too deep in the
vestibule, a PLF, and dehiscence of the superior
semicircular canal.
• Complications of middle ear exploration should be
rare, but great care should be taken to avoid a tear
in the tympanic membrane or injury to the chorda
tympani nerve.
• Excess fl uid from injection of the local anesthetic
and vasoconstrictor may permeate into the middle
ear and be mistaken for perilymph.
• Adipose tissue should not be used for packing the
PLF because it is more likely to atrophy and no
longer occlude the area of PLF.
• Laboratory markers for identifying perilymph, such
as β2-transferrin or fl uorescein, can be unreliable
and their absence misleading.

Chapter 120
Intracranial Complications of Otitis Media
William A. Wood and Yael Raz
Complications from acute otitis media or chronic otitis
media can be divided into extracranial complications
(i.e., facial nerve paralysis, labyrinthitis, subperiosteal
abscess) and intracranial complications. Intracranial
complications of otitis media include meningitis, epidu-
ral abscess, subdural abscess (empyema), brain abscess,
lateral sinus thrombophlebitis/sigmoid sinus thrombo-
sis, otitic hydrocephalus, and Gradenigo’s syndrome
(Fig. 120-1). On occasion, an intracranial complication
may be the initial symptom in a patient with a history
of untreated otitis media. Multiple complications may
coexist. Despite broad-spectrum antibiotics, complica-
tions of otitis media can result in high morbidity and
even mortality, and surgical management is often
necessary.
Spread of otitis media to intracranial structures may
occur either directly or hematogenously. Direct exten-
sion can occur via multiple mechanisms:1 preexisting
congenital abnormalities such as a Mondini deformity,
post-traumatic bony defects from temporal bone frac-
ture, erosion of bony barriers as a result of cholestea-
toma, normal communicating vein pathways from the
mastoid to the intracranial space, and spontaneous or
iatrogenic dehiscence of bone.2 Meningitis, historically
the most common intracranial complication of otitis
media, frequently spreads in children via a hematoge-
nous route or by extension from a local abscess.3 With
widespread Haemophilus infl uenzae type B and antipneu-
mococcal vaccination of children, the incidence of
meningitis as a complication of these two organisms has
become very low.1 Some recent series report a greater
frequency of lateral sinus thrombophlebitis/sigmoid
sinus thrombosis or brain abscess than meningitis. The
frequency of various intracranial complications in a
number of case series over the last decade is presented
in Table 120-1.4-17
Patients may initially have the classic signs of oto-
genic infection, such as foul-smelling otorrhea, otalgia,
headache, fever, vertigo, and sudden hearing loss. As
the disease progresses, later signs include mental status
changes such as confusion, obtundation or seizures,
and cranial nerve palsies. Many patients with intracra-
nial complications will have multiple complications,
such as meningitis in addition to an abscess, and the
otolaryngologist should seek to diagnose and treat all
of these complications. Patients may have concurrent
intratemporal complications such as subperiosteal
abscess, labyrinthitis, and facial nerve paresis.
MENINGITIS
INDICATIONS AND PATIENT SELECTION
Patients with meningitis may have the classic signs and
symptoms, such as headache, photophobia, spiking
fevers, mental status changes, nausea, and vomiting.
Physical signs that have been classically described for
evaluating meningitis, such as Kernig’s sign, Brudzin-
ski’s sign, and nuchal rigidity, were recently shown in a
prospective study of patients suspected of having men-
ingitis to have sensitivities of only 5% to 30%,18 and
hence clinical suspicion should remain high even
when these signs are negative on examination. An early
lumbar puncture is essential in suspected meningitis,
followed immediately by empirical antibiotic treatment,
pending culture results. In addition to opening pres-
sure, cell counts, Gram stain, and culture, a cerebrospi-
nal fl uid (CSF)–serum glucose ratio of less than 0.5 is
abnormal and greatly raises suspicion of meningitis.19
Current practice guidelines for suspected bacterial
meningitis recommend computed tomography (CT)
before lumbar puncture for patients in the following
categories: immunocompromised state, history of
central nervous system disease (e.g., stroke), new-onset
seizure, papilledema, abnormal level of consciousness,
or focal neurologic defi cit.20
1229

1230
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Table 120-1
RECENT REPORTED SERIES OF INTRACRANIAL COMPLICATIONS OF OTITIS MEDIA IN CHILDREN, ADULTS, AND COMBINED
GROUPS OF CHILDREN AND ADULTS
Reference and
Total Number of Patients
Patients with
ICCOM
Meningitis
Epidural
Abscess
Subdural
Abscess/
Empyema
Brain Abscess
Lateral Sinus
Thrombophlebitis
or Sigmoid Sinus
Thrombosis
Otitic
Hydrocephalus
Other*
Pediatric Series
Zanetti,4 2006, N = 45
13
6
3
0
1
7
0
2
Migirov,5 2005, N = 28
(11 children)
11
5
3
0
0
1
0
2
Leskinen,6 2004, N = 33
1
1
1
0
0
0
0
0
Luntz,7 2001, N = 223
(214 children)
19
7
1
1
6
0
5
Go,8 2000, N = 118
8
1
4
6
0
0
0
0
Kaftan,9 2000, N = 22
(3 of 22 <18 yr old)
3
3
0
0
0
0
0
0
Schwager,10 1997, N = 124
11 (4 patients
had >1
ICCOM)
5
5
0
2
5
0
0

Chapter 120
Intracranial Complications of Otitis Media 1231
Adult Series
Leskinen,11 2005, N = 50
9
4 (1 death)
0
0
4
1
0
0
Migirov,5 2005, N = 28
(17 adults)
17
8
2
2
5
2 (1 transverse,
1 sigmoid)
0
0
Kaftan,9 2000, N = 22
(19 of 22 >18 yr old)
19
12
0
1
5
0
0
1
(Gradenigo’s
syndrome)
Barry,12 1999, N = 79 with
otogenic meningitis
79
79
4
2
4
2
2
8
Series with Combined Children and Adults; Results Not Separated
Seven,13 2005, N = 32 with
59 ICCOMs
32
7
7
2
14
10
1
11
Penido,14 2005, N = 33
33
21
1
2
26 (3 deaths)
5
0
1
Matanda,15 2005, N = 343
(215 patients <20 yr old)
24
12
0
0
9
2
1
0
Goldstein,16 2000, N = 100
intratemporal complications
of otitis media
16
2
7
1
5
7
2
Osma,17 2000, N = 93,
57 with ICCOMs
(58% <20 yr old)
57
41
4
0
10
1
0
*Other includes cavernous sinus thrombosis, perisinus abscess, meningocele, petrous apex suppuration, internal jugular thrombosis, cerebritis, presuppurative encephalitis, and
ventriculitis. Some patients had more than one intracranial complication.
ICCOM, intracranial complication of otitis media.

1232
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
F
C
E
B
D
A
Figure 120-1. Intracranial complications of otitis media include
meningitis (A), epidural abscess (B), lateral sinus thrombosis (C),
subdural empyema (D), brain abscess (E), and petrous apicitis (F).
(Adapted from Vazquez E, Castellote A, Piqueras J, et al: Imaging of complica-
tions of acute mastoiditis in children. Radiographics 23:359-372, 2003.)
Fine-cut CT of the temporal bone, with and without
contrast enhancement, along with imaging of the brain
allows evaluation of related intracranial complications
such as a brain abscess, as well as detection of bone
defects in the middle fossa or posterior fossa plate and
other structural abnormalities. When otitis media is
diagnosed or suspected, the otolaryngologist should
perform a myringotomy and send the aspirate for
immediate Gram stain, in addition to culture and sen-
sitivity testing; a ventilation tube is placed. Antibiotics
should then be adjusted to the results of culture of the
middle ear aspirate and CSF. If the patient can tolerate
magnetic resonance imaging (MRI), it should be per-
formed because it has greater sensitivity for evaluating
the extent and type of intracranial infection.21
SURGICAL TECHNIQUE
Aside from myringotomy and tube insertion, meningitis
alone does not require additional surgical treatment.
However, if the patient fails to respond adequately to
systemic therapy, mastoidectomy should be considered
when the patient is neurologically stable enough to
tolerate the procedure, which may reveal a chronic
underlying cause (Fig. 120-2). Hearing should be moni-
tored closely. Possible sequelae include labyrinthitis
ossifi cans with resultant sensorineural hearing loss, in
which case early cochlear implantation should be
considered.
EPIDURAL ABSCESS
INDICATIONS AND PATIENT SELECTION
Patients with coalescent mastoiditis or chronic suppura-
tive otitis media with cholesteatoma are at risk for bony
erosion into the intracranial epidural space and abscess
formation. If the erosion occurs superiorly through the
A
B
Figure 120-2. Chronic mastoiditis in a patient with meningitis. A,
Antral block (arrow), chronic mastoiditis. B, Erosion of the posterior
fossa plate overlying the sigmoid sinus (arrow). At the time of the scan,
the patient was asymptomatic. She had severe cardiac risk and was
observed without surgical intervention. However, 6 months later the
patient was evaluated for otalgia, fever, and mental status changes.
Workup revealed meningitis. A mastoidectomy was performed
because of inadequate response to antibiotics. The antral block was
found to be secondary to a cholesterol granuloma.
tegmen, the abscess will form in the middle fossa. Simi-
larly, if the erosion occurs posteriorly, the abscess will
form in the posterior fossa, often around the sigmoid
sinus. Some authors refer to abscesses that are adjacent
to the sigmoid sinus as perisinus abscesses or empy-
emas. One recent large series of patients with epidural
abscesses found that 20% were secondary to otogenic
infection, in contrast to almost two thirds that were
secondary to infections of the paranasal sinuses.22

Chapter 120
Intracranial Complications of Otitis Media 1233
Patients with an otogenic epidural abscess classi-
cally have worsening temporoparietal headache in the
region of the affected ear,23 with or without mental
status changes such as lethargy. However, “silent”
abscesses may also be discovered on temporal bone CT
performed to assess the condition of the mastoid and
middle ear.24 If an intracranial complication is sus-
pected from the clinical or CT fi ndings, MRI provides
valuable additional information about the location and
extent of such complications. When loculated purulent
exudate, granulation tissue, or bony erosion is noted on
mastoidectomy, evaluation of the integrity of the bony
tegmen and surrounding bony confi nes of the intracra-
nial space is necessary to rule out an epidural abscess.
An epidural abscess may occur in association with other
intracranial complications of otitis media, such as
thrombophlebitis or thrombosis of the lateral or sigmoid
sinus, and hence the otologist should have a high
index of suspicion with regard to these other serious
conditions.
SURGICAL TECHNIQUE
An isolated epidural abscess secondary to mastoiditis
can usually be evacuated by a complete mastoidectomy,
with careful unroofi ng of the affected bony plates to
expose but not enter the dura (Fig. 120-3). Purulent
material and granulation tissue should be sent for
immediate Gram stain, culture, and sensitivity testing.
The mastoid is then irrigated with antibiotic solution.
If the abscess was not diagnosed preoperatively, follow-
up imaging should be conducted to evaluate for the
possible presence of other intracranial complications.
LATERAL SINUS THROMBOSIS
INDICATIONS AND PATIENT SELECTION
Infl ammation of the dural sinuses secondary to otitis
media can occur as a result of an adjacent epidural
abscess or via direct extension from communicating
venous channels between the mastoid and dural sinuses
(Fig. 120-4) and may lead to thrombosis. Once the wall
of a dural sinus is infl amed, a thrombus may form and
can propagate in the lumen of the sinus. In severe cases
it can lead to venous hemorrhage and cerebral infarc-
tion if collateral drainage is inadequate.
The lateral sinus is the combination of the trans-
verse and sigmoid sinuses. Patients with lateral sinus
thrombophlebitis and/or thrombosis (LST) secondary
to otitis will typically complain of headache, fever, and
photophobia, in addition to symptoms consistent with
mastoiditis. Frequently, other intracranial complica-
tions such as an epidural or subdural abscess or otitic
hydrocephalus coexist.25 Intramural thrombi can often
be diagnosed on contrast-enhanced CT, but MRI and
MR venography are considered the “gold standards” for
diagnosing and monitoring cerebral venous thrombosis
(Fig. 120-5).26
A number of recent case series have demonstrated
that the distribution of causes of LST is approximately
equally divided between acute otitis media and chronic
otitis media.27,28 Other series report an exclusive associa-
tion with chronic ear disease.29 Most recent series have
included fewer than 15 patients, thus indicating the
relative rarity of this complication with effective early
treatment of otitis media.
SURGICAL MANAGEMENT
Historically, the standard of care for LST has been, in
addition to intravenous antibiotics, a complete mastoid-
ectomy with exposure of the lateral sinus. Needle aspi-
ration of the sinus may be used to determine whether
purulent exudate is present (Fig. 120-6). If so, consid-
eration should be given to incision and evacuation of
the thrombus (Fig. 120-7). Bleeding from the lateral
sinus can be controlled by extraluminal compression
with Surgicel (Fig. 120-8). The medial wall of the sinus
is maintained intact. Opening of the sinus plus removal
of the clot are not necessary unless the sinus is grossly
infected.16 The role of postoperative anticoagulation is
unclear.31 In cases of noncoalescent mastoiditis, a con-
servative approach, including immediate myringotomy,
tube placement, and topical and intravenous antibiot-
ics, is reasonable.32 The patient is monitored closely,
and mastoidectomy and sinus exploration are per-
formed if the patient fails to improve. A thrombosed
sinus may recanalize spontaneously over a period of
several weeks.33
Figure 120-3. Exposure and drainage of an epidural abscess with
wide exposure of the middle fossa dura.

1234
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
Inferior
petrosal
vein
Vein of
Labbé
Mastoid emissary vein
Transverse sinus
Sigmoid sinus
Superior
petrosal vein
Cavernous
sinus
Figure 120-4. Anatomic relation-
ship between the dural sinuses and
the temporal bone.
Figure 120-5. Magnetic resonance venogram showing a fi lling
defect in the right sigmoid sinus indicative of thrombosis (arrow); the
patient also had an epidural abscess secondary to mastoiditis.
Figure 120-6. Palpation and aspiration of a thrombophlebitic
dural sinus.
SUBDURAL ABSCESS (EMPYEMA)
INDICATIONS AND PATIENT SELECTION
Previously, otitis media was among the leading causes
of subdural abscess34; however, over the last several
decades it has become more infrequent. One retrospec-
tive review of 32 patients with subdural empyema since
the 1970s found no cases secondary to otitis media35;
another similar series noted that previous craniotomy
was the most common risk factor for development of
an abscess and had been performed in two thirds of
cases. One very large series of 699 cases in a developing
country found an otogenic source in about 9% of
cases.36
Subdural empyema can develop via thrombophle-
bitis of small emissary veins traveling from an infected
mastoid or middle ear centrally through the dura,
where an abscess then develops between the dura and
arachnoid. This complication may occur in conjunction
with epidural abscess, meningitis, or brain abscess. Most
patients have fever and meningismus. Even though

Chapter 120
Intracranial Complications of Otitis Media 1235
in intracranial pressure carefully monitored via lumbar
puncture, along with the intravenous administration of
antibiotics. Drainage can be achieved by craniotomy or
CT-guided aspiration, in consultation with the neuro-
surgical service. If the otogenic source is chronic otitis
media, mastoidectomy is indicated.
BRAIN ABSCESS
INDICATIONS AND PATIENT SELECTION
Brain abscess is an ominous complication that can still
be fatal despite modern antibiotics and aggressive surgi-
cal treatment. The British writer Oscar Wilde died of
an otogenic brain abscess near the turn of the last
century; the postauricular Wilde incision is named for
his father, Sir William Wilde, one of the founding
fathers of otology.39 Most recent case series are from
developing countries because this complication is less
frequently seen in wealthier societies with greater access
to health care. A recent series of 41 patients from a
university center in Turkey found approximately one
case per year, with almost all patients having a history
of cholesteatoma.40 Another similar series of 36 patients
from India reported that all patients had cholesteatoma
at surgery, although one third had only granulation
tissue on otoscopy.41 A series of 20 patients with brain
abscesses in an Italian center over a 16-year period,
reported in the German literature, noted that 12 of
them were of otogenic origin.42
Many patients with an otogenic brain abscess will
have additional intracranial complications of otitis
media, including meningitis and epidural abscess. The
abscess usually forms by direct extension via osteitic
bone. If there is a defect in the tegmen tympani, an
abscess may form in the temporal lobe (Fig. 120-9); if
there is a defect over the sigmoid sinus, an abscess may
form in the cerebellum. The previously mentioned
Indian series noted a larger prevalence of cerebellar
abscess (17 versus 9), and the Turkish series reported
54% in the temporal lobe and 44% in the cerebellum.
Patients will usually have a headache of several days’
duration, along with foul-smelling otorrhea and often
mental status changes. Temporal bone CT may miss a
brain abscess, so imaging should also include brain CT
with contrast enhancement.
SURGICAL TECHNIQUE
The abscess itself must be addressed on an emergency
basis before rupture, which can lead to septicemia and
death. Mastoidectomy is necessary to remove any pre-
cipitating cholesteatoma, and in some cases the abscess
cavity itself may be drained through this approach. A
multidisciplinary approach is coordinated with the
neurosurgical service, and patients generally undergo
craniotomy in conjunction with mastoidectomy. Senn-
aroglu and Sozeri40 reported aspirating the abscess via
mastoidectomy after preparing the dura with povidone-
iodine, followed by irrigation and placement of drain-
age tubes, which are used for ongoing irrigation until
Figure 120-7. Incision and drainage of a thrombophlebitic dural
sinus
Figure 120-8. Extraluminal packing is used to control bleeding
from the dural sinus.
focal signs such as hemiparesis will develop in many
patients, almost 40% in the large series noted earlier
had no focal signs. Empyema can progress rapidly to
coma and death; when intracranial pressure rises
acutely, papilledema may be absent.37 Although imaging
evaluation of a patient with suspected intracranial com-
plications of otitis will usually include contrast-enhanced
CT, one recent radiologic review recommends diffu-
sion-weighted MRI to help distinguish subdural
empyema from a reactive subdural effusion.38
SURGICAL TECHNIQUE
Subdural empyema needs to be evacuated on an emer-
gency basis and the frequently accompanying increase

1236
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
the cavity shows collapse on follow-up CT. Antibiotics
are adjusted to culture results of the aspirate. A similar
approach was reported in a series of eight patients in
rural India, where neurosurgical consultation was not
available.43 In a series of eight patients from Germany,
two abscesses were drained by the neurotology team via
a mastoid approach alone, and two other cases required
a neurosurgical approach (all patients underwent mas-
toidectomy).44 In the Italian series of 20 patients noted
earlier, 17 underwent neurosurgical intervention.
OTITIC HYDROCEPHALUS
INDICATIONS AND PATIENT SELECTION
Otitic hydrocephalus is believed to occur as a result of
lateral sinus thrombosis. It is a rare complication char-
acterized by papilledema and ipsilateral abducens palsy
in the majority of cases; the exact mechanism is not
known and it can occur even if the contralateral lateral
sinus is patent.45 One series in India reported three
cases of tubercular origin.46 Previously it was believed
that the pathophysiology must also involve the superior
sagittal sinus, but this theory is debatable.47
Patients typically have signs of increased intracra-
nial pressure, such as nausea, vomiting, and diplopia.
Lumbar puncture may show opening pressures as high
as 480 mm H2O48 with otherwise normal CSF fi ndings
and hence must be performed with great care (e.g., in
the operating room with a compliant patient in the
lateral decubitus position) if brain stem tonsillar herni-
ation is a concern based on fi ndings of papilledema.
MRI and MR venography show transverse sinus throm-
bosis well.49 Importantly, one series of fi ve pediatric
patients from Germany over a 4-year period found that
all but one had already achieved resolution of acute
otitis media with antibiotic treatment 1 to 4 weeks previ-
ously but were found to have diplopia.50
SURGICAL TECHNIQUE
In the recent German series,50 all fi ve patients improved
only with surgical intervention; intravenous antibiotics
alone were not suffi cient treatment. Surgery included
mastoidectomy, myringotomy, and in some cases a
lumbar drain. If lateral sinus thrombosis is present, it
may be aspirated by needle, with possible incision and
drainage. Elevated intracranial pressure should be
treated medically with mannitol, acetazolamide, or
other diuretics.
PETROUS APICITIS/GRADENIGO’S
SYNDROME
INDICATIONS AND PATIENT SELECTION
An aerated petrous apex may become infected as an
extension of mastoiditis and otitis media and be dis-
posed to associated intracranial complications, includ-
ing epidural abscess, abducens palsy, and trigeminal
irritation, among others. The classic triad described by
Gradenigo in 1904 and 1907 included suppurative otitis
media, abducens paralysis, and deep facial or retrobul-
bar pain secondary to trigeminal involvement, although
only 42% (24 of 57) of the patients in his series had the
complete triad (Fig. 120-10).51 Petrositis can be associ-
ated with involvement of cranial nerves V and VI. As
noted by Gradenigo, abducens palsy occurs in a minor-
ity of cases of petrous apicitis, but symptoms vary,
and rarely this may be the only manifestation.52
The syndrome may occur in conjunction with other
A
B
Figure 120-9. A, Computed tomography scan demonstrating a left-
sided cholesteatoma (arrow) in a patient with canal atresia who had a
brain abscess (arrow) as seen on magnetic resonance imaging (B).

Chapter 120
Intracranial Complications of Otitis Media 1237
intracranial complications, and hence possible addi-
tional pathologies such as meningitis and lateral sinus
thrombophlebitis should be thoroughly evaluated
concurrently.
Petrous apicitis can occur secondary to acute otitis
media and as a complication of chronic ear disease.
Pneumatized petrous apices generally communicate
with mastoid air cells, thereby providing a route of
spread for infection, and some authors report that
even nonpneumatized or sclerotic petrous apices may
become infl amed.53 Anatomic studies have also demon-
A
B
C
Figure 120-10. Gradenigo’s syndrome. A, Axial computed tomogra-
phy scan in a patient with right-sided otalgia, otorrhea, and abducens
palsy. The right mastoid and petrous apex are opacifi ed, and there is
erosion of bone along the medial aspect of the petrous apex (arrow).
B, Soft tissue cuts reveal meningeal enhancement in this region (arrow).
C, Axial T1-weighted magnetic resonance image with gadolinium
enhancement reveals an abscess involving the petrous apex (arrow).
strated venules forming conduits from the cavernous to
the inferior petrosal sinus or jugular bulb.54 Infl amma-
tion of the petrous apex can irritate the abducens,
which travels under the petroclinoid ligament in Dorel-
lo’s canal.55 Similarly, the trigeminal (gasserian) gan-
glion or branches can become involved and result in
pain throughout the affected distribution.
Both CT and MRI have important roles in diagnos-
ing petrositis.56 CT with contrast enhancement can
show bony erosion, fl uid-fi lled opacifi cation, and possi-
bly abscess formation, but the contralateral petrous

1238
Section 13
Tympanic Membrane, Middle Ear, and Mastoid
apices cannot be assumed to be equivalently anatomi-
cally aerated for comparison. MRI can distinguish
between marrow, CSF, and purulence.
SURGICAL TECHNIQUE
If a trial of intravenous antibiotics does not lead to the
resolution of petrositis or if imaging shows areas of
necrotic bone, surgical management is indicated. One
recent case report detailed resolution of Gradenigo’s
syndrome without surgery in both a 6-year-old child in
whom the condition developed after acute otitis media
and a 70-year-old with a history of chronic ear disease.57
Another report noted one case in three resolving
with antibiotics, but the other two patients required
surgery.58
The petrous apex has been described as the least
surgically accessible portion of the temporal bone.59
Mastoidectomy and tympanostomy tube placement may
be suffi cient to allow drainage of the petrous apex air
cell tracts.60 Surgical approaches to an infl amed petrous
apex depend on the patient’s hearing status and tem-
poral bone anatomy and on the surgeon’s training and
include the infralabyrinthine, transcanal infracochlear,
transsphenoidal, translabyrinthine or subtotal petro-
sectomy, and middle fossa approaches (discussed in
Chapter 102).61,62
POSTOPERATIVE CARE/COMPLICATIONS
Complications of mastoidectomy and postoperative
care are described in Chapter 115. Additional sur-
veillance is necessary in a patient with intracranial
complications, including monitoring for CSF otorrhea/
rhinorrhea, cerebral edema, seizures, and pneumo-
cephalus. Monitoring in an intensive care unit with
imaging within 24 hours after surgical intervention is
warranted. Prolonged bed rest and possible neurologic
impairment leave patients predisposed to pulmonary
emboli, and prophylaxis may be warranted. A multidis-
ciplinary team that includes neurosurgery and infec-
tious disease consultants is recommended. Long-term
intravenous antibiotics may be indicated (with a periph-
erally inserted central catheter) for all intracranial com-
plications of otitis media.
The otolaryngologist must be alert to the possible
development of intracranial complications of otitis
media and, when suspected, must remain aware that
more than one such complication will often occur
simultaneously. For any patient with otorrhea, temporal
bone imaging should be considered. Early and effective
treatment of acute otitis media with antibiotics has
made the development of subsequent complications
more subtle and less fulminant. Temporal bone imaging
should be done on an urgent basis and should include
brain imaging if otitis is accompanied by headache,
fever, mental status changes, visual complaints, or other
signs or symptoms that may indicate a disease process
involving more than just the middle ear. Ambiguous or
inconclusive fi ndings on contrast-enhanced CT should
be followed by MRI, and a low threshold for admission
and further workup should be maintained until the
possibility of intracranial complications can be confi -
dently excluded.
PEARLS
• Patients often have more than one intracranial
complication.
• When evaluating for the possibility of intracranial
complications of otitis media, MRI provides better
detail of intracranial structures than CT.
• Hearing should be monitored closely after
meningitis with consideration given to early cochlear
implantation if hearing loss is accompanied by
radiologic evidence of labyrinthitis ossifi cans.
• Some complications (i.e., empyema) may progress
very rapidly, and emergency surgical intervention is
warranted.
PITFALLS
• Classic signs of meningitis (Kernig’s sign,
Brudzinski’s sign) are not very sensitive and may be
absent in a patient with otitic meningitis.
• Temporal bone imaging may miss an intracranial
abscess; suspicion should prompt dedicated brain
CT or MRI with contrast enhancement.
• Intracranial complications may occur several weeks
after treatment of an acute ear infection; thus, if
there is a history of recent acute otitis media, the
possibility of intracranial involvement should not be
dismissed on the basis of a normal otoscopic
examination.
• In patients with radiologic evidence of severely
elevated intracranial pressure, lumbar puncture may
result in cerebral herniation; particularly in patients
with otitic hydrocephalus, this procedure should be
performed with great care, preferably in the
operating room.
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Tympanic Membrane, Middle Ear, and Mastoid
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section 14
Facial Nerve
Chapter 121
Tumors of the Facial Nerve
Barry E. Hirsch and Michele St. Martin
Primary tumors of the facial nerve are relatively rare.
Bell’s palsy is the most common disorder that primarily
affects the facial nerve. Facial paralysis frequently results
from other pathologic processes affecting the posterior
fossa, temporal bone, parotid gland, and infratemporal
fossa. Secondary involvement of the facial nerve can
occur as a result of trauma or erosive tumor such as
cholesteatoma, primary squamous cell carcinoma,
glomus tumors, acoustic neuroma, meningioma, malig-
nant neoplasms of the parotid gland, and tumors meta-
static to the temporal bone.
The most common primary tumors of the facial
nerve are neuromas and hemangiomas. Other less
common primary tumors of the facial nerve include
neurofi broma, granular cell tumor, meningioma, and
primary glomus tumors. Malignant epithelioid cranial
nerve sheath tumor involving the facial and trigeminal
nerves has also been described,1 but most malignant
tumors of the facial nerve are the result of metastasis or
perineural invasion. Cancer of the parotid gland, such
as adenoid cystic carcinoma and mucoepidermoid car-
cinoma, is known to invade the facial nerve at the skull
base.2 Breast, lung, and renal cancers can also metasta-
size to the facial nerve, most often in the internal audi-
tory canal (IAC).3 Although primary tumors of the facial
nerve are relatively rare, the admonition of Sir Terence
Cawthorne, “All that palsies is not Bell’s,” must be con-
sidered when slowly progressive facial paresis develops.4
This chapter focuses on facial nerve neuroma and
hemangioma.
The nomenclature for neurogenic tumors of the
facial nerve includes the terms neurinoma, schwannoma,
and neurilemmoma, although neuroma is used in this
chapter to describe this tumor. Neuromas arise from
Schwann cells, the myelin-producing cells peripheral to
the axon, and are usually located eccentrically and com-
pressing the nerve. The histopathology may follow one
of two patterns. The fi rst is that of a dense array of cells
in a regular pattern (Antoni A), and the second dem-
onstrates areas of loose stroma and vacuolation (Antoni
B) (Fig. 121-1). Often there is a mixture of both pat-
terns, although neither suggests any prognostic implica-
tions. This is in contrast to neurofi bromas, which arise
from endoneurial connective tissue. These tumors are
more typically associated with neurofi bromatosis 1, or
von Recklinghausen’s disease.
Neuroma of the facial nerve is considered to be a
slowly growing tumor. It appears grossly as a diffuse
bulge of the facial nerve but characteristically involves
multiple segments along its course. A neuroma may
arise anywhere along the course of the facial nerve from
the root entry zone in the cerebellopontine angle
(CPA) to the extratemporal trunk of the nerve within
the parotid gland. Figure 121-2 combines the results of
two publications reviewing 287 cases of facial nerve
neuroma.5,6 The tympanic segment is most commonly
1241

1242
Section 14
Facial Nerve
involved, followed by the geniculate/labyrinthine and
vertical segments.
It is reported that up to 50% of patients with primary
neuroma do not present with signs or symptoms of
facial nerve dysfunction.7 The structures of the IAC, otic
capsule, and middle ear are subject to encroachment
and erosion by an expanding tumor of the facial nerve.
Common initial symptoms, other than facial nerve
paresis, include hearing loss, tinnitus, and vertigo or
dysequilibrium.
The existence of neuroma of the facial nerve iso-
lated to the porus of the IAC and CPA has been ques-
tioned. Published reports of such tumors have provided
insight into radiologic fi ndings that preoperatively may
differentiate an acoustic neuroma from a facial nerve
neuroma. Acoustic neuromas are usually centered on
the IAC. Demonstrating the bulk of tumor to be eccen-
tric to the axis of the IAC raises suspicion of facial nerve
neuroma.7 Facial nerve neuroma limited to the IAC or
fallopian canal may not demonstrate bony expansion
on computed tomography (CT). Contrast-enhanced
magnetic resonance imaging (MRI) is more sensitive
in revealing tumors of the facial nerve isolated to the
IAC.
Hemangioma is considered to be a vascular hamar-
toma composed of blood vessels. The blood supply
to the facial nerve originates from three separate
sources, thus creating a vascular arcade. The intracra-
nial and intrameatal segments of the facial nerve
are vascularized by the internal auditory artery,
which originates from the anterior inferior cerebellar
artery. The geniculate ganglion area is supplied by
the petrosal artery, which follows the course of the
greater superfi cial petrosal nerve. The petrosal artery
is a branch of the middle meningeal artery. The
third blood supply to the vertical and horizontal
facial nerve segments is from the stylomastoid artery.
This source has its origin from the posterior auricular
or occipital arteries. These vessels create a prominent
watershed vascular plexus over the geniculate ganglion
area.
Depending on the size of the vessel involved, hem-
angiomas of the facial nerve are categorized as capillary
or cavernous hemangioma. Similar to neuromas, this
histologic subclassifi cation does not have prognostic
implications. Hemangiomas of the facial nerve predom-
inantly occur at the geniculate ganglion and the
IAC. They rarely originate more distally along the
horizontal or vertical segments of the facial nerve.
Hemangiomas usually arise eccentrically from the
nerve and initiate remodeling of the surrounding tra-
beculated bone, on which they create spicules
and centers of ossifi cation. Because of their extrinsic
origin, it was believed that hemangiomas could be dis-
sected from the underlying nerve more easily than is
the case with schwannomas. However, recent publica-
tions suggest that hemangiomas of the geniculate gan-
glion often infi ltrate the facial nerve, thus requiring
sacrifi ce of the nerve with cable graft repair for com-
plete resection.8
The initial symptoms of hemangioma of the facial
nerve are dependent on the location. In contrast to
neuroma, hemangiomas of the facial nerve typically
manifest signs of facial nerve paresis or paralysis unless
they are isolated to the IAC. In this location, they fre-
quently cause progressive sensorineural hearing loss
with reduced word discrimination, similar to an acous-
tic neuroma. In contrast, hemangiomas of the genicu-
late ganglion predominantly produce slowly progressive
facial paralysis occurring over a period of months to
years. Facial nerve hemangioma is also an uncommon
cause of atypical hemifacial spasm.9,10 The degree of
facial paresis seen with hemangioma is considered to
be more severe than that occurring with a neuroma of
the same size. The gross appearance of hemangioma of
the facial nerve is similar to that of a red sponge. Small
CPA/intracranial
58 (20%)
Meatal
91 (31%)
Tympanic
159 (55%)
Vertical
136 (47%)
Chorda
tympani
3 (1%)
Stapedius 4 (1%)
Labyrinthine/
geniculate
139 (48%)
Infratemporal and
peripheral
41 (14%)
Figure 121-1. Histopathologic patterns of cellular distribution in
facial neuroma. A, Antoni A (cellular, more organized); B, Antoni B
(loose stroma, fewer cells, myxoid change).
Figure 121-2. Segmental distribution and frequency of facial neu-
romas in 287 cases. These tumors characteristically involve multiple
nerve segments. CPA, cerebellopontine angle.

Chapter 121
Tumors of the Facial Nerve 1243
tumors may cause severe symptoms and, until recently,
defi ed easy detection.
Radiographic imaging plays an important role in
the differential diagnosis of these tumors. Similar to
facial neuroma, identifi cation of hemangioma of the
facial nerve requires high-resolution bone-windowed
CT and MRI focused along the course of the facial
nerve. Recent reports suggest that gadolinium-enhanced
MRI has greater sensitivity than CT in detecting and
differentiating hemangiomas from other tumors of the
geniculate ganglion area.11 The CT fi ndings may dem-
onstrate irregular, indistinct bone margins contain -
ing bone spicules within the tumor. This honeycomb
appearance has been termed ossifying hemangioma.12 It
must be emphasized that the patient’s history and diag-
nostic imaging studies provide the critical information
necessary to make a presumptive diagnosis of primary
neoplasm of the facial nerve.
PATIENT SELECTION
Complete examination of the head and neck is neces-
sary. Examination of the face must include all branches
of the facial nerve, with attention directed to gross and
fi ne motor function. Evidence of synkinesis, mass
motion, and fasciculations is sought. These signs may
be further elicited by asking the patient to squeeze the
eyelids closed and perform a sustained exaggerated
smile or grimace. These maneuvers evoke latent fascicu-
lations or demonstrate subsequent weakness. Based on
the degree of paresis and synkinesis, the level of facial
function is defi ned by the House-Brackmann grading
system (Table 121-1).13 This system was devised to
describe recovery of facial function after surgery, infl am-
mation, or trauma. It has been adapted to describe
abnormalities ranging from mild weakness to complete
paralysis at initial examination.
The parotid gland and neck are palpated for evi-
dence of tumor or adenopathy, respectively. The fi fth
cranial nerve is tested for evidence of motor or sensory
abnormalities. Findings on otoscopy are usually normal,
although a mass in the middle ear aural polyp may
be evident. The results of tuning fork testing would be
reversed (bone greater than air or a negative Rinne
test) when ossicular chain movement is impeded by the
tumor. Signifi cant asymmetrical sensorineural hearing
loss may also be identifi ed with tuning fork testing.
Radiologic imaging is critical in establishing a pre-
sumptive diagnosis. Both high-resolution CT and MRI
can demonstrate a primary tumor of the facial nerve.
Thorough and precise radiologic imaging is mandatory
for tracing the entire course of the facial nerve from
the brain stem to the parotid gland. CT is better able
to show bone expansion or changes such as those seen
with ossifying hemangioma. This honeycomb appear-
ance with evidence of bone remodeling and ossifi cation
is highly suggestive of hemangioma (Fig. 121-3). In
addition, the structures of the otic capsule and middle
ear are more readily identifi ed on CT, and their degree
of involvement can be defi ned (Fig. 121-4). Radiologic
diagnosis of facial nerve neuromas can be based on the
location of nerve enlargement, surrounding bone
changes, or evidence of enhancement. MRI is more
sensitive for demonstrating such enhancement. Tumor
expansion of the geniculate ganglion area will be
evident on both MRI and CT, but diffuse facial nerve
involvement is readily apparent on gadolinium-
enhanced MRI (Fig. 121-5).
Intracranial or intrameatal (IAC) neuromas of
the facial nerve are more frequently diagnosed as
Table 121-1
HOUSE-BRACKMANN FACIAL NERVE GRADING SYSTEM
Grade
Description
Characteristics
I
Normal
Normal facial function in all areas
II
Mild dysfunction
Gross: Slight weakness noticeable on close inspection; may have very slight synkinesis
At rest: Normal symmetry and tone
Motion: Forehead—moderate to good function; eye—complete closure with minimal
effort; mouth—slight asymmetry
III
Moderate dysfunction
Gross: Obvious but not disfi guring difference between the two sides; noticeable but not
severe synkinesis, contracture, or hemifacial spasm
At rest: Normal symmetry and tone
Motion: Forehead—slight to moderate movement; eye—complete closure with effort;
mouth—slightly weak with maximal effort
IV
Moderately severe
dysfunction
Gross: Obvious weakness and/or disfi guring asymmetry
At rest: Normal symmetry and tone
Motion: Forehead—none; eye—incomplete closure; mouth—asymmetrical with maximal
effort
V
Severe dysfunction
Gross: Only barely perceptible motion
At rest: Asymmetry
Motion: Forehead—none; eye—incomplete closure; mouth—slight movement
VI
Total paralysis
No movement