Download Closed MET

完壁术式
——Fisch 技术
Closed MET
(Ugo Fisch Technique)
北京大学第三医院耳鼻咽喉科
马芙蓉
[email protected]
Closed Mastoido-Epitympanectomy
with Tympanoplasty
(Closed MET)
Surgery for Otitis Media and Cholesteatoma
Tympanum
Tympanoplasty (Myringoplasty+Ossicle Reconstruction)
Mastoid
Simple Mastoid Operation
Tympanum +Mastoid
Tympanoplasty
Open cavity: Ossicle reconstruction +Canal wall down
Closed cavity : Ossicle reconstruction +Canal wall up
Subtotal Petrosectomy with Preservation of Otic Capsule
Surgical Highlights
• General anesthesia
• Retroauricular skin incision
• Mastoidectomy
• Epitympanectomy
• Posterior tympanotomy
• Meatal skin flap
• Canalplasty
• Middle ear inspection
• Complete removal of
cholesteatoma matrix
• Tympanoplasty
Surgical Technique
• The closed mastoido-epitympanectomy with
tympanoplasty is a tympanomastoidectomy in
which particular emphasis is applied to the work
in the attic.
• A closed MET includes mastoidectomy, and
epitympanoplasty, posterior tympanotomy and
tympanoplasty.
•All bony overhang has been
eliminated. The shape of the canal is
that of an inverted truncated cone.
•A correct canalplasty facilitates
tympanic membrane grafting, speeds
up healing, ensures the self-cleansing
property of the external canal, and
Surgical site after
canalplasty
makes it easier to carry out secondstage tympanoplasty.
The tympanomeatal flap is raised
and the extent of cholesteatoma
invasion of the middle ear assessed.
The decision to perform a closed
cavity is made on the basis of:
(1)no evidence of Eustachian tube
dysfunction
(2) good pneumatization of the
Middle ear inspection
tympanomastoid cleft
(3) limited extension of
cholesteatoma.
• This step is necessary to avoid
inducing a sensorineural hearing
loss when working along the incus
and malleus in the attic.
• In most instances, the long
process of the incus is already
Division of the incudostapedial joint
eroded by the cholesteatoma so
that division of the incudostapedial
joint is superfluous.
Mastoidectomy
The mastoid plane is exposed
with two articulated retractors
supplemented by a third rigid
retractor placed between the
temporalis muscle and mastoid
Exposure of mastoid plane
tip.
•The antrum is identified at the
intersection of two grooves formed by
removing bone along the superior and
posterior canal wall.
•The entrance of the bony external canal
should not be lowered when drilled for
the antrum. This is why the canalplasty
should be completed before looking for
Identification of antrum
the antrum.
•The middle fossa dura and sigmoid
sinus are skeletonized at this stage
when working in a sclerotic mastoid.
Correct bone removal
a: The posterior canal wall should not be lowered during canalplasty and
mastoidectomy.
b: Lowering the posterior entrance of the canal carries the risk of
squamous epithelium ingrowth from the external canal into the mastoid
(meatomastoid fistula ).
•Schematic cross section through
the ear showing the correct(a) and
incorrect (b) shaping of the
posterior canal wall.
• Note that the posterior limb of the
endaural incision must be made
Correct bone removal
lower than the lateral entrance of
the external canal and how the
mastoid periosteal flap is rotated
against the posterior canal wall to
prevent atrophy of the bone and a
meatomastoid fistula.
Danger of incorrect bone removal
•The digastric ridge and the
stylomastoid periosteum are
exposed to identify the
stylomastoid foramen.
•The course of the mastoid
segment of the fallopian canal is
identified.
•The retrofacial cells are
exenterated.
Surgical site after mastoidectomy
The broken lines show
the position of the antrum.
•The sigmoid sinus and the
middle cranial fossa dura are
skeletonized.
Epitympanectomy
•The lateral wall of the attic is removed
with a diamond burr.
•The cholesteatoma fills the
epitympanum.
•The matrix is opened with small
tympanoplasty scissors.
•The contents of the cholesteatoma sac
are evacuated by suction.
•The size of the cholesteatoma is
Exposure of the attic
reduced to allow easier separation of
the matrix from the surrounding bone.
•The atrophic incus is removed.
•The cholesteatoma matrix is
elevated from the lateral
semicircular canal.
•The tympanic facial nerve is
identified along the inferior margin
of the lateral semicircular canal.
Identification of tympanic facial nerve
• Only on rare occasions, does
an extremely large
cholesteatoma prevent
adequate identification of the
facial nerve along the lateral
semicircular canal.
• In such a situation, it is best to
follow the mastoid facial nerve
from the stylomastoid foramen
into the area where the
anatomy has been distorted by
the lesion.
Identification of tympanic facial nerve
• EMG monitoring of facial
function is essential in such a
situation.
•Always expect a fistula when
elevating the cholesteatoma matrix
from the lateral semicircular canal.
•Look for a fistula before removing
the medial wall of the
cholesteatoma sac.
•In the presence of a fistula, leave
the covering skin until the end of
the operation to avoid damaging
Management of semicircular canal fistula
the inner ear.
•Remove the skin over the fistula
when the bone work and the
removal of the remaining matrix is
completed.
•Use constant irrigation. The
matrix covering the fistula is only
removed if the endostium is intact.
This is usually possible in fistulas
up to 2 mm in diameter.
Management of semicircular canal fistula •If the perilymphatic space is open,
the skin covering the fistula is
replaced in its original position.
If the matrix has been removed,
the intact endostium of the
fistula is covered with bone dust
( obtained by drilling ) mixed with
Management of semicircular canal fistula
fibrin glue (bone paste).
The fistula is finally covered with
fresh temporalis fascia placed
over the bone paste.
Management of semicircular canal fistula
•The malleus neck is divided and the
head of the malleus removed.
•The cholesteatoma matrix is carefully
detached from the walls of the
epitympanum, and the size of the
cholesteatoma sac is successively
reduced by cutting away excess matrix.
•The completely closed chorda-tensor
fold is removed.
•The matrix lying lateral to the facial
Exenteration of the attic
nerve is removed from the
supralabyrinthine and supratubal recess.
•The position of the geniculum,
petrosal nerve, and labyrinthine
segment of the facial nerve should be
known to avoid injury of a dehiscent
nerve.
• A spontaneous dehiscence of the
facial nerve may exist proximal to the
geniculum.
•EMG monitoring of the facial
muscles is very helpful in this phase
Exenteration of the attic
of surgery to avoid causing a lesion of
the facial nerve.
Posterior Tympanotomy
•The bone situated between the pyramidal
facial nerve and the chorda tympani is
drilled away along the tympanic segment
of the fallopian canal.
•The resulting opening to the middle ear is
the posterior tympanotomy.
•A lesion of the facial nerve should not
occur because the posterior tympanotomy
Removal of cholesteatoma
from the oval window
is carried out under direct visual control of
the nerve and with EMG monitoring of the
facial muscles.
•The size of the tympanotomy
depends on the extent of the
cholesteatoma in the facial recess and
sinus tympani.
•A wide exposure of the sinus tympani
requires sacrifice of the chorda.
•If the cholesteatoma is limited to the
superior half of the oval window
niche(above the stapes arch), matrix
can be accomplished at this stage,
Removal of cholesteatoma
from the oval window
working from both sides of the intact
canal wall (combined approach).
•Matrix covering the stapes and
oval window is removed after
completion of all bone work
because uncontrolled suction
irrigation might damage the
exposed inner ear.
• The last portion of
cholesteatoma invading the oval
window niche between the stapes
Removal of cholesteatoma
from the oval window
arch and facial nerve is exposed.
The removal of the matrix from
the oval window begins
anteriorly where the footplate
( or membrane covering the
oval window ) is best identified.
For the elevation of matrix from
the oval window, the same
precautions should be taken as
Removal of cholesteatoma
from the oval window
when working over a fistula of
the lateral semicircular.
•The posterior matrix is best removed
through the transcanal approach.
•Drilling a small notch in the posterior
canal wall may be necessary to
visualize the posterior footplate.
• Removal of matrix from the stapes
is performed in a posteroanterior
Removal of cholesteatoma
from the oval window
direction, taking advantage of the
stability offered by the stapedial
tendon.
•The matrix has been completely
removed from the oval window niche
and stapes.
•The notch in the posterior canal wall
will be reconstructed later on with
preserved septal or tragal cartilage.
•Cutting the stapes arch with
crurotomy scissors to remove matrix
surrounding the stapes arch is rarely
necessary.
Removal of cholesteatoma
from the oval window
• Manipulations around the stapes
arch require caution to avoid luxation
of the footplate.
•The supralabyrinthine and
supratubal recesses are
exenterated.
•Good knowledge of the anatomy
of the tympanic and labyrinthine
segment of the facial nerve is
necessary for this purpose.
•Keep in mind the acute angle
formed by the lateral tympanic
segment.
Surgical site following completion of
closed tympanomastoidectomy
•Note that the chorda-tensor fold
was removed to provide adequate
ventilation of the anterior
attic(arrow).
Tympanoplasty
•Primary reconstruction of the
ossicular chain is possible in this
case because the stapes, the
malleus handle, the tensor
tympani tendon, and the pars
tensa of the tympanic membrane
are intact.
•A modified Ionomer incus is
interposed between the stapes
head and malleus handle.
Tympanoplasty
•If the malleus handle is missing,
the reconstruction of the ossicular
chain is carried out at a second
stage.
•The malleus handle and the
stapes arch are missing.
•Silastic sheeting was
introduced into the tympanic
cavity and Eustachian tube
because of the defective
middle ear mucosa.
•Septal cartilage is used to
reconstruct the posterior
canal wall.
Packing and transmastoid drain
Schematic representation of packing
and transmastoid drain
•An anterior underlay of
temporalis fascia was used
to reconstruct the tympanic
membrane.
• Gelfoam pledgets impregnated
with Otosporin keep the meatal
skin and the underlaid fascia in
position over the tympanic
sulcus.
• The external canal is packed
with a strip of gauze
impregnated with antibiotic
mintment.
• The concha is covered by a
large gauze.
Packing and transmastoid drain
Schematic representation of packing
and transmastoid drain
•
A conventional pressure
dressing is applied over the
wound.
完壁术式
• 宋*，男，15岁
4472383
• 右耳反复流脓及听力
下降2年
• 紧张部后下边缘性穿
孔，鼓岬粘膜上皮化
• PTA 60dB
• 后继胆
• 鼓室成形术III型
• 上鼓室外侧壁重建