Canal wall up Mastoidectomy ( Intact Bridge Mastoidectomy) by Dr.Aditya Tiwari

1. “CANAL WALL UP
MASTOIDECTOMY”
By:
Dr. Aditya Tiwari,
Resident, Dept. of ENT.
16/09/2014

2. OUTLINE
 Introduction
 History
 Relation  Anatomy  Pathophysiology
 Etiology  Diagnosis
 Treatment  Defination.
 Indication & contraindications
 Pre op. evaluation & counseling
 Techniques
 Complications
 References.

3. INTRODUCTION
 Desciption of chronic and suppurative infections
of the mastoid have been discovered dating back
to ancient Greece.
 Mastoid surgery has evolved from simple
trephination for acute infections, to the canal wall
preserving mastoidectomy.
 The complete (or simple) mastoid operation,
refers to canal-wall-up (CWU) mastoidectomy,
with complete removal of diseases from temporal
bone lateral to otic capsule.
 It is usually accompanied by tympanoplasty &
ossicular chain reconstruction.

4. HISTORY
 Mastoid operation have been employed for over 300
years to control suppurative diseases of the ear, but
first proposed mastoidectomy date back more than
four centuries.
 Ambrose Pare proposed to operate on skull & drain
pus.
 Jean Petit of Paris reported the first successful mastoid
trephination operation in late 1700s.
 The first postauricular incision was introduced in 1853
by Sir Willian Wilde of Dublin.
 Schwartze & Eyeshell reported the use of cortical
mastoidectomy for management of acute mastoid
infections.

5.  Zaufal, in 1890, described the radical mastoidectomy with
the additional removal of the TM, ossicles & post. wall of EAC.
 Bondy described opening the epitympanum and leaving the
middle ear intact.
 In 1902, Sir Charles Balance was the first to advocate the
complete mastoid operation for control of advanced
suppuration of the ear.
 Lempart popularised the use of a drill & loupe magnification
in the 1928.
 With the introduction of Zeiss operating otologic microscope
in 1923 & description of CWU mastoidectomy by JANSEN, the
paradism for mastoid surgery changed dramatically for acute
& chronic mastoid infections.
 1958, the canal wall up mastoid was then popularized by
House. He also introduced the suction irrigation system and
retractors in mastoid surgery.

6. RELATION OF THE MASTOID ANTRUM
 There are four parts to
the temporal bone:
petrous, tympanic,
mastoid, and squamous
 A transmastoid
procedure allows access
to the facial nerve,
internal carotid, jugular,
and internal auditory
canal

8. ANATOMY- AXIAL MASTOID
 VII- seventh cranial nerve;
 VIII- eighth cranial nerve;
 APA- anterior petrous
apex;
 Ca- carotid artery;
 CT- chorda tympani;
 EAC- external auditory
canal;
 ET- Eustachian tube;
 Fn- facial nerve;
 IAC- internal auditory
canal;
 KS- Körner septum;
 LSC- lateral semicircular
canal;
 PPA- posterior petrous
apex;
 PSC- posterior
semicircular canal

9. PATHOPHYSIOLOGY
 Primary role of CWU mastiodectomy is in the control of
chronic otitis media, with and without cholesteatoma &
acute mastoiditis.
 It is also used as a standard approach for cochlear
implantation, excision of tumors & surgery for vertigo.
 Incision & drainage of subperiosteal abscess,& placement
of tympanostomy tubes & antibiotics, without
mastoidectomy, suffice in the treatment of most of cases of
acute mastoiditis.

10.  Acute mastoiditis arises from untreated acute otitis
media, otitis media that fails to respond to antibiotics.
 Coalescent mastoiditis is acute mastoiditis in which a
localised collection of pus has accumulated in the
mastoid, with evidence of erosion of the normal bony
septae within the mastoid cavity.
 Persistant purulent otorrhea for more than 3 weeks
after AOM, pain behind the ear, or pain deep in the ear
are indications that coalescence may be developing.
 Many signs & symptoms seen in both AOM &
coalescent mastoiditis, but their persistance 2-3
weeks after the onset of infection is more s/o
coalescent mastoiditis.

11.  It can present as a postauricular subperiosteal
abscess & definatively diagnosed by CT scan.
 Subacute mastoiditis – slow, silent progression of a
coalescent abscess, is a potentially dangerous
consequence of partially treated AOM. It evolves over
several weeks.
 CSOM defined as chronic inflammation of the middle
ear & mastoid, can be seen with or without
cholesteatoma.
 Most commanly it manifests as hearing loss &
intermittant otorrhea. Usually painless but acute
condition is painful. Vertigo is uncomman but if
present concerns for labyrinthine fistula or
inflammation.

12.  Pathologic findings of CSOM includes osteitis (most
often seen in ossicle, otic capsule & mastoid bone) ,
mucosal edema with submucosal gland formation,
granulation tissue, tympanosclerosis, cholesterol
granulomas, cholesteatoma, & TM retraction and
perforation.
 Bone erosion from osteitis can result in ossicular
discontinuity, dural exposure with or without brain
herniation, meningitis & labyrinthine fistula.
 Granulation tissue most commanly seen in
epitympanum & round window niche, blocking the
aditus  preventing aeration of the mastoid &
subsequent resolution of infection.

13. ETIOLOGY OF CSOM
CSOM is believed to caused by
1. ETD  persistant middle ear discharge
(serous/purulent) mucosal edema formation of
granulation tissue.
2. Bacterial infection via chemical mediators
 Granulation tissue formation initiated in inflamed
mucosa bacterial toxin + inflammatory mediators
acts on edematous mucosa rupture of the BM of
epithelia
 Inflammatory cells in underlying lamina propria
extrude through BM secrets AGF, EGF leads to
fibroblast recruitment, neovascularisation & polyp
formation.

14.  TM affected by the enzymes contained in the granulation
tissue & chronic effusion breaks down its collagen
skeleton.
 The weakening of TM & negetive pressure in the middle
ear from ETD develops retraction pocket in the TM.
 Deepening of the retraction pockets leads to contact with
the underlying mucosa or granulation tissue & fibrous
band cause perforation.
 Deep retraction pockets & perforation set the stage for the
genesis of cholesteatoma.

15. DIAGNOSIS
ACUTE MASTOIDITIS:-
a) Begins as AOM Deep thrombing ear pain with
asso. with pus in the middle ear purulent
otorrhoea.
b) TM erythematous & bulges laterally
c) Fever, leukocytosis, tender mastoid, tender post
auricular skin
COALESCENT MASTOIDITIS:-
a) AOM persisting over days or weeks after
infection
b) Disproportionate deep pain, mastoid tenderness,
erythema or swelling.

16. CSOM:-
a) Foul smelling intermittant otorrhoea, hearing loss,
otalgia, headache.
b) Conductive hearing loss is comman. Its greater than
30dB suggest ossicular erosion. SNHL ranging from 5
to 33 Db.
c) EAC should be noated for edema, cholesteatoma. TM
should be noated for perforation, retraction,
atelectasis, or cholesteatoma.
d) Look for scutum erosion, ossicular erosion,
granulation tissue, vertigo(raising suspicion of
labyrinthitis or fistulas)

17. PAEDIATRIC CHOLESTEATOMA
Cholesteatoma is more aggressive in paediatric patients
due to the following reasons:-
a) Immature eustachian tube  facilitate TM retraction &
cholesteatoma
b) Increased amount of growth factor in children  faster
growth rates in cholesteatoma
c) Increased & better aeration in paediatric patients 
facilitate spread of cholesteatoma through middle ear &
mastoid  complicate disease removal
d) Faster replication rate of keratinocytes in paediatric
cholesteatoma Vs adults.

18. TREATMENT
MEDICAL TREATMENT
a) Broad spectrum antibiotics – oral or i.v.
b) Ototopical antibiotics.
c) Insertion of tympanostomy tube.
d) Analgelsics.
e) Antihistaminics.
f) Antacids – oral or i.v.

19. SURGICAL THEORY & PRACTICES
 Simple Mastoidectomy
 Closed or Canal Wall Up Mastoidectomy
a) Cortical mastoidectomy
b) Combined approach tympanoplasty
c) Tympanoplasty with mastoidectomy
 Open or Canal Wall Down Mastoidectomy
a) Atticotomy
b) Radical mastoidectomy
c) Modified radical mastoidectomy

20.  Modifications of intact canal wall Mastoidectomy:
1) Atticotomy with preservation of the intact
bony bridge
2) Atticotomy with preservation of a partly
resorbed bony bridge
3) Atticotomy with removal of the bridge
4) Widening of the ear canal
 Atticotomy openings of various sizes with
preservation of the intact non resorbed bony
bridge
 The goal of this atticotomy is to obtain a good view
into the anterior attic. The bridge remains in its
normal position

21. DEFINITIONS
 Cortical mastoidectomy:- This is an operation
performed to remove the mastoid antrum & air cell
system and aditus & antrum, with preservation of
intact post. bony EAC wall without disturbing the
existing middle ear content.
 Combined approach tympanoplasty:- This is an
operation performed to remove disease from the
middle ear & mastoid by the way of
a) the mastoid
b) a posterior tympanotomy, &
c) the transcanal route, followed by the
reconstruction Of the middle ear transformation
mechanism

22.  SCOTT BROWN DIAGRAME

23.  Tympanoplasty with mastoidectomy:- This is an
operation performed to eradicate disease from the
middle ear and mastoid & to reconstruct the hearing
mechanism with or without tympanic membrane
grafting. e.g.
a) Combined approach tympanoplasty or cortical
mastoidectomy with tympanoplasty
b) Obliteration technique – muscle or other
obliteration of an open mastoid cavity with
tympanoplasty
c) Canal wall reconstruction technique –
reconstruction of the outer attic post. Canal wall of
an open mastoid cavity, with tympanoplasty
d) Open cavity technique – open or canal wall down
mastoidectomy with tympanoplasty

24.  ATTICOTOMY- remove all part of outer attic wall( scutum)
and adjacent deeper post meatal wall to expose the attic
(epitympanum) and when necessary the aditus and
antrum to gain acess to these sites and their content and /
or to remove disease limited to this site
 RADICAL MASTOIDECTOMY- to eradicate all middle ear
and mastoid disease , in which mastoid antrum and air cell
system ( when present) , aditus and antrum, attic and
middle ear( mesotympanum and hypotympanum) are
converted in to a common cavity exteriorzed to the
external auditory meatus. During this procedure TM, incus,
malleus all removed except stapes ( foot plate alone or with
stapes supra structure if healthy.
 RM- TM or reminant thereof and ossicular remenants
( usually the malleus handle and stapes) are retained

26. INDICATIONS
 3 priorities in surgery for CSOM are :-
a) eradication of disease
b) prevention of disease recurrence
c) preservation or restoration of hearing
 Mastoidectomy in CSOM has 3 primary
indications :-
a) eradication of disease & infection
b) approach for removal of cholesteatoma
c) establishing aeration
d) previous tympanoplasty failure & perforated TM
with persistant suppurative drainage.

27. CONTRAINDICATIONS TO CWU
MASTODECTOMY
1) Unresectable posterior canal wall defect
2) Patient in which proper follow up is questionable
3) Unresectable matrix involving the labyrinth, facial
nerve, carotid, dura, sinus tympani.
4) Only hearing ear
5) Patients with labyrinthine fistula
6) Long-standing ear disease
7) Poor eustachian tube function
Active infection &
otorrhoea are not c/i
to surgery, but ear
should be made dry
pre op. since the rate
of post op infection is
higher when an ear is
operated while
draining.

28. PREOPERATIVE EVALUATION
 Preoperative audiometry.
 IMPEDENCE
 X RAY mastoid
 HRCT scan of the Temporal bone.
(pneumatization, and position of the tegmen and
the sigmoid sinus and extend of the disease)
 EUM

29. PRE-OP COUNSELING - RISKS OF SURGERY
 Facial paralysis
 Vertigo
 Tinnitus
 Hearing loss
 Staged procedure
 Need for long term follow-up and routine aural
toilet

30. OPERATIVE TECHNIQUE FOR CWU
MASTODECTOMY
PREPARATION
 Pre operative antibiotic or steriods
 Supine position with head turned away from affected
ear
 Hair may be shaven if it is in the operating field, or
taped to keep it out of the field.
 Injection with lignocaine with epinephrine
(postaurally and canal skin in sup. , post, inf )
 Antibiotics ( ciprofloxacin 400 mg iv or betadine soln
mixed with saline) for irrigation

31. APPROACHES: (SOFT TISSUES)
 Endaural
 Retroaural
 Vasular strip incisions

32. Retroauaral approach Endaural approach
 Attic is oblique in postero
anterior direction,
distance to attic is longer.
 Mastoidectomy is easy to
be extended
 Cavity obliteration by
flaps is possible
 Both trans meatal and
transcortical routes can
be taken
 Cavities produce is larger
 Attic view is direct latero
medially and distance to
attic is shorter
 Difficult to extend
 Cavity obliteration not
possible
 Posterior tympanum and
sinus tympani is better
viewed
 Only transmeatal route is
route of choice
 Cavities produce is

33. ROUTES: (BONE)
 Transcortical
starts over cortex of mastoid process
also described as outside in
 Transmeatal
starts in the bone of ear canal
also described as inside out
atticotomy antrostomy  retrograde
mastoidectomy

34. SIMPLE MASTOIDECTOMY
Indication –
1) acute mastoiditis,
commonly called
“coalescent mastoid”
2) Medical management
failure of chronic
suppurative otitis
media/mastoiditis
3) As an approach to:
a) Facial nerve decompression
b) Endolymphatic sac
decompression
c) Labyrinthectomy

35.  A post-auricular 1cm post. to sulcus approach is used .
 Young children the mastoid tip is not well developed
and the stylomastoid foramen is located more
superficially, making the facial nerve vulnerable to
surgical trauma. The inferior aspect of the incision is
more posterior and is not carried down as far to avoid
injuring the facial nerve .

36. Carry the incision to the loose areolar tissue over the
temporalis facia..
CORTICAL MASTOIDECTOMY
The cortex is exposed by an
incision through the linea
temporalis, with a vertical cut
extended to the posterior
mastoid tip, in a T fashion. An
elevator is then used to free the
cortex off the soft tissue.
C shaped incision provides better exposure in a previously
drilled cavity, prevent injury to the important underlying
structure such as sigmoid sinus & middle cranial fossa.

37. Cortex exposed
a) Sup. - over the tegmen
b) Post. - over sigmoid
sinus
c) Ant. - level of EAC
meatus
d) Inf. – mastoid tip
 Self retaining retractors
are positioned and the
surface landmarks are
identified,which include
the spine of Henle,
cribriform area, & linea
temporalis.

40.  MacEwen’s triangle shows the
location of the antrum.
 MacEwen’s triangle is defined as
the posterior EAC border, the
anterior line of the zygomatic
arch and the line that connects
the two.
 The antrum is 15 mm medial the
this.
 Removing bone along the linea
temporalis
 Identify underlying tegmen ( pink
hue)
 Middle cranial fossa dura
delineated to its superior extend.

41. CANALPLASTY
 Using 2mm diamond burr, excess tympanic bone at
the tympanomastoid & tympanosquamous suture line
is removed.
 If required, the entire EAC can be enlarged, from 12
o’clock to 6 o’clock position posteriorly.
 The distance of facial nerve from the annulus in the
posterior-inferior quadrant of the EAC ranges from
1.9mm to 5.7mm facial nerve is at most risk to
injury during surgery.
 Often removal of this small amount of bone greatly
improves the exposure, ensuring better disease
resection & graft placement.

42. Completed canalplasty with entire annulus
visible

43.  Various drills are available and there are common
principles related to bur selection
 Larger bur preferred over smaller ones when possible
 A bur with a cutting surface is selected for cortical
bone, were diamond grain surface is for removing the
last layer of bone over facial nerve, sigmoid sinus,
tegmen, & opening the facial recess.
 Suction irrigation is critical to prevent excessive heat
transfer to underlying structures & to keep the bone
cool.
 Diamond burrs are effective at controlling bleeding in
the bone by driving bone dust into the lumen of the
small vessels
 Also, it is important to “saucerize” the edges of the
mastoid cavity to provide visualization.

44.  Cortical bone removed post to EAC (post- sigmoid
sinus bluish hue and sinodural angle , inf-
mastoid tip). Cortical bone is removed inferiorly
to the mastoid tip
 Surface of the tegmen followed medially towards
the antrum and the air cells are exposed.
KOERNER SEPTUM
penetrated
ANTRUM

46.  Dural plate and lateral
semicircular canal
 Postero-anterior view through
antrotomy and aditus ad
antrum into epitympanum
Dural
plate
LSSC
BODY OF
INCUS
SHORT
PROCESS
FACIAL
NERVE
DURAL
PLATE
LSSC

47. Sigmoid sinus, sinodural angle
and dural plate
Correct length of a cutting burr in
the drill
A diamond burr can be
lengthened in order to safely drill
deeper in the mastoid
DURAL
PLATE
SINODURAL
ANGLE
SIGMOID
SINUS

48. SIMPLE (DISEASED) CANAL WALL UP
MASTOIDECTOMY
 This is an extension of the simple mastoidectomy
with greater access to the attic, labyrinth,
endolyphatic sac, antrum and facial nerve.
 Opening of the aditus ad antrum allows access to
the epitympanum, and the incus and malleus may
be removed for greater access
 The canal wall remains up.

49. INDICATIONS
 Treatment of Cholesteatoma & suppurative mastoiditis
 Exposure of mastoid segment of facial nerve.
 Cochlear implant, in which a posterior tympanotomy is
part of the procedure
 Labyrinthectomy and mastoid trauma
 Retrolabyrinthine approachs to the vestibular nerves
 Exposere of the sigmoid sinus for obliteration before
petrosectomy

50.  Exposure of the mastoid region in CAT, to
delineate the descending portion of the
facial nerve & to provide the access for
opening the posterior tympanotomy into
the middle ear.
 Saccus decompression surgery, to offer the
safest & widest access to the posterior fossa
dura.
 Translabyrinthine operations, to provide
the exposure of the bony labyrinth needed
for its exenteration to allow access to the
IAM.

51. ATTIC DISSECTION POST.
EPITYMPANOTOMY
 Performed by following the tegmen anteriorly & by
thining the canal wall posteriorly & superiorly.
 Canal wall thinned laterally to medially.
 Drilling out of zygometic root opening of the attic
Granulation & cholesteatoma removed.
 Attic cell are opened completely & fully exposed in
any epitympanic disease. Ant. attic is most comman
site of residual disease.
 As the epitympanum approached from the post to
ant,the tegmen is carefully followed as it usually dips
inferiorly.

52.  After the Dissection , the anterior epitympanum,
zygomatic cells, body of incus and head of malleus are
identified.
 Cultures can then be taken from the mastoid mucosa,
if needed.

53. FACIAL NERVE:-
 IDENTIFICATION is most
important to avoid injury
 Travels as GG sup to
cochleariform process &
oval window. Post to oval
window takes inf. turn to
take on a more vertical
course.
 LSC lies just sup to facial
nerve as it complete it
transition to the vertical
segment.

54.  SECOND GENU is located a few mm
anteromedial to the lat. SSC & is ANATOMICAL
LANDMARK for localizing the facial nerve.
 Diagrastric ridge another land mark
 Burr stroke should be the parallel to the
course of the nerve
 Its gently uncovered until it is observed
through a thin layer of bone.
 If the disease is limited to the antrum,
uncovering the vertical segment of the facial
nerve is rarely done.

55.  Relations of VIIn to short process of incus;
superior semicircular canal (SCC); lateral
semicircular canal (LSC); posterior semicircular
canal (PSC); dura; and sigmoid sinus
DURA
SSC
SIGMOID SINUS
FACIAL
NERVE
INCUS
LSC

56.  Distal portion of mastoid segment of facial
nerve (arrow) is identified close to digastric
ridge

57. FACIAL RECESS (POST. TYMPANOTOMY)
 Not required in all CWU mastoidectomy, employed
only when dictated by the location of the disease.
 Thin the posterior canal wall
 Boundaries:-
a) Superior: Incus or incus buttress
b) Posterior: Facial nerve
c) Anterior: Bony EAC , chordae tympani
d) Inferior: Bifircation of facial nerve &
chordae tympani

58. Boundaries of the Facial recess

59.  Access to the mesotympanum can be gained by
removing the bone in the facial recess after thinning
the post. canal wall.
 For additional exposure, the facial recess can be
extended inf. by sacrificing the chorda tympani nerve.
 Entire mesotympanum &
hypotympanum can usually be
accessed through the mastoid by the
extended facial recess approach.

60.  Chorda tympani nerve is identified as it branches off
the vertical segment of the facial nerve & traced sup.
Toward the incus.
 Facial recess is opened with a 2 mm diamond burr,
starting sup. where it is widest.
 EXTENDED FACIAL RECESS approach involve sharply
sectioning the chorda tympani nerve & extending the
recess ear inferior along the facial nerve course.
 The lateral boundary of the exposure becomes the
annulus of the tympanic membrane.

62. Landmarks for posterior tympanotomy
A) VIIn, B) chorda tympani & C) short process of
incus
A
B
C

63. FACIAL RECESS
 A = antrum, C = chorda tympani, F = facial nerve, HSC
= horizontal semicircular canal, I = incus, R = round
window, S = stapes

64. EPITYMPANOTOMY
 If the cholesteatoma does not extend significantly into
the epitympanum, an epitympanotomy (atticotomy) is
performed
 This involves exposure of the head of the malleus and
the incus to remove soft tissue from the epitympanum.
 The lateral wall of the epitympanum or attic is
removed with a diamond burr; drilling is commenced
at 12 o’clock relative to EAC, taking care not to make
drill contact with the malleus or incus which is
immediately medial to the outer attic wall, or to breach

65. Direction of drilling with epitympanotomy or
epitympanectomy

67. EPITYMPANECTOMY
 This is indicated when cholesteatoma extends medial
to the ossicles or overlies the lateral semicircular
canal; in cases of bony erosion of the ossicles due to
cholesteatoma, the ossicles need to be removed
 The incus is removed by mobilising it with a 2,5mm.
45° hook and rotating it laterally, taking care not to
injure the underlying facial nerve .
 The malleus head is severed with a malleus nipper
applied across its neck.

68.  The head of the malleus is removed leaving the
tensor tympani tendon intact.
 Clear cholesteatoma from the epitympanum.
 Detailed knowledge of facial nerve anatomy is
crucial to avoid injury to the nerve when drilling or
removing cholesteatoma in the epitympanum.
 The tympanic and labyrinthine segments and
geniculum all lie in this very confined space and
may be dehiscent.
 The tympanic segment lies in the floor of the
anterior epitympanic recess.

69. Anatomy of anterior epitympanic recess: Facial nerve
(VIIn); Tegmen tympani (TT); Cog; Supratubal recess
StR; Cochleariform process (CP); Eustachian tube (ET
TT
VIIn
Cog
StR
CP
TTymp
ET

70.  The cochleariform process is a fairly consistent
landmark and the nerve lies directly superior to it;
the semicanal of the tensor tympani is sometimes
mistaken for the facial nerve; however this canal
ends at the cochleariform process.
 The Cog is a bony process in the anterior
epitympanum which extends from the tegmen
tympani and points to the facial nerve.
 Geniculate ganglion and GSPN seen once the Cog
and cochleariform process have been drilled away
(as shown follow)

71. View of epitympanum with cog and cochleariform process drilled
away: Tympanic (VII.T) and Labyrinthine (VII.L) segments of
facial nerve and Geniculate Ganglion (GG) and Greater Superficial
Petrosal nerve (GSP); Superior Semicircular Canal (SSC); Lateral
Semicircular Canal (LSC); Dura; Tensor Tympani tendon (cut)
(TeT)

72. Completed closed mastoidoepitympanectomy

73. FISTULA OF LSC
A small dimple or flatttening in the matrix
covering the bone over LSC may believe as a
fistula
LARGE SMALL
Greater then 2 mm diameter Smaller then 2 mm
diameter
Convert it in to a canal wall
down procedure
Second look procedure 12
month later or repair it by
fascia or perichondrium

75. CombinedApproachTympanoplasty
(i.e.“CanalWallUp”,“IntactCanalWall”,“Closed-cavity
tympanomastoidectomy”)
 Prevent tympanomastoid cavity
considered in diploic or pneumatic air cell
systen with disease
 Primary objective is removal of the disease,
not the preservation of post EAC wall.
 Posterior EAC wall drilled to widen
Korner’s septum drilled & antrum is exposed
Saucerization of the outer cortex not so imp as
in complete mastoidectomy

76.  Aditus enlarged to readily visualise incus
epitympanum inspected through the aditus &
antrum.
 The facial recess & sinus tympani are exposed
& cleared of disease tympanoplasty is
accomplished.
 A silicone rubber sheet may be placed,
extending from the middle ear into the
antrum ensures the free flow of air between
the middle ear & mastoid cavity.

77. Removing cortex over
antrum
Antrotomy doneKorner’s
septum encounteredremoved
to expose antrum

78. Incus identified & aditus enlarged
to expose attic
Critical oval window area & recess
visualised through a) canal &
b)mastoid
Complete
mastoidectomy

79. Open Cavity Mastoidectomy
 Excision of the conchal cartilage via endaural or
postaural approach Korner flap or endaural
incision to creat a flap can be constructed
connect them with post. incision parallel to
tympanic annulus.
 The endaural incision extended from the post.
annulus incision in EAC to conchal bow large
crescent shaped piece of conchal cartilage
removed without injuring canal skin & retaining
continuity with the Korner flap.

80.  To provide an opening adequate to allow
drainage & surgical defect, meatoplasty should
comfirtably accept the surgeon’s finger.
 To prevent post op. stenosis by granulation
tissue formation curettage, steroid antibiotic
ointment, Thiersch grafting using very thin
split thickness skin (3 weeks after surgery).
 If stenosis occurs, it will be necessary to
elevate & preserve meatal skin & to drill or
curette the bone widely to creat a large meatus.

81. Completed mastoidectomy with tympanoplasty a) Conchal
cartilage is excised to create a large meatus. & b) Korner flap
is developed

82. The graft is placed in position(a). & the musculofacial
pedicle is placed into the finished mastoid cavity(b).If
it is large, post. Wound will be sutured & drained &
the Korner flap placed on top of the muscle through
an endaural exposure.

83. ADVANTAGES OF CWU
MASTOIDECTOMY
 Rapid healing time
 Easier long-term care
 Hearing aids easier to fit
 No water precautions

84. DISADVANTAGES OF CWU
 Technically more difficult
 Staged operation often necessary
 Higher chances of recurrent or residual
disease
 Residual disease harder to detect
 Children with cholesteatoma
 2nd look is required to rule out recurrence
or residual disease.
 Periodical & meticulous follow up needed.

85. COMPLICATION
 It occurs as a result of :–
a) Inadequete surgical exposure
b) Failure to recognize the anatomical variation.
c) Granulation or bleeding obscuring the surgical
field.
 They are as follows-

86. 1) Bleeding  due to injury to the jugular bulb and
dural plate or sigmoid sinus
2) SNHL  high frequences losses
3) Vertigo
4) Infection
5) Granulation tissue
6) Brain herniation
7) CSF leak

87. 6) Intracranial injury:-
a) Exposure of dura with spinal fluid leak
b) Small herniation of brain (less than 5mm)
managed with gentle bipolar cautery.
c) Large herniation of brain (more than 5mm)
managed with middle fossa craniotomy approach,
with the assistance of nerurosurgeon

88. 7) Facial nerve injury:-
a) Mastoidectomy is the most comman cause of iatrogenic
facial nerve palsy.
b) When graeter than 50% of nerve is transected, managed
by resecting the injured segment & grafting the nerve.
c) In case of subtotal transection of the facial nerve, it is
proximally & distally decompressed and injury is assessed.
8) Suppurative labyrinthitis.
9) Postauricular haematomas ( if the patient coughs
or strains during the postoperative period)

89. REFERENCES
 Bailey BJ, et al, eds. Head and Neck Surgery -
Otolaryngology. 4nd ed. Philadelphia Pa: Lippincott-
Raven; 2006
 Antonelli PJ, Dhanani N, Giannoni CM, et al. Impact of
resistant pneumococcus on rates of acute
mastoiditis. Otolaryngol Head Neck
Surg. Sep 1999;121(3):190-4
 Shambaugh GE, Glasscock ME. Canal wall up
mastidectomy. Surgery of the Ear.
 Shambaugh GE, Glasscock ME: open cavity mastoid
operation Surgery of the Ear.
 Scott brown 6th edition anatomy of the middle ear
 Bluestone CD. Acute and chronic mastoiditis and chronic
suppurative otitis media. In: Feigin RD, editor, Wald ER,
Dashefsky B, guest editors. Seminars in pediatric infectious
diseases. Vol 9. Philadelphia: WB Saunders; 1998;9:12–26.