A concise presentation on anatomy, approach and techniques of mastoid surgery

1. MASTOIDECTOMY
Kartik Mittal
6th
semester
MAMC

2. HEADINGS
 INTRODUCTION
 CLASSIFICATION
 Comparing CWU vs CWD
 SURGICAL ANATOMY
 INSTRUMENTS USED
 Pre-op imaging
 CORTICAL MASTOIDECTOMY-definition,
indications, operating techniques
 COMPLICATIONS

3. INTRODUCTION
 PRIMARY AIM OF ANY EAR SURGERY IS TO
REMOVE THE DISEASE,AND MAKE THE
EAR SAFE AND DRY, AND SECOND
PRIORITY is to PRESERVE/RECONSTRUCT
HEARING, BUT NEVER AT THE COST OF
PRIMARY AIM…..
 Mastoidectomy provides an access to remove
1.diseased air cell of mastoid in mastoiditis
2.cholesteatoma
3.granulation tissue in otitis media

4.  EXPLORATORY MASTOIDECTOMY-
 The initial MASTOID EXPLORATION till
antrum is reached is same for all mastoid
surgeries.
 Preservation of the canal wall is preferred.
 The decision to remove the wall is most
often made during surgery, when the
extent of the disease is fully
appreciated.
 Mastoidectomy(cwu) is also used as a
standard approach for
 1. Cochlear implantation,
 2. Excision of tumors of lateral skull base(like
schwannomas, meningiomas, glomus-temp

5. CLASSIFICATIONS
 Traditionally, classified as :
1. Simple (cortical) mastoidectomy
2. Modified radical mastoidectomy
3. Radical mastoidectomy
 Depending on the fact whether
postero-superior canal is removed or not,
 1. Canal Wall Up mastoidectomy
 2. Canal Wall Down mastoidectomy.

6. SUBCLASSIFICATION
CANAL WALL UP (CWU) CANAL WALL DOWN
(CWD)
FOR ATTICOANTRAL
DISEASE REMOVAL
1. Simple/ cortical/
Schwartze’s
mastoidectomy
1. Modified Radical
Mastoidectomy/ bondy’s
Procedure
2. Classic Intact Canal Wall
Mastoidectomy/ Combined
Approach Tympanoplasty (CAT)
2. Radical Mastoidectomy
3. Atticotomy
4. Atticoantrotomy

7. CWU PROCEDURES
 DISEASE REMOVED WHILE RETAINING THE
POSTERIOR WALL INTACT.
 THUS, AVOIDING AN OPEN MASTOID
CAVITY
 ADV-DRY EAR WHICH PERMITS EASY
RECONSTRUCTION OF HEARING
 DISADV-RESIDUAL/RECURRENCE OF
CHOLESTEOTOMA in these cases is very high
 SO, RE-EXPLORATORY FOLLOW-UP IS
ADVICED AFTER 6 MONTHS

8.  1)Disease is removed both permeatally and
through-
 2)POSTERIOR TYMPANOTOMY
APPROACH-
 A window is created b/w mastoid and middle ear,
through facial recess, to reach sinus tympani, don
along with cortical mastoidectomy
COMBINED
APPROACH-

10. Comparison of CWU vs
CWD
 MEATUS
 DEPENDENCE
 RECURRENCE/RE
SIDUAL DISEASE
 2ND
LOOK
SURGERY
 PATIENT
LIMITATIONS
 AUDITORY
REHABILLITATIO
N
CWU
NORMAL
DOES NOT
REQUIRE ROUTINE
CLEANING
HIGH RATE
AFTER 6
MONTHS TO RULE
OUT
CHOLESTEOTOMA
NONE, ALLOWED
SWIMMING
EASY TO WEAR
AID IF NEEDED
CWD
WIDELY OPEN MEATUS
COMMUNICATING WITH
MASTOID
HIGH DEPENDENCE ON
DOCTOR FOR YEARLY
CLEANING OF MASTOID
CAVITY
LOW RATE, THUS A
SAFER PROCEDURE
NOT REQUIRED
SWIMMING CAN LEAD TO
INFECTION
PROBLEMS IN FITTING A
HEARING AID DUE TO
LARGE MEATUS AND
SOMETIMES, DUE TO
INFECTED MASTOID
CAVITY

11. POST-SURGICAL
PROBLEMS- {5 D’S}
(MAINLY IN CWD)
1.Deafness-30dB
2.Dizziness-on thermal stimulation of
LSC(due to a single cavity)
3.Debris Collection- desqamated
epithelium
4.Discharge from infected debris
5.Dependence-on doctor for yearly
cleaning of cavity

12.  The temporal bone consists of four parts:
squamous, tympanic, mastoid, and petrous
 temporal line extends posteriorly from the
zygomatic root and is the insertion site for the
temporalis muscle.
SURGICAL
ANATOMY

15.  A cribriform area lies within Macewen’s triangle,
an imaginary triangle defined by three lines-
 1. Temporal line
 2. Line formed by the superior and posterior margins
of the external bony meatus (This line goes through
the suprameatal spine)
 3. Line drawn perpendiular to the first line and
tangential to the second.
 Mastoid antrum lies around 1.25 to 1.5 cm deep
from the surface of Macewen’s triangle.
 Cymba concha is the soft tissue anatomical
landmark for the mastoid antrum.

17. Fascial recess is a
depression in posterior
wall,Bounded medically by
vertical part of VII and
laterally by
Chorda tympani.
Exposure of fascial recess
provides a direct approach
Into the middle ear without
disturbing the posterior
canal.
This procedure is called
posterior tymaponotomy,
used in
Intact canal technique

18. Mastoid develops from the sqamous and petrous bones
Petrosquamosal suture may persist as a bony plate called KORNER’S
SEPTUM
Imp. Surgically as it may cause difficulty in locating antrum and other
deeper air cells
Leading to incomplte removal of disease
Thus, MASTOID ANTRUM CANNOT BE REACHED UNLESS IT IS
REMOVED

19. INSTRUMENTS USED
 MOLLISONS’S MASTOID
RETRACTOR

20.  JANSEN’S SELF RETAINING MASTOID
RETRACTOR
 LEMPERT’S ENDAURAL RETRACTOR

21.  LEMPERT’S ENDAURAL
SPECULUM

22.  MASTOID GAUGE
 ELECTRIC BURR

23. LEMPERT’S
CURETTE/SCOOP
MacEWEN
CURETTE &
CELL SEEKER

24.  FARABEUF
PERIOSTEAL
ELEVATOR
 CROCODILE
FORCEPS

25. OPERATING
MICROSCOPE-
focal length 200-250mm

26.  ADEQUATE-CONTINUOUS-IRRIGATION
while drilling-
 1.to wash away bone dust-improving visualisation
 2.to decrease risk of heat injury from drilling
 3.to maintain a clean cutting surface on the bur.
 Haemostasis for bleeding-
 1.bipolar cautery
 2.bone wax
 3.diamond spurr(lot of bone dust seals bleeding
vessels)

27.  a) cutting bur b)cutting diamond bur (note the
course texture) c) a diamond bur.

28.  Cutting burrs are efficient at removing large
amounts of bone in a small amount of time.
 Diamond burrs are very good at delicate
dissection around important structures, thinning
the bone off the sigmoid sinus, tegmen, facial
nerve, and opening the facial recess.
 During the mastoidectomy, larger burrs are used
first and the burr size is sequentially decreased
as the areas of dissection get narrower.

29. PRE-OPERATIVE IMAGING
 A pre-op TEMPORAL BONE HRCT is used to
determine-
 1)Location of tegmen,sigmoid sinus, facial
nerve,inner ear structure or a low lying dura
 2)to determine any abnormal anatomy of
temporal bone due to disease or previous
surgery
 3)identification of dehiscences in
tegmen/sinus- may have risk of CSF leak,
encepalocele, bleeding or rarely,air embolus
 4)Fistulas into otic capsule

30. CORTICAL
MASTOIDECTOMY
 CORTICAL/SIMPLE/COMPLETE
MASTOIDECTOMY (Schwartze 1873) is
COMPLETE EXENTERATION OF ALL
ACCESSIBLE MASTOID AIR CELLS and
converting them into a single cavity.
 It is a CWU procedure where posterior meatal
wall is left intact.
 MIDDLE EAR STRUCTURES ARE NOT
DISTURBED IN THIS PROCEDURE.

31. INDICATIONS OF CORTICAL MASTOIDECTOMY
1) ACUTE Coalescent Mastoiditis
2) Masked Mastoiditis (latent)
3) INCOMPLETELY RESOLVED AOM with reservoir
sign
4) CSOM TTD Active Refractory to antibiotics.
5) Secretory otitis media Refractory to antibiotics
6) Diffuse serous and diffuse suppurative labrynthitis (of acute
mastoiditis)
7) Approach to:
-Endolymphatic sac surgery.
-Facial nerve decompression.
-Vestibulo cochlear nerve section.
-Trans/Retrolabyrinthine Approach for CP angle access
in ACOUSTIC NEUROMA(and other tumors)
-Cochlear implant surgery.

32. Specific indications of cortical
matoidectomy in acute mastoiditis-
1) Subperiosteal abscess
2) Sagging of posterio-superior meatal wall
3) Positive reservoir sign
4) Worsening of patient even after adequate
medical treatment for 24hrs
5) Complicated mastoiditis- facial
paralysis,labrynthitis,i/c complication
DRY EAR FOR 6 WEEKS IS THE
MOST IMPORTANT PRE
OPERATIVE PRE REQUISITE

33. OPERATIVE
TECHNIQUES(CWU)
Position-
supine with face turned to one side and ear to be
operated is placed at the uppermost position
Preparation-
 General anesthesia without paralytic agents and with
continuous facial nerve Monitoring.
 Tragus and postauricular skin are injected with 1%
lidocaine with epinephrine (1: 100,000) to provide
hemostasis and local anesthesia.
 “Pre-scrub" the ear and the entire side of the head,
including hair, with betadine.

34. The surgical site is
then prepped and draped in sterile fashion.

35.  1)ENDAURAL APPROACH-
 A)excision of osteomas of ear canal
 B)large tympanic membrane perforation
 C)attic cholesteotomas with limited extension into antrum
 D) MRM where disease limited to attic,antrum or part of
mastoid
 LEMPERT I-
 Semicircular incision from 12o to 6o clock position in
posterior meatal wall at bony-cartilagenous junction
 LEMPERT II-
 Start from first incision at 12o clock and then passes
upward curvillinear b/w tragus and crus of helix.
 It passes through the incisura termanalis and thus does
not cut the cartilage.
 Used for both mastoid and
 external canal surgeries
SURGICAL APPROACHES TO THE EAR in
CWU

36.  2)POSTAURAL/WILDE’S INCISION-
 A)starts from highest attachment of pinna, follows the
curve 1cm behind retroauricular groove and ends at
mastoid tip.
 B)Some surgeons prefer it in sulcus itself
 C)Slanting posteriorly in <2yrs children due to
underdeveloped mastoid with a superficial facial nerve
 Used in-
 1)cortical mastoidectomy
 2)MRM/RM
 3)tympanoplasty-when perforation extends anterior to
handle of malleus

37. SURGICAL APPROACH
& INCISIONS 1)INCISION-
 The postaural incision is made from
helical rim to mastoid tip,
approximately 1 cm posterior to the
sulcus.
 Incision cuts soft tissues upto
periosteum, but
 temporalis muscle is spared

39. 2)Exposure of lateral surface of
mastoid and MacEwen’s triangle
 Periosteum is incised in the line of first
incision
 A horizontal incision may be made along
the lower border of temporalis muscle for
more exposure
 Periosteum is scraped from the mastoid
surface
 Sternoclidomastoid fibres are sharply cut
 Self retaining mastoid retractor is applied

40. 3)Removal of mastoid cortex and
exposure of antrum
 Cortex removed with burr
 Antrum is exposed in area of
suprameatal/McEwens triangle
 12-15mm deep to surface

41. • ADEQUATE-CONTINUOUS-
IRRIGATION while drilling-
• 1.to wash away bone dust-improving
visualisation
• 2.to decrease risk of heat injury from drilling
• 3.to maintain a clean cutting surface on the
bur.
• Haemostasis for bleeding-
• 1.bipolar cautery
• 2.bone wax
• 3.diamond spurr(lot of bone dust seals
bleeding vessels)

42. 4)Removal of mastoid air
cells
 All accessible mastoid air cells are
removed leaving behind the bony
plate of tegmen tympani above, the
sinus plate behind and posterior
meatal wall infront.

43.  The surgeon should look for the emergence of
a pink hue under the bone as it is thinned
over the tegmen, accompanied by a change
(more "tinny") in the sound of the burr.
 Once located, the surface of the tegmen is
followed medially toward the antrum.
 The middle fossa dura is always delineated as
it is the superior extent of the dissection.

44.  After identification of the tegmen, cortical bone
is removed behind the EAC, keeping the
posterior wall of the EAC thin, but intact.
 A key landmark in performing mastoid surgery
is the antrum with the dome of the horizontal
semicircular canal (HSCC) along its floor as a
bulge. The ease of locating the antrum
depends largely on the degree of mastoid
pneumatization.

45.  As the bone over the sigmoid sinus is thinned,
a bluish hue will become apparent beneath
the bone.
 With the tegmen, sigmoid sinus, and posterior
canal wall identified, the antrum can now be
dissected, following the tegmen anteriorly.
 Korner's septum, the embryologic remnant of
the fusion plane between the petrous and the
squamous bones is often encountered next.
After penetrating Koerner's septum, the antrum
is uncovered and the surgeon can identify the
lateral semicircular canal.

47.  The mastoid segment of the facial nerve also
lies medial to the plane of the short process of
the incus at the base of the posterior canal wall.
 This is why it nerve can get injured.
 If the canal wall is not thinned appropriately, a
wall of air cells continues to cover the facial
nerve, and the dissection is carried too far
posteriorly, potentially exposing the posterior
side of the facial nerve to injury.
 Removing air cells from the posterior bony
canal wall until it is only a few millimeters thick
is essential.

48. 5)Removal of mastoid tip
and finishing the cavity
 Lateral wall of MASTOID TIP is removed,
exposing fibres of posterior belly of
digastric
 ZYGOMATIC CELLS(in zygoma root) and
RETROSINUS CELLS(b/w sinus plate and
cortex) are removed
 A finished cavity should have BEVELLED
EDGES so that soft tissue can easily sit
and obliterate the cavity.

49. 6)CLOSURE
 the ear canal and mastoid cavity are irrigated
extensively with antibiotic-containing saline solution to
remove any bone dust and remaining squamous
debris.
 The self-retaining retractors are removed
 The postauricular incision is closed in two layers.
 In case of infection or bleeding, a drain maybe left at
lower end of incision for 24-48hrs
 Meatal pack is kept to avoid stenosis of ear canal
 Mastoid dressing is applied

50.  The incision is covered in antibiotic ointment
and a Glasscock ear dressing (Otomed) is
applied.

51. POST-OPERATIVE CARE
 1)antibiotics started preoperatively are
continued postop for at least 1 week.
 If culture swab is taken during surgery, the
sensitivity may dictate a change in drug.
 2)drain, if put, is removed in 24-48 hrs and
sterile dressing is done.
 3)stitches are removed on the 6th
day.

52. COMPLICATIONS
 Trauma to Facial Nerve-FACIAL PARALYSIS
 Dislocation of incus
 Horizontal Semicircular injury with POSTOP
GIDDINESS & NYSTAGMUS
 Trauma to Dura of middle cranial fossa
 Sigmoid Sinus and Jugular Bulb Injury-
PROFUSE BLEEDING.
 POSTOP WOUND INFECTION

53. Thank you