MASTOIDECTOMY Kartik Mittal

6th semester MAMC

HEADINGS INTRODUCTION CLASSIFICATION Comparing CWU vs CWD SURGICAL ANATOMY INSTRUMENTS USED Pre-op imaging CORTICAL MASTOIDECTOMY-definition,

indications, operating techniques COMPLICATIONS

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

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 bone paragang, epidermoids)

CLASSIFICATIONS Traditionally, classified as :1. Simple (cortical) mastoidectomy 2. Modified radical mastoidectomy3. Radical mastoidectomy

Depending on the fact whether postero-superior canal is removed or not,

1. Canal Wall Up mastoidectomy 2. Canal Wall Down mastoidectomy.

SUBCLASSIFICATIONCANAL 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

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

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, done along with cortical mastoidectomy

COMBINED APPROACH-

Comparison of CWU vs CWD

MEATUS DEPENDENCE RECURRENCE/

RESIDUAL DISEASE

2ND LOOK SURGERY

PATIENT LIMITATIONS

AUDITORY REHABILLITATION

CWUNORMALDOES NOT REQUIRE ROUTINE CLEANINGHIGH RATEAFTER 6 MONTHS TO RULE OUT CHOLESTEOTOMANONE, ALLOWED SWIMMINGEASY TO WEAR AID IF NEEDED

CWDWIDELY OPEN MEATUS COMMUNICATING WITH MASTOIDHIGH DEPENDENCE ON DOCTOR FOR YEARLY CLEANING OF MASTOID CAVITYLOW RATE, THUS A SAFER PROCEDURENOT REQUIREDSWIMMING CAN LEAD TO INFECTIONPROBLEMS IN FITTING A HEARING AID DUE TO LARGE MEATUS AND SOMETIMES, DUE TO INFECTED MASTOID CAVITY

POST-SURGICAL PROBLEMS- {5 D’S}

(MAINLY IN CWD)1.Deafness-30dB2.Dizziness-on thermal stimulation

of LSC(due to a single cavity)3.Debris Collection- desqamated

epithelium4.Discharge from infected debris5.Dependence-on doctor for

yearly cleaning of cavity

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.

SURGICALANATOMY

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.

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 approachInto the middle ear without disturbing the posterior canal.This procedure is called posterior tymaponotomy, used in Intact canal technique

Mastoid develops from the sqamous and petrous bonesPetrosquamosal suture may persist as a bony plate called KORNER’S SEPTUMImp. Surgically as it may cause difficulty in locating antrum and other deeper air cellsLeading to incomplte removal of diseaseThus, MASTOID ANTRUM CANNOT BE REACHED UNLESS IT IS REMOVED

INSTRUMENTS USED MOLLISONS’S MASTOID

RETRACTOR

JANSEN’S SELF RETAINING MASTOID RETRACTOR

LEMPERT’S ENDAURAL RETRACTOR

LEMPERT’S ENDAURAL SPECULUM

MASTOID GAUGE

ELECTRIC BURR

LEMPERT’S CURETTE/SCOOP

MacEWEN CURETTE & CELL SEEKER

FARABEUF PERIOSTEAL ELEVATOR

CROCODILE FORCEPS

OPERATING MICROSCOPE-

focal length 200-250mm

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)

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

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.

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

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.

INDICATIONS OF CORTICAL MASTOIDECTOMY1) ACUTE Coalescent Mastoiditis2) Masked Mastoiditis (latent)3) INCOMPLETELY RESOLVED AOM with reservoir sign4) CSOM TTD Active Refractory to antibiotics.5) Secretory otitis media Refractory to antibiotics6) 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.-Combined Approach Tympanoplasty.

Specific indications of cortical matoidectomy in acute

mastoiditis-1) Subperiosteal abscess2) Sagging of posterio-superior meatal wall3) Positive reservoir sign4) Worsening of patient even after

adequate medical treatment for 24hrs5) Complicated mastoiditis- facial

paralysis,labrynthitis,i/c complication DRY EAR FOR 6 WEEKS IS THE

MOST IMPORTANT PRE OPERATIVE PRE REQUISITE

OPERATIVE TECHNIQUES(CWU)

Position- supine with face turned to one side and ear to

be operated is placed at the uppermost positionPreparation- 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.

The surgical site isthen prepped and draped in sterile

fashion.

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

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

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

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

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

• 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)

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.

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.

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.

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.

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.

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.

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

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

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.

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

Thank you