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TYMPANOPLASTY - TYMPANIC MEMBRANE REPAIR

Shambaugh: Surgery of the Ear - MS ENT PG Exam Notes

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1. DEFINITION & GOALS

1. Eradicate middle-ear disease → achieve a dry ear
2. Restore hearing → by closing TM perforation (grafting) ± ossicular reconstruction

• Graft "take" rate
• Hearing improvement (post-op air-bone gap)

Even if hearing does NOT improve, a dry intact ear = partial success

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2. WULLSTEIN CLASSIFICATION (Types I-V)

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3. INDICATIONS

• Tympanic membrane perforation with hearing loss
• With or without middle-ear pathology: tympanosclerosis, retraction pockets, cholesteatoma

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4. CONTRAINDICATIONS

Absolute:

• Poor general health
• Malignant tumors of outer/middle ear
• Uncontrolled cholesteatoma
• Malignant otitis externa
• Complications of chronic ear disease (meningitis, brain abscess, lateral sinus thrombosis)
• Only hearing ear (risk of irreversible SNHL)

Relative:

• Non-functioning Eustachian tube
• Acute exacerbation of CSOM
• Chronic mucoid discharge with allergic rhinosinusitis
• Chronic otitis externa
• Smoking - 3x increase in long-term graft failure

Age-specific notes:

• Children: delay until age 8-10 unless cholesteatoma or bilateral perforations; prefer cartilage "shield" grafts (resist even ET dysfunction); otitis media in contralateral ear = poor prognosis
• Elderly: safe with modern anesthesia if general health is acceptable

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5. PREOPERATIVE EVALUATION

• Complete H&E including head and neck exam
• Operating microscope for otoscopy
• Audiogram within 3 months - pure-tone air + bone conduction + speech discrimination
• Confirm with tuning fork tests

• Clean ear canal under microscope
• Acetic acid 1.5% irrigation (body temperature) 2-3x/day
• Antibiotic drops covering Pseudomonas
• Oral antibiotics if refractory
• Culture & sensitivity for refractory/immunosuppressed/unusual infections

Imaging:

• Dry central perforations → no imaging needed
• Cholesteatoma/atelectasis/chronic drainage → HRCT temporal bones
• To R/O brain herniation if CT shows tegmental defect → MRI temporal bones

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6. INFORMED CONSENT - Key risks to discuss

• Failure of graft take (need for revision)
• Hearing loss (including SNHL)
• Facial nerve injury
• Taste disturbance (chorda tympani)
• Tinnitus and dizziness
• Need for hearing aid
• Cholesteatoma recurrence

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7. GRAFTING MATERIALS

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8. SURGICAL APPROACHES (3 approaches)

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9. GRAFTING TECHNIQUES (2 techniques)

A. UNDERLAY TECHNIQUE (preferred)

• Graft placed medial to TM remnant/annulus and manubrium of malleus
• Initially reported by Glasscock (1973)
• Steps:
  1. Postauricular incision; raise periosteum
  2. Harvest graft (temporalis fascia/areolar tissue) - kept to dry
  3. Inject local anesthetic into ear canal (4 quadrants)
  4. Create tympanomeatal flap - incisions at 6 and 12 o'clock positions ~6 mm lateral to annulus; elevate from posterior to anterior
  5. Enter middle ear; inspect ossicular chain
  6. Remove middle-ear pathology; place Gelfilm over promontory if adhesions removed
  7. Pack middle ear with Gelfoam
  8. Place graft medial to annulus and manubrium
  9. Return tympanomeatal flap to position
  10. Pack ear canal with Gelfoam pledgets soaked in antibiotic ointment
  11. Close postauricular incision; apply mastoid dressing

B. OVERLAY TECHNIQUE

• Graft placed lateral to TM remnant/annulus but medial to manubrium
• Steps:
  1. Postauricular approach; vascular strip removed and folded away
  2. Remove ALL skin from ear canal medial to bony-cartilaginous junction + squamous epithelium of TM remnant - keep in saline
  3. Annulus left in place; canaloplasty performed if needed
  4. Remove middle-ear pathology; pack middle ear with Gelfoam
  5. Place graft lateral to annulus and medial to manubrium (slit made superiorly to accommodate manubrium)
  6. Graft should extend over posterior canal wall
  7. Avoid draping flap over anterior canal wall (prevents anterior sulcus blunting)
  8. Replaced removed epithelium in original position; Gelfoam in anterior sulcus
  9. Return vascular strip; pack with Pope's ear wick in antibiotic ointment
  10. Close postauricular incision; mastoid dressing

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10. CANALOPLASTY

• Indicated when anterior bony wall bulges → poor visualization of anterior sulcus
• Failure to see anterior sulcus = improper graft placement = procedure failure
• Technique: Beaver blade #74 - horizontal incision medial to bulge above anterior sulcus; Beaver #67 - two vertical incisions either side → elevate skin flap → high-speed drill removes obstructing bone

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11. TRANSCANAL FAT GRAFT MYRINGOPLASTY

• For small persistent perforations (post-tympanostomy tube extrusion, myringoplasty failure)
• Can be done under local anesthesia (outpatient)
• Earlobe adipose tissue harvested; edges of perforation denuded of epithelium; fat inserted in dumbbell fashion through perforation; Gelfoam placed over graft
• Post-op: ofloxacin drops, no nose blowing, water precautions

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12. CARTILAGE TYMPANOPLASTY

• Island cartilage technique preferred (tragal/auricular cartilage with attached perichondrium)
• Especially for:
  • Children with ET dysfunction
  • Atelectatic ears
  • Revision cases
  • Posterior retraction pockets
• Cartilage resists negative middle ear pressure - won't retract
• Results equivalent to fascia for graft take

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13. POSTOPERATIVE CARE

• Antibiotic drops at bedtime
• Shower allowed with cotton ball in ear canal soaked in petroleum ointment
• Keep water away from postauricular incision for 2 days
• NO nose blowing until TM healed
• If sneeze unavoidable → keep mouth OPEN
• Oral antibiotics if ear infected at time of surgery

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14. COMPLICATIONS

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15. TYMPANOPLASTY FAILURE & REVISION

• Poor ET function
• Inadequate visualization of anterior sulcus
• Extensive tympanosclerosis of TM remnant
• Inadequate anterior Gelfoam support
• Previous overlay technique
• Recurrent/residual cholesteatoma

• Persistent/recurrent perforation
• Blunting of anterior sulcus
• Graft lateralization
• Epithelial pearls
• Conductive hearing loss

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16. RESULTS (Shambaugh Table 28-1)

• Graft take rate overall: >90%
• Benign perforations: 93-97% graft take
• Hearing within 20 dB of bone level: 85-90% of cases

1. ET dysfunction
2. Cholesteatoma
3. Atelectasis
4. Previous tympanoplasty failure
5. Lateralized TM
6. Smoking (3x long-term graft failure)

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17. QUICK EXAM MNEMONICS

• Gelatin film (Gelfilm)
• Rim of perforation MUST be removed
• Areolar tissue (Moon 1970)
• Fascia temporalis (gold standard)
• Tragal perichondrium/cartilage
• Graft placement: underlay = medial; overlay = lateral
• Infant/child = cartilage shield
• Vascular strip (preserved in overlay, elevated in underlay)
• Exclusive to small holes = fat graft (dumbbell)

• Underlay: graft Under annulus and malleus handle; fewer complications; Glasscock technique
• Overlay: graft Over annulus but Under malleus; more complications (blunting, pearls, lateralization)

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18. HIGH-YIELD ONE-LINERS FOR MCQ/SAQ

1. Most common graft material = temporalis fascia
2. Wullstein Type I = myringoplasty (TM repair only, ossicles intact)
3. Type III = columella effect (stapes directly contacts new TM)
4. Type IV = acoustic coupling (ABG ~20-25 dB best possible)
5. Contraindication in only hearing ear = risk of SNHL
6. Chemical for freshening perforation edges = trichloroacetic acid (or silver nitrate)
7. Graft for children = cartilage shield (resistant to ET dysfunction)
8. Small perforation outpatient repair = fat graft myringoplasty from earlobe
9. Smoking risk = 3x long-term failure
10. Avoid nitrous oxide = it diffuses into middle ear and displaces the graft
11. No nose blowing postoperatively to avoid positive pressure disturbing graft
12. Graft take success rate = >90% (93-97% for benign perforations)
13. ET function test: no reliable preop test exists
14. HRCT indicated when = cholesteatoma, atelectasis, chronic drainage
15. Chorda tympani recovery = 76% complete recovery

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OSSICULOPLASTY

Scott-Brown's Otorhinolaryngology Head & Neck Surgery, 8th Edition, Vol. 2 - MS ENT PG Exam Notes

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1. DEFINITION & OVERVIEW

Homograft ossicles are NOT recommended because of the theoretical risk of transferring prion disease (CJD)

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2. TERMINOLOGY (Box 85.1)

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3. CLASSIFICATION OF DEFECTS

Austin-Kartush Classification (Most widely used)

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4. PROGNOSTIC FACTORS

Ideal conditions for ossiculoplasty:

• Stable, well-ventilated middle ear
• Intact tympanic membrane
• NO active middle ear infection
• NO cholesteatoma

Middle Ear Risk Index (MERI) - by Kartush

Belluci Classification of Otorrhoea:

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5. GRAFTING MATERIALS

A. AUTOGRAFT (Best choice when available)

• Incus (gold standard) - most common; used for interposition
• Malleus head - when incus not available
• Cortical bone - from mastoid or external auditory canal
• Cartilage - less stable, prone to displacement and resorption

• Incus not uniformly present in diseased ears
• Requires skill and time to sculpt
• Risk of residual disease if enveloped in cholesteatoma (careful assessment needed; some surgeons autoclave before reimplantation)
• Low-cost option when available

B. HOMOGRAFT (Falling out of favour)

• Cortical bone, cartilage, ossicles, en bloc ossicular chain with TM attached

• Risk of viral infection and CJD (prion disease) transmission
• 2 cases of CJD in ear surgery (cadaveric dura mater and pericardium - NOT from homograft ossicles)
• No reported CJD cases from homograft TM or ossicles, but risk remains theoretical
• Requires ossicle bank infrastructure
• NOT recommended by Shambaugh; discouraged in Scott-Brown

C. ALLOPLASTIC MATERIALS

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6. SURGICAL APPROACH BY AUSTIN-KARTUSH TYPE

Type A: Malleus + Stapes PRESENT (M+ S+) - most common (60%)

1. Eroded long process of incus - bridging with autologous tissue:
   • For small gap between stapes head and incus long process remnant
   • Materials: autologous cortical bone (mastoid/EAC) or cartilage
   • Risk: instability for longer defects; partial resorption, displacement, or bony ankylosis
2. ISJ (Incudo-Stapedial Joint) Prosthesis:
   • First dedicated prosthesis reported 1993 - cuboidal hydroxyapatite with circular aperture for stapes head + groove for long process remnant
   • Modern designs: titanium self-securing clips
   • Placed between stapes head and incus long process remnant
3. Autologous Ossicle Interposition (most popular):
   • Repositioning of incus first described by Hall and Rytzner (1957)
   • Incus body placed on stapes head, short process directed toward and medial to malleus handle
   • Modifications: groove in short process to rest against malleus handle, or lateral to malleus handle
   • Malleus head used if incus unavailable (brought into direct contact with TM)
4. Stapes-to-Malleus (PORP configuration):
   • Preserves catenary lever mechanism of TM
   • Prosthesis placed medial to malleus handle → reduces extrusion risk vs. direct TM contact
   • Drawback: malleus-stapes offset means force vector is never perfectly in line with stapes
   • If angle > 45 degrees relative to stapes axis → significant tilting + loss of sound transmission
   • Solution: Malleus Relocation - separate malleus handle from TM; divide tensor tympani; stretch/avulse anterior suspensory ligament; reposition malleus posteriorly over stapes head (superior ligament left in place for support)
5. Stapes-to-TM (PORP without malleus contact):
   • Used when malleus handle orientation unfavorable (anterior angulation/medial displacement)
   • Disadvantage: loss of catenary lever; prosthesis unstable without fixed lateral attachment
   • Requires cartilage strip between TM and prosthesis head (reduces extrusion)
   • Prosthesis design: drawing-pin shape with strut attaching to stapes head + perpendicular flat disc
   • Some surgeons use TORP on intact stapes - shaft between stapes crura directly onto footplate for improved stability

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Type B: Malleus PRESENT, Stapes ABSENT (M+ S-) - 23%

1. Homograft incus interposition - long process rests on footplate; sculpted notch at opposite end for malleus handle; results highly variable
2. TORP:
   • Similar to PORP but longer strut reaching stapes footplate; medial end flattened to rest on footplate
   • Stability improved with cartilage "shoe" on footplate OR specially designed footplate prosthesis
   • Footplate shoe anchors prosthesis, reduces displacement, directs force through centre of footplate

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Type C: Malleus ABSENT, Stapes PRESENT (M- S+) - 8%

• Absence of malleus handle = major independent prognostic factor for poor outcomes
• Loss of TM-malleus amplification + loss of fixed prosthesis attachment

1. Stapes-to-TM reconstruction (same as type A option above)
2. Neomalleus creation using incus, cortical bone, or cartilage strip (from root of helix) - Black showed superior results with neomalleus assembly vs. columella alone
3. Malleus Replacement Prosthesis (Vincent et al.) - recent development; mean ABG 12.5 dB vs 23.3 dB with TORP alone; reduced prosthesis displacement
4. Homograft tympanic membrane with attached malleus handle

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Type D: Malleus + Stapes ABSENT (M- S-) - 8%

• Most challenging defect; worst outcomes
• Requires combination of above techniques
• Options: autologous tissue + ossicle interposition or TORP
• Footplate-to-TM, OR neomalleus/malleus replacement prosthesis for stability

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7. OPERATIVE CONSIDERATIONS

Length of Prosthesis:

• Lower tension (shorter prosthesis) = BETTER sound transmission but higher displacement risk
• Higher tension (longer prosthesis) = worse sound transmission but more secure
• Must balance acoustic benefit vs. displacement risk

Cartilage Interposition:

• Standard practice between prosthesis head and TM
• Reduces extrusion risk
• Debate whether needed for titanium prostheses (Pringle questioned necessity)

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8. STAGING - ONE-STAGE vs. TWO-STAGE

• High risk of residual/recurrent cholesteatoma
• Significant TM retraction (increases prosthesis displacement/extrusion risk)
• Poor Eustachian tube function

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9. OSSICULOPLASTY IN CHOLESTEATOMA (Active Squamous COM)

• Rupa et al.: examined 60 mallei + 53 incudes from cholesteatoma ears → NO squamous epithelial cells found
• Dornhoffer et al.: examined 11 incudes → squamous epithelial cells found in 7/11 (64%)
• Theoretical risk of causing recurrent cholesteatoma from reimplanted ossicle
• However: no reported case of recurrent cholesteatoma arising from allograft incus in any large surgical series
• Regeneration of epithelial cells without blood supply is considered very unlikely

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10. OUTCOMES

When malleus and stapes superstructure BOTH PRESENT (Type A):

• ABG 0-10 dB in only 50% of patients
• ABG 0-20 dB in 80% of patients (Iurato et al. review of 20 published reports)
• No significant difference in hearing outcomes between different prosthesis types (Iurato)

When stapes superstructure ERODED (Type B/C/D):

• Mills: mean improvement 14 dB with intact stapes arch vs. only 6 dB with eroded stapes arch
• Shinohara: 68% success at 1 year for PORP (incus only replaced) vs. 46% for TORP (incus + stapes absent)
• At 5-year follow-up: success falls to 60% (PORP) and 34% (TORP) → results deteriorate over time

Key outcomes message:

"Audiometric results frequently deteriorate over time, and complications may present after many years" - surveillance is required long-term

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11. COMPLICATIONS

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12. AUDIT AND RESEARCH

• No universally accepted definition of "successful outcome" for ossiculoplasty
• Most studies are single-surgeon case series with short follow-up (1 year)
• Very few RCTs in ossiculoplasty literature
• Confounders: population differences, case complexity, surgical technique
• MERI scoring helps adjust for case complexity in comparisons
• Surgeons must record and audit their own results for accurate patient consent

"While prosthesis design and surgical technique undoubtedly affect results, the status of the middle ear is probably the most significant factor in outcome"

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13. HIGH-YIELD EXAM SUMMARY TABLE

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14. QUICK MNEMONIC

• A = All present (M+ S+) = PORP situation = best results (60%)
• B = stapes Bone gone (M+ S-) = TORP needed (23%)
• C = Cap (malleus) gone (M- S+) = neomalleus needed (8%)
• D = Double trouble (M- S-) = worst outcomes (8%)

• Hydroxyl (earliest ceramic = hydroxyapatite)
• Alloplastic first = 1952 Wullstein
• Titanium = 1990s (best modern material)
• Cartilage interposition needed for Plasti-Pore
• Homograft = NOT recommended (CJD risk)

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CANAL WALL UP (CWU) MASTOIDECTOMY

Shambaugh: Surgery of the Ear - MS ENT PG Exam Notes

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1. DEFINITION

• Intact Canal Wall (ICW) Mastoidectomy
• Combined Approach Tympanoplasty (CAT)
• Closed technique mastoidectomy

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2. CWU vs. CWD - KEY COMPARISON (Exam Favourite)

Shambaugh's view: "Preservation of the canal wall is preferred" - decision to remove wall is most often made INTRAOPERATIVELY when disease extent is fully appreciated.

Important: Difference in hearing outcomes between CWU and CWD may be due to extent of disease rather than presence/absence of the canal wall. Ossicular erosion is a more important determinant of hearing outcome.

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3. INDICATIONS FOR CWU MASTOIDECTOMY

• Chronic Suppurative Otitis Media (CSOM) with cholesteatoma - primary indication
• Cholesteatoma of the middle ear/attic/mastoid
• Failed medical management of CSOM
• Middle ear granulation tissue or polyp not responding to treatment
• Acute coalescent mastoiditis
• As access for cochlear implantation (facial recess approach)
• Children with cholesteatoma - strongly prefer CWU to preserve canal wall

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4. CONTRAINDICATIONS FOR CWU

• Unreconstructable posterior canal wall defect
• Patients in whom proper follow-up is questionable (important - because second-look is needed)
• Unresectable matrix involving: labyrinth, facial nerve, carotid, dura, sinus tympani

• Active infection and otorrhoea (but make ear as dry as possible preoperatively; higher postoperative infection rate if operated while draining)

Intraoperative indications to CONVERT to CWD:

1. Labyrinthine fistula
2. Unresectable disease on facial nerve or stapes footplate
3. Low-lying tegmen limiting attic access
4. Unresectable sinus tympani disease
5. Unreconstructable posterior canal wall defect

Preoperative factors favouring CWD (rare):

• Obvious posterior canal wall erosion on CT
• Large labyrinthine fistula on CT
• Elderly or patients where second-look is inadvisable
• Disease in only hearing ear (occasionally)

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5. PREOPERATIVE EVALUATION

• Full history + head and neck examination + binocular otomicroscopy
• Audiogram (pure tone audiometry - air and bone conduction)
• CT scan is NOT obtained routinely in all patients

• Vertigo
• Facial palsy
• Pain or other complications
• Revision surgery (especially if previous surgery done elsewhere)

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6. SURGICAL TECHNIQUE - STEP BY STEP

Preparation

• General anesthesia - NO paralytic agents (continuous facial nerve monitoring required)
• Continuous facial nerve monitoring - MANDATORY throughout
• Injection: 1% lidocaine with epinephrine 1:100,000 into tragus and postauricular skin (hemostasis + local anesthesia)
• Use dental carpules/syringe to avoid accidental high-concentration epinephrine injection
• Pre-scrub entire side of head including hair with betadine
• Preoperative antibiotics and steroids given to every patient
• Ciprofloxacin 400 mg added to saline irrigation (1L) = antibiotic-impregnated irrigation

Incision & Exposure

• Postauricular incision made ~1.5-2 cm behind postauricular crease
• Periosteal incisions:
  • First: along linea temporalis (temporal line) to level of EAC - carried superior to EAC for adequate attic exposure
  • Second: perpendicular to linea temporalis down to mastoid tip
• For revision surgery: C-shaped periosteal incision preferred (avoids inadvertent entry into old cavity and injury to exposed sigmoid sinus/dura)
• Periosteum elevated with Lempert elevator: superiorly over tegmen, posteriorly over sigmoid sinus, anteriorly to EAC meatus
• Vascular strip identified and reflected posteriorly
• Two self-retaining retractors placed perpendicular to each other for exposure

Graft Harvest

• Temporalis fascia or areolar tissue harvested from above the postauricular incision at this point (early in procedure, to allow drying before use)

Middle Ear Dissection (Done BEFORE mastoidectomy in this approach)

• Tympanomeatal flap elevated anteriorly, carefully dissected free from ossicular chain
• Diseased portion of TM removed (prevents graft failure)
• Middle ear assessed: extent of disease, ossicular status, facial nerve
• Cholesteatoma gently dissected from middle ear to expose ossicles and facial nerve
• Keep cholesteatoma/retraction pocket INTACT when possible to prevent disease seeding
• If ossicular discontinuity/erosion: remove incus and malleus EARLY to protect stapes and footplate from drill injury during subsequent mastoidectomy
• Scutum (lateral attic wall) may be partially removed to improve attic access - amount removed depends on disease extent; be careful as facial nerve is at risk here

Mastoidectomy Drilling Principles

• Cutting (fluted) burrs = efficient rapid bone removal; used with caution near vital structures
• Diamond burrs = for delicate dissection near facial nerve, dura, tegmen, sigmoid sinus, LSCC; also controls small vessel bleeding by driving bone dust into lumen
• Start with LARGEST burr possible → progressively decrease size as dissection narrows
• Never drill under a ledge or in a recess without 360-degree view around burr
• Never drill PERPENDICULAR to the facial nerve - always parallel

• Clears bone dust and blood; keeps burr clean
• Ample irrigation MANDATORY with diamond burrs near facial nerve - prevents thermal injury

Step-by-Step Mastoid Drilling (CWU)

• Use 5 or 6 mm cutting burr
• Remove bone along linea temporalis → identify tegmen
• Signs of reaching tegmen: pink hue appearing under thinning bone + sound of burr changes (more "tinny")
• Follow surface of tegmen medially toward antrum
• Always delineate middle fossa dura - it is the superior limit of dissection
• Failure to delineate dura = risk of inadvertent damage to ossicles and lateral semicircular canal

• Behind EAC (keep posterior wall thin but INTACT)
• Inferiorly to mastoid tip
• Posteriorly to sigmoid sinus and sinodural angle
• Progress medially, removing cortical bone between these planes
• Sign of reaching sigmoid sinus: bluish hue as bone thins over it

• Antrum = most valuable "safe" landmark in CWU
• From antrum you access: LSCC medially (opens to fossa incudis), epitympanum anterosuperiorly, external genu of facial nerve
• Körner's septum (petrosquamous septum) may be encountered and must be removed to reach true antrum

• Tegmen (superior limit)
• Lateral semicircular canal (LSCC) - key landmark; dense compact bone; lies just superior to facial nerve at transition to vertical segment; posterior canal extends posteroinferiorly to posterior SCC
• Incus (body) - visualised from antrum in fossa incudis; short process of incus points to facial recess
• Sigmoid sinus (posterior limit)
• Sinodural angle (Citelli's angle) - between tegmen and sigmoid sinus
• Digastric ridge - leads to facial nerve at stylomastoid foramen

• Thin the posterior canal wall before opening facial recess
• Important to improve exposure and facilitate middle ear/attic dissection
• Facial nerve at most risk at this area
• Even a small amount of bone removal greatly improves exposure

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7. FACIAL RECESS (POSTERIOR TYMPANOTOMY)

Anatomy - Triangular space bounded by:

• Posteriorly: Facial nerve (vertical segment)
• Superiorly: Incus buttress (fossa incudis)
• Anterolaterally: Chorda tympani nerve

Short process of incus points directly to facial recess

Technique:

1. Identify facial nerve first (IMPERATIVE before opening recess)
2. Landmarks for facial nerve: LSCC lies just superior; digastric ridge leads to nerve at stylomastoid foramen; "herald" air cell just lateral to second genu of facial nerve
3. Thin bone over facial nerve with large diamond burr + copious irrigation - strokes always PARALLEL to nerve
4. Small bleeding vessels alongside nerve = controlled with epinephrine-soaked Gelfoam or bipolar cautery
5. Identify chorda tympani (branches off vertical segment, traced superiorly toward incus)
6. With all borders delineated, open recess with 2-mm diamond burr, starting superiorly (widest part)
7. Preserve small rim of bone overlying the facial nerve

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8. SECOND-LOOK PROCEDURE

• CWU mastoidectomy usually requires second-look in 6-12 months
• Purpose: assess disease recurrence + ossicular chain reconstruction (OCR)
• Decision for second-look made at time of initial surgery
• Document extent and location of disease carefully at initial surgery
• Approach for second-look: Transcanal middle ear exploration (usually sufficient - examines stapes, facial nerve, sinus tympani = primary areas of cholesteatoma recurrence)
• Postauricular approach indicated if: extensive dural involvement or poor attic exposure at initial surgery

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9. ACUTE MASTOIDITIS - Special Scenario

• Goal = simple evacuation of pus from mastoid; NOT complete anatomical dissection
• Full anatomical dissection is difficult due to inflammation, granulation tissue, bleeding
• Start with large cutting burr → remove cortical bone until pus encountered in coalescent cavity
• Coalescent cavity often only a few mm under cortex
• Widely open the cavity → evacuate all pus
• Copious irrigation with antibiotic-containing saline

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10. POSTOPERATIVE CARE

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11. COMPLICATIONS

A. Surgical Exposure Problems

• Inadequate exposure → inability to remove disease + risk of injury to vital structures
• Always maintain orientation by positively identifying: tegmen, LSCC, facial nerve, cochleariform process, ossicles

B. Bleeding

• Not usually a major problem UNLESS sigmoid sinus or jugular bulb injured
• Small amounts of bleeding obscure field → greater risk of injury to underlying structures
• Management of field bleeding: stop surgery → pack with epinephrine-soaked Gelfoam → wait a few minutes → resume (never operate in blood-obscured field)

• Small injuries: bipolar cautery
• Larger injuries: risk of air embolus
  • Place finger over tear to prevent bleeding and air entry
  • Rotate patient toward surgeon + head-down position
  • Repair: Gelfoam over injury + small cotton pledget + gentle pressure
  • Remove cotton before closure (delayed granulation reaction + infection)

C. Granulation Tissue

• Extremely adherent to facial nerve, dura, or ossicles
• Remove parallel and tangential to underlying structures (not perpendicularly)

D. Facial Nerve Injury (Most feared complication)

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12. CWU vs CWD - DETAILED EXAM TABLE

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13. HIGH-YIELD EXAM POINTS

1. Most common indication for CWU mastoidectomy = cholesteatoma with CSOM
2. Key contraindication = unreconstructable posterior canal wall defect + unreliable follow-up
3. Facial nerve monitoring is MANDATORY during the entire procedure
4. NO paralytics during surgery - needed for facial nerve monitoring
5. Largest burr first - always, reduces risk of inadvertent penetration
6. Never drill perpendicular to facial nerve - always parallel
7. Diamond burr + copious irrigation near facial nerve - prevents thermal injury
8. Linea temporalis = starting landmark for mastoidectomy
9. Tegmen identified first - superior limit of dissection
10. LSCC = most important safety landmark - always identify before going deeper
11. Short process of incus points to facial recess - key anatomical guide
12. Facial recess borders: facial nerve (posterior), incus buttress (superior), chorda tympani (anterolateral)
13. Air embolus risk with sigmoid sinus injury → finger on tear + head-down position
14. Cotton must be removed before closure when packed into sigmoid sinus injury
15. Second-look in 6-12 months - usually transcanal approach for residual disease check
16. Körner's septum (petrosquamous septum) = bony plate that can be confused for mastoid floor - must be removed to reach true antrum
17. Anesthetic-related postoperative facial palsy resolves within 4 hours
18. Children: prefer even third-look rather than converting to open cavity

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14. MNEMONIC

• Tegmen identified first (linea temporalis)
• Antrum opened (follow tegmen medially)
• LSCC identified (key landmark)
• Lateral canal wall thinned (posterior EAC wall)
• Facial recess opened (if needed)
• Incus seen (fossa incudis)
• Sigmoid sinus defined (posterior limit)
• Hemostasis throughout

• Canal wall unreconstructable
• Labyrinth - unresectable matrix
• Ear in only hearing patient (sometimes)
• Advanced unresectable disease on facial nerve
• N / poor follow-Up patient
• Patient with sinus/carotid unresectable disease

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OPEN CAVITY MASTOID OPERATIONS

Shambaugh: Surgery of the Ear - MS ENT PG Exam Notes

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1. OVERVIEW & CLASSIFICATION OF OPEN CAVITY OPERATIONS

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2. HISTORICAL EVOLUTION (Exam Favourite)

• Radical mastoidectomy - classical; all structures exteriorised including ET obliteration; largely abandoned
• Bondy (1910) modified it - preserved TM and ossicles; limited dissection (inside-out); but short-term results led to residual disease due to incomplete mastoid dissection
• Modified radical mastoidectomy (Jansen 1958 + evolution) - complete mastoidectomy with tympanoplasty; seals middle ear to avoid chronic drainage; best current technique; achieves dry self-cleaning cavity in 95% of cases
• Epithelial pearls occur in 5-6% of CWD cases; treatable in-office

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3. CWD FUNDAMENTAL ADVANTAGE OVER CWU

Canal-wall-down has LESS restricted exposure of sinus tympani, facial recess, and epitympanum → correspondingly reduced risk of residual disease.

• Thomassin showed: CWU had 47.7% residual disease at second-look. With endoscopic inspection during primary CWU, this dropped to 5.5% - comparable with CWD results.

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4. INDICATIONS

A. Modified Radical Mastoidectomy Indications:

• Cholesteatoma extending into attic, antrum, or mastoid (primary indication)
• Patients unwilling or unable to undergo two-stage CWU approach
• Occasional/inexperienced otologic surgeon - MRM is simpler than CWU technically
• Intraoperative findings during CWU requiring conversion (see CWU notes)

B. Classic Radical Mastoidectomy (VERY limited indications now):

1. Unresectable cholesteatoma extending down the Eustachian tube or into petrous apex
2. Promontory cochlear fistula caused by cholesteatoma
3. Chronic perilymphatic fistula
4. Resection of temporal bone neoplasms with periodic monitoring

Even in ears with large TM perforation + ossicular destruction + cholesteatoma, Shambaugh recommends: do NOT obliterate ET, do NOT strip middle ear mucosa, do NOT remove ossicular remnants - as these can be used in future tympanoplasty. Classic radical mastoidectomy is reserved for unusual situations only.

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5. CONTRAINDICATIONS FOR OPEN CAVITY OPERATIONS

• CSOM without cholesteatoma - NOT an indication; preserve canal wall
• Acute otitis media with coalescent mastoiditis - CWD contraindicated
• Persistent secretory otitis media
• Chronic allergic otitis media
• Tuberculous otitis media - treat with chemotherapy first; surgery only for persistent drainage

• Wide exposure of sigmoid sinus, dura, and facial nerve by aggressive disease

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6. DIAGNOSIS OF CHOLESTEATOMA (Preoperative)

• Pars flaccida / marginal perforation or retraction → stratified squamous epithelium extends into attic → ALWAYS means cholesteatoma
• Attic perforation (actually an invagination) = ALWAYS a cholesteatoma
• Granulation tissue or polyp from attic perforation = infected cholesteatoma
• Rarely: central perforation with mucoid discharge may have cholesteatoma in middle ear/attic
• Size of attic defect bears little relation to extent of cholesteatoma

• Non-contrast HRCT temporal bone - excellent: shows erosion of SCC, cochlea, fallopian canal, dural plates, sigmoid sinus; scutum erosion + soft tissue in attic = diagnostic
• MRI with gadolinium - adjunct to CT; for extensive tegmen erosion → shows meningoencephalocele, dural inflammation, intracranial infection
• MR angiography - for sigmoid sinus thrombosis (suspected when posterior fossa dural plate and sigmoid sinus erosion seen)

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7. WHEN CAN CHOLESTEATOMA BE MANAGED CONSERVATIVELY?

• When attic defect is large and cholesteatoma sac is shallow → accumulated desquamated debris can be removed by microdebridement and suction

1. Radiographic evidence of an enlarged, smooth-walled cavity (bone erosion by expanding sac)
2. Involvement of vital structures (SCC, facial nerve, tegmen)
3. Other signs of progressive disease

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8. PREOPERATIVE ASSESSMENT FOR MRM

• Careful microscopic inspection and cleaning of ear
• Remove pus, mucus, cholesteatoma debris under microscopic suction
• Polyps: gentle traction with suction or microcup forceps
  • CAUTION: avoid significant retraction - polyp may be attached to facial nerve, labyrinthine fistula matrix, or stapes superstructure/footplate
• Control active suppuration preoperatively:
  • 1.5% acetic acid irrigations (1 part white vinegar + 2 parts boiling water, cooled) via infant nasal-bulb syringe several times daily - mechanical debridement
  • Antibiotic ear drops after irrigation
  • For 2-4 weeks preoperatively

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9. BONDY'S INSIDE-OUT MASTOIDECTOMY - IN DETAIL

What is Bondy's?

• TM and ossicular chain are PRESERVED
• Disease is confined to attic/mastoid NOT involving the middle ear/ossicular chain
• Done via "inside-out" approach = start from the canal side, going inside-out

Principle:

"With experience, and in carefully selected patients, this procedure can be performed entirely from the canal side ('inside out'), thereby creating the smallest possible cavity."

When is Bondy's Indicated?

• Attic/antrum cholesteatoma with intact middle ear and TM
• Disease that has NOT invaded the ossicular chain or mesotympanum
• Patient has hearing worth preserving
• Selected, carefully assessed cases

Bondy's Procedure Step-by-Step:

1. First incision: Starting at "12 o'clock" on superior canal wall, ~1 cm from outer edge of canal → extends down posterior canal wall in incisura terminalis to nearly "6 o'clock" → then at right angles outward 2-3 mm to edge of (but NOT into) conchal cartilage
2. Second incision: Again from "12 o'clock" on superior canal wall → extends directly upward in incisura terminalis to point halfway between meatus and upper edge of auricle. (Can extend further upward if greater exposure needed without encountering vessels)

1. Perform limited intact canal wall mastoidectomy first - identify antrum and LSCC (gives reference for depth)
2. Stay superior in the dissection
3. Identify antrum; remove superior and posterior canal wall until only a thin rim of bone remains over the ossicles
4. Use medium-sized burr drawn medially to laterally to facilitate bone removal
5. Remove final rim of bone with a small curette (NOT drill - to avoid traumatizing intact ossicular chain)
6. Proceed from canal side ("inside out") → creates the smallest possible cavity
7. Meatoplasty is MANDATORY to facilitate postoperative cleaning

• TM and ossicular chain PRESERVED
• Only the attic and mastoid are exteriorised
• Smaller cavity than complete mastoidectomy
• Peripheral air cells may be isolated from Eustachian tube → if mucosa continues to produce mucus, it discharges into mastoid cavity (a known drawback)

Limitation of Bondy (why it evolved to MRM):

Bondy was predicated on limited dissection - this often spared hearing in the short term BUT resulted in:

• Recurrent cholesteatoma (incomplete dissection)
• Persistent aural discharge (infection of remaining mastoid air cells)
• This is why complete mastoid exenteration (MRM) was developed as the modern standard

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10. TECHNIQUE OF CLASSIC RADICAL MASTOIDECTOMY & BONDY - ATTICOTOMY PHASE (SHARED)

Atticotomy Bone Removal (same for both):

• Most cholesteatoma matrix is closely applied to bone with finger-like extensions into small cells and haversian canals
• ALL extensions must be followed to their end with operating microscope
• Exceptions - when to LEAVE matrix:
  1. Matrix firmly adherent to exposed dura or sigmoid sinus → leave (risk of injury)
  2. Matrix over a semicircular canal fistula → leave (risk of postoperative serous labyrinthitis). Some prefer to dissect and apply thin fascia graft immediately.
  3. Matrix firmly attached to exposed facial nerve → leave
  4. Matrix in mesotympanum covering stapes footplate → leave at initial operation (risk of labyrinthitis). At second operation (after ear is dry and healed) → dissect and tympanoplasty

Bone Removal Beyond Cholesteatoma:

• Evacuation of sac + removal of matrix + curettage of softened osteitic bone adjacent = usually sufficient
• Mastoid cells outside cholesteatoma sac: remove if infected/osteitic/granulating; leave if intact

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11. TAKING DOWN THE BRIDGE AND FACIAL RIDGE

1. Elevate meatal skin from bone first
2. Remove remaining superior osseous meatal wall in small bites with a narrow rongeur
3. With small (000) curette → always working outward away from fallopian canal and facial nerve → take down anterior and posterior spines of notch of Rivinus (anterior and posterior buttresses of bridge)
4. Keep tympanic segment of facial canal in view
5. Inspect ossicles/remnants:
   • Cholesteatoma enveloping medial surface of malleus head or incus → remove ossicles
   • Cholesteatoma lateral to ossicles → matrix may be left or carefully removed; ossicles left undisturbed
   • Long process of incus absent + matrix against mobile stapes head (nature's myringostapediopexy) → leave this matrix undisturbed

1. Bony horizontal semicircular canal (above)
2. Tympanomastoid suture (in posterior meatal wall)
3. Digastric ridge (in mastoid tip)

Note: In radical and Bondy mastoidectomies, tip cells rarely need removal, so digastric ridge as landmark becomes less dependable.

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12. MODIFIED RADICAL MASTOIDECTOMY - FULL TECHNIQUE

Key Differences from Bondy:

• Complete removal of posterior canal wall (not limited)
• Middle ear is sealed (tympanoplasty added)
• All mastoid air cells exenterated
• Facial ridge fully lowered to level of facial nerve
• Hearing is secondary but tympanoplasty improves it

Technique:

• Identify incudostapedial joint through facial recess → cut → remove incus

• Full cortical mastoidectomy → identify: antrum, LSCC, incus, tegmen, sigmoid sinus
• Identify vertical segment of facial nerve
• Open facial recess (using digastric ridge and LSCC as landmarks)

• Identify incudostapedial joint through facial recess → cut → remove incus
• Posterior canal wall taken down with rongeur
• Facial ridge lowered until thin layer of bone remains over vertical segment of facial nerve
• Chorda tympani nerve MUST be sacrificed

• Remove disease from horizontal segment of facial nerve
• Malleus/any remnant: cut tensor tympani tendon at cochleariform process → remove malleus → access anterior epitympanum

• Anterior epitympanum drilled down to become continuous with anterior canal wall
• Inferior canal wall drilled until confluent with mastoid tip (no bony overhang)
• Anterior buttress (posterior canal wall meets tegmen) → completely removed → smooth continuum between mastoid tegmen and tegmen tympani
• Posterior buttress (posterior canal wall meets floor of EAC, lateral to facial nerve) → also removed
• Sinus tympani: most difficult; if disease extends here and stapes absent → pyramidal eminence removed with small diamond burr; use right-angle hooks, whirlymbird dissectors, micromirrors, surgical telescopes

• Smooth-walled, free of active disease
• Ovoid or rectangular shape
• Facial ridge must be LOW - stapes is the only remaining ossicle
• Mastoid bowl saucerized - gentle transition without ledges
• Copious irrigation

• 1% lidocaine with 1:100,000 epinephrine infiltrated into conchal bowl
• Expose entire posterior conchal bowl with iris scissors through fibrous periosteum
• With finger in conchal bowl: semilunar incision into cartilage posteriorly until knife tip felt through anterior skin
• Crescent-shaped cartilage (~1.5 × 2 cm) excised
• Körner flap created by incisions through EAC skin:
  • Inferior incision: 6 o'clock → into conchal bowl → curved around inferior margin
  • Superior incision: 12 o'clock → between tragus and anterior helix
  • Creates long posteriorly based flap to line the mastoid bowl

• Retract auricle and flap anteriorly
• Remove epinephrine-soaked Gelfoam; pack middle ear and ET with saline-moistened Gelfoam to level of anterior annulus
• Fascia graft placed:
  • Medial to anterior annulus and drum remnant
  • Extends over stapes to facial ridge into mastoid bowl
  • Cover as much mastoid bone as possible - reduces granulations, speeds epithelialization
  • Especially cover: perilabyrinthine, retrofacial, zygomatic, and peritubal cell tracts

• If stapes present: fascia graft placed directly onto capitulum
• If stapes lower than facial ridge: augment height with malleus head goblet prosthesis atop capitulum
• If stapes absent: autologous tissue preferred over alloplastic prostheses
• Ossicular reconstruction is best staged in CWD (atelectasis and adhesions more common postoperatively)
• Approach: transmeatal if adequate meatoplasty (10-12 mm speculum fitting); postauricular if meatus too small

• 3.0 polyglactin 910 (Vicryl) suture placed subdermally at both edges of base of Körner flap → secured to musculoperiosteum at edge of mastoid cavity

• Postauricular incision closed with subcuticular absorbable suture
• Mastoid bowl filled with ointment or packed with gauze
• Mastoid dressing applied

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13. SKIN GRAFTING THE RADICAL OR BONDY CAVITY

• Siebenmann first recommended Thiersch skin grafting for rapid healing
• Shambaugh's experience: Primary split-thickness skin grafting is NOT desirable
  • When graft takes by first intention: epithelial lining closely applied to bone without intervening connective tissue
  • Surface rough and uneven; excessive desquamation; prone to breakdown and granulations; tends to invade crevices
• With thoroughly performed radical/Bondy operation + matrix removal: cavity nearly always heals without troublesome granulations if sterile technique observed
• If surgeon wishes to shorten healing time: apply skin graft 2-3 weeks postoperatively AFTER cavity is lined by thin layer of healthy granulations (provides desired subepithelial connective tissue layer)

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14. POSTOPERATIVE CARE (CWD/MRM)

• Keep ear dry
• Avoid nose blowing
• Oral antibiotics NOT used routinely

• Debride granulations
• Silver nitrate application (NEVER near exposed facial nerve)
• 2% gentian violet painting
• Antibiotic otic drops

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15. RECONSTRUCTION IN CWD - OSSICULOPLASTY SPECIFICS

• Stapes superstructure below level of horizontal facial nerve → PORP or sculpted ossicle (malleus head) possible
• Absent stapes superstructure → TORP preferred
• Postoperative atelectasis and adhesion formation MORE common after CWD → stage ossicular reconstruction
• Access: transmeatal if meatoplasty adequate (10-12 mm speculum)
• Flap for transmeatal approach: anteriorly based tympanomastoid flap, incision parallel to facial nerve, beginning 3-5 mm superior to fallopian canal, passing posterior-superior to horizontal SCC, extending inferiorly 3-5 mm posterior to facial ridge
• CAUTION: Short flap can encroach on facial nerve; too long = may not cover middle ear

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16. RESULTS

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17. HIGH-YIELD EXAM ONE-LINERS

1. Bondy = inside-out; TM + ossicles PRESERVED; smallest cavity
2. Radical = all exteriorised; ET obliterated; hearing sacrificed
3. MRM = complete mastoidectomy + tympanoplasty; most used; 95% dry ear
4. Attic perforation/invagination = ALWAYS cholesteatoma
5. Granulation or polyp from attic = infected cholesteatoma
6. Size of attic defect = no relation to cholesteatoma extent
7. Bondy drawback = residual cholesteatoma/discharge from remaining air cells
8. Radical drawback = chronic middle ear mucosa drainage
9. MRM overcomes both drawbacks by: complete air cell exenteration + tympanoplasty
10. Most often poorly performed step = taking down the facial ridge
11. Chorda tympani = always sacrificed in CWD
12. Silver nitrate = never near exposed facial nerve
13. Skin graft timing = 2-3 weeks post-op after granulation tissue bed forms
14. Primary split-thickness skin grafting = NOT recommended by Shambaugh
15. Facial ridge landmarks: LSCC (above) + tympanomastoid suture + digastric ridge
16. Körner flap = lining flap from posterior EAC skin to epithelialize mastoid bowl
17. Meatoplasty: crescent cartilage of ~1.5 × 2 cm excised from conchal bowl
18. ET in cholesteatoma surgery = should NOT be obliterated (even in radical - reserve for unusual cases)
19. CWD residual disease ~5.5% vs CWU without endoscopy ~47.7%

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18. COMPARISON TABLE: THREE TYPES OF OPEN CAVITY

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