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Chronic Suppurative Otitis Media (CSOM)

Note: Dhingra's Diseases of Ear, Nose and Throat is not directly available in the digital library. The following long answer is written following Dhingra's exact classification framework and teaching structure, supplemented by content from Shambaugh Surgery of the Ear and Cummings Otolaryngology Head and Neck Surgery - the most authoritative ENT references available.

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Definition

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Classification (Dhingra)

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Etiopathogenesis

Predisposing Factors

• Negative middle ear pressure
• Serous/mucoidal effusion
• Recurrent ascending infection from the nasopharynx

• Recurrent acute attacks in childhood
• Inadequate antibiotic treatment

• Adenoid hypertrophy (especially in children) - blocks eustachian tube opening
• Chronic sinusitis, chronic tonsillitis
• Cleft palate - impairs levator veli palatini function

• Low socioeconomic status, overcrowding, malnutrition
• Immunodeficiency
• Racial predisposition (Native Americans, Inuit - higher prevalence)

Pathogenesis

• Produces collagenases, proteases that erode bone
• Exerts direct pressure causing bone necrosis
• Grows expansively, eroding ossicles, tegmen, sigmoid sinus, labyrinth, and facial nerve canal

Microbiology

Microbial biofilms are now recognized as a key factor in treatment resistance and disease persistence. Biofilm bacteria are up to 1000x more resistant to antibiotics than planktonic forms.

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Histopathology

• Tubotympanic type: Mucosal edema, subepithelial round cell infiltration, goblet cell metaplasia, mucopurulent exudate, and fibrovascular granulation tissue. The tympanic membrane shows loss of fibrous middle layer.
• Atticoantral type: All the above plus cholesteatoma matrix (keratinizing squamous epithelium) with keratin lamellae, surrounding perimatrix of fibrous tissue, and osteoclastic bone erosion.

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Clinical Features

Symptoms

• Tubotympanic type: Mucoid or mucopurulent, non-offensive, intermittent (often precipitated by URTI or water entry), profuse
• Atticoantral type: Scanty, purulent, foul-smelling (due to bone destruction and anaerobic organisms), continuous

• Typically conductive, ranging from 20-60 dB depending on perforation size and ossicular integrity
• Sensorineural component may coexist (5-33 dB SNHL) due to toxin diffusion across the round window membrane
• Conductive loss > 30 dB suggests ossicular erosion
• Paradoxically, hearing may be preserved even with ossicular erosion if cholesteatoma bridges the gap (columella effect)

• Typically absent in uncomplicated CSOM
• If present, strongly suggests: intracranial complication, masked mastoiditis, malignancy, or acute exacerbation

• Labyrinthine fistula (semicircular canal erosion by cholesteatoma)
• Labyrinthitis
• Perilymph leak

Signs (on Otoscopy/Otomicroscopy)

• Central perforation in pars tensa (safe area - rim of tympanic membrane preserved)
• Mucosal lining of middle ear visible - may look pale/normal or hyperemic
• Mucoid discharge in the canal
• Aural polyp may protrude through perforation

• Attic perforation (in pars flaccida) or posterosuperior marginal perforation
• White, glistening keratin-like material (cholesteatoma pearls) in the attic/posterior superior quadrant
• Foul-smelling discharge
• Granulation tissue around perforation
• Scutal erosion (erosion of the lateral wall of the epitympanum) - a key sign
• Aural polyp (more aggressive, bleeds easily)

1. Attic or marginal perforation
2. Foul-smelling discharge
3. Presence of cholesteatoma
4. Granulation tissue
5. Any complication sign (vertigo, facial paresis, headache)

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Investigations

1. Otoscopy / Otomicroscopy

• First-line examination
• Reveals perforation type, discharge nature, presence of cholesteatoma, granulations, polyps
• Microscopy allows detailed examination under magnification

2. Tuning Fork Tests

• Rinne test: Negative (BC > AC) indicating conductive hearing loss
• Weber test: Lateralizes to the affected (diseased) ear
• Absolute Bone Conduction (ABC) test: Normal in pure CHL; reduced if SNHL component present

3. Pure Tone Audiometry (PTA)

• Documents the degree and type of hearing loss
• Air-Bone Gap (ABG) assessment
• ABG > 30 dB suggests ossicular erosion
• Speech discrimination testing for functional assessment

4. Tympanometry

• Type B (flat) tympanogram - confirms perforation (cannot build up pressure)
• Used to document before and after surgery

5. Microbiological Investigations

• Ear swab for culture and sensitivity - identifies causative organisms and guides antibiotic therapy
• Done before starting topical antibiotics
• Common findings: Pseudomonas aeruginosa, S. aureus, mixed anaerobes

6. Imaging

• Investigation of choice for CSOM, especially atticoantral type
• Key findings:
  • Soft tissue mass in attic/mastoid (cholesteatoma)
  • Scutal erosion (erosion of lateral epitympanic wall)
  • Ossicular erosion (especially incus long process)
  • Tegmen erosion
  • Sigmoid sinus plate erosion
  • Mastoid air cell opacity
  • Labyrinthine fistula (erosion of lateral semicircular canal)
  • Facial nerve canal involvement
• Limitation: Cannot reliably differentiate cholesteatoma from granulation tissue/fibrous tissue

• Non-echo-planar DWI (non-EPI DWI) is now the gold standard for detecting residual/recurrent cholesteatoma post-surgery
• T1: cholesteatoma isointense to brain
• T2: hyperintense
• DWI: shows restricted diffusion (bright signal) - distinguishes cholesteatoma from other middle ear masses
• Also evaluates intracranial complications

7. Mastoid X-Ray (Schuller's View) - Historical

• Largely replaced by CT
• May show clouding of mastoid air cells, bone destruction
• Still used where CT is unavailable

8. Additional Investigations for Complications

• CBC, ESR, CRP - markers of infection/inflammation
• Blood cultures if sepsis suspected
• Lumbar puncture (after ruling out raised ICP) if meningitis suspected
• MRI with contrast for sigmoid sinus thrombosis, epidural abscess, subdural empyema, brain abscess

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Management

Aims of Treatment

1. Eliminate active infection and achieve a dry ear
2. Eradicate disease (especially cholesteatoma)
3. Prevent recurrence and complications
4. Restore/preserve hearing

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A. Medical Management

• Most important step in medical management
• Methods: dry mopping, suction under microscopy
• Removes infected discharge, biofilms, debris
• Frequency: every 1-2 weeks in clinic; daily dry mopping by patient at home

• Most effective therapy for wet CSOM
• Ciprofloxacin ear drops (0.3%) - First choice; excellent anti-pseudomonal coverage; not ototoxic
• Ciprofloxacin + dexamethasone - Combined formulation for faster resolution
• Ofloxacin - Also safe and effective
• Important: Aminoglycoside drops (neomycin, gentamicin) are potentially ototoxic when used through a perforation - avoid unless no alternatives
• Duration: 2-4 weeks
• Topical steroids reduce mucosal edema and granulation

• Reserved for:
  • Acute exacerbations
  • Failure of topical therapy
  • Suspected complications
  • Perioperative use
• Oral: Ciprofloxacin (most commonly used)
• IV: Anti-pseudomonal cover (pip-tazo, ceftazidime) for severe cases or complications

• Treat underlying ET dysfunction
• Nasal decongestants, steroid nasal sprays for rhinitis/sinusitis
• Adenoidectomy in children with hypertrophied adenoids

• Patient must keep ear dry - cotton wool with petroleum jelly during bathing/swimming

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B. Surgical Management

Tubotympanic CSOM (Safe ear)

• Repair of the tympanic membrane perforation alone
• Indications: Dry perforation, absence of middle ear disease, adequate Eustachian tube function, no cholesteatoma
• Graft materials (Dhingra):
  • Temporalis fascia - most commonly used (underlay technique)
  • Tragal perichondrium
  • Cartilage (reinforcement in high-risk cases)
• Techniques:
  • Underlay technique - graft placed medial to tympanic membrane remnant (most common)
  • Overlay technique - graft placed lateral to annulus
• Approach: Postaural / endaural / transcanal
• Success rate: 85-95% in first attempt

• Combines myringoplasty with ossicular chain reconstruction
• Wullstein's classification:
  • Type I: Myringoplasty (intact ossicular chain)
  • Type II: Ossicular chain partially damaged; graft placed on incus/malleus remnant
  • Type III: Malleus and incus absent; graft on stapes head (Columella effect)
  • Type IV: Only stapes footplate mobile; graft on footplate - creates sound protection for round window
  • Type V: Stapes footplate fixed; fenestration of lateral semicircular canal

• Exenteration of mastoid air cells while preserving the posterior canal wall and middle ear structures
• Indicated when mastoid disease (mastoiditis) coexists with CSOM
• Can be combined with tympanoplasty

Atticoantral CSOM (Unsafe ear) - Surgery is mandatory

• Posterior canal wall preserved
• Exenteration of mastoid air cells + attic + epitympanum
• Advantage: Better aesthetics, easier hearing aid fitting, less postoperative care
• Disadvantage: Higher recurrence rate, needs second-look surgery (at 6-12 months) to detect residual/recurrent cholesteatoma
• Staged procedure: Ossicular reconstruction done at second-look operation

• Posterior EAC wall removed - creates an open mastoid cavity (meatoplasty)
• Radical mastoidectomy: Removes all middle ear contents including ossicles, leaves only stapes footplate
• Modified radical mastoidectomy (Bondy's operation): Preserves functioning ossicular chain and tympanic membrane remnant; only removes cholesteatoma and attic disease
• Advantage: Better exposure, lower recurrence rate, avoids second-look
• Disadvantage: Requires lifelong cavity maintenance, water restriction, hearing aid fitting difficult

1. Labyrinthine fistula
2. Only hearing ear (cannot risk residual disease)
3. Unresectable cholesteatoma on facial nerve/stapes footplate
4. Low-lying tegmen limiting attic access
5. Unreconstructable posterior canal wall
6. Patient unable to attend follow-up for second-look
7. Revision cases with recurrent cholesteatoma

• Reconstruction of the ossicular chain using:
  • Autograft: Incus interposition
  • Alloplastic prostheses: Partial ossicular replacement prosthesis (PORP), Total ossicular replacement prosthesis (TORP)
  • Bone cement

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C. Management of Complications

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Complications of CSOM

Extracranial Complications

1. Mastoiditis (acute/coalescent/masked)
2. Labyrinthitis (circumscribed - fistula; diffuse - serous/suppurative)
3. Facial nerve palsy (from cholesteatoma erosion)
4. Petrositis (Gradenigo syndrome: otorrhea + diplopia + deep facial pain)
5. Subperiosteal abscess - postauricular swelling pushing the pinna forward and downward
6. Bezold's abscess - tracks down sternomastoid
7. Citelli's abscess - tracks to digastric triangle
8. Luc's abscess - tracks to zygomatic root

Intracranial Complications

1. Extradural abscess
2. Subdural empyema
3. Meningitis (most common intracranial complication)
4. Brain abscess (temporal lobe or cerebellar)
5. Lateral sinus thrombophlebitis (sigmoid sinus thrombosis)
6. Otitic hydrocephalus

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Summary Flowchart

CSOM
├── TUBOTYMPANIC (Safe)
│   ├── Central perforation, mucoid discharge, no cholesteatoma
│   ├── Medical: Aural toilet + Topical ciprofloxacin
│   └── Surgery: Myringoplasty / Tympanoplasty
│
└── ATTICOANTRAL (Unsafe/Dangerous)
    ├── Attic/marginal perforation, foul discharge, cholesteatoma
    ├── Scutal erosion, granulations, HRCT confirmation
    └── Surgery: MANDATORY
        ├── CWU Mastoidectomy (+ second look at 6-12 months)
        └── CWD Mastoidectomy (Radical / Modified Radical)
            └── Meatoplasty for cavity care

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Key Points to Remember (Dhingra Exam Notes)

• CSOM = middle ear cleft inflammation > 6-12 weeks with TM perforation + discharge
• Tubotympanic = Safe = Central = Mucoid = Mucosal type
• Atticoantral = Unsafe = Marginal/Attic = Foul = Squamous/Cholesteatoma type
• Cholesteatoma is dangerous because it erodes bone via collagenase enzymes
• "Safe ear" can become dangerous if neglected (develops granulations, polyps, intracranial spread)
• HRCT temporal bone is the investigation of choice
• Non-EPI DWI MRI is gold standard for detecting residual cholesteatoma post-surgery
• Topical ciprofloxacin is the safest and most effective topical antibiotic (non-ototoxic)
• Aminoglycosides are contraindicated through perforated TM
• Surgery for atticoantral CSOM is always indicated - the only question is which type

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CHRONIC SUPPURATIVE OTITIS MEDIA (CSOM)

A Complete Long Answer - Dhingra Framework

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DEFINITION

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CLASSIFICATION (Dhingra)

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ETIOPATHOGENESIS

Predisposing Factors

1. Eustachian tube dysfunction - the root cause
2. Repeated attacks of Acute Otitis Media (AOM) - especially in childhood
3. Upper respiratory tract conditions:
   • Adenoid hypertrophy (most common in children)
   • Chronic sinusitis
   • Chronic tonsillitis
   • Cleft palate (impairs levator veli palatini function)
   • Allergic rhinitis
4. Low socioeconomic status - overcrowding, malnutrition, poor hygiene
5. Immunodeficiency - primary or secondary
6. Pre-existing tympanic membrane perforation - portal of entry for infection
7. Racial predisposition - Native Americans, Inuit have higher prevalence
8. Biofilm formation - highly organized bacterial communities protected from antibiotics and host immunity

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ETIOPATHOGENESIS FLOWCHART

┌─────────────────────────────────────────────────────────────────────┐
│   PREDISPOSING FACTORS                                              │
│   (Adenoids, URTI, Allergy, Cleft palate, Low socioeconomic)       │
└──────────────────────────────┬──────────────────────────────────────┘
                               │
                               ▼
┌─────────────────────────────────────────────────────────────────────┐
│   EUSTACHIAN TUBE DYSFUNCTION                                       │
│   Impaired ventilation → Negative middle ear pressure              │
└──────────────────────────────┬──────────────────────────────────────┘
                               │
                               ▼
┌─────────────────────────────────────────────────────────────────────┐
│   PERSISTENT MIDDLE EAR EFFUSION (Serous or Purulent)              │
│   Mucosal edema → Goblet cell / submucosal gland metaplasia        │
│   (Mucosa converts to secretory type → self-perpetuating effusion) │
└──────────────────────────────┬──────────────────────────────────────┘
                               │
                               ▼
┌─────────────────────────────────────────────────────────────────────┐
│   BACTERIAL INFECTION + BIOFILM FORMATION                          │
│   Toxins + inflammatory mediators → basement membrane rupture      │
│   Lamina propria cells enter middle ear lumen                      │
│   Angiogenic + epithelial growth factors activated                 │
└──────────────────────────────┬──────────────────────────────────────┘
                               │
                               ▼
┌─────────────────────────────────────────────────────────────────────┐
│   GRANULATION TISSUE + POLYP FORMATION                             │
│   Fibroblast recruitment + neovascularization                      │
│   Polyp may extrude through TM into EAC                            │
└──────────────────────────────┬──────────────────────────────────────┘
                               │
                   ┌───────────┴────────────┐
                   ▼                        ▼
    ┌──────────────────────┐    ┌────────────────────────────────────┐
    │  TUBOTYMPANIC TYPE   │    │      ATTICOANTRAL TYPE             │
    │  (Mucosal disease)   │    │    (Squamous/Cholesteatoma)        │
    │                      │    │                                    │
    │ Granulation enzymes  │    │ Negative pressure + TM atrophy    │
    │ break collagen of TM │    │ → Retraction pocket               │
    │                      │    │   (Pars flaccida / post-sup)      │
    │ CENTRAL PERFORATION  │    │                                    │
    │ (pars tensa, with    │    │ Pocket accumulates keratin debris  │
    │  residual rim)       │    │ → Self-cleaning fails             │
    │                      │    │ → CHOLESTEATOMA SAC forms         │
    │ Mucoid/mucopurulent  │    │                                    │
    │ odorless discharge   │    │ Collagenase/Protease production   │
    │                      │    │ → Bone erosion (scutum, ossicles, │
    │ ± Tympanosclerosis   │    │   tegmen, labyrinth, facial nerve)│
    │ ± Cholesterol        │    │                                    │
    │   granuloma          │    │ FOUL-SMELLING discharge           │
    │                      │    │ COMPLICATIONS (intra/extracranial)│
    └──────────────────────┘    └────────────────────────────────────┘

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Cholesteatoma - Mechanism of Bone Destruction

• Secreting collagenases, proteases, and acid phosphatases
• Direct pressure causing osteoclast activation and osteonecrosis
• Stimulating cytokines (IL-1, TNF, PGE2) that mediate bone resorption
• Enlarging progressively into the mastoid, epitympanum, and beyond

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CLINICAL FEATURES

Symptoms

• TT type: Profuse, mucoid or mucopurulent, non-offensive, intermittent (triggered by URTI or water entry into ear)
• AA type: Scanty, purulent, foul-smelling (due to anaerobic organisms and bone necrosis), often continuous

• Typically conductive (CHL) - due to TM perforation, ossicular discontinuity, or both
• Degree: 20-60 dB depending on perforation size and ossicular status
• ABG > 30 dB suggests ossicular erosion
• SNHL component (5-33 dB) may coexist - toxins diffusing across the round window membrane
• Paradox: hearing may be preserved despite ossicular erosion if cholesteatoma bridges the gap (columella effect)

• Typically absent in uncomplicated CSOM
• If present: suspect intracranial complication, malignancy, or acute exacerbation

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Signs on Otoscopy / Otomicroscopy

• Central perforation of pars tensa - annular rim of TM is preserved
• Mucoid or mucopurulent discharge in the canal
• Middle ear mucosa visible through perforation - may be pale/normal or hyperemic/edematous
• Aural polyp may protrude through the perforation (arises from promontory granulations)
• Tympanosclerosis - chalky white plaques on TM (healed CSOM)

• Attic perforation (pars flaccida) or posterosuperior marginal perforation
• White, glistening keratin/cholesteatoma material visible in attic
• Foul-smelling discharge
• Granulation tissue around retraction pocket
• Scutal erosion (lateral epitympanic wall erosion) - key diagnostic sign on CT
• Aural polyp - soft, fleshy, bleeds easily

1. Foul-smelling discharge
2. Attic or posterosuperior marginal perforation
3. Cholesteatoma visible
4. Granulation tissue
5. Vertigo, facial paresis, headache (sign of complication)
6. Bone erosion on imaging

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Pathology Comparison (Shambaugh Table 26-3)

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INVESTIGATIONS

1. Otoscopy / Otomicroscopy

• First-line, essential examination
• Documents: perforation type and size, discharge character, presence of cholesteatoma, granulations, polyps, scutal erosion

2. Tuning Fork Tests

3. Pure Tone Audiometry (PTA)

• Documents type and degree of hearing loss
• Air-Bone Gap (ABG): present in CHL
• ABG > 30 dB strongly suggests ossicular erosion
• Speech discrimination score assesses functional hearing
• Baseline essential before any surgery

4. Tympanometry

• Type B (flat) tympanogram - confirms perforation (pressurization fails)
• Important for pre- and post-operative documentation

5. Microbiological Investigations

• Ear swab for culture and sensitivity (C&S) - taken before starting antibiotics
• Common isolates:
  • TT type: Pseudomonas aeruginosa, S. aureus, Proteus mirabilis
  • AA type: P. aeruginosa, S. aureus, Bacteroides, Peptostreptococcus (anaerobes)
• Guides choice of topical and systemic antibiotic

6. Imaging

• Pars flaccida cholesteatoma: Scutal erosion + medialization of ossicular chain
• Pars tensa (posterosuperior) cholesteatoma: Erosion of posterior-superior canal wall + lateralization of ossicular chain; scutum intact

• Non-echo-planar DWI (non-EPI DWI) - Gold standard for detecting residual or recurrent cholesteatoma post-surgery
• DWI shows restricted diffusion (bright signal) unique to cholesteatoma
• T1: isointense to brain; T2: hyperintense
• Also evaluates intracranial complications (abscess, meningitis, sinus thrombosis)

7. Mastoid X-Ray (Schuller's View)

• Now largely superseded by CT
• May show: cloudiness of mastoid air cells, bone destruction, sclerosis
• Still useful where CT is unavailable

8. Additional Investigations for Complications

• Full blood count (FBC), ESR, CRP - markers of systemic infection
• Blood culture - if septicemia suspected
• Lumbar puncture - if meningitis suspected (after excluding raised ICP)
• MRI with gadolinium contrast - brain abscess, sigmoid sinus thrombosis, subdural empyema

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MANAGEMENT

Aims of Treatment

1. Eliminate active infection - achieve a dry ear
2. Eradicate disease - especially cholesteatoma
3. Prevent complications and recurrence
4. Restore hearing where possible
5. Reconstruct the tympanic membrane

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A. Medical Management

Step 1: Aural Toilet (Most Important Step)

• Dry mopping with cotton wool swabs
• Suction clearance under microscopic guidance (best method)
• Removes discharge, debris, and biofilm
• Frequency: every 1-2 weeks in clinic; daily home mopping by patient
• Creates a clean, dry environment for topical antibiotics to work

Step 2: Topical Antibiotics

• Ciprofloxacin 0.3% ear drops - First choice
  • Excellent anti-pseudomonal activity
  • Non-ototoxic - safe through perforations
  • Instill 3-4 drops, 2-3 times daily
• Ciprofloxacin + Dexamethasone - reduces mucosal edema and speeds resolution
• Ofloxacin - also safe and effective
• Duration: 2-4 weeks; review at 4-6 weeks
• ⚠️ Aminoglycoside drops (gentamicin, neomycin) are CONTRAINDICATED through a perforation - risk of cochlear/vestibular ototoxicity

Step 3: Systemic Antibiotics

• Acute exacerbations / acute-on-chronic infection
• Failure of topical therapy
• Suspected complications
• Perioperative prophylaxis

• Oral: Ciprofloxacin (most commonly used; 500 mg BD x 7-10 days)
• IV: Piperacillin-tazobactam or ceftazidime for severe infection/complications
• Anaerobic cover: Metronidazole for foul-smelling discharge

Step 4: Treat Underlying Cause

• Nasal decongestants / intranasal corticosteroid sprays (for rhinitis, ET dysfunction)
• Treat chronic sinusitis, tonsillitis
• Adenoidectomy in children with hypertrophied adenoids
• Allergy management

Step 5: Patient Instruction

• Keep ear dry at all times - cotton wool with Vaseline during bathing/swimming
• Avoid forceful nose blowing (raises nasopharyngeal pressure)
• No swimming until ear is dry and repaired

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B. Surgical Management

Tubotympanic CSOM - Surgical Options

• Repair of the tympanic membrane perforation without middle ear exploration
• Indications:
  • Dry perforation (ear dry for minimum 6 weeks)
  • Adequate eustachian tube function
  • No active infection, no cholesteatoma
  • No significant middle ear disease on otoscopy/CT
• Graft Materials (Dhingra):
  • Temporalis fascia - most commonly used (ideal thickness, good take rate)
  • Tragal perichondrium
  • Cartilage (for reinforcement in high-risk perforations)
  • Fat (for small perforations)
• Techniques:
  • Underlay (Medial graft) technique - graft placed medial to TM remnant (most common, 85-95% success)
  • Overlay (Lateral graft) technique - graft placed lateral to annulus (used for anterior perforations)
• Approach: Postaural (most common) / Endaural / Transcanal (small perforations)
• Contraindications: Active infection, poor ET function, only hearing ear (relative), non-compliant patient

• Exenteration of mastoid air cells, preserving posterior canal wall and middle ear
• Indicated when mastoiditis coexists with TT CSOM
• Often combined with tympanoplasty

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Atticoantral CSOM - Surgery is MANDATORY

ATTICOANTRAL CSOM
│
├── SURGERY ALWAYS INDICATED
│
├─────────────────────────────────────────────────────────┐
│                                                         │
▼                                                         ▼
CANAL WALL UP (CWU) Mastoidectomy              CANAL WALL DOWN (CWD) Mastoidectomy
(Modified Radical / Intact Canal Wall)          (Radical / Modified Radical)
│                                               │
│ Posterior EAC wall PRESERVED                 │ Posterior EAC wall REMOVED
│ Better cosmesis, no cavity care               │ Creates open mastoid cavity
│ Harder hearing aid fitting                   │ Requires lifelong cavity care
│ NEEDS second-look (6-12 months)              │ No second-look usually needed
│ Higher recurrence rate                       │ Lower recurrence rate
│                                               │
└─ Preferred when: limited disease,            └─ Preferred when: labyrinthine fistula,
   good mastoid pneumatization,                  unresectable disease, only hearing ear,
   reliable follow-up possible                   low tegmen, patient unable to follow up

• Posterior canal wall preserved
• Mastoid air cells, antrum, and epitympanum exenterated
• Cholesteatoma removed under microscope
• Middle ear structures and ossicular chain preserved when possible
• Staged procedure: Ossicular reconstruction at second-look operation (6-12 months)
• Second-look mandatory to detect residual/recurrent cholesteatoma

• Removes posterior EAC wall - produces one large cavity (mastoid + middle ear + EAC)
• Radical mastoidectomy: Removes all middle ear contents; leaves only stapes footplate; no hearing reconstruction (cavity only)
• Modified radical mastoidectomy (Bondy's operation): Removes attic disease and cholesteatoma while preserving a functioning ossicular chain and TM remnant; hearing preserved
• Meatoplasty is essential to ensure the cavity drains, self-cleans, and can be examined

1. Labyrinthine fistula
2. Only hearing ear (cannot risk residual disease)
3. Cholesteatoma on facial nerve or stapes footplate (unresectable with CWU)
4. Low-lying tegmen limiting attic access
5. Unreconstructable posterior canal wall defect
6. Unreliable follow-up (patient unable to attend for second-look)
7. Extensive or recurrent cholesteatoma

• Done at primary or second-stage surgery
• Options:
  • Autograft: Incus transposition (most common)
  • PORP (Partial Ossicular Replacement Prosthesis): replaces incus; rests on stapes head
  • TORP (Total Ossicular Replacement Prosthesis): replaces malleus + incus; rests on footplate
  • Bone cement / hydroxyapatite prostheses

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C. Management Flowchart

CSOM PATIENT PRESENTS
        │
        ▼
HISTORY + OTOSCOPY + AUDIOMETRY
        │
   ┌────┴────┐
   │         │
   ▼         ▼
TT TYPE   AA TYPE
(Central   (Attic/marginal
 perf)      perf/cholesteatoma)
   │         │
   ▼         └──────────────────► HRCT TEMPORAL BONE
MEDICAL                                    │
TREATMENT                                  ▼
(Aural toilet +                    SURGERY MANDATORY
Topical Ciprofloxacin              (CWU or CWD mastoidectomy)
+/- Systemic Abx)
   │
   ▼
DRY EAR         FAILED (> 6 weeks)
   │                    │
   ▼                    ▼
MYRINGOPLASTY /   SURGICAL REVIEW
TYMPANOPLASTY     (± HRCT, ± mastoidectomy)

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COMPLICATIONS OF CSOM

Extracranial (Extradural) Complications

Intracranial Complications

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KEY EXAM POINTS (Dhingra Summary)

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