Atelectasis of the Middle Ear

Definition

Pathophysiology

1. Negative middle ear pressure develops
2. The tympanic membrane is progressively drawn medially
3. Repeated bouts of acute otitis media (AOM) lead to collagen destruction and thinning of the fibrous layer of the tympanic membrane (demonstrated by Sadé and Berco), reducing its structural resistance to inward retraction
4. The tympanic membrane drapes progressively over the ossicles and onto the promontory

Grading / Classification

• Deguine classification (pars tensa retraction)
• Tos classification (pars flaccida retractions, particularly relevant to cholesteatoma precursor pockets)

Clinical Presentation

Symptoms

• Hearing loss — typically conductive, slowly progressive; due to obliteration of the middle ear space and, in advanced stages, ossicular erosion (particularly the long process of incus)
• Aural fullness — sensation of blocked ear
• Autophony in some patients
• Recurrent otorrhoea — if co-existing OME or secondary infection occurs
• Otalgia — usually mild or absent; significant pain suggests secondary infection
• In many patients, particularly children, the condition is asymptomatic and detected incidentally on otoscopy

Signs on Otoscopy

• Tympanosclerosis (white chalky plaques)
• Amber/dull appearance if OME is co-existing
• Retraction pockets in pars tensa or pars flaccida — the most dangerous finding as they represent precursors to primary acquired cholesteatoma

Investigations

1. Otoscopy / Endoscopy / Pneumatoscopy

• Gold standard for diagnosis and staging
• Pneumatoscopy (Siegle speculum) assesses TM mobility — reduced or absent in atelectasis
• Endoscopic otoscopy provides magnification and enables staging
• Retraction pockets must be assessed: are they self-cleaning (keratin naturally migrates out) or progressive/non-cleaning (keratin accumulates — cholesteatoma precursor)?

2. Audiological Assessment

• Pure tone audiogram (PTA) — typically shows conductive hearing loss (air-bone gap); degree correlates with stage
• Tympanometry — type B (flat) curve if effusion present; type C (negative peak) if ETD without effusion
• Stapedial reflex testing — absent in significant conductive loss

3. Eustachian Tube Function Tests

• Toynbee test, Valsalva manoeuvre — clinical assessment of tube patency
• Sonotubometry or tubomanometry — objective measures used in research and some centres

4. Imaging

• High-resolution CT (HRCT) of the temporal bone — indicated when:
  • Ossicular erosion is suspected (particularly incus long process)
  • Retraction pocket depth cannot be fully assessed
  • Cholesteatoma is a differential diagnosis
  • Pre-operative planning for surgical management
  • Shows degree of middle ear space obliteration, ossicular chain integrity, mastoid pneumatisation
• MRI (non-EPI DWI sequences) — increasingly used to differentiate cholesteatoma from inflammatory tissue, particularly when recurrence after surgery is suspected

5. Examination Under Microscope / Microlaryngoscopy

• Allows precise assessment of retraction pockets and their extent
• Essential pre-operatively

Management

Conservative (Stages I–II, Early Stage III)

• Treatment of contributing upper respiratory conditions: allergic rhinitis, adenoidal hypertrophy, chronic rhinosinusitis
• Nasal corticosteroid sprays for allergic rhinitis
• Autoinflation (Otovent balloon) — may improve ETD and partially reverse early retraction
• Hearing aids as a temporising measure in bilateral disease with hearing loss

• Early-stage retractions that are fully visible and self-cleaning may be monitored with regular otoendoscopy (3–6 monthly intervals)
• Serial audiograms to detect progression

Surgical Management

• Indicated for Stages I–III when ETD is the main driver and the TM is not yet adherent
• Sadé (1992) demonstrated improvement in atelectatic ears following ventilation tube insertion
• Graham and Knight reported reversal of atelectasis with grommets in selected cases
• Tubes bypass the dysfunctional eustachian tube, restore positive middle ear pressure, and allow the TM to return toward a more normal position
• Repeated insertion may be required; longer-term T-tubes are preferred in refractory cases

• Indicated in Stage III–IV when:
  • Significant hearing loss or ossicular erosion is present
  • Retraction pocket is progressive or non-self-cleaning
  • After grommet insertion has failed to reverse atelectasis
• Goal: reinforcement of the atelectatic/thinned tympanic membrane
• Techniques include cartilage tympanoplasty (cartilage shield or palisade) — cartilage is rigid and resists re-retraction; provides durable repair
• Temporalis fascia, perichondrium, or tragal cartilage may be used
• Cummings notes that myringoplasty for reinforcement of the atelectatic TM is indicated in extreme cases with hearing loss or ossicular erosion

• When ossicular erosion has occurred (typically long process of incus or stapes superstructure)
• Performed concurrently with tympanoplasty
• Options: partial ossicular replacement prosthesis (PORP), total ossicular replacement prosthesis (TORP), incus interposition

• Self-cleaning and stable: surveillance
• Progressive, non-self-cleaning, or keratin-accumulating: surgical excision with reconstruction
• The approach escalates to canal wall down or canal wall up mastoidectomy if cholesteatoma has developed

• Indicated when cholesteatoma has developed from an atelectatic retraction pocket
• Also used in combination with tympanoplasty in cases of poor mastoid pneumatisation to improve the long-term ventilation reservoir for the middle ear

Complications

Summary

• Formatted title banner with subtitle
• All 8 sections: Definition, Pathophysiology, Grading, Clinical Presentation, Investigations, Management, Complications, Summary
• Two clinical images embedded — the Sadé-Berco staging diagram and the otoscopic photo of atelectasis with effusion
• Colour-coded tables (navy headers, alternating rows) for easy reading
• Full source citations at the bottom