Section 10

Describe the image and give 2 differential diagnoses?

  • Featureless tympanic membrane
  • Squamous debris lining the external ear canal and tympanic membrane
  • Attic retraction 
  • Attic granulation

Differential diagnosis:

  1. Mucosal chronic suppurative otitis media
  2. Squamous chronic suppurative otitis media

Describe what type(s) of hearing loss this can cause and why?

  • Conductive hearing loss due to possible erosion of ossicles and destruction of tympanic membrane
  • Sensorineural hearing loss due to involvement of the inner ear

List 2 other possible symptoms other than hearing loss (excluding complications.

  • Otorrhea – foul smelling
  • Persistent otitis media
  • Vertigo
  • Facial weakness

What surgery might you offer this patient?

  • Tympanoplasty
  • Atticotomy
  • Combined approach tympanoplasty
  • Modified radical mastoidectomy

List 5 possible complications of surgery.

  • Facial nerve palsy
  • Abnormal sense of taste
  • Tinnitus
  • Vertigo
  • CSF leak
  • Bleeding
  • Loss of hearing including dead ear
  • Pinna numbness
  • Dressing reaction to BIPP

Following surgery for this, describe two methods for surveillance for recurrence

  • Second look surgery
  • MRI with diffusion weighted imaging

Supporting Information

Cholesteatoma – can be congenital or acquired. Non-neoplastic but destructive layers of keratin in a cavity lined with squamous epithelium.  

  • Congenital – embryonic rests – epidermoid in origin behind in-tact TM, no otorrhoea/perforation, no ear trauma or previous surgery. 
  • Acquired – posterior, superior TM insult – altered self cleaning → mastoid erosion. 
    • Primary – tympanic membrane retraction
    • Secondary – trauma, ear surgery, perforation etc
  • Presentation – otorrhoea, dizziness (labyrinthine fistula), hearing loss
  • Investigation – PTA/Tymp + CT temporal bone – classic sign is soft tissue in Prussak’s space and blunting of scutum. Reasons for CT scan:
    • Plan approach – extent of mastoid pneumatisation, high jug bulb, low dura. 
    • Other abnormalities
    • Facial nerve dehiscence
    • Look for bony destruction and fistula
    • Extent of soft tissue abnormality
    • Revision cases
    • Medico-legal requirement
  • Treatment – conservative with drops and toilet. Surgical tympanomastoid surgery – canal wall up/down etc. 2 goals – safe ear. Second goal, hearing reconstruction. 
  • Sinus tympani → common site of recurrence → poor accessibility

Mastoidectomy – used to deal with disease of the mastoid air cells. Either an end/post-aural approach gains access to attic, tegmen and sigmoid sinus. There are many techniques:

  1. Cortical mastoidectomy – acute mastoiditis – no cholesteatoma. Post-aural incision down to the periosteum, mastoid drilled to reveal mastoid air cells. McEwans/suprameatal triangle used to identify mastoid antrum 1.5-2cm deep. 
    1. Anterior line – posterior superior EAC
    2. Superior line – temporal line  or line drawn from base of zygomatic arch
    3. Posterior line – line joining the two

Bone is left over sigmoid sinus and tegmen. 

  1. Modified radical mastoidectomy – cholesteatoma
    1. Cortical mastoid performed
    2. Posterior canal wall taken down
    3. The disease can be taken away from anterior to posterior making the cavity as small as the disease
    4. The cavity can be obliterated with fat/bone. It can also be lined with a fascia graft. 
    5. Hearing can be reconstructed at the same time as for tympanoplasty or left. 
  • Combined approach tympanoplasty – cholesteatoma 
  • Cortical mastoid
    1. Extended to posterior tympanotomy – facial recess – triangular region bounded by the facial nerve medially, the chorda tympani nerve laterally, and the fossa incudis superiorly.
  • Canal wall left up as risk of recurrence

Risk of mastoid surgery

  • Facial nerve damage
  • CSF leak
  • Labyrinthine fistula – defect in the bone that exposes the endosteum of the labyrinth (NOT perilymph fistula – leak of perilymph fluid into middle ear from oval or round window). Symptoms include:
  • Positive fistula sign – increased pressure in EAC – deviation of eyes away from fistula
  • Tullio phenomenon – vertigo with loud noises.
  • Damage to ossicles 
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