w4 Flashcards
portions of eustachian tube
2 portions 1/3 lateral= bony medial 2/3 = fibrocartilaginous portion to nasopharynx
Normal functions of ET
- Ventilation: aeration & pressure regulation of ME & nasopharynx
- Protection: from nasopharyngeal secretions ascending into ME and sudden pressure change
- Clearance: mucociliary action clears secretions from ME into nasopharynx
ET closed at rest but opens regularly
Swallowing evey 4-6 swallows, yawning, changes in atmospheric pressure
abnormal or impaired function ET
impaired opening or closing; defective mucociliary clearance
prevalence of ET dysfunction
generally 0.9% , new survey 4.6%
etiology of Obstructed ET or failure to open regularly
Obstruction: masses in ME or nasopharynx
o Inflammation due to allergy, infection or sinusitis, negative ME pressure & retraction of TM
Etiology of Patulous eustachian tube (open ET)
o Rapid weight loss
o Pregnancy
o Unknown
ET dysfunction can have additional pathologies like
- Recurrent acute otitis media or om with effusion
- Hearing loss
- Chronic retraction of the MT
o Adhesions to ossicles and retractions pockets
o Retraction pocket can evolve into cholesteatoma
Acute otitis media
rapid onset inflammation and infection in ME
Middle ear effusion
fluid in the ME without reference to etiology, pathogenesis, pathology or duration
Otorrhea
discharge from 1 or more following sites: external auditory canal, ME, mastoid, inner ear or intracranial cavity
Otitis media with effusion
inflammation of ME with fluid; no signs and symptoms of acute infection (Redness, foul smell)
Recurrent AOM
: well documented & separate AOM episodes greater than or = to 3 in 6 months or 4 in 12
When to suspect ET dysfunction Obstructed or closed ET
- Fullness or pressure
- Otalgia (pain)
- Difficulty popping ears
- Baro-challenged: poor pressure equalization (flying, scuba diving)
Recurrent AOM
well documented & separate AOM episodes greater than or = to 3 in 6 months or 4 in 12
when to suspect ET dysfunction Patulous ET (constantly open ET)
- Fullness
- Pulsatile tinnitus including clicking sensation
- Autophony of voice or breathing
Findings during audiological assessment for occluded ET
History: OM with effusion or acute
Otoscopy: retracted TM
Abnormal tympanogram: negative TPP, reduced static admittance
HL: conductive component
- Above all may be absent- additional testing may be necessary
Findings during audiological assessment for patulous ET
Oscillations in admittance during tympanometry or acoustic reflex testing
- Synchronized with pulsatile tinnitus and respiration
Valsalva procedure
record a pre-test tympanogram
- ET and Me are inflated by a forced but gentle expiration
- Re-measure tympanogram: ensure patient doesn’t swallow
- Tympanometric peak pressure shifts
valsalva procedure caution
Contraindications:
- Vascular/coronary disease or abnormal bp
- Retrinopathy or glaucoma
- 3rd trimester pregnancy
Violent exhalation during Valsalva could induce:
- Damage to the inner ear
- Fainting
- More serious problems for those with any of above medical conditions
Toynbee test
- deflation test to assess changes vin resting ME pressure
Procedure: record a pre-test tympanogram, perform closed nose swallowing, remeasure tympanogram, tympanometric peak pressure shifts, usually negative pressure change
ET dysfunction Audiological assessment
: standard audiometry, acoustic immittance (astatic admittance, TPP, inflation deflation tests to assess changes in resting ME pressure)
- Hold nose and blow, introduce positive pressure and tympanogram shifts to right
ET dysfunction: Medical examination
Otoscopy or pneumatic otoscopy:
Valsalva test: overpressure in ME can be observed as a budging TM
Toynbee test: observe changes in TM mobility during swallowing with nose closed
Politzer test
similar to the Valsalva test, but nasopharynx is passively inflated
1. Compress or block nostrils
2. Rubber tube attached to an air bag is inserted into 1 nostril and used to inject positive pressure
3. Patient then swallows or repeats “K K K” to open ET
4. TM is observed via otoscopy
Flexible nasopharygoscope
Physical examination allows visualization of pharyngeal end of ET
- Goal: to investigate potential obstruction of ET by nasal or pharyngeal masses such as enlarged adenoids, soft tissue growths
imaging
MRI & CT: visualize the ET
- Nasopharyngeal masses (carcinoma)
- ME masses (e.g, cholesteatoma)
what is a cholestatoma
- Middle ear mass described as cyst or tumour
o Epidermal inclusion cyst formed from stratified squamous epithelium
o Not a neoplasm (noncancerous) - Can erode ossicles and spread to invade and damage surrounding tissues (i.e., bony walls of ME cavity)
mean age of aqcuired cholestotoma
9 years
mean age of Congenital cholesteatoma
5.6 years
Congenital cholesteatoma Pathology
residual embryonic cells trapped in ME
- Squamous epithelial cells that produce keratin
Congenital cholesteatoma appearance
white mass medial to normal TM in ME cavity: “Keratin pearl”
Congenital cholesteatoma clinical features
normal TM with no prior history of otorrhea, perforation or canal atresia
Congenital cholesteatoma course of disease
chronic recurring inflammation and OM, permanent change in ME Mucosa
acquired cholesteatoma pathology
TM retraction, TM perforation, skin and other debris enter ME
acquired cholesteatoma presentation
history of poor ET function, chronic OM
what is acquired cholesteatoma
Invasion of skin cells (squamous epithelia) into ME cavity
Cyst-like pouch forms with:
- Dead and viable squamous epithelial cells
- Keratin shed by viable cells
- Enzymes that erode bone
- Cholesterol crystals
- Bacteria
acquired cholesteatoma subdivided into
primary and secondary
Primary acquired cholesteatoma
ET dysfunction leading to negative ME Pressure
- Sucks in retraction pocket, Pouch or sac by stretching TM
- Pocket can contain epithelial cells that produce keratin and otorrhea
- Eventually invades ME forming cholesteatoma
Secondary acquired cholesteatoma
: squamous cell migration through perforation in TM
Common sites in ME for cholesteatoma
(1) Pars flaccida into posterior and anterior epitympanum (2) posterior pars tensa into mesotympaum
Course of cohlesteatoma and complication
- Capacity to invade & erode adjacent structures
ME: erosion of saccules & wall
Posterior: extend into mastoid
Superior: invade brain cavity (meningitis & abscess)
Medial wall: erosion of bony labyrinth
Lateral scc: sudden vertigo
Cochlea: sudden SNHL
Inferior: below bony wall of ear canal bony lies facial nerve
audiologic Case history complaints cholesteatoma
fullness/pressure in ear, HL, otorrhea, otalgia, dizziness or vertigo, muscle weakness on one side of face
audiologic assessment
case history
- Standard audiometric procedures (otoscopy, PT, acoustic immittance)
PT thresholds with cholesteatoma
vary with involvement of ME ossicles & cochlea, normal conductive or mixed loss of varying degree
acoustic immitance with cholesteatoma
vary from normal to abnormal depending on involvement of ossicle and TM
audiologic managment of cholesteatoma
: amplification, aural rehab
medical management of cholesteatoma
cleaning ear (debridement) & antibiotics to reduce pain, stop drainage and control infection
Conservative management: regular follow with repeated cleaning when surgery contraindicated (anaesthetic risks, age and systematic disease)
standard treatment of cholesteatoma
surgery to protect from serious complications
Goal of surgery: remove cholesteatoma & infected tissue, achieve infection free dry ear, preservation or restoration of facial function & hearing
cholesteatoma surgery
Single or 2 stage:
1. Cholesteatoma removal
2. Follow up or revision surgery for
a. Reconstruction (rebuild walls of ME or canal, reduce size of mastoid cavity, facial nerve repair, repair or replace ossicles)
b. Removal of recurrence of cholesteatoma
tympanoplasty
removal of cholesteatoma from ME through TM which is then repaired
mastoidectomy
mastoid bone explored to remove any cholesteatoma that involves mastoid bone and ME
2 types of mastoidectomy
- Canal wall up
- canal wall down
canal wall up
posterior wall of External ear canal intact
a. Smaller
b. No mastoid cavity requiring cleaning
c. Higher risk of recurrence
canal wall down
a. For med-large cholesteatomas
b. Much lower incidence of recurrence
c. Larger than normal ear canal opening & larger open cavity which can accumulate debris and cause issues with water (vertigo in cold or hot, need plugs for swimming)
2 types of canal wall down
1) Radical mastoidectomy (2) modified radical mastoidectomy
Radical mastoidectomy
extensive removal of bony structures (including TM & ossicles) to form common open space, obliteration of ET conductive/mixed with maximum conductive component HL
modified radical mastoidectomy
less extensive surgery, more common, ME cavity intact, TM & ossicles retained or replaced with prosthesis, variable degree of post-op conductive or mixed HL
Audiologic management& outcomes for cholesteotoma
- counselling about expectations for hearing postop
- troublesome cavities limit success with amplification, altering resonant frequency and inadequate aeration due to occlusion
- can consider BAHA, reconstruction of mastoid cavity and EAC to reduce size and improve function
