Middle Ear Flashcards
What is the incidence of malleus ankylosis during primary surgery for otosclerosis
0.4- 1.6%.
What is the incidence of tympanic membrane perforation 6 months after pressure equalizing tube extrusion
0.5-2%.
What is the incidence of facial nerve paralysis in patients with chronic otitis media and cholesteatoma
1%.
What are the expected residual hearing levels after PORP and TORP
15 dB conductive hearing loss PORP; 25 dB conductive hearing loss TORP.
What % of congenital cholesteatomas are bilateral
3%.
In patients with chronic otitis media but not cholesteatoma, what level of hearing loss is associated with ossicular chain disruption or fixation
30 dB or more.
What is the rate of extrusion of middle ear prostheses
4- 7%.
What is the incidence of malleus ankylosis during revision surgery for otosclerosis
4.5- 13.5%.
What is the mean age of presentation for congenital cholesteatoma
4.5 years.
What % patients have erosion of the scutum with cholesteatoma
42%.
What % of cholesteatomas are complicated by a labyrinthine fistula
5 - I O%.
What is the overall success (accounting for extrusion, HL, and graft take) at 4 months using TORP or PORP
58% TORP; 64% PORP.
What % of cases of otosclerosis are bilateral
85%.
Why is stapedectomy dangerous in patients with Meniere’s disease
A dilated saccule may sit immediately beneath the footplate and be injured upon entry into the vestibule.
How do the surgical findings differ during removal of congenital cholesteatoma from removal of cholesteatoma associated with chronic suppurative otitis media
Absence of inflammatory changes/adhesions and easier removal with potential for complete preservation of the middle ear mucosa.
What are the indications for using plastic sheeting in middle ear surgery
Absence of mucosa on the promontory, in most of the middle ear, or in the middle ear cleft (except in the eustachian tube).
What are the indications for simple mastoidectomy
Acute coalescent mastoiditis with complications or acute mastoiditis that does not resolve after appropriate antibiotic therapy and myringotomy.
How should an extruded prosthesis be managed
Allow spontaneous extrusion; TM may heal and make a spontaneous connection.
What are the 2 parts of a cholesteatoma
Amorphous center surrounded by keratinized squamous epithelium.
What are the complications of lateral tympanoplasty
Anterior blunting, lateralization, epithelial pearls, canal stenosis.
What are the indications for performing a lateral tympanoplasty
Anterior or large perforations, revision tympanoplasty, or if the anterior canal wall is in the way.
What is the most commonly involved site of otosclerosis in the temporal bone
Anterior to the oval window at the fissula ante fenestrum.
What is the management of injury to the sigmoid sinus during mastoidectomy
Apply gentle pressure, place a Surgicel or Gelfoam patch, and continue with surgery.
In a child with spontaneous CSF leak to the middle ear, where is the leak most commonly located
Around the stapes footplate.