CHPT 126
Cranial-Base Surgery
• See quiz handout
CHPT 127
Surgical Techniques to Enhance
Prosthetic Rehabilitation
Mastoid Surgery
Quinton Gopen, M.D.
UCLA Medical Center
April 25th, 2012
Mastoidectomy
• Canal Wall Up
– Facial Recess approach
• Atticotomy
• Canal Wall Down
Canal Wall Up
• Skin incision
– Fascia harvest
• Periosteal incision
• Bone removal
– Sequential landmarks
– Identify
• Tegmen
• Mastoid antrum
• Lateral semicircular canal
– Optional
• Incus
• Facial Nerve
• Sigmoid sinus
Facial Recess
• Perform a canal wall up mastoidectomy
• Thin the posterior canal wall
Boundaries:
• Superior:
• Posterior:
• Anterior:
• Inferior:
incus or incus buttress
facial nerve
bony ear canal, chordae tympani
bifrication of facial nerve and
chordae tympani
Facial Recess
Atticotomy
• Only indicated for disease limited to the
attic and middle ear space
• Do not use for posterior extension into the
mastoid/antrum!
Canal Wall Down
Canal Wall Down
• Keys:
– Take canal wall down to level of facial nerve
• (avoid high facial ridge)
– Wide meatoplasty
• For postoperative mastoid bowl cleaning and aeration
– Line mastoid cavity
• Split thickness skin graft or fascia
• Avoids excessive granulation tissue and drainage
– Saucerize and remove air cells thoroughly
• No rough edges – smooth cavity
– Remove mastoid tip
• Helps to avoid difficult to reach inferior extent of cavity
Labyrinthine Fistula
Controversies
• CWU vs CWD
– Mandatory CWD
•
•
•
•
Unreconstructable EAC defect
Labyrinthine fistula
Poor health
Poor compliance
• 2nd look procedure
– Recividism or recurrence
– Middle ear endoscopy
• Mastoid Oblitteration
• Pediatrics vs. Adult
Controversies
• Pediatric Cholesteatoma more aggressive
than adult?
– DeCorso 2006 Review of 60 children versus
308 adults with acquired cholesteatomas
• All underwent CWD T/M
• Found higher incidence of incus and malleus
erosions, more advanced stage, and higher
incidence of recurrence
– Generally accepted that more extensive
disease in children compared to adults and
that residual and recurrent disease found at
higher rates
Board Review
Board Review
• Where is the most likely area a fistula
will form when cholesteatoma is
present?
• Choices:
– Cochlea
– Posterior SSC
– Lateral SSC
– Superior SSC
Board Review
• A surgeon performing a cholesteatoma
excision via a canal wall up
mastoidectomy calls you. The surgeon
states that the cholesteatoma was not
difficult to remove and that a facial nerve
monitor was in use and did not
demonstrate any aberrant responses. The
child awoke with facial weakness per his
report. He states that the eye closure is
good but there is no lip movement upon
maximal effort. He calls you for your
management?
Board Review
• Lesion within petrous apex that is
hyperintense on T1 and T2 MRI sequences
that does not enhance with gadolinium?
• Choices:
–
–
–
–
–
Normal bone marrow
Cholesteatoma
Cholesterol granuloma
Glomus tumor
Acoustic neuroma
Board Review
• Lesion within petrous apex that is
hypointense on T1, hyperintense on T2
and does not enhance with gadolinium
• Choices:
–
–
–
–
–
Normal bone marrow
Cholesteatoma
Cholesterol granuloma
Glomus tumor
Acoustic neuroma
Board Review
• While in surgery, the surgeon notes that
the cog has been eroded by
cholesteatoma. What is the most likely
other structure to be affected?
• Choices
–
–
–
–
–
lateral semicircular canal
vertical facial nerve segment
tympanic facial nerve segment
intracannalicular facial nerve segment
Jugular bulb
Cog and Supratubal Recess
AJNR 18: 1109-1114 1997
Board Review
• What is a boundary of the sinus
tympani?
• Choices:
– chorda tympani
– cochleariform process
– pyramidal eminence
– tensor tympani
– tympanic membrane
Board Review
Discussion:
The sinus tympani is a
depression along the
posteromedial wall of the
middle ear cavity. It lies
between the bony labyrinth
medially and the pyramidal
eminence and facial nerve
laterally - can be seen on the
following histologic section
answer: pyramidal eminence
Board Review
• Patient has a tympanic retraction pocket
extending into the sinus tympani. The retraction
pocket is inadvertently transected during middle
ear exploration. The tympanic membrane defect
was repaired with a graft. Which postoperative
complication is he at greatest risk for?
• Choices:
– cholesteatoma of the mesotympanum medial to the
incus
– cholesteatoma of the epitympanum lateral to the
incus
– tympanic membrane perforation
– damage to the lateral semicircular canal
– perilymphatic fistula at the oval window
Board Review
Discussion:
The patient is at risk for
cholesteatoma given the
retained pocket left in the
sinus tympani. Since the
sinus tympani is NOT in the
epitympanum but rather lives
in the mesotympanum as a
depression along the medial
wall along with the round
window niche (inferior) and
the oval window niche
(superior) I would expect the
cholesteatoma to be in the
mesotympanum medial to the
incus
answer: cholesteatoma of the
mesotympanum medial to the
incus
Anatomy of the Temporal Bone
With Surgical Implications
(Gulya/Schuknecht)
Board Review
• Difficult removal of cholesteatoma but surgeon thinks
nerve was not injured. Postoperatively patient has
complete facial nerve paralysis persisting for one
week. On POD #7 stimulation of facial nerve on that
side results in brisk movement of face. How to
manage this patient?
• Choices:
–
–
–
–
–
middle ear exploration with facial nerve decompression
Observation
MRI scan
Middle fossa approach with facial nerve decompression
Transmastoid approach with facial nerve
decompression
Board Review
Discussion:
Within the first 3 days after onset of complete
paralysis, the results of NET, MST, and ENoG yield
little useful information as Wallerian degeneration
distal to the stimulation area has not yet occurred
and the results always indicate incomplete
degeneration. Because of this limitation, the
prognosis cannot be established until the sixth or
seventh day after paralysis by NET, MST, or ENoG.
In this case we are 7 days out, the nerve still
stimulates implying that it is intact - so I would
argue that we leave it alone!
• answer: observation only