Dr. T. Balasubramanian M.S. D.L.O.
This surgical procedure is
performed to treat deafness due to otosclerosis. Otosclerosis is
caused by fixation of the foot plate of stapes which prevents
efficient sound transmission to the oval window. The deafness
caused is conductive in nature.
The surgical procedure is performed under local
anesthesia. Advantages of performing this surgery under
local anesthesia are:
1. Improvement in hearing can be ascertained on the table.
2. Bleeding is minimal under local anesthesia.
Indications for stapedectomy:
1. Conductive deafness due to fixation of stapes.
2. Air bone gap of atleast 40 dB.
3. Presence of Carhart's notch in the audiogram of a patient with
4. Good cochlear reserve as assessed by the presence of good
Contraindications for stapedectomy:
1. Poor general condition of the patient.
2. Only hearing ear.
3. Poor cochlear reserve as shown by poor speech discrimination scores
4. Patient with tinnitus and vertigo
5. Presence of active otosclerotic foci (otospongiosis) as evidenced by
a positive flemmingo sign.
Since a patient with otosclerosis is also an ideal
candidate for hearing aid and surgery, the patient must be
properly counselled regarding the advantages and disadvantages of both.
with adrenaline mixed in concentration of 1:1000 is used to infiltrate
the external auditory canal. 0.25 ml of the solution is
infiltrated using a 27 gauge needle. Infiltration is given as
illustrated in the diagram.
Fig showing the sites of infiltration of local
Exposure: A large speculum is used
to straighten the external auditory canal. A curved or
triangular incision is made in the external canal skin begining at 2mm
away from the annulus. The incision extends from 11 o clock
position to 6 o clock position as viewed in the right ear. The
tympano meatal flap is elevated up to the annulus. Using a sharp
pick the annulus is slowly lifted from its groove, the middle ear
mucosa is exised and the middle ear proper is entered.
Fig showing incision made in the right ear
In most patients the posterior superior bony overhang
must be curetted using a curette (designed by House). The long
process comes into view. Curetting is continued till the base of
the pyramidal process is visualised. Oval window is
visualised. At this point round window reflex is tested by moving
the handle of malleus and looking for movement of round
window membrane. In otosclerosis this reflex is absent.
Using a hand burr a small fenestra about 0.6mm in diameter is made
over the foot plate. The stability of the incus is left intact
because the stapedial tendon is not cut at this point. From
now on the steps may vary according to the surgeon's viewpoint.
Some surgeons would like to insert the piston at this stage without
disturbing the stability of the incus. The distance between the
long process of incus and the foot plate is measured using a measuring
rod. Appropriate size teflon piston is introduced and humg over
the long process of the incus and is crimped after ascertaining whether
its lower end is inside the fenestra. The stapedial tendon
is cut at this point and the supra structure of the stapes is
disarticulated and removed. The Tympanomeatal flap is
Complications of stapedectomy:
1. Facial palsy
2. Vertigo in the immediate post op period
4. Perilymph gush
5. Floating foot plate
6. Tympanic membrane tear
7. Dead labyrinth
8. Perilymph fistula
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