Myringotomy

It is incision of the tympanic membrane with the purpose
to drain suppurative or nonsuppurative effusion of the
middle ear or to provide aeration in case of malfunctioning
eustachian tube. Ventilation tube (grommet) may
also be required in the latter case.
Indications
1. Acute suppurative otitis media
(a) Severe earache with bulging tympanic membrane.
(b) Incomplete resolution with opaque drum and
persistent conductive deafness.
(c) Complications of acute otitis media, e.g. facial
paralysis, labyrinthitis or meningitis with bulging
tympanic membrane.
2. Serous otitis media.
3. Aero-otitis media (to drain fluid and "unlock" the
eustachian tube).
4. Atelectatic ear (grommet is often inserted for long-term
aeration).
Contraindications
Suspected intratympanic glomus tumour. Myringotomy
in these cases can cause profuse bleeding. Tympanotomy
is preferred.
Anaesthesia
In infants and children, always use general anaesthesia. For
adults, general anaesthesia is used only when tympanic
membrane is acutely inflamed. If there is no inflammation,
myringotomy can be done under local anaesthesia or no
anaesthesia at all.
Steps of Operation
1. Ear canal is cleaned of wax and debris.
2. Operation is ideally performed under operating microscope
using a sharp myringotome and a good suction
apparatus.
3. In acute suppurative otitis media, a circumferential
incision is made in the posteroinferior quadrant of
tympanic membrane, midway between hundle uf
malleus and tympanic annulus, avoiding injury to
incudostapedial joint (Fig. 75.lA).
4. In serous otitis media, a small radial incision is given
in the posteroinferior or anteroinferior quadrant and
all the effusion sucked out (Fig. 75.1B).
When ventilation tube is to be inserted, incision should
be just enough to admit the tube (Fig. 75.2).
Pitfalls of Myringotomy
1. When tympanic membrane is thick, incision may
remain only in the superficial layers of drumhead
without cutting through its entire thickness.
2. Incision in the posterior meatal wall. This may happen
when distinction between drum-head and posterior
meatal wall is lost, when both are inflamed.
Post-operative Care
Daily mopping of ear discharge will be required in cases
of acute suppurative otitis media. In serous otitis media,
just leave a wad of cotton wool for 24-48 hours.
Drum incisions usually heal rapidly. No water should
be permitted to enter the ear canal for at least one week,
and if a grommet has been inserted, entry of water is
prevented so long as grommet is in position.
Complications
1. Injury to incudostapedial joint or stapes.
2. Injury to jugular bulb with profuse bleeding, if jugular
bulb is high and floor of the middle ear dehiscent.
3. Middle ear infection.