Tuesday, December 28, 2010

Radical Mastoidectomy

Radical Mastoidectomy is a procedure to eradicate disease
from the middle ear and mastoid without any attempt to
reconstruct hearing. Posterior meatal wall is removed and
the entire area of middle ear, attic, antrum and mastoid is
converted into a single cavity. All remnants of tympanic
membrane, ossicles (except stapes footplate) and mucoperiosteallining
are removed (Fig. 77.1). Eustachian tube is
obliterated by a piece of muscle or cartilage. Aim of the
operation is to permanently exteriorise the diseased area
for inspection and cleaning. The radical mastoidectomy is
infrequently required these days.
Indications
1. When all cholesteatoma cannot be safely removed,
e.g. that invading eustachian tube, round window
niche, perilabyrinthine or hypotympanic cells.
2. If previous attempts to eradicate chronic inflammatory
disease or cholesteatoma have failed.
3. As an approach to petrous apex.
4. Removal of glomus tumour.
5. Carcinoma middle ear. Radical mastoidectomy followed
by radiotherapy is an alternative to en bloc
removal of temporal bone in carcinoma middle ear.
Anaesthesia
Mos tly, general anaesthesia is given. Local anaesthesia
can be used in selected cases.
Position
Patient lies supine with face turned to one side and the
ear to be operated upper-most.
Steps of Operation
1. Incision. Postaural (Fig. 77.2) or endaural
(Fig. 77.3).
Horizontol
Eust. tube
opening closed
with muscle
ROIJr:vl w.i.r.I.rlnw
Fig. 77.1 Radical mastoidectomy. The entire area of
mastoid, middle ear, attic and antrum is exteriorised.
Eustachian tube is obliterated and no attempt is made to
reconstruct the hearing mechanism .
2. Retraction of soft tissues and exposure of mastoid
area. Mastoid area from posterior root of zygoma to
behind the suprameatal triangle and from temporal line
above to the lower part of mastoid tip below is exposed
by elevating the periosteum and the wound retracted.
3. Removal of bone and exposure of attic and
antrum. With the help of burr, bone is removed from
the area of suprameatal triangle, spine of Henle, root of
zygoma to just above the anterior meatal wall, upper part
of superior meatal wall is also removed. This will expose
attic and antrum. Identify the tegmen antri and lateral
semicircular canal.4. Removal of the "bridge" and the buttresses.
Deeper part of superior osseous meatal wall that bridges
over the notch of Rivinus is removed.
Anterior spine of the notch (anterior buttress) and
posterIor spIne of th.e notc.h. (posterior buttre",,) are abo
removeJ. This removes the late ral attic wall. The incus
and the malleus are also removed.
5. Lowering the facial ridge. The deeper part of posterior
meatal wall that overlies the vertical part of facial
nerve is called facial ridge. It is removed as much as possible
within the safety of VIIth nerve so that the mastoid
cavity is freely accessible from the meatus.
6. Toilet of middle ear. Remnants of tympanic
membrane with its annulus and sulcus tympanicus are
removed. Middle ear mucoperiosteum along with any
polyp or granulation tissue is removed. Malleus and incus
are removed if not already done. Stapes is left intact.
Eustachian tube opening is closed by curetting its mucosa
and plugging the opening with tensor tympani muscle or
piece of cartilage.
7. Inspection of the cavity and irrigation. It is necessary
to ensure complete exteriorisation of the attic,
antrum and middle ear and mastoid cavity into external
aud itory meatus . Any bony overhangs are removed and
cavity smoothened with polishing burr. Finally, it is irri gated
with saline to remove any blood or bone particles.
8. MeatopIasty. A flap, based laterally at the concha
is raised from posterior and superior meatal wall and
turned into the mastoid cavity to cover the area of the
facial ridge. This helps in the epithelialisation of the
mastoid cavity. A piece of conchal cartilage can be
removed to enlarge the meatus and to facilitate inspection
and access to cavity.
9. Obliteration of the cavity. If mastoid cavity is
very large, it may be obliterated with temporalis muscle
or other soft tissues, taking care that no vestige of disease
(cholesteatoma) is buried underneath .
10. Closure of wound. The cavity is packed with
ribbon gauze, impregnated with an antibiotic/antiseptic
and the wound is dosed withmterrupted suture:.
Masto id dressing is applied.
Post-operative Care
1. Dressing. First dressing is done on 3rd or 4th day
Replace the outer gauze and cotton and look for any
signs of perichondritis or infection of meatal pack.
Second dressing is done on 6th or 7th day when stittches
are removed and meatal pack is changed. Thereafter
change the pack at weekly intervals or leave the cavity
unpacked with regul ar suction and cleaning till
epithelialisation is complete.
2. Antibiotic. A suitable antibiotic is given for about
week.
3. Cavity care. Usually, cavity is fully epithelialised in
2-3 months. It shou ld be period ically checked (every
4-6 months) in the first year and then annually .
removal of any debris or infection. Any granulation tissue
which delays epithelialisation is removed or cauterized.
Complications
1. Fac ial paralysis.
2. Perichondritis of pinna.
3. Injury to dura or sigmoid sinus.
4. Labyrinthitis, if stapes gets dislocated.
5. Severe conductive deafness of 50 dB or more. This
due to removal of all ossicles and tympanic membrane.
6. Cavity problems. Twenty five percent of the cavities
do not heal and continue to discharge, require
regular after-care.
Modified Radical Mastoidectomy: It is a modification of radical mastoidectomy where as
much of the hearing mechanism as possible is preserved.
The disease process which is often localised to the attic
and antrum is removed and the whole area fully exteriorised
into the meatus by removal of the posterior meatal
and lateral attic wall (Fig. 78.1).
Indications
1. Cholesteatoma confined to the attic and antrum.
2. Localised chronic otitis media.
Irreversibly damaged tissues are removed, preserving
the rest to conserve or reconstruct hearing mechanism.
Anaesthesia
Mostly general, local anaesthesia can be used in selected
cases.
Position
Same as for cortical mastoidectomy.
Steps of Operation
1. Incision, postaural or endaural.
2. Retraction of soft tissues and exposure of mastoid
area.
3. Removal of cortical bone and exposure of antrum
and attic.
Steps 2 and 3 are the same as in radical mastoidectomy.
4. Removal of diseased tissue. Cholesteatoma, granulations
or unhealthy mucosa is removed. Incus and head
of malleus often require removal, if cholesteatoma
engulfs them or extends medial to them. They are
preserved if possible. Lateral attic wall is removed
to fully exteriorise the attic.
5. Facial ridge is lowered.
6. Mastoid cavity is smoothened with polishing burr,
removing any overhangs and then irrigated with
normal saline.
7. Reconstruction of hearing mechanism. Pars tensa of
tympanic membrane and middle ear, if healthy, are left
undisturbed. If disease extends into middle ear, only
the irreversible tissues are removed. Reconstruction
of tympanic membrane or ossicular chain, if damaged,
can also be done (mastoidectomy with tympanoplasty
operation) .
8. Meatoplasty and closure of wound is same as in
radica l mastoidectomy.
Post-operative Care and Complications
Same as in radical mastoidectomy.

6 comments:

  1. what should be done in continuous post-operative discharge?

    ReplyDelete
    Replies
    1. Months later I've come across this, I know.
      But I've been through two of these ops, any questions just ask.
      Cheers, Holza.

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    2. Holly, I had a radical mastoidectomy in 1975, can that cause very slow nerve damage that you will have for the rest of your life? Nerve degradation in a very slow way. Tomashley75@yahoo.com

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  2. how long it can take maximum for hearing to get restored or to get to the maximum possible level after radical modified mastoidectomy.answer plz

    ReplyDelete
  3. It depends on how your hearing has been affected. If it's just due to fluid/infection build up behind the ear drum and through sinuses etc. If it's due to that, you'll be right.
    You need to find out after they have done a CT scan, where the disease in your ear has spread. Unfortunately in my case, it affected my "hearing bones", you know, the staple, and the two other bones that create sound in your ear. 2.5 of mine was removed due to disease. So stuff all hearing in that ear. My right is good enough ;) Don't sweat it. Takes a little while to adjust either way. Any questions I am happy to help where I can. I've had two of these done over the last 15 years. Cheers, Holza.

    ReplyDelete
    Replies
    1. My son had a radical mastoidectomy. He is only 7. His Dr would like to go back in now (6 months later) to make sure nothing has grown back, assure nothing was left behind and install prosthetics (replace ear bones). I'm having second thoughts about putting him through that again but wondering if I will regret it later. Did you have any follow up to your mastoidectomy such as reconstruction? Would you have liked to?

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