1-24. RADICAL MASTOIDECTOMY
a. General. Radical mastoidectomy involves the removal of the mastoid air
cells, the tympanic membrane, the involved malleus, incus, chorda tympani, and
mucoperiosteal lining which converts the middle ear and the mastoid into one cavity.
This procedure may be used to treat a chronic otitis media (inflammation or infection of
the middle ear) that has spread into the mastoid air cells, and when skin from the
external auditory canal has grown into the middle ear (cholesteatoma) where it acts as a
foreign body. Radical mastoidectomy may also be done to provide adequate exposure
in the treatment of facial nerve decompression to drain an extradural abscess in the
bony labyrinth.
b. Preparation of Operating Room. This requires an extensive setup of
instruments and other sterile items. These are set up in the appropriate sizes and
numbers, as prescribed locally.
c. Operative Procedure.
(1) An endaural or postural incision is made using a Bard-Parker knife.
Bleeding vessels are clamped and ligated. With a second knife, the periosteum
(connective tissue over bone) is incised and freed to form a flap. The wound is
retracted with a self-retaining retractor.
(2) The meatus flap is cut, exposing the mastoid area by means of a
circumferential knife, narrow periosteal elevator, and curved scissors.
(3) The mastoid antrum is exposed. By means of round cutting burrs
attached to an electric drill, the bone of the outer cortex is removed. The osseous metal
walls are removed with rongeurs or burrs. The wound is irrigated and suctioned.
Cotton pledgets are used for sponging the operative site.
(4) The thin bridge of bone between the meatus and antrum is removed with
angular dissectors and fine currettes.
(5) The tympanic membrane, malleus, incus, and mucoperiosteal lining of
the middle ear cavity are excised by means of stapes instruments, as for a stapes
operation.
(6) The tympanic cavity is cleaned. The wound is closed with sutures. A
musculo-plasty may be done by taking a strip of temporalis muscle from above the ear
and placing it in the mastoid cavity. In time, the skin grows over the muscle.
(7) The mastoid cavity is usually packed with a strip of 1/2 x 8 inch gauze
packing that has been impregnated with petrolatum or an antibiotic ointment. The
wound is closed.
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