Special Surgical Procedures II
LESSON 1: Eye, Ear, Nose, and Throat (EENT) Surgery
Section II: EAR SURGERY
1-24
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.
(8) The ear dressing is applied, including a shaped ear pad. Fluffed 4 x 8 inch gauze sponges are placed around and behind the affected ear and then flat compresses over the affected ear. A gauze bandage is applied in a particular manner to hold the dressings in place and avoid pressure.
