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Ear surgery
is a specialty that encompasses the operative treatment of deformities
and infections of the ear and adjacent structures and the operative
treatment of deafness.
The intricacy and delicacy of the ear's inner structures delayed the
development of modern ear surgery until the late 19th century.
Before 1885, the majority of attempts to operate for deafness or for
severe ear infection produced disastrous consequences.
The era of modern ear surgery began in 1885, when Hermann Schwartze
and Adolf Eysell, German otologists, presented to medical science
a well developed procedure for draining and permanently opening the
mastoid air cells to eliminate chronic infections of the middle ear
cavities.
Tympanoplasty.
Since 1950, many surgical procedures have been developed to reconstruct
damaged middle ear parts. Recent innovations have been greatly facilitated
by the operating microscope, which permits surgeons to perform detailed
repairs on the delicate structures deep within the middle ear.
A severely scarred or damaged eardrum can be replaced by grafting
connective tissue from the surface of the nearby temporalis muscle.
If the damage includes the middle ear bones, the whole tympanic
membrane and ossicular chain may be transplanted from a cadaver
organ donor. Stapes Prostheses.
Conduction deafness may result from scarring of the stapes at the
oval window, so that sound vibrations can no longer pass into the
cochlear canals.
Early surgical procedures for this problem included remobilization
(fracturing the scar tissue or replacing the oval window membrane
or both) and fenestration (making a new opening into the cochlear
canals).
The development of prosthetic parts to replace some or all of the
ossicular chain has simplified the surgery and improved the results.
Stapes prostheses
made out of Teflon, tantalum, or ceramic are installed in a place
of the damaged parts to restore sound conduction form the eardrum
to the cochlea.
Cochlear Prostheses.
In sensorineural deafness, the hair of the organ of Corti are usually
damaged or absent, preventing sound vibrations from being turned
into electrical signals in the auditory nerve fibers.
If the auditory nerve is still functional, hearing may be partially
restored by implanting electrodes in the cochlea and directly stimulating
the nerve fibers by electrical current.
Several devices now available convert sounds picked up by an external
microphone into electrical signals that are then transmitted across
the skin to surgically implanted electronic devices.
These neural prosthetic devices apply tiny electrical currents to
one or more electrodes distributed along the cochlea, causing the
nearby auditory nerve fibers to be activated.
The nerve activity is interpreted by the brain as sound, just as
if it had come from the missing hair cells.
However, the quality of the sound is, as yet, quite poor, and even
in the best cases, it is barely sufficient for partial understanding
of speech.
Plastic Surgery of the Ear
Plastic-surgery procedures are used for deformities of the ear
that are present at birth or acquired through injury.
For example, the "cauliflower" ear, which is a thickening
of the external ear due to multiple traumas, can be built into a
fairly normal appearing ear by the transplantation of cartilage
and skin from other parts of the body.
Similarly, plastic surgery of the ear also can improve the appearance
of persons whose ears naturally protrude excessively.
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