A Discussion of Chronic Ear Disease
Chronic Ear Infection
The diagnosis of chronic otitis media (infection of the middle ear) is made when the ear has chronic (long standing) infection. The treatment for chronic ear disease varies depend upon whether the condition is active or inactive, whether or not there is involvement of the mastoid bone (the hard bone behind the ear) and whether or not there is a hole in the eardrum. Symptoms for chronic ear disease include ear discharge, hearing impairment, tinnitus (head noise), dizziness, pain or, rarely, weakness of the facial muscles.
In order to understand chronic ear infection, one must have some knowledge of the hearing mechanism.
The External Ear
The external ear consists of the auricle and the external ear canal. These structures collect the sound waves and transmit them to the eardrum.
The Middle Ear
The middle ear lies between the eardrum and the inner ear. This chamber contains three bones of hearing: the malleus (hammer), the incus (anvil) and the stapes (stirrup). Vibrations of the eardrum are transmitted across the middle ear space by these three small ear bones. Movement of the third bone (stapes or stirrup) results in fluid waves in the inner ear.
The middle ear chamber is lined by a membrane similar to the lining of the nose and contains secreting glands and blood vessels. This chamber is connected to the back of the nose by a narrow tube called the Eustachian tube.
The Eustachian tube serves to maintain equalisation pressure between the middle ear chamber and the outside atmosphere, as evidenced by the popping sensation noted in the ear during altitude changes.
The Inner Ear
The inner ear is enclosed in dense bone and contains fluids and the tiny hearing cells. The inner ear is lined by a delicate transparent membrane supplied by microscopic blood vessels, in this small chamber fluid waves resulting from movement of the stapes are transformed into electrical impulses in the nerve.
Types of Hearing Impairment
The external and middle ear conduct and transform sound; the inner ear receives it. When there is a problem in the external or middle ear, a conductive hearing impairment occurs. When a problem occurs in the inner ear, a sensorineural or nerve hearing impairment is the result. Difficulty in both conduction and sensorineural hearing results in a mixed impairment.
Chronic Ear Disease -- The Diseased Middle Ear
Chronic ear disease affects the eardrum and/ or the three small ear bones. Chronic middle ear infection may cause a perforation (hole) in the eardrum, partial or total destruction of one or all of the three little ear bones, or scar tissue. The damage from chronic ear disease usually causes a conductive hearing loss.
Sometimes chornic ear infection can lead to ear drum skin growing in the middle ear, a condition called cholesteatoma. Typically cholesteatoma is a condtion that is treated by surgery to prevent the serious complications of the disease such as facial muscle weakness, permanent deafness, dizziness and brain abscess.
Medical Treatment For Chronic Ear Disease
Medical treatment frequently will stop ear drainage. Treatment consists of careful cleaning of the ear and, at times, the application of antibiotic powder or ear drops. Antibiotics by mouth may be helpful in certain cases.
Surgical Treatment For Chronic Ear Disease
For many years surgical treatment was instituted in chronic otitis media primarily to control infection and prevent serious complications. Changes in surgical techniques now have made it possible to reconstruct the diseased hearing mechanism in most cases.
Various tissue grafts may be used to replace or repair the eardrum. These include covering of muscle from above the ear (fascia) and covering of ear cartilage (perichondrium). A diseased ear bone may be replaced by plastic prosthesis (TORP or PORP), cartilage, or may be repositioned (relocated).
A thin piece of plastic frequently is used behind the eardrum to prevent scar tissue from forming and to promote normal function of the middle ear and motion of the eardrum. When the ear is filled with scar tissue or when all ear bones have been destroyed, it may be necessary to perform the operation in two stages. At the first stage a piece of stiff plastic is inserted to allow more normal healing without scar tissue. At the second operation this plastic is removed and we attempt to restore hearing. A decision in regard to staging the operation is made at the time of the first surgery.
Myringoplaysty (Type 1 Tympanoplasty)
Most ear infections subside and the structures of the middle ear heal completely. In some cases, however, the eardrum may not heal and a permanent perforation (hole) in the eardrum results.
Myringoplasty is the operation performed for the purpose of repairing a perforation in the eardrum when there is no middle ear infection or disease of the ear bones. This procedure seals the middle ear and may improve the hearing.
Surgery is performed under local or general anaesthesia either through the ear canal or via an incision behind the ear in the hairline. Ear tissue is used to repair the defect in the eardrum. Healing is complete in most cases in 3 months, at which time any hearing improvement is usually noticeable.
An ear infection may cause a perforation of the eardrum, damage the mucosa and damage the three ear bones that transmit sound from the eardrum to the inner ear and hearing nerve. Tympanoplasty is the operation performed to eliminate any infection and repair both the sound transmitting mechanism and any perforation of the eardrum. This procedure seals the middle ear and improves the hearing in many cases. In cases not requiring repair of the eardrum, the operation is usually performed under local anaesthesia through the ear canal as an outpatient at the hospital.
Most tympanoplasties are performed through an incision behind the ear under general anaesthesia. The perforation is repaired with ear tissue (fascia) that is harvested from the patient’s own tissue overlying the chewing muscle above the ear. Sound transmission to the inner ear is accomplished by replacing diseased ear bones with an artificial ear bone (prosthesis) that remains in place for the rest of your life.
In some cases it is not possible to repair the sound transmitting mechanism and the eardrum at the same time. In these cases the eardrum is repaired first and, six months or more later, the sound transmitting mechanism is reconstructed (see planned second stage).
The surgery is usually done as day surgery and the patient may return to work in four to six days. Healing is usually complete in 3 months. A hearing improvement may not he noted for a few months.
Types of Mastoid Surgery
Mastoid surgery is performed when chronic infection involves the mastoid bone behind the ear. There are two techniques of mastoid surgery: canal wall up and canal wall down. The decision on which mastoid technique is to be used is usually made at the time of surgery.
Canal wall up mastoidectomy is preferred by some surgeons because little, if any, precautions are necessary after the ear has healed (three to four months).
Canal wall down surgery is necessary 40% of the time because of the extent of the disease or the development of the mastoid bone. Healing may be prolonged. Canal wall down surgery results in a larger ear opening (meatus) but little difference in the appearance of the ear. Periodic cleaning of the mastoid (ear) cavity is necessary every 6 to 12 months in the office, indefinitely; and it may be necessary to permanently avoid water in the ear.
Tympanoplasty with Mastoidectomy
Active infection may in some cases stimulate skin of the ear canal to grow through a perforated eardrum into the middle ear and mastoid. When this occurs a skin-lined cyst known as cholesteatoma is formed. This cyst may continue to expand over a period of years and destroy the surrounding bone. If a cholesteatoma is present the drainage tends to be more constant and frequently has a foul odour. In many cases the persistent drainage is due only to chronic infection in the bone surrounding the ear structures.
Once a cholesteatoma has developed or the bone has become infected, it is rarely possible to eliminate the infection by medical treatment. Antibiotics placed in the ear and used by mouth only result in a temporary improvement in most cases. Recurrence after treatment has stopped is frequent.
A cholesteatoma or chronic ear infection may persist for many years without difficulty except for the annoying drainage and hearing loss (blockage). It may however by local expansion and pressure involve important surrounding structures. If this occurs the patient will often notice a fullness or a low-grade aching discomfort in the ear region. Dizziness or weakness of the face may develop. Rarely, cholesteatoma can spread to involve the structures around the brain, causing meningitis or abscesses within the brain. If any of these symptoms occur it is imperative that one seek immediate medical care.
Surgery may be necessary to eradicate the infection and prevent serious complications. When the destruction by cholesteatoma or infection is widespread in the mastoid, the surgical elimination is indicated. Surgery is performed though an incision behind the ear. The primary objective is to eliminate infection and to obtain a dry, safe ear.
In most patients with cholesteatoma it is not possible to eliminate infection and restore hearing in one operation. The infection is eliminated and the eardrum rebuilt in the first operation. This is a 2 to 4 hour operation and requires a general anaesthetic. The patient may usually return to work in three to five days.
When a second operation is necessary to restore the hearing mechanism and to reinspect the ear spaces for any residual (remaining)disease, it will be performed twelve to 15 months later.
On rare occasions a radical mastoid operation may be necessary to control infection in a case thought originally to be suitable for tympanoplasty.
TymPlanoplasty: Planned Second Stage
The purpose of this operation is to reinspect the ear spaces for disease and to improve the hearing.
Surgery involves an incision behind the ear under general anaesthesia. The ear is inspected for any residual disease. Sound transmission to the inner ear is accomplished by replacing missing ear bones.
The patient may return to work in four to six days. Healing is usually complete in 3 months. Hearing improvement is frequently noted at that time.
Tympanoplasty with Revision Mastoidectomy
The purpose of this operation is to eliminate discharge from a previously created mastoid cavity defect and to improve the hearing.
The operation is performed under general anaesthesia through an incision behind the ear. The mastoid cavity may be obliterated with muscle from behind the ear or with bone. At times, the ear canal is rebuilt with cartilage or bone. The eardrum is repaired and, if possible, the hearing mechanism is restored. In most cases however, a second operation is necessary to obtain hearing improvement (see Tympanoplasty: Planned Second Stage).
The surgery is usually done as an outpatient at the hospital and the patient may return to work after four to six days. Complete healing of the inside of the ear may take four to six months.
Modified Radical Mastoidectomy
The purpose of this operation is to eradicate the infection without consideration of hearing improvement. It is usually performed in those patients who may have very resistant infections or have infection in the only hearing ear. Occasionally it may be necessary to perform a radical mastoid operation in some case that originally appeared suitable for a tympanoplasty. This decision is made at the time of surgery. A fat or bone graft from the ear is necessary at times to help the ear heal properly.
The radical mastoid operation is performed under general anaesthesia with an overnight stay at the hospital. The patient may usually return to work in four to six days. Complete healing may require up to four months.
What to Expect Following Surgery
There are some symptoms which may follow any ear operation.
Taste Disturbance and Mouth Dryness
Taste disturbance and mouth dryness are not uncommon for a few weeks following surgery. In some patients this disturbance is prolonged.
Tinnitus (head noise) frequently present before surgery is almost always present temporarily after surgery. It may persist for one to two months and then decease in proportion to the hearing improvement. Should the hearing be unimproved or worse, the tinnitus may persist or be worse.
Numbness of Ear
Temporary loss of skin sensation in and about the ear is common following surgery. This numbness may involve the entire outer ear and may last for up to one year.
The jaw joint is in intimate contact with the ear canal. Some soreness or stiffness in jaw movement is very common after ear surgery. It usually subsides within one to two months.
Ear pain when you chew or move your neck , following any chronic ear surgery is expected for 7 days. Pain killing medication controls the discomfort. When the ear is healing itching in the canal is common and as the nerve fibres regenerate around the ear, sharp shooting pains lasting for a few seconds are common.
Risks and Complications of Surgery
Fortunately, major complications are rare following surgery for correction of chronic ear infection.
Ear infection with drainage, swelling and pain may persist following surgery or, on rare occasions, may develop following surgery due to poor healing of the ear tissue. Where this is the case, additional surgery might be necessary to control the infection.
Loss of Hearing
In 3% of the ears operated the hearing is further impaired permanently due to the extent of the disease present or due to complications in the healing process. On occasions there is a total loss of hearing in the operated ear. If hearing worsens, we can offer rehabilitation options including hearing aids, Bone Anchoured Implants or Cochlear (bionic) ears.
In some cases a two stage operation is necessary to obtain satisfactory hearing and to eliminate the disease. The hearing is usually worse after the first operation in these instances.
Dizziness may occur immediately following surgery due to swelling in the ear and irritation of the inner ear structures. Some unsteadiness may persist for a week post-operatively. On rare occasions, dizziness is prolonged and may require extensive balance exercises.
10% of patients with chronic ear infection due to cholesteatoma have a labyrinthine fistula (abnormal opening into the balance canal). When this problem is encountered, dizziness may last for six months or more, and can rarely be permanent.
The facial nerve travels through the ear bone in close association with the middle ear bones, ear drum and the mastoid. A rare post-operative complication of ear surgery is temporary paralysis of one side of the face. This may occur as the result of an abnormality or a swelling of the nerve and usually subsides spontaneously.
On very rare occasions the nerve may be injured at the time of surgery or it may be necessary to excise it in order to eradicate disease. When this happens a skin sensation nerve is removed from the upper part of the neck to replace the facial nerve. Paralysis of the face under these circumstances might last up to 2 years and there would be permanent residual weakness. Eye complications requiring treatment by a specialist could develop.
A haematoma (collection of blood under the skin) develops in a very small percentage of cases, prolonging hospitalisation and healing. Re-operation to remove the clot may be necessary if this complication occurs.
Complications Related to Mastoidectomy
A cerebral spinal fluid leak (leak of fluid surrounding the brain) is a rare complication. Re-operation may be necessary to stop the leak. Intracranial (brain) complications such as meningitis or brain abscess or even paralysis were common cases of chronic otitis media prior to the antibiotic era. Fortunately these are now extremely rare complications.
Travel Restrictions Following Surgery
You should have someone drive you to and from the hospital. Air travel is permissible 48 hours after surgery.
If you do not have surgery performed at this time, it is advisable to have annual examinations especially if the ear is draining. Should you develop dull pain in or about the ear, increased discharge, dizziness, twitching or weakness of the face, you should immediately consult your Doctor. Should you have any questions in regard to your ear problem, please do not hesitate to contact us at the Norwest ENT Group.
Adapted from the Patient Discussion Booklet
Series of the University of Utah Otolaryngology.
Reprinted by Permission.
Reproduction in part or whole of this material is restricted by copyright law unless express written permission is granted by the Norwest ENT Group.
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