MYRINGOTOMY EAR TUBES

Myringotomy and ear tubes
Definition : Myringotomy is a surgical procedure in which a small incision is made in the eardrum (the tympanic membrane), usually in both ears. The English word is derived from myringa, modern Latin for drum membrane, and tome, Greek for cutting. It is also called myringocentesis, tympanotomy, tympanostomy, or paracentesis of the tympanic membrane. Fluid in the middle ear can be drawn out through the incision. Ear tubes, or tympanostomy tubes, are small tubes open at both ends that are inserted into the incisions in the eardrums during myringotomy. They come in various shapes and sizes and are made of plastic, metal, or both. They are left in place until they fall out by themselves or until they are removed by a doctor.

Purpose
Myringotomy with the insertion of ear tubes is an optional treatment for inflammation of the middle ear with fluid collection (effusion) that lasts longer than three months (chronic otitis media with effusion) and does not respond to drug treatment. This condition is also called glue ear. Myringotomy is the recommended treatment if the condition lasts four to six months. Effusion refers to the collection of fluid that escapes from blood vessels or the lymphatic system. In this case, the effusion collects in the middle ear.

Initially, acute inflammation of the middle ear with effusion is treated with one or two courses of antibiotics. Antihistamines and decongestants have been used, but they have not been proven effective unless there is also hay fever or some other allergic inflammation that contributes to the problem. Myringotomy with or without the insertion of ear tubes is not recommended for initial treatment of otherwise healthy children with middle ear inflammation with effusion.

In about 10% of children, the effusion lasts for three months or longer, when the disease is considered chronic. In children with chronic disease, systemic steroids may help, but the evidence is not clear, and there are risks.

When medical treatment doesn’t stop the effusion after three months in a child who is one to three years old, is otherwise healthy, and has hearing loss in both ears, myringotomy with insertion of ear tubes becomes an option. If the effusion lasts for four to six months, myringotomy with insertion of ear tubes is recommended.

The purpose of myringotomy is to relieve symptoms, to restore hearing, to take a sample of the fluid to examine in the laboratory in order to identify any microorganisms present, or to insert ear tubes.

Ear tubes can be inserted into the incision during myringotomy and left there. The eardrum heals around them, securing them in place. They usually fall out on their own in six to 12 months or are removed by a doctor.

While the tubes are in place, they keep the incision from closing, keeping a channel open between the middle ear and the outer ear. This allows fresh air to reach the middle ear, allowing fluid to drain out, and preventing pressure from building up in the middle ear. The patient’s hearing returns to normal immediately and the risk of recurrence diminishes.

Demographics
In the United States, myringotomy and tube placement have become a mainstay of treatment for recurrent otitis media in children. An article published in the March 1998 Consumer Reports stated that the ' … number of myringotomies has risen nearly 250 percent in recent years, making the operation the sixth most common operation in the United States.' According to the New York University School of Medicine, myringotomy and tube placement is the most common surgical procedure performed in children as of 2003, largely because otitis media is the most common reason for children to be taken to a doctor's office.

Myringotomy in adults is a less common procedure than in children, primarily because adults benefit from certain changes in the anatomy of the middle ear that occur after childhood. In particular, the adult ear is less likely to accumulate fluid because the Eustachian tube, which connects the middle ear to the throat area, lies at about a 45-degree angle from the horizontal. This relatively steep angle means that the force of gravity helps to keep fluids from the throat containing disease organisms out of the middle ear. In children, however, the Eustachian tube is only about 10 degrees above the horizontal, which makes it relatively easy for disease organisms to migrate from the nose and throat into the inner ear.

Myringotomies in adults are usually performed as a result of barotrauma that is also known as pressure-related ear pain or barotitis media. Barotrauma refers to earache caused by unequal air pressure on the inside and outside of the eardrum. Adults with very narrow Eustachian tubes may experience barotrauma in relation to scuba diving, using elevators, or frequent flying. A myringotomy with tube insertion may be performed if the condition is not helped by decongestants or antibiotics.

Most myringotomies in children are performed in children between one and two years of age. One Canadian study found that the number of myringotomies performed was 12.8 per thousand for children 11 months old or younger; 54.2 per thousand for children between 12 and 23 months old; and 11.1 per thousand for children between three and 15 years old. Sex and race do not appear to affect the number of myringotomies in any age group, although boys are reported to have a slightly higher rate of ear infections than girls.

Description When a conventional myringotomy is performed, the ear is washed, a small incision made in the eardrum, the fluid sucked out, a tube inserted, and the ear packed with cotton to control bleeding.

Recent developments include the use of medical acupuncture to control pain during the procedure, and the use of carbon dioxide lasers to perform the myringotomy itself. Laser-assisted myringotomy can be performed in a doctor’s office with only a local anesthetic. It has several advantages over the older technique: it is less painful; less frightening to children; and minimizes the need for tube insertion because the hole in the eardrum produced by the laser remains open longer than an incision done with a scalpel.

Another technique to keep the incision in the eardrum open without the need for tube insertion is application of a medication called mitomycin C, which was originally developed to treat bladder cancer. The mitomycin prevents the incision from sealing over. As of 2003, however, this approach is still in its experimental stages.

There has also been an effort to design ear tubes that are easier to insert or to remove, and to design tubes that stay in place longer. As of 2003, ear tubes come in various shapes and sizes.

Diagnosis / Preparation
The diagnosis of otitis media is based on the doctor’s visual examination of the patient’s ear and the patient’s symptoms. Patients with otitis media complain of earache and usually have a fever, sometimes as high as 105°F (40.5°C). There may or may not be loss of hearing. Small children may have nausea and vomiting.

When the doctor looks in the ear with an otoscope, the patient’s eardrum will look swollen and may bulge outward. The doctor can evaluate the presence of fluid in the middle ear either by blowing air into the ear, known as insufflation, or by tympanometry, which is an indirect measurement of the mobility of the eardrum. If the eardrum has already ruptured, there may be a watery, bloody, or pus-streaked discharge.

Fluid removed from the ear can be taken to a laboratory for culture. The most common bacteria that cause otitis media are Pneumococcus, Haemophilus influenzae, and Moraxella catarrhalis. Some cases are caused by viruses, particularly respiratory syncytial virus (RSV). A child scheduled for a myringotomy should not have food or water for four to six hours before anesthesia. Antibiotics are usually not needed.

If local anesthesia is used, a cream containing lidocaine and prilocaine is applied to the ear canal about 30 minutes before the myringotomy. If medical acupuncture is used for pain control, the acupuncture begins about 40 minutes before surgery and is continued during the procedure.