Ear Grommets

Middle Ear Drainage and Insertions of Tympanostomy Tubes (MEDITS) is an operation performed to drain fluid from the middle ear cleft. This is performed predominantly in children.

The symptoms of fluid in the middle ear cleft involves diminished hearing acuity, altered behaviour, recurrent infection, persisting or recurrent earache.
 The presence of fluid in the middle ear is always associated with decreased hearing acuity and occasionally with fluctuating pain and sense of unsteadiness.

The procedure is performed under light general anaesthetic. Using an operating microscope, a small cut is made in the eardrum, the fluid is sucked out and a bypass tube or grommet is inserted.

What are Grommets?

Ear Grommets

Grommets are small metallic or polyteflon tubes placed through the eardrum to help treat either recurrent acute otitis media or glue ear. They allow air to follow into the middle ear in the presence of a blocked eustachian tube restoring equal pressure between the middle ear and the atmosphere and they allow the fluid to drain either out the tympanostomy tube or to be reabsorbed into tissues. This equalization of pressure is important for middle ear good health while the Eustachian tube is itself not working.

Indication for grommets

  • Three or more significant ear infections occurring within a six month period
  • Complication of otitis media
  • Glue ear when present for more than three months especially in the presence of documented conductive hearing loss and/or evidence of scarring or damage to the eardrum.

Benefits of Grommets

  • Hearing – Grommets return hearing to normal or near normal provided there is no damage to the nerve of hearing. Restoration of normal hearing is especially important in children with delayed speech development, learning difficulties or intellectual impairment
  • Behavioural problems associated with glue ear are often improved by grommets
  • As grommets allow air to enter the middle ear cleft a retracted pocket in the eardrum is likely to return to normal and it nearly always prevents further damage to the ear drum and/or to the three small bones of the middle ear
  • In children who have recurrent otitis media, grommets usually decrease the frequency of infection

Insertion of grommets

Grommets are inserted under a gaseous general anaesthetic. Children are not paralysed and they are not intubated. The surgical procedure involves the use of an operating microscope, a small cut in the eardrum, aspiration of some of the fluid and insertion of a tympanostomy tube.

The child returns home after several hours in recovery. Most surgeons recommend that water be excluded from the ear while the grommet is in-situ.

Types of grommet

Grommets come in a variety of sizes from a very small metal tube (Kurz tube) through a Shepherds tube to a Collar Button tube right up to large Goodie T tubes. As a rule of thumb, the bigger the grommet, the longer it stays in, but the bigger the grommet, the bigger the cut and the greater the risk of the hole where the grommet was not healing spontaneously. With the Kurz tube (the smallest) the risk of the perforation not closing is less than 1%. With a Shepherds tube it is about 1%, with a Collar Button rube about 1-2% and with a larger tube like a Goodie T tube about 5-10%. A hole that persists after extrusion of a grommet may require a minor secondary surgical procedure to close the hole.

Ear discharge of the grommet may occur at any time. It is usually recommended that water be excluded from the ear. With an upper respiratory tract infection a sterile serous fluid may come out through the grommet. This is not serious and requires no treatment.

Early Extrusion

The grommets are designed to stay in for between six months to a year. During this period of time between 85 -90 children in 100 grow and develop enough to not require a second tube. In 10-15 cases, a second tube will be required.

Early displacement of a grommet is defined as a grommet coming out in less than 3 months. If this is the case, depending on the eustachian tube status a grommet may need to be inserted.

The hole in the grommet may become blocked if there has been mucopurulent discharge. Sometimes this can be unblocked by use of sodium bicarbonate ear drops. Sometimes it renders the grommet non-functional and the grommet itself needs to be removed. Thinning of the eardrum at the site of grommet insertion can occur. This occurs in less than 1/3 of cases and is usually of no functional significance.

Calcium deposits and scarring (tympanosclerosis) can occur at the site of grommet insertion. Several studies however have shown that the likelihood of tympanosclerosis is greater with the persistence of fluid in the middle ear cleft than if the fluid is aspirated and a grommet is inserted. A small plaque of tympanosclerosis does not significantly interfere with the vibration of the eardrum hence does not affect hearing.

Recurrent infection around the grommet can lead to the formation of granulation tissue. This can block the grommet, lead to mucopurulent discharge or intermittent bleeding. Once the grommet, which is a foreign body, has become colonised by antibiotics and a cycle of recurrent infection and/or granulation tissue is established the grommet needs to be removed. When there is infection in and around the grommet and/or granulation tissue the appropriate treatment is by topical ear drops. The only ear drop that has been shown not to be ototoxic is ciprofloxacin. If any ear drops are required this is probably the ear drop of choice.

Ancillary procedures

Several large American studies have shown that if grommets need to be inserted on more than two occasions, adenoidectomy should be performed as this reduces the chance of any subsequent glue ear formation. In children who have evidence of post nasal obstruction, low grade chronic rhinosinusitis and/or who adopt a chronic mouth open posture at rest, adenoidectomy at the time of grommet insertion should be considered.

Risks of not having treatment

It is important for parents to realise that the persistence of fluid in the middle ear cleft can lead to ongoing conductive hearing loss which has been documented to affect speech and language development, learning, behaviour and balance.

  • The presence of ongoing fluid can damage the eardrum.
  • The presence of ongoing fluid can damage the three little bones of the middle ear.
  • If a cycle or recurrent infection is established then the toxins from that middle ear infection can damage the nervous hearing permanently.