Tympanostomy tube, also known as a grommet or myringotomy tube, is a small tube inserted into the

eardrum In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the ...

in order to keep the middle ear aerated for a prolonged period of time, and to prevent the accumulation of fluid in the middle ear. The operation to insert the tube involves a myringotomy and is performed under local or

general anesthesia General anaesthesia (UK) or general anesthesia (US) is a medically induced loss of consciousness that renders the patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general ...

. The tube itself is made in a variety of designs. The most commonly used type is shaped like a grommet. When it is necessary to keep the middle ear ventilated for a very long period, a "T"-shaped tube may be used, as these "T-tubes" can stay in place for 2–4 years. Materials used to construct the tube are most often

plastics Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptabi ...

such as

silicone A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cookin ...

Teflon Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemo ...

Stainless steel Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's r ...

tubes exist, but are no longer in frequent use.

Medical uses

Inserting grommets is a common surgical procedure for treating children around the world. Grommets are most commonly used to help improve hearing for children who have a condition commonly called " glue ear" (persistent

otitis media Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, ...

with

effusion In physics and chemistry, effusion is the process in which a gas escapes from a container through a hole of diameter considerably smaller than the mean free path of the molecules. Such a hole is often described as a ''pinhole'' and the escap ...

) in both ears, and for preventing ear infections in children who have frequent middle ear infections. Grommets are temporary and often fall out after 12–14 months as the ear heals. Guidelines state that tubes are an option in: * Recurrent acute

: three ear infections in six months or four infections in a year. The evidence for this recommendation; however, is weak. * Chronic

with persistent effusion for six months (one ear) or three months (both ears). * Persistent

eustachian tube In anatomy, the Eustachian tube, also known as the auditory tube or pharyngotympanic tube, is a tube that links the nasopharynx to the middle ear, of which it is also a part. In adult humans, the Eustachian tube is approximately long and in d ...

dysfunction *

Barotrauma Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in tensi ...

: Especially for prevention of recurrent episodes (e.g., after air travel, hyperbaric chamber treatment). * Grommets should not be inserted in children who have only one episode of otitis media with effusion (OME) that lasts less than 3 months., which cites *

Adverse effects

Ear discharge ( otorrhoea) is common in 25–75% of children after grommets are inserted. Treatments to prevent this discharge before it occurs should be limited to children who have a higher risk of otorrhoea and it is not clear which preventative treatment is better. The risk of having persistent tympanic membrane perforation following the procedure may be low, and has been estimated at 2%. Other adverse effects are estimated at: blockage of the tympanostomy tube (7%), formation of

granulation tissue Granulation tissue is new connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any siz ...

(4%), grommet falls out too early (4%), and the tympanostomy tube may move towards the middle ear (0.5%). There is also a risk related to

. Long term effects include visible changes to the

tympanic membrane In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the a ...

. These changes usually resolve on their own and do not usually require medical treatment or result in hearing problems that are clinically significant.

Mechanism of action

Grommets work by improving drainage in the ear and allow air to circulate in the ear. Grommet placement has been shown to improve hearing in children with glue ear and may lead to fewer middle ear infections in children who have regular episodes of acute

. Grommets can be used to apply antibiotics drops in children with persistent middle ear infections.

Procedure

Although myringotomy with tube insertion can be performed under

local anesthesia Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It ...

during a regular doctor's appointment in co-operative adults, patients requiring tube insertion are very often young children. Since damage to the ear is possible unless the patient stays quite still while being manipulated, any patient who may have difficulty lying still during the procedure typically undergoes myringotomy and tube insertion under general anesthesia. The insertion of tympanostomy tubes is one of the most common surgical procedures performed on children. In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, the procedure accounts for more than 20% of all ambulatory surgery in children under 15 years. For children with ear discharge, antibiotic ear drops may be more effective than antibiotics taken by mouth. It is not clear if antibiotic drops are better than rinsing the ear with saline. It is usually suggested that children keep their ears dry for the first two weeks after having the procedure. It is not thought to be necessary for children to wear ear plugs when swimming or keep their ears dry after the first two weeks as the potential benefit is very small. It is approximated that a child would need to wear ear plugs for 2.8 years to prevent one additional ear infection.

Outcome

Tympanostomy tubes generally remain in the

for six months to two years, with T-tubes lasting up to four years. They generally spontaneously fall out of the eardrum as the skin of the eardrum slowly migrates out towards the ear canal wall over time. The eardrum usually closes without a residual hole at the tube site but in a small number of cases a perforation can persist. There is debate among clinicians as to whether long-lasting tubes are associated with a higher incidence of adverse outcomes, such as persistent perforation, cholesteatoma, tympanosclerosis and others, as opposed to tubes designed to last for shorter durations.

References

{{Reflist Audiology Diseases of middle ear and mastoid Implants (medicine) Ear surgery