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
The outer ear, external ear, or auris externa is the extern ...
in order to keep the
middle ear
The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear).
The mammalian middle ear contains three ossicles, which transfer the vibrations of the eardrum into waves in the ...
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
A myringotomy is a surgical procedure in which an incision is created in the eardrum (tympanic membrane) to relieve pressure caused by excessive buildup of fluid, or to drain pus from the middle ear. A tympanostomy tube may be inserted through th ...
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
Curtain grommets, used among others in shower curtains.
A grommet is a ring or edge strip inserted into a hole through thin material, typically a sheet of textile fabric, sheet metal or composite of carbon fiber, wood or honeycomb. Grommets ar ...
. 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 polymers, synthetic or semi-synthetic materials that use polymers as a main ingredient. Their Plasticity (physics), plasticity makes it possible for plastics to be Injection moulding, moulded, Extrusion, e ...
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, cooking ...
or
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 Chemou ...
.
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 corros ...
tubes exist, but are no longer in frequent use.
Medical uses
![Ear Tube](https://upload.wikimedia.org/wikipedia/commons/9/96/Ear_Tube.png)
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
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, ...
" (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 escape ...
) 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
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, ...
: three ear infections in six months or four infections in a year.
The evidence for this recommendation; however, is weak.
[
* Chronic ]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 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 tens ...
: Especially for prevention of recurrent episodes (e.g., after air travel, hyperbaric chamber
A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of ...
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
A perforated eardrum (tympanic membrane perforation) is a hole in the eardrum. It can be caused by infection (otitis media), trauma, overpressure (loud noise), inappropriate ear clearing, and changes in middle ear pressure. An otoscope can be u ...
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 size ...
(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 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 ...
.
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 air ...
. 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
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, ...
and may lead to fewer middle ear infections in children who have regular episodes of acute 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, ...
. 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 primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, 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 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
The outer ear, external ear, or auris externa is the extern ...
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