By Marcello Cherchi, MD PhD
For patients
A tympanostomy tube is the tube doctors sometime put in the ears of children who get lots of ear infections. These tubes are sometimes also used in adults who have trouble draining their ears.
For clinicians
Overview
A tympanostomy tube connects the middle ear with the external ear. Placing a tympanostomy tube is an office-based procedure performed by an otolaryngologist. The purpose of the tympanostomy tube is to connect the middle ear cavity with the external auditory canal; this equalizes pressure on both sides of the tympanic membrane (and thereby may help Eustachian tube dysfunction), and can also promote drainage of undesired middle ear fluid (such as an effusion) or instillation of medication into the middle ear (such as steroids or antibiotics). Tympanostomy tubes are usually temporary and fall out on their own. Complications of tympanostomy tube placement include occlusion of the lumen (by cerumen or other debris), or medial migration of the tympanostomy tube (such that it falls completely into the middle ear space).
Introduction
A tympanostomy tube goes by several other names, including myringotomy tube, ventilation tube, pressure equalizing (PE) tube, and grommet. In layman’s terms these are the “tubes” sometimes put the ears of children who suffer from frequent ear infections.
Placement of a tympanostomy tube is an office procedure performed by a neuro-otologist (otolaryngologic surgeon). The otolaryngologist applies a topical anesthetic to the eardrum, makes a small incision (called a myringotomy) and then inserts the tube such that part of the tube is within the middle ear space and part of the tube is in the external auditory canal.
Tympanostomy tubes are usually intended to be temporary; after they fall out of the eardrum, the tiny hole left behind will usually heal over. In some cases when longer-term use of a tympanostomy tube is required, the surgeon may use a tympanostomy tube that has pledgets, intended to keep the device in place for longer.
Mechanism
The presence of a tympanostomy tube accomplishes several things, including (1) making the middle ear and the external auditory canal one continuous space so that there is no pressure differential across the tympanic membrane; (2) permitting passage of fluid between the middle ear and external auditory canal.
Equalizing pressure between the middle ear and the external auditory canal may help manage symptoms of Eustachian tube dysfunction.
The passage between the middle ear and external auditory canal can facilitate drainage of undesired fluid (such as an effusion) from the middle ear into the external auditory canal, and permit instillation of medications (such as steroids or antibiotics) from the external auditory canal into the middle ear.
Adverse effects
As with any invasive procedure, the main risks of tympanostomy tube placement include bleeding and infection. After the tympanostomy tube falls out (or is removed), there is some risk that the small hole in the tympanic membrane will not heal.
While the tympanostomy tube is in place, its lumen can get clogged by cerumen, proteinaceous fluid from the middle ear space, blood, or other debris. If the luminal occlusion is complete, it can compromise the pressure-equalization function of the tympanostomy tube.
A rare complication of tympanostomy tube placement is that the tube migrates medially and completely enters the middle ear space (Kumar, Khan, Davis 2000). In this circumstance the otolaryngologist may perform a larger myringotomy in order to retrieve the tympanostomy tube.
Cautions and contraindications
While the tympanostomy tube is in place, patients should avoid submerging their ears in water, because this could permit non-sterile water to pass from the external auditory canal into the middle ear, thereby increasing the risk of a middle ear infection.
Relevance in neuro-otology
Probably the most common application of tympanostomy tube placement in adult neuro-otology is to treat Eustachian tube dysfunction. Much less commonly, a tympanostomy tube may be placed to allow repeat instillation of eardrops (such as steroids for Ménière’s disease).
References
Kumar M, Khan AM, Davis S (2000) Medial displacement of grommets: an unwanted sequel of grommet insertion. J Laryngol Otol 114: 448-9. doi: 10.1258/0022215001906039
