Otitis media (OM), or an ear infection behind the ear drum (tympanic membrane or TM for short) are one of the most common ENT diseases. This occurs mostly in children under 4 years of age, but it can occur quite frequently in adults. And one of the common surgeries for this are ear tubes. More precisely, the surgical procedure is called a myringotomy and tube (or M&T for short).
Many patients and parents are curious about the procedure and the steps required to achieve tube placement. The mechanism of otitis media and how tubes function have been covered in Otitis Media and Ear Tubes.
How’s it Done? The Step by Step Procedure
First of all, and contrary to certain people’s common wisdom, you first need to make an incision into the tympanic membrane (TM). I know this sounds obvious, but believe me when I tell you an insurance carrier denied this part of the procedure for a child, declaring on the phone—and this is the God’s-honest truth--“We’ll approve the tube but not the myringotomy.”
Absurd. There’s not even a billing code for that, since, well…it doesn’t exist. And the very nature of their decision was—for lack of better words—utterly stupid. Those bozos wanted me to put the child to sleep, under anesthesia, and simply place the tube onto the TM, rendering it a totally worthless procedure, with the potential risks and absolutely none of benefits.
This is the reason prior authorizations are so scary--medical decisions are made by those with little to no medical knowledge who attempt to usurp the knowledge and experience of doctors and other healthcare providers. Read more about the insanity in The Stupidity of Prior Authorizations if you dare. But I digress.
Getting back to the procedure which is done under an operating microscope. For young children, this requires a brief, general anesthesia in an operating room setting with an anesthesiologist and support staff; this is safest for the child. Since the target of the procedure is very small, the size of a dime, it’s impossible to do this with a writhing and wiggling child no matter how many people hold her down. In adults, this often is done under local anesthesia in the office setting with no sedation or general anesthesia. Most folks do well in this setting.
The patient is reclined in the supine position lying flat, with the head turned to the opposite side. The microscope is used to view the TM. In the office setting, the TM needs to be numbed. Sometimes we’ll place a 4% lidocaine cream into the ear canal and onto the TM in order to numb everything from the canal on down. Afterwards this is suctioned and part of the ear drum is further anesthetized. I use phenol in our practice, which works very well. I warn the patient that they will feel a temporary burning or stinging sensation that lasts for a few seconds. In children under anesthesia, these steps are not needed.
Next a myringotomy (myrngo- is Latin for tympanic membrane and -otomy is the suffix for creating an opening into something) is done with a long, narrow blade. Another term is tympanotomy derived from the Greek for “drum.” Thus one term is from Latin, the other Greek. Medical lingo—go figure. The blades can have a plastic disposable handle or a metal handle with disposable blades. The blades are positioned at an angle from the handle to prevent the surgeon’s hand from blocking the line of site to the intended target. The incision is about 1/8 inch long.
Most patients do not feel the incision at all. The middle ear is lightly suctioned though the myringotomy to remove any fluid. One often will hear a loud noise, and many times if there is copious amounts of fluid, the patient will notice an immediate improvement in hearing.
Sometimes a myringotomy is done alone to drain the ear, especially if a patient is experiencing considerable pain or has a complication from the OM such as a facial nerve paralysis. This is also known in layperson’s speak as “lancing the eardrum.”
Next the tube is placed. The tube allows the ventilation of the middle ear to keep it at normal, atmospheric pressure. Synonymous names for ear tubes are pressure equalizing (PE) or ventilation tubes. The are also known as tympanotomy tubes (tympanostomy is the actual opening in the TM after the -otomy is done). The tube is typically grasped with a small alligator forceps. One edge of a flange or rim is placed into the myringotomy. Keep in mind, these tubes as small, 3mm or less in diameter. Care is taken to push and position the tube such that one flange is entirely on the other (medial side) of the TM while the other (for tubes with flanges on both ends) flange remains lateral to (or on the outside of) the TM. A fine sharp instrument called a pick is often used to accomplish this. The incision then heals around the tube, sealing the tube within the TM.
All of these steps are often done in ten minutes or less per ear. Under general anesthesia, the whole procedure for both ears can be done in about 15 minutes, including the time to put the child asleep and then waking them up prior to moving them out of the OR.
There is a plethora of tube types, born out of designs by ENT surgeons over the decades and often named after their creator. During my residency a few old timers reminisced about making their own tubes back in their early days, cutting thin plastic tubing into small pieces and melting the ends to create a flange. The basic tube design is just that—a hollow tube open at both ends—with a flange to prevent the tube from falling into the middle ear or falling out of the TM and onto the canal. Flange types are highly variable--round rims or collars, oval and beveled rims, T-shaped designs, shafts with a rim on only one end; there are scores of designs available. I’ll just list two of my favorites.
1. Bobbin or grommet tubes, which look like a squat spool, made of fluoroplastic, silicone or stainless steel. These tubes typically remain in place for 8-12 months. The pictures at the beginning show placement of this style of tube. Keep in the mind, the opening in the center of the tube is very small, a little more than 1mm diameter.
2. Long dwell T-tubes, designed to remain in place for a couple of years or longer or until they are removed. They are harder to insert--one must fold the flanges together and insert them through the myringotomy (see figure below) but easier to remove. However, they may be prone to larger TM perforations once extruded or removed.
Indications
for Myringotomy and Tubes
Indications for a M&T been covered before in more detail in Otitis Media and Ear Tubes but I’ll provide a brief synopsis as follows.
Recurrent
acute OM
Acute OM occurs where the infection happens over a short period of time, ie, in a day or less, where the child or adult has ear pain, often fevers. These typically occur with a cold or URI (upper respiratory infection). Most often the findings are pus behind the TM and a very inflamed, erythematous (red) TM. The pain and discomfort usually lasts for a day or several days until it resolves on its own or is treated with an oral antibiotic.
Note, patients often ask about ear drops to treat OM, but the only drops indicated are topical anesthetic drops to numb the ear. Antibiotic drops with or without a steroid will not work in this condition since the infection is behind (medial to) the TM. Unless there is a hole or a tube in the TM, the drops cannot enter the middle ear.
In recurrent OM, a patient has an acute OM which resolves completely, but recurs sometime later. The time variable between acute OMs varies, but if it occurs every 4 times in 9 months with two episodes occurring within 30 days of one another, then this is termed “otitis prone1,” This happens frequently in children under 4 yrs of age, since their eustachian tubes have not matured and often close easily, preventing proper ventilation of the middle ear.
A M&T is recommended for 3 or more episodes of acute OM in a six-month period or 4 in one year. My rule of thumb has been an episode ever 4-6 weeks needing antibiotics, having at least 3 episodes, or if they are becoming more difficult to treat with antibiotics (ie, requiring stronger antibiotics). The reason tubes work for recurrent OM: the tube keeps middle ear pressure normal whether the eustachian tube is closed or open. This prevents onset of OM in the first place (see Eustachian Tube Dysfunction, Part 1)
Chronic
OM
Chronic OM with an intact TM mostly refers to persistent fluid in the middle ear, often occurring after an acute OM. Sometimes fluid develops behind the TM without pain from a cold or during an airflight or travel up and down altitudes. This is also called chronic otitis media with effusion (COME).
Studies have shown an antibiotic may help in these cases, but only one course should be used.. Practitioners should avoid repeated antibiotics to get rid of fluid, especially if the child is not having recurrent acute OM on top of this, fevers or significant pain. Additional antibiotic courses have not proven to resolve COME sooner.
Middle ear fluid tends to resolve in 90% of patients by three months. Afterwards, those residual 10% do not resolved. The recommendation then is a M&T for COME for 3 or more months and with hearing loss especially in children (Clinical Practice Guidelines2). Some adults do not want to wait that long. For those with troublesome hearing loss that is greatly affecting quality of life (often in patients with preexisting hearing loss or those who already have hearing aids) or persistent discomfort, the case can be made to do the procedure sooner.
Why not simply perform a myringotomy and drain the fluid in COME? Answer: the myringotomy incision will heal within a week. This does not allow sufficient time for the inflamed middle ear mucosa to fully heal and for the eustachian tube to regain it function. Once the incision heals, the fluid often recurs. Thus the need for a tube.
In adults, we often must check the nasopharynx for any unusual findings that might mechanically block the ET. Children can have this problem as a function of their immature eustachian tubes. I do this for nearly every adult with COME. This requires a nasopharyngoscopy, a rather hideous-looking procedure that is actually not as uncomfortable as it looks, providing the doc exercises a bit of human kindness to properly decongest and numb the nose with topical medications. This procedure is relatively short--takes about a minute--but is vital to rule out something nasty such as a nasopharyngeal tumor which is a more life-threatening condition. If none is found, then treatment directly towards the ear can proceed.
Recurrent
on Chronic OM
Then there are those unfortunate enough to have both conditions, where COME exists, but on top of this an acute OM occurs, where the persistent fluid becomes purulent—infected with bacteria. In this case the poor child or adult has persistent hearing loss and a chronic sense of ear plugging, along with recurrent bouts of painful acute OM. An M&T is done if they’ve met either or both of the criteria described in the two OM categories above.
What to expect after a M&T procedure
Ear tubes generally stay in place for 8-12 months and eventually the ear drum pushes them out. Typically the TM is healed afterwards but there is a small percentage that have a persistent hole (perforation) that may or may not need repair later down the line.
While the tubes are in place, there are fewer or no ear infections. If the patient has an infection, you’ll know right away by the yellow or green drainage coming out of the ear. Treatment is easier since antibiotic ear drops can be used which goes into the ear, through the tube and directly to the target middle ear. Thus, an oral antibiotic can be avoided, which needs to be swallowed, circulated systemically in the blood stream order to get to the target.
Since tubes create a hole through the TM, we instruct patients to prevent water from getting into the ears, particularly from rivers, lakes or oceans given the potential for nasty organisms to enter the middle ear. Use of ear plugs (silicon putty or preformed ear plugs) while bathing or swimming work well. A cotton ball with a lightly layer of Vaseline over the cotton ball works well when bathing or showering when washing one’s hair or head.
There you have it. Hope this has enlightened you into the world of ear tubes.
Ref.
1: Int
J Pediatr Otorhinolaryngol. 1991 May;21(3):201-9.
Ref. 2: Otolaryngol Head Neck Surg. 2004 May;130(5 Suppl):S95-118.
©Randall
S. Fong, M.D.
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medicine, health and the weirdness of life in general, check out the rest of
the blog site at randallfong.blogspot.com
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