Ossiculoplasty (repair of hearing bones)
What is an ossiculoplasty?
This is an operation that is used to repair the ossicles or hearing bones. Ossiculo- means “hearing bone” and –plasty means “to fix”.
Why is an ossiculoplasty performed?
It is usually performed in patients who have a problem with their ossicular chain that is causing a hearing loss, usually a conductive hearing loss. People may develop an ossicular chain problem for several reasons including:
Trauma – this is most commonly seen in road traffic accidents when the temporal bone of the skull (the part of the skull that houses structures of the ear) is fractured. During such an injury, the ossicles may become dislocated. Barotrauma (trauma due to pressure changes) or acoustic trauma (trauma due to very loud noises) may also cause ossicular disruption.
Infection – chronic infection within the middle ear may cause erosion of one or more of the ossicles over time. The most common place for erosion to occur is at the point where the incus (anvil) meets the stapes (stirrup).
Cholesteatoma – this is a skin cyst that develops due to an abnormal migration of dead skin into the middle ear. The cholesteatoma may result in recurrent infections that can cause erosion or may itself directly erode the ossicles.
Immobility – occasionally people are born with ossicles that do not move properly due to abnormal connections between the bones.
How is an ossiculoplasty performed?
Ossiculoplasty is usually performed under a general anaesthetic. To get access to the ear drum and the ossicles behind, a cut is either made behind the ear (a post-auricular approach) or inside the ear canal (an endaural approach), depending on which approach gives the best access for that particular ear. Occasionally, in people with very wide ear canals, no cut is needed and the operation can be done directly down the ear canal (a permeatal or transcanal approach). A decision about which approach is best suited for you will often be made in the clinic but this decision can occasionally be changed at the time of surgery if the access to the ear drum is not as good as originally thought. These incisions are the same ones used during tympanoplasty (ear drum repair) and pictures of them can be seen on the tympanoplasty page here.
Once the ear drum is accessible, it is lifted up to expose the middle ear and the ossicles. The ossicular chain is then examined to determine the nature of the problem and is then repaired, usually with an artificial bone (a prosthesis).
A small piece of cartilage is then the harvested from around the ear, usually from the tragus, the small projection that lies in front of the ear canal, and which is sometimes pierced. Sometimes it is harvested from part of the the bowl of the ear known as the concha cymba. More about harvesting cartilage from the tragus can be seen here. This piece of cartilage is placed between the prosthesis and the ear drum to prevent it from being pushed out.
Once the ossicular chain has been reconstructed, the ear drum is placed back into position. The ear canal is then packed with an ear wick (a type of non-dissolvable dressing) near the entrance. The wound is then stitched close using dissolvable sutures. A head bandage may or may not be applied.
The facial nerve, which passes through the ear on its way to supply the muscles of the face, is monitored in all cases with a facial nerve monitor. This helps to protect the facial nerve from injury. To do this, tiny needles are placed above the eye, at the corner of the mouth and on the chest. These are removed at the end of the operation and you may feel some short-lived discomfort or develop bruising in these areas. Mr Trinidade does not generally shave hair for this procedure.
The ear may stick out for a couple of weeks (especially if a post-auricular approach was used) but this will return to normal once the swelling subsides and a scar forms.
What are the risks of ossiculoplasty?
Ossiculoplasty is a common operation with minimal risks, but as with all operations, there are risks that you need to be aware of. These include:
Bleeding and infection
As with any operation, these are standard risks. Bleeding is usually in the form of an ooze, which settles within the first 24 hours. Sometimes, there is significant bleeding that collects under the skin forming a haematoma. This usually needs to be evacuated with a small procedure. Infection may cause redness and swelling around the wound site or show as drainage from the ear canal. Oral and topical antibiotics may be required.
The taste nerve runs along the back of the ear drum and may be bruised during surgery resulting in an abnormal taste in the mouth, usually salty or metallic, or may make certain foods taste strange. It is usually temporary and resolves after several weeks or months. The risk of this is about 1 to 2%.
Any ear operation has the risk of worsened hearing. This risk of this in ossiculoplasty is about 0.5 to 1%. Often the hearing loss is due to fluid or blood collection within the middle ear during the healing phase and can take up to about 3 months to resolve. Rarely it is a permanent loss.
In less than 1% of cases, the facial nerve is injured. This may lead to a partial or full weakness of the face that very rarely is permanent. The use of a facial nerve monitor helps to avoid this risk.
About 2-3% of patients will experience some tinnitus (ringing in the ear) following surgery. This is usually temporary and resolves with time. In some people it is persistent, but the majority of people are able to ignore it without it becoming bothersome.
Ossiculoplasty has a failure rate of about 1 to 2%. This may be as a result of dislodgement of the prosthesis. It may also occasionally be due to an issue with the technique, especially if the ossicular chain was difficult to access in the first place. In cases of failure, revision surgery can be undertaken and usually solves the issue.
What is the aftercare following ossiculoplasty?
After surgery, you will have a wick within the ear and will therefore not be able to hear very well from that ear. If you have had a head bandage applied, this can be taken off at home the following morning. This will often be blood-stained and is normal. Take regular pain medicine for the first 2 to 3 days, or longer if needed. If you stopped aspirin before the operation, this can be restarted the day after surgery.
Do not wash your hair for 2 days, after which you may do so, but you must not get water inside the ear. The best way to protect the ear from getting wet is to place a cotton ball smeared in Vaseline into the bowl of the ear during showering/bathing (click here to see how). Apply antibiotic ointment to the wound twice daily for 1 week.
Your first follow up with Mr Trinidade will be in 1 to 2 weeks. Two days before your appointment, start applying ear drops to your ear (you will be supplied with this before leaving the hospital). This will help to soften the wick so that it can be easily removed in the clinic. If your wick has come out before this time, do not worry. Just start using the ear drops as prescribed and keep water out of it.
At the clinic, your wound will be inspected and the ear wick will be removed. This can sometimes be uncomfortable but is usually straightforward and takes less than a minute to do. Once the wick is out, you will be asked to continue ear drops for a further week. As the stitches are dissolvable, they will not need to be removed in the clinic.
You can start showering/bathing without cotton wool protection at 4 to 6 weeks after the operation. You are encouraged to start gently popping your ears by pinching your nose and blowing out (called a Valsalva manoeuvre; click here to see how to perform one) after 6 weeks. Your second visit to the ENT clinic will be approximately 3 months after the operation when a hearing test will be performed.
Any signs of infection (pain, swelling, drainage, fever) should be reported to your GP or to the ENT clinic. Flying and diving should be avoided for 6 to 8 weeks after the operation. Mr Trinidade advises that you have your ear checked prior to resuming diving.
Read more about tympanoplasty here.
Read more about mastoidectomy here.
An example of a prosthesis that Mr Trinidade uses during ossiculoplasty. This one is used to replace the incus and is partially made of titanium, which is MRI-safe. It is 2.5 mm in length