Aural Atresia Repair/Canalplasty

Canalplasty is the surgical technique offered to open and create an ear canal. This surgical procedure involves drilling a channel into the skull, creating an opening for the new ear canal. The ear canal is then lined using grafted tissue. The newly created ear canal alone will allow for better sound localization. However, hearing loss may still be present due to the anatomy of the middle and inner ear. A CT scan may reveal that some of the inner ear structures are missing or malformed. Aural Atresia repair can help restore hearing loss by manipulating these middle ear bones and restoring hearing loss to within normal hearing range (20dB). Depending on the actual anatomy of the ear, it is possible that an ossicular prosthesis can be used to replace one of the missing or damaged bones still allowing Dr. Rivas to restore hearing. An ossicular prosthesis can be made of two materials, titanium or hydroxyapatite. The earliest age that Dr. Rivas will perform canalplasty/aural atresia repair is around 4 years of age.

Following surgery, a tube may be required to be worn in the newly reconstructed ear canal for approximately 3 weeks and will be removed by Dr. Rivas. The newly reconstructed ear canal will need be cleaned by an ear surgeon every 6-12 months (on-going) in order to remove any build up of skin debris (since the ear canal will not secrete ear wax (cerumen) as it is a man made canal. This cleaning is referred to as a deep microscopic cleaning.

A CT scan may reveal that some of the inner ear structures are missing or malformed. Depending on the actual anatomy of the ear, it is possible that an ossicular prosthesis can be used to replace one of the missing or damaged bones still allowing the surgeon to restore hearing through canalplasty. A prosthetic ear bone or replacement prosthesis can be made of two materials, titanium or hydroxyapatite. In fact, even if an individual rates a 6 out of 10 on the “J” scale, it still may be possible for an individual to be a candidate for canalplasty based on their individual anatomy of the ear.  Sometimes, a decision can depend on the anatomy that is seen at the time of surgery as a CT scan may not always reveal that all inner ear structures are present.

What determines if a patient can be a candidate for Aural Atresia Repair/Canalplasty?

A patient must be a candidate for aural atresia repair/canalplasty as not all patients are candidates for aural atresia reconstruction. A CT scan of the middle and inner ear is required before determining if a patient can have aural atresia repair/canalplasty. A CT scan will help Dr. Rivas determine what the middle ear anatomy consists of (functioning cochlea and middle ear bones ) and if hearing loss can be restored. Various considerations are taken into account for each individual patient. For example:

• Is the aural atresia bilateral or unilateral?
• Does a canal stenosis exist?
• Does the patient have a possible cholesteatoma?
• How is the hearing in each ear?
• What is the patient’s age?
• How is the patient’s language development?
• Does the patient have a separate intellectual impairment or other medical problems?
• Can the patient wear an amplification device or not?
• How does the patient look externally?
• Is facial paralysis present?
• Is there a severe mandibular abnormality?
• What grade of Microtia does the patient have?
• Has the patient already had microtia reconstruction? If so, what type? What are the surgical results?
• Does the patient have an adequate amount of bone through which to drill?
• Are the middle ear and the mastoid aerated (have enough space)?
• What do the 3 middle ear bones look like (are they damaged, malformed, or fused together)?
• Is the facial nerve in a reasonable position?
• Is the cochlea functioning?
• Most importantly, what does the family feel about the possibility of surgery?
• What are the results of the CT scan?

In general, a CT scan is not helpful until the patient is about the age for reconstruction of the external ear. Therefore, a CT scan in an infant seldom provides useful information and usually is not necessary. Other X-Ray scans, such as an MRI, are not useful since the bone anatomy that Dr. Rivas needs to see is more clearly demonstrated by CT scanning.

Scoring for the Jahrsdoerfer Grading System:

A 10 point grading scale is used to determine candidacy for Aural Atresia based on how the patient’s middle and inner ear is structured. This 10 point scale is called the Jahrsdoerfer or “J” scale, developed by Dr. Robert Jahrsdoerfer, and is used to grade the individual’s ear anatomy. The “J” scale is broken down on the following point system:

• Stapes bone 2
• Oval window open 1
• Middle ear space 1
• Facial nerve 1
• Malleus-incus complex 1
• Mastoid pneumatization 1
• Incus-stapes connection 1
• Round window 1
• External ear 1
• Total Possible Score 10

A candidate must score with a 6 or higher out of 10, with 10 being the optimal score achieved based on ear structure (middle/inner).
6 out of 10 means there is a 60% chance the patient will achieve normal to near normal hearing.
7 out of 10 means there is a 70% chance the patient will achieve normal to near normal hearing.
And so on…

If the score is below a 6, the individual may not be considered a candidate as the surgery could be considered risky or not being an option for a successful surgical outcome.

Some advantages of this surgery are:

• Improved hearing
• Improved ability to localize sound
• No external hearing device is visible
• Removal of cholesteatoma (if present)
• Not a particularly painful procedure

Some disadvantages of aural atresia surgery can be:

• Cannot be performed in all patients due to anatomical constraints
• The canal in most patients remains patent yet does not always stay open; revision surgery may be necessary
• The hearing might not improve to a ‘normal’ level or (unlikely) even degrade
• The ear can develop a condition called myringitis which means that the ear canal can be moist like mucosa rather than lined with healthy skin as in the normal state.
• Risk of injury to the facial nerve

Atresia repair and BAI

In this video from July 2019, Dr. Alejandro Rivas Campo discusses aural atresia repair and Bone-Anchored hearing aid Implantation (BAI). He explains normal ear anatomy and how it is altered with microtia and atresia, including Treacher Collins (mandibulofacial dysostosis), Nager Syndrome (acrofacial dysostosis), Cruzoun’s Craniofacial Dysostosis, Goldenhar’s Syndrome, and Hemifacial Microsomia. He also explores considerations of surgery and what makes a patient a suitable candidate for atresia repair.

To make an appointment, e-mail us at:   MicrotiaAtresiaClinic@VUMC.org or call ph:  615-343-6166.