Eardrum perforation is a common ear condition encountered in the Pediatric Ears, Hearing, and Balance Center. It can be caused by a severe ear infection resulting in the rupture of the eardrum with drainage. Some pediatric patients have injury to the ear from falling into the water and this can also cause an eardrum perforation. Another common cause of a persistent perforation occurs following placement of tympanostomy tubes. In most young children, ventilation of the middle ear is paramount and we often do not recommend formal tympanoplasty surgery to repair a small perforation after extrusion of a tympanostomy tube until a child is older.
Small tympanic membrane perforations associated with a recent severe ear infection and drainage or from injury will often close on their own. In other cases, chronic infection and drainage associated with a perforation or larger perforations will not heal on their own and may require surgical repair. In the setting of a patient with a history of chronic infections and tympanostomy tube placement, keeping the ear ventilated by way of a persistent perforation may actually be therapeutic.
The size and location of a tympanic membrane perforation will also affect the hearing. Smaller perforations that are found either towards the front or in the lower portion of the eardrum will have less of an impact on the hearing of a child than a larger perforation found in the back of the eardrum as this is the location of the hearing bones for the ossicles of the middle ear. In addition, the larger perforation found in the back or lower portion of the eardrum will likely be associated with more water exposure associated infections than a small perforation found further up on the drum itself.
The indications for surgical repair in a child with an eardrum perforation would be persistent infections associated with the perforation that are not amenable to topical antibiotics and have been associated with a significant degree of conductive hearing loss based upon hearing testing. In general, younger children who have a persistent perforation, we elect observation due to the concerns of persistent eustachian tube dysfunction which might either affect the success of surgical repair, or if surgical repair is successful in closing the perforation, there would still be a chance that another myringotomy and tympanostomy tube would be needed, creating another perforation in the tympanic membrane itself. However, larger perforations that are total to subtotal at whatever age, would likely be best served by surgical repair.
There are several different surgical approaches to repairing a tympanic membrane perforation in the pediatric patient. Smaller perforations found towards the back of the eardrum that are more central as opposed to near the edge of the drum are amenable to a transcanal approach. The tissue used for the repair can be the lining of the cartilage from behind the outer ear and at times cartilage itself is also used to help provide greater stability to the reconstruction. The lining of the cartilage and/or the cartilage itself can also be harvested from the area of the tragus which is found in front of the opening to the ear itself. In other cases, a small incision can be made in a hidden area behind and above the ear near the hairline and fascia from the temporalis muscle can be used from that site in order to graft a new tympanic membrane. In some cases a very tiny skin graft can be used, but is often not necessary in most pediatric cases where the perforation is relatively small.
For larger perforations and perforations found near the edge of the drum, a more formalized approach may be necessary. This will necessitate a small incision made in the hidden area behind the ear. The ear is gently turned forward and the ear canal is exposed. The margins of the eardrum hole are then cleaned of remaining skin and the ear canal is gently widened with a surgical drill. A combination of fascia or temporalis muscle can be used to graft the eardrum and in some cases with a combination of a very tiny skin graft taken from a hidden area underneath the arm and near the armpit. This will be a lateral graft or total drum replacement approach. In larger perforations that are more posterior, an underlay or medial graft approach could be used where the posterior canal would need to be widened and grafting material can be placed underneath the remaining portion of the tympanic membrane. In both cases the ear canal is then packed with temporary packing which is removed during the post surgery period. The procedure is generally an outpatient surgery with about a week off from school. The pain is minimal at worst. A bandage is worn for two days and then removed, usually at home. The outer ear does stick out for a period of time and will then return to its baseline several weeks to months after surgery.
Risks of surgical repair include recurrence of the eardrum perforation. This may potentially be more frequently encountered in the pediatric population because of the dysfunctional eustachian tube that often is associated with younger children. Other risks include scarring of the eardrum that may result in some dampening of the hearing. With the rapid growth of a child, there is an increased risk that scarring can occur and even very complete opening of the ear canal and placement of the graft can result in some blunting or scarring following surgery. In addition, there are some children in whom successful tympanoplasty surgery is performed, but with recurrent otitis media, a tympanostomy tube has to be placed, thereby creating a new opening in the newly grafted drum. Other less common risks include change in taste which is usually temporary. Facial nerve injury is a common concern among parents and this is an extremely rare event. As with all ear surgeries performed at the Mass. Eye and Ear, we have a separate neural monitoring team to monitors the activity of the facial nerve during any ear operation. We believe that this team approach helps to reduce the risks associated with ear surgery in regard to the facial nerve.
Surgical recovery is a week or so off school. Depending on the degree to which the tympanic membrane had to repaired will dictate how long the healing process takes. It generally takes from three months and sometimes up to a year for the ear canal skin to mature over a newly grafted drum. Water precautions must be maintained as per surgeon’s instructions.
Daniel Lee, M.D., FACS