Pediatric Otosclerosis Treatment & Management

Updated: Nov 30, 2015
  • Author: Joe Walter Kutz, Jr, MD, FACS; Chief Editor: Ravindhra G Elluru, MD, PhD  more...
  • Print
Treatment

Medical Care

For the vast majority of patients with otosclerosis, the principal goal is remediation of hearing loss. Only a small minority of patients have vestibular symptoms that are pronounced and warrant treatment solely on that basis.

Use of sodium fluoride to arrest development of otosclerosis was championed by Shambaugh and was fairly widespread in the 1960s and 1970s. [5, 6] Fluoride ions replace the usual hydroxyl group in hydroxyapatite. The result is a fluorapatite complex resistant to osteoclastic degradation. Sodium fluoride therapy is now less commonly used, but it still has supporters. The recommended dosage is 20-120 mg/day. Effectiveness is monitored by noting the disappearance of the Schwartze sign, repeating audiometric testing, and performing follow-up computed tomography (CT).

Hearing loss can be effectively remediated by using amplification. Hearing aids can often provide almost complete elimination of the conductive hearing loss and aided thresholds can return to near normal.

Their utility notwithstanding, hearing aids can be poorly accepted, for various reasons. The presence of the occlusive mold within the external auditory canal produces an unpleasant effect, termed the canal occlusion effect, which hearing aid users describe as producing sound quality similar to that of "hearing in a barrel." Moreover, the devices are generally not worn at night, are sometimes difficult to adjust, can produce shrill screeching noises (as a result of feedback), and do not provide natural sound quality. Additionally, in 21st-century American society, hearing aids carry the stigma of infirmity or disability.

Next:

Surgical Care

Most patients elect surgical repair. If surgery is considered in the pediatric population, the patient should be not be prone to the development of otitis. This could result in a higher incidence of postoperative sensorineural hearing loss (SNHL). Surgery for otosclerosis is very successful, and more than 90% of patients experience complete elimination of conductive hearing loss (ie, <10 dB of residual air-bone gap). The operation is a day surgical procedure that can be performed in 45-60 minutes with general or local anesthesia. [7, 8]

Procedure

The first step in the surgical procedure is elevation of the tympanic annulus from its sulcus, so that the tympanic membrane can be reflected anteriorly. Elevation provides access to the entire posterior middle ear, including the ossicular chain. Once the drum has been elevated, small instruments are used to palpate the ossicular chain and to confirm that the stapes is fixed and immobile within the oval window niche.

Once the diagnosis is confirmed, incisions are made in the mucosa around the footplate to free it from the remainder of the middle ear mucosa. Often a small vessel extends over the anterior lip of the oval window niche. This vessel can produce significant bleeding and should be controlled prior to attempted footplate removal so that the bleeding can be controlled before the oval window is opened.

Before removal of the stapes, a graft must be obtained that can be used to seal the open oval window after footplate removal. A small piece of vein can be taken from the hand. Although a hand vein provides an excellent graft, obtaining the graft requires that a second operative site be exposed and prepared. More commonly, tragal perichondrium is used. Perichondrium can be obtained from the tragus of the ear within the same surgical field.

A measurement is made to determine how long the prosthesis needs to be. Once the graft material has been obtained and cut to the appropriate size, a control hole is made in the center of the fixed footplate. After the control hole has been made, the incudostapedial joint is separated, and the stapedius tendon is cut. The suprastructure of the stapes then is fractured away. Because the stapes footplate is fixed in the oval window, pressure on the crura causes them to fracture at their base.

Next, the control hole is slightly enlarged (0.1 mm) with a right-angle hook. Larger instruments are used to extract the remainder of the footplate. The graft then is placed over the open oval window, and the prosthesis is positioned to span the gap between the distal portion of the incus and the grafted oval window. The eardrum is returned to its anatomic position, and the procedure is terminated after the canal has been filled with nonototoxic antibacterial ointment.

As an alternative to removal of the entire footplate, a small hole can be drilled into the footplate that is slightly larger than the piston of a prosthesis. (A laser has also been used to make the hole. [9] ) Such a procedure is referred to as a stapedotomy, [10] to be distinguished from the classic stapedectomy, in which the complete footplate is removed. Both procedures have high success rates, and little long-term difference between them has been demonstrated.

In patients with otosclerosis, audiography should be performed on an annual basis indefinitely.

Complications

Various operative and postoperative complications are possible.

In 1-2% of cases, all hearing is lost in the operated ear, resulting in complete SNHL. Such a catastrophic perioperative loss is irremediable. Neither revision surgery nor amplification provides any meaningful hearing improvement. The exact circumstances that create such catastrophic injuries are unclear. However, cases of complete SNHL that follow an entirely uneventful surgical procedure are well documented.

Permanent facial nerve injury occurs in fewer than 1 per 100 (probably <1 per 1000) cases.

In 1-2% of cases, a tympanic membrane perforation results from elevation of the eardrum. Such tympanic membrane perforations are generally in the posterior and are relatively easy to repair.

Because the chorda tympani lies directly across the ossicular chain, it must either be mobilized or, in some cases, divided to afford access to the oval window niche. Consequently, alteration of taste may follow the operation. This condition generally resolves in a few weeks to a couple of months.

Dysequilibrium and vertigo with nausea and vomiting are frequent in the immediate postoperative period and often last for several days. Long-term balance disturbance occurs but is very uncommon.

Individuals may develop tinnitus after the operation. Some patients who had tinnitus preoperatively have worse tinnitus postoperatively. However, most patients who experience hearing improvement report either significant improvement in their tinnitus or no meaningful change.

The operation is performed in only one ear at a time; the worst-hearing ear should be approached first. Many patients desire correction of the second ear if the operation on the first ear was successful. The second ear should be treated surgically only if the surgeon is convinced that the operation has been successful in the first ear and that the result is permanent. As a general rule, 3-12 months should elapse between the first and second operations.

Previous