Stapedectomy is a microsurgical procedure which is done for the treatment of otosclerosis. The operation can be done through the ear canal. Anaesthesia is usually general (The patient is completely asleep).
An incision is made within the ear canal near the ear drum (an internal incision that neither need be sutured back nor can be seen externally.).
The ear drum is then carefully raised and the ear surgeon uses the operating microscope to see the structures in detail.
The middle ear is now opened. The bones of hearing are evaluated, confirming the surgeon's diagnosis of otosclerosis.
The new bone is usually visible, and the stapes bone is tested. It does not move when pressed. The stapes bone is now separated from the incus (anvil.)
Freed from the stapes, the incus and malleus (hammer) bones can now move when pressed. Micro-instruments are used to cut the stapedial tendon and remove the arch of the stapes bone, and the stapes bone remnant is removed from the middle ear.
The window that joins the middle ear to the inner ear and which serves as a platform for the stapes bone, is now opened with micro-pics and hooks, creating a tiny opening (0.6 mm).
Once the opening is made in the window, the artificial bone (prosthesis) is placed onto the incus bone and gently inserted. The prosthesis is then clipped gently onto the incus and the new assembly is gently pressed to confirm that its movement is correct. A blood clot is used to help seal the hole in the window and the space around the prosthesis.
The ear drum is then folded back into its normal position and held down with a small gelatin sponge.
The hearing improvement obtained is usually permanent.
This is a picture of a piston-type stapes prosthesis. The small hook-like portion of the prosthesis is crimped around the incus, the bone in front of the stapes. The cylindrical portion of the prosthesis is inserted into the inner ear.
Hearing Improvement after Stapes Surgery:
Hearing improves after stapes surgery. Improvement is usually masked or concealed because of fluid accumulation behind the ear drum and ointment, gelfoam and dressing in the ear canal. Improvement in hearing will often be apparent within three weeks following surgery. Maximum hearing, however, is obtained in approximately 4 months. The degree of hearing improvement depends on how the ear heals. In the majority of patients, the ear heals perfectly and hearing improvement is as anticipated. In a small percentage of patients (5%), the hearing improvement is only partial or temporary due to fibrous refixation. In these cases the ear usually may be reoperated with a good chance of success. Surgery for the second ear is never considered until at least one year after a successful operation on the first ear.
Most patients with otosclerosis notice tinnitus (head noise) to some degree. The amount of tinnitus is not necessarily related to the degree or type of hearing impairment. Tinnitus can develop from irritation of the delicate hair cells in the inner ear. The hair cells are connected to the hearing nerve. Since the nerve carries sound, the irritation is manifested as ringing, roaring, or buzzing. It is usually worse when the patient is fatigued, nervous, or in a quiet environment. Following successful surgery, tinnitus is reduced or eliminated in over 50-80% of all individuals.
Complications Following Stapedectomy:
Dizziness is normal for a few hours following stapedectomy and may result in nausea and vomiting. Some unsteadiness is common during the first few post-operative days; dizziness on sudden head movements may persist for several weeks. On rare occasions, dizziness is prolonged.
Taste disturbance is not uncommon for a few weeks following surgery. In 5% of the patients this disturbance is prolonged.
Loss of Hearing:
In about 2% of patients the hearing may be further impaired due to the development of scar tissue, infection, blood vessel spasm, irritation of the inner ear, or a leak of inner ear fluid (called a fistula). In 1% of patients, complications in the healing process may be so great that there is severe loss of hearing in the operated ear. This may be to the extent that one cannot obtain benefit from a hearing aid in that ear. For this reason the poorer hearing ear is selected for surgery.
Ear Drum Perforation:
A perforation (hole) in the ear drum membrane is an unusual complication. It develops in less than 1% of patients and is usually due to an infection. Fortunately, should this complication occur, the membrane often heals spontaneously.
If you are a suitable candidate for surgery, you are also likely to benefit from a properly fitted hearing aid. If you have otosclerosis and are not suitable for stapes surgery, you may still benefit from a properly fitted aid. Fortunately, patients with otosclerosis almost never become "totally deaf", but will almost always be able to hear with a hearing aid or with surgery plus an aid. The older the patient, the less the tendency for further hearing loss due to the hardening process of otosclerosis.
If you are a suitable candidate for surgery and do not have the stapes operation at this time, it is recommended that careful hearing tests be done at yearly intervals.