Otosclerosis is a disease of ear bone degeneration that most commonly develops during the teen or early adult years. In otosclerosis, the consistency of the sound-conducting bones of the ear changes from hard, mineralized bone to spongy, immature bone tissue. This can result in a buildup of inappropriate bone around the stapes foot-plate (a bone in the middle ear). This buildup of bone causes the stapes to become fixed and prevents it from vibrating normally. The lack of vibration prevents sound from being conducted to the inner, leading to a conductive hearing loss.
Stapedectomy is a surgical treatment for otosclerosis. In stapedectomy, the immobilized stapes is removed, and a tiny platinum or stainless steel prosthesis is inserted in the middle ear to replace it. The artificial prosthesis is less than 1/8 of an inch long. There are variations in stapedectomy depending on the extent of the disease. More extensive damage may require removal of the entire stapes footplate, while a small focus of disease allows for removal of less tissue. In patients with very extensive thickened tissue covering the oval window (obliterative otosclerosis), stapedectomy can not be performed. In such cases the stapes suprastructure is removed and the surgeon uses a small drill to thin out the oval window. An opening is made in the footplate, and the prosthesis is then positioned.
This surgery is extremely effective, and usually restores normal hearing in patients with conductive hearing loss. Patients can usually return to work in about a week.
Stapedectomy is usually performed on an outpatient basis. Either local or general anesthesia may be used, depending on the comfort of the surgeon and the patient. The use of local anesthesia allows the patient to be awake and report any vertigo or nausea, which may indicate impending damage to the inner ear. General anesthesia is considered safer by many surgeons, however. A small tissue graft, usually taken from a vein in the patient’s hand, is taken and used to seal the oval window after the prosthesis is inserted.
Risks of stapedectomy include imbalance, tinnitus, changes in taste, dry mouth, perforation of the tympanic membrane, injury to facial nerves, and cochlear deafness.
In some cases, surgery is not possible and a hearing aid may be used instead. People who should not have stapedectomy include those who experience frequent changes in barometric pressure (pilots and divers), elderly patients with a baseline imbalance, people whose vocations demand excellent balance, and anyone with known Meniere’s disease (stapedectomy often causes permanent profound hearing loss in patients with Meniere’s disease). If a person has a perforated tympanic membrane due to middle ear infection, the infection must be cleared and the membrane healed before stapedectomy. Patients with sensorineural hearing loss or mixed hearing loss may not improve after stapedectomy, and would not be likely to benefit from surgery.
Description, diagrams, and animated views of stapedectomy surgery may be found online at The Ear Surgery Information Center.