Tinnitus, the perception of sound without an external source, is a symptom, not a disease. There is no single surgical procedure designed to cure tinnitus itself. Instead, surgery is an option only when tinnitus is caused by a specific, identifiable medical condition that can be physically corrected. For a small subset of individuals, the persistent ringing or buzzing is a direct result of an underlying structural or vascular issue within or near the ear.
In these cases, a surgical intervention aims to resolve the root cause, with the reduction of tinnitus as a secondary benefit. The decision to proceed with surgery follows an exhaustive evaluation, and its application is reserved for a narrow and well-defined group of patients.
Identifying Surgically Treatable Causes of Tinnitus
A number of specific medical conditions can produce tinnitus as a symptom, and some have surgical remedies. One such condition is otosclerosis, a disorder characterized by abnormal bone growth in the middle ear that fixes the stapes bone in place, leading to conductive hearing loss and tinnitus. Another source can be tumors, the most common being an acoustic neuroma (vestibular schwannoma). This benign tumor grows on the vestibulocochlear nerve connecting the inner ear to the brain, and its pressure can cause hearing loss, balance problems, and tinnitus.
Pulsatile tinnitus, a rhythmic sound that syncs with the patient’s heartbeat, points toward vascular issues. This can be caused by arteriovenous malformations, which are tangled connections between arteries and veins, or glomus tumors, which are vascular growths in the ear or at the base of the skull. In some instances, a blood vessel may press directly against the auditory nerve, a condition known as vascular compression, which can also generate tinnitus.
Other structural problems can also be the source of the sound. Superior canal dehiscence syndrome involves a thinning or absence of the bone overlying one of the semicircular canals in the inner ear, creating a “third window” that can cause dizziness and auditory disturbances. In certain advanced cases of Meniere’s disease, an inner ear disorder, destructive procedures may be considered to alleviate severe vertigo and related tinnitus. Finally, muscle spasms in the middle ear, known as myoclonus, can also be a rare, but treatable, cause.
Types of Surgical Procedures
The surgical procedure recommended depends on the underlying diagnosis. For patients with otosclerosis, the standard surgery is a stapedectomy or stapedotomy. In this microsurgical procedure, a surgeon removes all or part of the immobilized stapes bone and replaces it with a tiny prosthesis, allowing sound waves to be transmitted to the inner ear. This restoration of hearing can lead to a reduction in the associated tinnitus.
When tinnitus is caused by an acoustic neuroma, the treatment is the surgical removal of the tumor. The goal is to resect the growth while preserving the function of nearby nerves, particularly the facial nerve and, if possible, the hearing nerve. The complexity of this neurosurgical procedure depends on the tumor’s size and location, but relieving pressure on auditory structures can sometimes alleviate the tinnitus.
For pulsatile tinnitus resulting from vascular compression of the auditory nerve, a procedure called microvascular decompression may be performed. This involves a neurosurgeon placing a small, soft pad between the offending blood vessel and the nerve, cushioning it from the vessel’s pulsations. In cases of superior canal dehiscence syndrome, surgeons can use a bone graft or cement to plug the opening in the semicircular canal, restoring the inner ear’s normal fluid dynamics.
In situations where tinnitus is linked to profound sensorineural hearing loss, a cochlear implant may be an option. While not a direct surgery for tinnitus, the implant bypasses damaged parts of the inner ear to stimulate the auditory nerve directly. This introduction of external sound signals to the brain can suppress the perception of tinnitus for many individuals, making it an indirect surgical approach for this patient group.
The Evaluation Process for Surgical Candidates
The path to determining if a patient is a suitable candidate for surgery is thorough. It begins with a consultation with a specialist, an otolaryngologist (ENT) or a neurotologist. The physician will take a comprehensive medical history, asking specific questions about the tinnitus, such as its pitch, loudness, and whether it’s constant or intermittent. This discussion helps to narrow down the potential underlying causes.
Following the history, a series of diagnostic tests is required to pinpoint the source of the problem. A comprehensive audiological evaluation involves a battery of hearing tests to measure the extent and type of any hearing loss, which is often associated with tinnitus. These tests help differentiate between conductive issues, like otosclerosis, and sensorineural problems that might point toward a nerve-related cause.
Imaging studies are often the next step to visualize the structures of the ear and brain. Magnetic Resonance Imaging (MRI) is effective for identifying soft tissue abnormalities like acoustic neuromas or evidence of vascular compression. A Computed Tomography (CT) scan is better for examining bone, making it the preferred choice for diagnosing conditions like superior canal dehiscence. For suspected vascular issues causing pulsatile tinnitus, a Magnetic Resonance Angiogram (MRA) may be used to map blood vessels.
Surgical Outcomes and Associated Risks
The success of surgery in resolving tinnitus is variable and tied to how effectively the underlying condition is treated. For stapes surgery to correct otosclerosis, studies show a high success rate, with one 2018 review finding that tinnitus improved in about 85% of patients. Surgeries to repair superior canal dehiscence or decompress a blood vessel can lead to complete resolution if the structural problem is the sole cause. For other conditions, the outcome is less certain, as after the removal of an acoustic neuroma, tinnitus may improve, remain unchanged, or worsen in some cases.
Patients should have realistic expectations. A reduction in the loudness or bothersome nature of the tinnitus is a more common outcome than its complete disappearance. In some instances, the surgery may successfully treat the primary condition, like hearing loss, without a significant impact on the tinnitus. The duration of the tinnitus before surgery can also influence the outcome, as longer-standing tinnitus may be less likely to resolve completely.
All surgical procedures carry inherent risks, including infection, bleeding, and adverse reactions to anesthesia. Specific to these ear surgeries, a primary risk is further hearing loss, with a small chance of creating total deafness in the operated ear. Dizziness and vertigo are common in the immediate postoperative period and can persist for weeks or months as the body’s balance system adapts.
Because the facial nerve runs near the surgical field in many of these procedures, there is a risk of temporary or, in rare cases, permanent facial weakness. Other potential complications include a change in taste, as the nerve for taste on one side of the tongue is near the eardrum. The failure of the procedure to resolve the primary issue might also necessitate revision surgery.