Vestibular neurotomy is widely and effectively used in the treatment of intractable vertigo due to Ménière’s disease and some other otogenic vertigo that has failed to respond to pharmacological or conservative surgical treatment. The main advantage of vestibular neurectomy is that for 85-99% of patients with Ménière’s disease, it can eliminate vertigo while preserving hearing, thus greatly improving the quality of life of the patient. 1. Diagnosis and treatment of Ménière’s disease Ménière’s disease occurs mostly in middle-aged people, and typical cases present with a quadruple syndrome of episodic vertigo, fluctuating hearing loss, tinnitus, and ear stuffiness. It is now believed that Ménière’s disease is due to endolymphatic fluid accumulation or swelling of the endolymphatic space, which eventually leads to vagal fibrosis. The mechanism of vertigo attacks secondary to rupture of the membranous structures of the endolymph lies in the mixing of high potassium endolymphatic fluid with low potassium ectolymphatic fluid, and the inward flow of potassium ions drives depolarization of the vestibular nerve endings, leading to vertigo and nystagmus. The diagnosis of Ménière’s disease lies mainly in the assessment of symptoms: recurrent episodes of vertigo, lasting from tens of minutes to hours and able to be relieved relatively quickly, episodes of clarity, tinnitus, dullness and fluctuating hearing loss associated with vertigo. Pharmacological treatment is effective in 70-90% of patients, however, a significant number of patients are insensitive to pharmacological treatment and eventually become disabled as a result. For these patients, surgical treatment should be considered. The decision to operate or not to operate is based on the frequency of vertigo episodes, the hearing loss in the affected ear, a careful assessment of the emotional state and the occupational status. Among the different surgical techniques performed today, various vestibular deprivation techniques are often recommended. The rationale behind these techniques is that, on the one hand, the disturbed vestibular afferents are eliminated through functional deprivation and, on the other hand, the unilateral vestibular afferents can be compensated centrally, thus relieving the symptoms. Based on the advantages of vestibular neurotomy, this technique has been widely used in the treatment of intractable vertigo due to Meniere’s disease. The vestibular neurotomy has evolved over a long period of time, with Krause first applying a total transcranial VIII cranial nerve dissection in 1898 to control vertigo due to Meniere’s disease, and House creating the cranial middle fossa approach in 1961, which became the main procedure for more than 20 years. In 1978, Silverstein and Norrel introduced the posterior vagal approach, which was simpler and had fewer complications than the cranial fossa approach, but it had a smaller field of view and poorer exposure of the pontocerebellar horn. In 1986, Silverstein introduced the posterior sigmoid sinus approach, which allowed for better selective dissection of vestibular nerve fibers. Since then, various techniques such as posterior sigmoid sinus-internal auditory tract approach, combined posterior vagus-posterior sigmoid sinus approach, and inferior vagus approach have been introduced into the clinic. In general, the posterior vagus approach does not adequately expose the VIII cranial nerve and requires abdominal fat to fill the operative cavity, as well as having a high risk of postoperative cerebrospinal fluid leakage. The advantages of this technique include faster and better exposure of the VII and VIII cranial nerves in the pontocerebellar horn and a lower incidence of cerebrospinal fluid leakage. However, the main disadvantage is the high incidence of postoperative headache, which may be related to postoperative adhesions of muscle fibers to the meninges and muscle pulling on the meninges when the neck is moved, which is expected to be reduced by cranioplasty. Currently, the majority of surgeons in the United States use a posterior sigmoid sinus approach, and one-third of surgeons use multiple approaches. 3. Identification and management of the middle vestibular nerve Some scholars believe that intraoperative monitoring of auditory evoked potentials can help determine whether the cochlear nerve is damaged, but we have found that this technique is not very useful either theoretically or practically. The identification of each component of the VII/VIII cranial nerve complex can be clearly accomplished by relying on anatomical landmarks. After exposing the pontocerebellar angle, the arachnoid membrane, which is wrapped around the surface of the bundle, is slightly separated microscopically and the vestibular nerve above and the sural nerve below can be clearly seen, with a clear cleft between the two (cochlear vestibular fissure) in 75% of cases and a small artery visible from behind as a demarcation mark. When cutting the vestibular nerve, care is taken to keep the tip of the microscissors superior to avoid damaging the facial nerve located anteriorly and to cut a small section of the nerve to prevent possible regenerative connections. 4. precautions Complications of vestibular neurotomy include intraoperative bleeding, postoperative incisional infection, cerebrospinal fluid leakage, meningitis, tinnitus, hearing loss, and facial palsy. a decade-long retrospective study reported by Goksu showed a very low rate of postoperative complications (2.5%) with the combined posterior sigmoid sinus-posterior vagus approach, and the most common complication was abdominal hematoma due to fat extraction (4.5%) rather than cranial complications. No incisional infections or meningitis occurred in any of the patients we treated. Postoperative cerebrospinal fluid leakage occurred in about 10% of patients and was controlled by lowering cranial pressure and local compression bandaging. One patient developed delayed mild facial palsy on the operated side two weeks after surgery and recovered completely after treatment with hormones and neurotrophic agents. Complete blockage of vestibular impulse afferents on the lesioned side is the primary purpose and therapeutic rationale of vestibular neurectomy, and all procedures have good control rates for vertigo, but even after combined vestibular neurectomy with vagotomy, recurrence of vertigo or balance disorders may occur. Most of these patients with a main report of dizziness can get complete relief within two years; a few patients show persistent but mostly mild and rarely affect the patient’s life. This may be related to incomplete nerve severance, nerve regeneration, etc., or to concurrent or sequential contralateral ear or central disease, as well as non-auricular vertigo. In addition, a few patients exhibit a persistent sense of instability, which may be related to uncompensated or incomplete central compensation, and timely postoperative vestibular rehabilitation can help to obtain vestibular compensation more quickly. Tinnitus and hearing status are also the focus of postoperative observation after vestibular neurectomy. Hearing loss may occur after surgery, but objectively speaking, assessing the long-term effects of vestibular neurotomy on hearing is difficult due to the fluctuating nature of the patient’s hearing and the fact that the surgery itself does not alter the natural progression of the disease. If a 10 dB rise in pure tone hearing threshold is defined as hearing loss, the incidence is 27-50%, but mostly does not exceed 30 dB, with rare cases of total deafness. For postoperative tinnitus, improvement rates of up to 75% have been reported, but a review of the literature shows a wide variation in tinnitus improvement rates reported by each (21-75%), and there are also reports of non-significant differences between the postoperative improvement rates and the placebo-treated and untreated groups. There is no clear prognostic indicator. Overall, the frequency and severity of preoperative vertigo episodes did not correlate with prognosis, but those patients with heavier preoperative self-assessment had more difficulty achieving optimal outcomes. The presence of contralateral tinnitus suggests a poorer prognosis. There is a tendency for patients with previous allergic disease and visual disorders to have a worse prognosis, probably due to the potential association of Ménière’s disease with allergic reactions and the greater susceptibility of visual disturbances to balance disorders and vertigo in a state of vestibular dysfunction.