vestibular neurectomy

Frazier (1904) first removed the 8th cranial nerve through the posterior cranial fossa to eliminate vertigo; Dandy (1932) reported 624 cases of vestibular nerve resection for vertigo, cutting off the afferent nerve of the vestibular nerve receptor, which can improve Meniere's disease. Symptoms, eliminate vertigo, but not for the cause, but for symptomatic surgery. Treating diseases: Meniere's disease Indication Vestibular neurotomy is available for: 1. Anyone who has uncontrollable dizziness and has good hearing, who has failed the endolymphatic sac surgery, may consider a cranial fossa or a vestibular nerve severing. The optimal rate of endolymphatic sac surgery is 60% to 70%, while the efficiency of vestibular nerve resection is more than 90%. This operation does not solve the lost water, the postoperative hearing is still fluctuating, and finally leads to loss or loss, so it is not appropriate to perform this technique in the early stage. 2. Incomplete amenorrhea continued with positional vertigo, residual retinal function, ice water perfusion can still lead to nystagmus, cutting vestibular nerve can get good results. 3. Atypical peripheral vertigo, that is, the lesion is located in the labyrinth, vestibular nerve or vestibular ganglion within the range of ischemic or micro-acoustic neuroma, only the in-segment surgery is not enough to control the symptoms, in order to block the abnormal impulse of the vestibular terminal, it should Vestibular nerve resection. 4. Anyone with uncontrollable peripheral vertigo, vertigo caused by semi-circular canal fistula after mastoidectomy, persistent vertigo after middle ear or humerus surgery, vertigo caused by traumatic brain injury or sudden deafness, conservative treatment is invalid Practicable vestibular nerve resection. Surgical procedure 1. Transvaginal vestibular nerve resection is suitable for conservative treatment and endolymphatic sac decompression, severe deafness, vestibular dysfunction. (1) Incision: 1.5 cm behind the back of the ear to make an arc-shaped incision, cut the skin, subcutaneous tissue, and peel the periosteum, and place the retractor. (2) Drilling and mastoid: according to the mastoid radical approach, open the sinus, mastoid cavity and upper tympanic cavity to make the mastoid cavity contour. (3) Open and lost: In order to facilitate the operation, the drill bone and the hammer bone can be taken out, the open bone is lost with the electric drill, the outer, front and rear semi-regular lumens are exposed, the vestibule is opened, the inner wall of the vestibule is exposed, and the ampulla of the front half tube is a useful sign. The upper vestibular nerve can be traced. The posterior superior posterior wall of the vestibular wall is the upper vestibular nerve entry, distributed in the upper and outer semicircular canals and the sac. (4) Open the inner auditory canal: mark the white point of the sieve-like area, drill the diamond inward and backward in the microscope under the microscope, and thin the upper, the posterior and the anterior bone wall of the inner auditory canal, and remove the thinned shell. The inner auditory canal wall, when the inner auditory canal is exposed, and the inner bone of the auditory canal is ground, carefully rub the bone of the facial nerve labyrinth, protect the facial nerve under the vision, chase the inner ear, do not damage the meninges, on the meninges. With a small incision, the upper vestibular nerve can be seen, the vertical iliac crest is exposed upwards (Bill septum), and the front of the vertical iliac crest is the facial nerve. The upper vestibular nerve and facial nerve must be clearly separated, the adhesion between them should be carefully separated, and the transverse and lower vestibules should be exposed downward. Nerve, at this time, the cerebrospinal fluid overflows into the surgical field, gently sucks out, and waits for it to reduce or stop leaking before performing surgery. (5) Cutting the vestibular nerve: the facial nerve is located in front of the anterior and transverse iliac crest, and should be protected. The lower part is the sacral nerve; the upper and lower parts are the upper and lower branches of the vestibular nerve. The branch of the anterior inferior cerebellum generally does not extend into the inner ear canal. This arterial injury is hemorrhage by bipolar electrocautery. Use a small hook to separate the facial nerve from the vestibular nerve. If the vestibular nerve is severed under the diaphragm, a vestibular nerve including the vestibular ganglion is removed. Severe tinnitus and severe hearing loss in patients with severe cranial nerve severing, it can be seen above the upper auditory canal. At the same time, you can check whether there is a tumor in the cerebral cerebellar triangle (6) Close the operating cavity: After the nerve is cut, cover the inner auditory canal with free diaphragmatic muscle flap or abdominal fat to prevent cerebrospinal fluid leakage, fill the mastoid cavity with musculoskeletal flap or gelatin sponge, and suture according to the level. 2. After vaginal vestibular neurotomy, the three semicircular canals are removed from the cerebral cerebellar triangle after being lost. For patients with practical hearing and unable to control the onset of vertigo, vestibular neurotomy can be performed. The advantage of this approach is that the damage is simple and the injury is The risk of the auditory nerve and facial nerve is small, and the shortcoming is that the visual field is small, and the vestibular ganglion can not be removed. The surgical procedure is the same as that of the labyrinth of the vestibular nerve, and the incision is made in the ear. The routine mastoidectomy is performed, the posterior wall of the external auditory canal is preserved, the contour of the vertical section of the facial nerve is recognized and ground, and the surface of the sigmoid sinus is removed by diamond drilling. And posterior cranial fossa plate, exposing the posterior cranial fossa brain plate and sigmoid sinus, can press the sigmoid sinus to move it backward, the posterior semicircular canal position is constant, protrudes about 2mm behind the outer semicircular canal, and grinds its contour with a diamond bit, but not Grind out the blue, cut the meninges between the posterior semicircular canal and the sigmoid sinus into the posterior cranial fossa, and put it into the posterior cranial fossa automatic retractor, compress and pull the sigmoid sinus, so that the cerebral cerebellar triangle is better exposed. The key is to Exposure of the sigmoid sinus without massive bleeding. Intravenous injection of 20% mannitol 250 ~ 500ml half an hour before the meninges were cut, reducing brain tissue volume. The sigmoid sinus is pulled backwards. After the meninges are opened, the cerebellopontine triangle is exposed. The trigeminal nerve, facial nerve, auditory nerve, glossopharynx and vagus nerve can be seen. The vestibular nerve and the auditory nerve are like a nerve. Under the microscope, the crack can be seen between the two. Clear, separate the vestibular nerve before it is separated, in the pons cerebellar triangle area, the facial nerve is attached to the back of the cochlear nerve, opposite to the position of the internal auditory canal, from the inner auditory canal to the brainstem facial nerve from above to below, the cochlear nerve From the back to the front and bottom of the brain stem. The nerve stimulator can be used to confirm the facial nerve. Stimulating the distal part of the vestibular nerve can cause mild facial muscle movement. The impulse can be transmitted to the facial muscle through the vestibular and facial nerve anastomosis, and the sinus nerve is stimulated to not produce facial muscle movement. The color of the vestibular nerve is different from that of the cochlear nerve. The former is darker. Some authors use brainstem electrical response audiometry (ABR) to monitor the cochlear nerve. After clarifying the anatomical relationship between the facial nerve, the cochlear nerve and the vestibular nerve, the vestibular nerve should be cut with a sharp knife, microsurgical scissors, or krypton laser beam. The anterior inferior cerebellar artery that supplies the brainstem should be prevented from being damaged. The meninges and the mastoid cavity should be sutured after strict hemostasis. Fill in fat, prevent cerebrospinal fluid leakage, suture the skin, and dress up. 3. Posterior sigmoid sigmoidectomy is suitable for poor mastoid gasification and sigmoid sinus advancement. It is not suitable for patients with posterior sinus approach. The advantages are the same as that after getting lost, the operation is simple, the damage hearing function and the risk of facial nerve are small. The disadvantage is that the vestibular ganglion cannot be removed and there is a paralysis of the neuroma. 2cm from the posterior sulcus of the ear to make a curved incision deep into the periosteum, the top line of the arc is the vertical line of the posterior edge of the mastoid, the upper end of the incision does not exceed the sacral line, the lower end is not lower than the tip of the mastoid, the arc string is no more than 3cm, and the bone coat is separated. . Cut the occipital scalpel bone about 2cm × 3cm, in order to avoid damage to the stem pores, it is best to use an electric drill to remove the skull. Before the skull is removed, the stripper extends between the skull and the sinus, separating the two, gently Push down, if the sinus is damaged, it can be pressed with gelatin sponge. The upper edge of the bone window reaches the transverse sinus, and the leading edge is near the sigmoid sinus. The dura mater is made into a "skull"-shaped incision, and the transverse sinus must be avoided when cutting. In order to facilitate the suture of the dura mater, the edge of the dural incision should be kept at a certain distance from the edge of the bone window. Before the dura mater, 250 ml of mannitol is rapidly instilled. The cerebellum is protected by the brain cotton during the exploration, and the cerebellum can be gently pressed by the brain plate. The cerebral cerebellar triangle was explored, and the follow-up surgical procedures were the same as getting lost. Before cutting off the upper vestibular nerve, the facial nerve and the vestibular nerve anastomosis were separated by a micro-scalpel, then the upper and lower branches of the vestibular nerve were cut, and the meninges and skin were sutured layer by layer. 4. Transcranial scapular vestibular neurotomy (1) Incision: The incision begins at the natural hairline, 0.5 to 1 cm in front of the base of the auricle, and extends 7 to 8 cm from the plane of the zygomatic arch. An automatic retractor is placed. In addition to the superficial temporal artery ligation, other small blood vessels are coagulated to stop bleeding. When the incision is deep into the plane of the temporalis fascia, it is separated along the sacral line by a stripper, and a 2cm×5cm pedicled fascia fascia flap is used. The basal fascia is in the infraorbital fossa, which is the deep side of the zygomatic arch. The flap is turned up with the periosteum. The muscles on both sides of the muscle flap are placed in an automatic retractor, and the lower part of the field must be exposed to the sacral root. (2) Flipping up the bone plate: use a power drill or a gas drill to open a 3cm × 3cm square bone window in the sacral scale, the lower edge of which is as close as possible to the iliac crest and its extension. After the edge of the bone window is worn through, the bone flap is picked up, stored in physiological saline for use, and returned to the original position at the end of the operation. (3) Lifting the meninges: Separate the meninges of the middle cranial fossa with a stripper at the margin of the skull, remove the excessively high bone margin, place the automatic retractor, and completely stop the bleeding with bipolar coagulation. At the bottom of the middle cranial fossa, three signs should be recognized: 1 spine hole--is the middle part of the meninges into the skull, which is the mark of the forefront of the meninges; 2 the shallow nerves of the rock are separated from the genic ganglia and are worn at the face of the facial nerve. Out, between the meninges and the bottom of the cranial fossa, located in the posterior inferior sinus of the meningeal; 3 arcuate bulges, the arched ridges are sometimes not obvious after the meninges are lifted, and the superficial nerves are parallel to the rock and are easily recognizable. From the knee ganglion forward, the facial nerve can be traced. The meninges are picked up from the back to the front, and the rock shovel must be recognized at the back end. There is an upper sinus in the rock sulcus, and damage should be avoided. Pulec reported that about 15% of the cases of the facial nerve of the knee ganglion without bone plate coverage, separated from the back and forward under the microscope can avoid lifting the large shallow nerve. (4) Grinding the internal auditory canal: using diamond to remove the superficial nerve from the superficial nerve to the surface of the geniculate ganglion until the occipital ganglion is exposed, and the facial ganglion is exposed along the genic ganglia, and the path of the facial nerve is almost Parallel to the anterior semicircular canal, the internal auditory canal is located between the superficial nerve of the rock, the facial nerve hole and the posterior arch bulge, and the bone can be removed to open the inner ear canal. For accurate positioning, the bow can be gently swelled until the front half tube blue line is exposed, but the semicircular tube cannot be opened. Fisch et al. measured the angle between the inner auditory canal and the front semicircular canal at 45° to 60°. The bone on the upper auditory canal was removed with a small diamond drill, usually 5 to 10 mm thick, and the inner wall of the inner ear canal was ground into a 1 cm × 1 cm large bone window. The thickness of the upper wall of the internal auditory canal varies greatly, about 5-10 mm. After the bone is removed, the meninges of the inner auditory canal are close to the meninges. It is best to leave a thin piece of bone on the upper wall of the internal auditory canal. Wait until the other. Open the bone after removing it. (5) Open the internal auditory canal: the small hook removes the residual thin bone piece on the upper wall of the inner auditory canal, the opener expands the inner auditory bone window in the forward and backward directions, and cuts the full length dura mater of the internal auditory canal with a knife, and a large amount of cerebrospinal fluid is visible. After the flow rate is slowed down, the dura mater is lifted, the auditory nerve and the facial nerve can be seen, and the lateral iliac crest (Bill septum) can be seen by exposing the lateral end of the inner auditory canal. This is the bony separation of the facial nerve and the vestibular superior nerve. The upper facial nerve is connected with the posterior vestibular nerve. The inner auditory canal divides the vestibular nerve into two upper and lower branches. The inner part is thick and the blood vessels are the vestibular ganglion. There is a anterior inferior cerebellar artery between the facial nerve and the vestibular nerve. (6) vestibular neurotomy: under the 16 to 25 times operating microscope, the location of the facial nerve is identified at the top of the internal auditory canal. Separate the vestibular nerve with a small hook and a special knife. In particular, separate and cut the anastomosis between the vestibular and facial nerves. The small hook evokes the vestibular superior nerve. The other hand uses a small knife or a small shear to cut the lower vestibular nerve. The small scorpion raises the proximal rupture of the vestibular nerve. The anterior and posterior sacral nerves can be seen and separated. A vestibular nerve trunk including the large vestibular ganglion is cut off. If the deafness and tinnitus are serious, the cochlear nerve is also Can be removed for a period to avoid the occurrence of neurofibroma in the future. (7) Closing the wound: filling the inner auditory canal with a free or pedicled iliac muscle flap, returning the temporal lobe, returning the sacral scalp bone plate, suturing the diaphragm, subcutaneous tissue and skin, placing the drainage tube under the skin, and then splicing The rubber rinse ball is suctioned under vacuum and aseptically bandaged. complication 1. Wound infection: In the case of strict disinfection and a large number of antibiotics after surgery, the chance of infection has been significantly reduced, but there should be immediate preventive measures such as hemostasis and pressure dressing for subcutaneous hematoma. 2. Cerebrospinal fluid leakage and meningitis: Because the subarachnoid space and the mastoid air chamber communicate with each other, cerebrospinal fluid leakage can be formed, which mainly occurs when the surgical transsexual approach is performed, and the open mastoid gas is carefully filled with muscle or fat transplantation before the end of the operation. Room, closed the mouth. Although closed cerebrospinal fluid leakage can occur, the method of semi-recumbent, dehydration, diuresis and wound healing can be used to stop it naturally. If the cerebrospinal fluid is severely leaked, the cranial fluid can be placed through the lumbar cuff or the fistula can be closed again. There is little chance of meningitis. Once an unexplained high fever occurs, the cause of lumbar puncture should be determined. If it is bacterial meningitis, it should be treated with sensitive antibiotics for pathogenic bacteria. 3. Intracranial hematoma: In the middle of the cranial fossa, an epidural hematoma may occur. The dura mater is sutured to the edge of the bone flap and the epidural drainage tube is placed to avoid epidural hematoma. If the patient's postoperative consciousness changes, or accompanied by contralateral limb dyskinesia, the ipsilateral pupil dilated, the possibility of epidural hematoma cerebral palsy should be considered. If the brain CT diagnosis is made, the hematoma should be removed immediately and completely hemostasis. 4. Cerebral edema: Cerebral edema can occur within 48 hours after surgery. It can cause cerebral edema due to surgery, and cerebral edema hinders venous return. Disorders of consciousness and autonomic dysfunction are signs of cerebral edema. Brain CT can be found to narrow the ventricles and resuscitate carefully. Large doses of methylprednisolone or dexamethasone should be given intravenously. 5. Auditory nerve and facial nerve injury: Auditory nerve injury is difficult to recover; facial nerve injury is often temporary, can be treated with hormones, if facial nerve fracture is feasible facial nerve anastomosis, transplantation and other operations.