During microvascular decompression (MVD) 1962 Gar-dne, it was found that microvascular compression was closely related to the occurrence of hemifacial spasm. Based on this, it is considered that hemifacial spasm is a common reversible pathophysiological state, which is caused by the slight continuous compression of facial nerve by the vascular structure of cerebellopontine angle. It provides a theoretical basis for the future development of microvascular decompression. Jannetta =1977 ~1992 microvascular decompression for 78 cases of hemifacial spasm, and 924 cases reported in Kobdra 1984~ 1994 in Japan all achieved satisfactory results and accumulated rich experience. From 1987 to 1998, we treated 368 patients with hemifacial spasm with this method. Within 2 months after operation, the spasm disappeared by 93.7%, partially relieved by 4% and unchanged by 2.3%. At present, the commonly used microvascular decompression method is: the patient lies on his back with his head facing the healthy side. Local anesthesia plus diazepam for analgesia or general anesthesia. Incision of hairline behind ear; Or there is a transverse incision at the lower end of the lower flat mastoid tip. The skin incision is 3~4cm, the skull is drilled under the intersection of occipitomastoid suture or near the edge of breast protrusion, and then the enlarged bone window is opened, with a diameter of about 1.5~2cm, reaching the inner edge of lateral sigmoid sinus and the lower edge of transverse sinus from top to bottom. The dura mater was cut into a shape of ⊥. and then hung up. The operation was carried out with a five-fold magnifying glass or microscope under the illumination of a cold light source. Cerebrospinal fluid was released, and after cerebellum subsided, a 0.5cm wide brain pressure plate was inserted to expand the exposure range. Confirm the internal ear foramen, and lift the cerebellar villous lobule backward to expose the beginning of vestibular nerve and facial nerve root. Rapidly separate the arachnoid membrane in the cerebellopontine region with micro scissors, carefully explore the surface of the initial segment of the facial nerve root, and carefully separate the compression artery from the initial segment of the facial nerve root. Cut a piece of polyester or Teflon cotton of suitable size and put it between the facial nerve and blood vessels. Wrap polyester sheet around the root of facial nerve and fix both ends with silver clips. Or put a muscle between the artery and the nerve. After stopping bleeding completely, suture the incision in layers. Microvascular decompression also has some complications. With the passage of time, positive surgical experience and the renewal of surgical instruments, postoperative complications are significantly reduced compared with before. Barker( 1995) reported that ipsilateral hearing loss and deafness were 3.2%, and the incidence of facial muscle weakness was 7.4%.

The following link is "analysis of 37 cases of hemifacial spasm treated by microvascular decompression of facial nerve root":

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