A Clinical Study Of Neuroendoscope-assisted Microvascular Decompression In The Treatment Of Hemifacial Spasm

Abstract: Objective: To analyze the possible cause ofHFS. To investigate the curative effect and safety ofneuroendoscope-assisted microvascular decompression (MVD) forhemifacial spasm（HFS）. Methods: The clinical data of28patientswith HFS were analyzed，which were treated with endoscope-assistedMVD from March2010to September2011. Preoperatively allpatients underwent MRI（magnatic resonance imaging）or CT（computedtomography）to exclude secondary cause of the disease，and3D-TOF-MRA （three dimensional time-of-flight magneticresonance angiography） examination to find out therelationship between the offending vessels of HFS and the facialnerve. During the operation，the root exit zone(REZ)of facial nerve wasexposed through suboccipital sigmoid sinus approach.And theneuroendoscope was used to show the relationship between the nerveand the offending vessels around it， precise confirmation of thecompressing vessel,and confirmation of the proper position of the Teflonprothesis and precise detachment of compressing vessel. Patients werefollowed up．Result： Compressing vessels were identified in allpatients intraoperatively． The offending vessel were anterior inferior cerebellar artery(AICA) in13patients(46.4％)，posteriorinferior cerebellar artery(PICA) in8(28.6％)，vertebral artery（VA） in1(3.6％) and vessels complex in6(21.4%). At discharge, symptoms of23patients (82.1％)completely relieved,3patients（10.7%）significantlyimproved，2patients(7.1％)partly improved. The follow-up was6~24months (mean12.6months), and all patients were undergoingfollowing-up monitoring. The spasm was disappeared in26(92.9％)HFS cases, recurrent in1（3.6%），and1showed inefficacy（3.6%）.Majorcomplications included headache in6cases（21.4%）, dizziness in4（14.3%）, tinnitus in3（10.7%）, delayed facial palsy in2(7.1％),Hearing-impaired in2(7.1％). And no another serious complicationswere noted，including cerebrospinal fluid leakage,infection,and death.Conclusion： It is the direct and main cause of HFS thatresponsible vessal compresses the root entry zone of facial nerve. Theneuroendoscope-assisted MVD is an ideal method to treat HFSbecause it has the function of increasing the effective rate and decreasingthe complications. Elaborate neuro-radiological exam before operation,skilled microneurosurgery and neuroendoscope technique,correctidentification of the offending vessel and sufficientdecompression are very important for safety and high performance of thesurgery.