Curative effect and surgical skills of microvascular decompression via keyhole for 138 cases of hemifacial spasm

Objective To discuss the efficacy of microvascular decompression(MVD) for hemifacial spasm(HFS).Methods We analyzed the clinical data of 138 cases of HFS by MVD.Through flocculonodular,the root exit zones(REZ) of the facial nerve were exposed via keyhole approach.After identifying the responsible vessels,a pad of Teflon cotton was gently interposed to maintain the separation of the REZ and the responsible vessels.Function of the acoustic nerves was monitored throughout the procedure by means of brainstem auditory evoked potential.Results Vascular compression in the facial nerve roots REZ was found in all patients.Hemifacial spasm stopped immediately after the operation in 106 patients.The post-operative symptom duration was 1 week in 20 patients,3 months in 10 patients.Facial spasm recurred in 2 cases.Five patients had delayed decreased hearing.One had hearing loss.Conclusions MVD is the most effective method for hemifacial spasm.Skilled technique of microsurgery via keyhole approach could lead to minimal operative injury.The exposure of the REZ of facial nerve roots,responsible vessels identification and Teflon insertion are the key factors which affect the efficacy of decompression.Monitoring the brainstem auditory evoked potential in operation can prevent or decrease the complications of MVD,especially dysaudia.