Microvascular decompression for hemifacial spasm: A systematic review of vascular pathology, long term treatment efficacy and safety.

INTRODUCTION: Hemifacial spasm (HS) is a rare disorder caused by the compression of facial nerve root exit zone (REZ) at the brainstem by a vascular loop. Microvascular decompression (MVD) is a popular treatment modality for HS. OBJECTIVE: The purpose of this study was to determine the long-term efficacy and safety of MVD for HS by assessing the effect of the procedure from the literature published over the last 25 years. MATERIALS AND METHODS: A systematic data review from 1992 to 2015 using specific eligibility criteria yielded 27 studies on MVD for HS, the data of which were pooled and subjected to a meta-analysis. RESULTS: The pooled odds ratio (OR) revealed by the meta-analysis showed that anterior inferior cerebellar artery was the most common offending vessel in 37.8% (95% confidence interval [CI]: 27.8-47.7%) of the patients. Complete resolution of HS was seen in 88.5% (95% CI: 86.7-90.4%) of the patients after a long-term follow up. The complication rate was low following MVD, the most common being temporary facial paresis in 5.9% (95% CI: 4.3-7.5%) of patients. CONCLUSIONS: MVD is a safe and effective treatment for HS with long-term benefits and a low complication rate.