The outcome of microvascular decompression for hemifacial spasm: a systematic review and meta-analysis

Microvascular decompression (MVD) is the first choice of surgery for hemifacial spasm (HFS). MVD surgery for vertebral artery (VA)-associated HFS is more difficult than for non-VA-associated HFS. There is controversy about the cure rate and complication of MVD for HFS in previous studies. We searched PubMed, Web of Science, and Embase for relevant publications. Based on the search results, we compared the outcomes of MVD for VA-associated HFS and non-VA-associated HFS. At the same time, we analyzed spasm-free rates and the complications and assessed the relationship between VA-associated HFS and gender, left side, and age. For analysis, six studies that included 2952 patients in the VA-associated group and 604 in the non-VA-associated group were selected. The effective rate of MVD was not significantly different between both groups (OR?=?1.16, 95% CI 0.81–1.67, P?=?0.42). Compared to non-VA-associated group, the transient complications (OR?=?0.64, 95% CI 0.46–0.89, P?=?0.008) and permanent complications (OR?=?0.28, 95% CI 0.15–0.54, P?=?0.0001) occurred more frequently in VA-associated group. The rate of hearing loss was significantly higher in VA-associated HFS than non-VA-associated HFS (OR?=?0.35, 95% CI 0.19–0.64, P?=?0.0007); the facial paralysis after operation was not significantly different between both groups (OR?=?1.25, 95% CI 0.91–1.72, P?=?0.17). There were older patients (WMD?=?3.67, 95% CI 3.29–4.05, P?P?P?