OBJECTIVE Dominant vertebral artery (DVA), tortuosity, and elongation of the vertebrobasilar artery system are frequently observed in hemifacial spasm (HFS). However, the morphological characteristics of the tortuosity of vertebrobasilar artery system have not yet been elucidated. In this study, we presented a novel method for the measurement of the bending length (BL) of the basilar artery(BA) or vertebral artery (VA) to assess the tortuosity of vertebrobasilar artery system in HFS patients. METHODS The demographic and morphological characteristics of 135 patients with HFS admitted to the neurosurgical department to undergo microvascular decompression (MVD) were analyzed in this retrospective study. The BL was defined to appraise the tortuous degree of the vertebrobasilar artery system, and according to the BL value, the patients with HFS were divided into two groups: tortuous vertebrobasilar artery (TVA) and non-TVA groups. Additionally, the vessels responsible for HFS were analyzed based on the results of magnetic resonance imaging (MRI) of the two groups. The patients were followed up for 2-6 years post-discharge, and the effect of MVD operation was compared between the two groups. RESULTS DVA was detected in 60.2% of HFS patients; the incidence of left-sided HFS in the TVA group was significantly higher than that in the non-TVA group (P = 0.013). The proportion of multiple responsible vessels in the TVA group was 68.4% (54/79), while that in the non-TVA group was 4.1% (2/49). The complication rate of the two groups was different, and that of the tortuous group was higher than that of the non-tortuous group. CONCLUSIONS The morphological characteristics of the vertebrobasilar artery system in patients with HFS were complex. The measurement of BL is an easy and reliable tool to assess the tortuosity of the vertebrobasilar artery system in HFS patients.

中文翻译：

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面肌痉挛患者椎基底动脉系统的形态学特征及弯曲长度测量评估迂曲度

目的 在面肌痉挛 (HFS) 中经常观察到优势椎动脉 (DVA)、椎基底动脉系统的曲折和伸长。然而，椎基底动脉系统迂曲的形态特征尚未阐明。在这项研究中，我们提出了一种测量基底动脉 (BA) 或椎动脉 (VA) 弯曲长度 (BL) 的新方法，以评估 HFS 患者椎基底动脉系统的曲折度。方法本回顾性研究分析了135例入院接受微血管减压术（MVD）的HFS患者的人口统计学和形态学特征。BL定义为评价椎基底动脉系统的曲折程度，根据BL值，将HFS患者分为两组：曲折椎基底动脉（TVA）组和非TVA组。此外，根据两组的磁共振成像（MRI）结果分析了负责 HFS 的血管。患者出院后随访2～6年，比较两组MVD手术效果。结果 在 60.2% 的 HFS 患者中检测到 DVA；TVA组左侧HFS的发生率显着高于非TVA组（P=0.013）。TVA组多责任血管比例为68.4%（54/79），而非TVA组为4.1%（2/49）。两组并发症发生率不同，曲折组并发症发生率高于非曲折组。结论HFS患者椎基底动脉系统的形态学特征复杂。BL 的测量是评估 HFS 患者椎基底动脉系统弯曲度的一种简单可靠的工具。