Iwami Kenichiro, Watanabe Tadashi, Yokota Mao, Hara Masato, Osuka Koji, Miyachi Shigeru
Department of Neurosurgery, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi Prefecture, 480-1195, Japan.
Acta Neurochir (Wien). 2021 Sep;163(9):2435-2444. doi: 10.1007/s00701-021-04899-9. Epub 2021 Jul 4.
We present a case series of underwater microvascular decompression (MVD) for hemifacial spasm (HFS) and an evaluation of its feasibility and safety.
This retrospective study was conducted at a single institution and included 20 patients with HFS who underwent underwater MVD between September 2019 and January 2021. Surgery was performed in 3 steps, as follows: exoscopic wound opening (soft tissue, bone, dura, and arachnoid around the cerebellomedullary cistern), underwater endoscopic surgery (decompression of the facial nerve), and exoscopic wound closure. In underwater endoscopic surgery, the surgical field was continuously irrigated with artificial cerebrospinal fluid. Abnormal muscle response and brainstem auditory evoked potentials (BAEPs) were monitored.
Neurovascular conflicts were clearly observed in all patients without fogging and soiling of the endoscope lens. HFS was completely relieved in 19 patients (95%). An amplitude reduction of wave V of BAEPs of more than 50% was not observed in any of the cases. In 5 cases (25%), the latency of wave V of BAEPs was prolonged for more than 1.0 ms; these changes completely or near completely returned to baseline values at dural closure in all 5 cases. A postoperative complication of transient facial palsy was observed in 1 patient (5%) during postoperative days 10-30. There were no other complications.
Our findings suggest that underwater MVD is a safe and feasible option for the treatment of HFS. However, it did not show advantages over conventional endoscopic MVD when the protective effect on the eighth cranial nerve was evaluated.
我们展示了一系列用于治疗面肌痉挛（HFS）的水下微血管减压术（MVD）病例，并对其可行性和安全性进行了评估。
这项回顾性研究在单一机构进行，纳入了20例在2019年9月至2021年1月期间接受水下MVD的HFS患者。手术分三步进行，如下：内镜下伤口切开（小脑延髓池周围的软组织、骨、硬脑膜和蛛网膜）、水下内镜手术（面神经减压）和内镜下伤口闭合。在水下内镜手术中，手术视野用人工脑脊液持续冲洗。监测异常肌肉反应和脑干听觉诱发电位（BAEP）。
所有患者均清晰观察到神经血管冲突，内镜镜头无雾化和污染。19例患者（95%）的HFS完全缓解。所有病例均未观察到BAEP的V波幅降低超过50%。5例患者（25%）的BAEP的V波潜伏期延长超过1.0毫秒；所有5例患者在硬脑膜闭合时，这些变化完全或几乎完全恢复到基线值。1例患者（5%）在术后第10 - 30天出现短暂性面瘫的术后并发症。无其他并发症。
我们的研究结果表明，水下MVD是治疗HFS的一种安全可行的选择。然而，在评估对第八颅神经的保护作用时，它并未显示出优于传统内镜MVD的优势。
