Turkish Neurosurgery 2023 , Vol 33 , Num 6
Microstructure and Reasonable Management of the Arachnoid Associated with the Infrafloccular Approach for Microvascular Decompression of the Facial Nerve
Le ZHOU1,Jianqiang QU1,Mengyao SUN1,Junjie QUAN1,Xianxia YAN1,Yanbing MA2,Jiehua XU2
1The Second Affiliated Hospital of Xi?an Jiaotong University, Xi?an City, Department of Neurosurgery, Shaanxi Province, The People?s Republic of China
2Institute of Basic Medicine, Xi?an Jiaotong University Health Science Center, Department of Human Anatomy and Histoembryology, Xi?an City, Shaanxi Province, The People?s Republic of China
DOI : 10.5137/1019-5149.JTN.31625-20.2 AIM: To understand the arachnoid microstructure during infrafloccular approach for facial nerve microvascular decompression (MVD).

MATERIAL and METHODS: This study recruited 55 patients with hemifacial spasm who underwent MVD. Retrospective analyses of the MVD surgical videos were performed to reveal the arachnoid microstructure during the procedures. Cadaveric head specimens (n=8, on 16 sides) were dissected for observation of the microstructure of the arachnoid in the cerebellopontine angle.

RESULTS: The arachnoid membrane surrounding the facio-cochleovestibular and lower cranial nerves forms two arachnoid sheaths. Both arachnoid sheaths contain two parts: the outer membranous and inner trabecular part. The membranous part is an intact and translucent membrane that wraps around nerves. The inner trabecular part is located beneath the membranous part and forms a trabecular network that connects the membranous arachnoid, nerves, and blood vessels to form a physical structure.

CONCLUSION: The arachnoid connects the facio-cochleovestibular and lower cranial nerves, blood vessels, and cerebellum as a complex physical entity. Therefore, during MVD surgery, sharply dissecting the arachnoid before retracting the flocculus and relocating the offending vessels helps reduce nerve injury. Keywords : Arachnoid, Microvascular decompression, Facial nerve

Corresponding author : Jiehua XU, xujiehua@mail.xjtu.edu.cn