Penetrating Offending Vessel, The Most Surgically Demanding Type during Microvascular Decompression Surgery in Hemifacial Spasm

Abstract

Abstract INTRODUCTION Microvascular decompression (MVD) is the most effective and curative treatment option for neurovascular compression syndrome and it is increasingly performed around the world. This study aimed to identify and describe the most technically difficult cases, which were the patients with penetrating offending vessel through the facial nerve, from our experiences and to give surgical tips for the successful MVD. METHODS Surgical records and intraoperative video of hemifacial spasm patients with penetrating offending vessels were reviewed. Interposition of Teflon felt between nerve and vessel was pursued, and neurectomy was avoided as much as possible. RESULTS Five patients with hemifacial spasm were identified as having a penetrating offending vessel through the facial nerve during the last 5 yr of MVD surgery in our institution. Four AICAs and one PICA were the causative vessels. Partial neurectomy was required in 1 patient. During the median follow-up of 6 mo (range, 1-26), all patients were spasm-free. No patients including the one with partial neurectomy were involved in facial palsy or hearing loss. CONCLUSION MVD in HFS patients with penetrating offending vessel through the facial nerve is the most surgically challenging and demands a high surgical skill. Interposition with Teflon felt is effective and neurectomy should be avoided. Intraoperative monitoring of free-running EMG and abnormal muscle response are helpful to decide the extent of surgery.