Purpose: Microvascular decompression (MVD) surgery has been accepted as a potentially curative method for hemifacial spasm (HFS). The primary cause of failure of MVD is incomplete decompression of the offending vessel due to inadequate visualization. This study is aimed at evaluating the benefit of endoscopic visualization and the value of fully endoscopic MVD.
Methods: From March 2016 to March 2018, 45 HFS patients underwent fully endoscopic MVD in our department. From opening the dura to preparing to close, the assistant held the endoscope and the surgeon operated. Abnormal muscle response (AMR) and brainstem auditory evoked potentials (BAEP) were monitored. For every patient, the offending vessel was transposed or interposed and achieved complete decompression. AMR was used to evaluate the adequacy of decompression at the end of the surgery. The intra-operative findings and postoperative outcomes and complications were analyzed.
Results: Immediately after surgeries, 39 patients (86.7%) achieved excellent result; 2 cases (4.4%) had good result. So the postoperative effective rate was 91.1% (41/45). During 12-36 month follow-up, the outcomes were excellent in 42 cases (93.3%) and good in 2 cases (4.4%), and the effective rate reached to 97.8% (44/45). No recurrence was noted. The postoperative complications were found in 2 patients (4.4%). One patient (2.2%) showed delayed facial palsy on the tenth day but was fully recovered 1 month later. Intracranial infection was noticed in 1 patient (2.2%) and was cured by using intravenous antibiotics for 2 weeks. There was no hearing impairment, hoarseness, or other complications.
Conclusions: Fully endoscopic MVD is both safe and effective in the treatment of HFS. Electrophysiological monitoring is helpful to gain a good result and reduce hearing impairment.
Keywords: Electrophysiological monitoring; Endoscope; Hemifacial spasm; Microvascular decompression.