Missed Culprits in Failed Microvascular Decompression Surgery for Hemifacial Spasm and Clinical Outcomes of Redo Surgery

Abstract

To identify causes of recurrent hemifacial spasm (HFS) after initial microvascular decompression (MVD) and to assess the feasibility of redo MVD. The study included 21 patients who underwent redo MVD over the last 2 decades. Their medical charts were retrospectively reviewed for preoperative medical history, previous and redo MVD intraoperative findings, and previous and redo MVD postoperative outcomes. Redo MVDs were the second operation in 20 patients and the third operation in 1 patient. The median interval between previous and redo MVD was 46.3 months (range, 14.4-188.2 months). Compression of offending vessels such as a vein or perforating artery located medial to or at the cisternal segment of the facial nerve was found to be a possible cause of previous MVD failure. MVD failure resulted from neglect of offending vessels in 10 patients, insufficient decompression in 7 patients, and untouched neurovascular compression sites in 4 patients. Spasm-free rates after redo MVD were 80.5% at 1 year and 90.5% in the last year of follow-up (median, 15.8 months; range, 3.6-152.0 months). Permanent hearing loss and facial palsy were each observed in 2 patients (9.5%). In addition, 1 patient each experienced cerebellar infarction and vocal cord palsy. Redo MVD remains a feasible treatment option for patients with HFS who failed to benefit from previous MVD, but it is associated with an increased risk of cranial nerve and vascular injuries.