Microvascular decompression for treating hemifacial spasm: lessons learned from a prospective study of 1,174 operations.

The authors critically analyzed a large series of patients with hemifacial spasm (HFS) and who underwent microvascular decompression (MVD) under a prospective protocol. We describe several "lessons learned" that are required for achieving successful surgery and proper postoperative management. The purpose of this study is to report on our experience during the previous 10 years with this procedure and we also discuss various related topics. From April 1997 to June 2009, over 1,200 consecutive patients underwent MVD for HFS. Among them, 1,174 patients who underwent MVD for HFS with a minimum 1 year follow-up were enrolled in the study. The median follow-up period was 3.5 years (range, 1-9.3 years). Based on the operative and medical records, the intraoperative findings and the postoperative outcomes were obtained and then analyzed. At the 1-year follow-up examination, 1,105 (94.1%) patients of the total 1,174 patients exhibited a "cured" state, and 69 (5.9%) patients had residual spasms. In all the patients, the major postoperative complications included transient hearing loss in 31 (2.6%), permanent hearing loss in 13 (1.1%), transient facial weakness in 86 (7.3%), permanent facial weakness in 9 (0.7%), cerebrospinal fluid leak in three (0.25%) and cerebellar infarction or hemorrhage in two (0.17%). There were no operative deaths. Microvascular decompression is a very effective, safe modality of treatment for hemifacial spasm. MVD is not sophisticated surgery, but having a basic understanding of the surgical procedures is required to achieve successful surgery.