MICROSURGICAL VASCULAR DECOMPRESSION FOR HEMIFACIAL SPASM - A RETROSPECTIVE STUDY OF A 65 PATIENT SERIES AND LITERATURE-REVIEW

The results of a series of 65 consecutive patients operated on to reli eve hemifacial spasm (HFS) at Pierre Wertheimer Hospital in Lyon and a t Henri Mondor Hospital in Creteil, using the same microvascular decom pression (MVD) method, are reported. MDV was performed through a retro mastoid keyhole approach. A neurovascular conflict (NVC) was found in 62 cases (i.e., 95.5 %). The conflicting vessel was the posterior infe rior cerebellar artery (PICA) in 23 cases (35.4 %), the anterior infer ior cerebellar artery (AICA) in 22 cases (33.8 %), the vertebro-basila r artery (VBA) with PICA and/or AICA in 13 cases (20 %), and VBA alone in 4 cases (3.1 %). The conflicting artery was maintained apart from the REZ of VII nerve by interposin,g a ball made of Teflon fibers and/ or a plaque of Dacron. Forty-five patients (69.2 %) were totally cured , 16 patients (24.6 %) had only a partial (more than 50 %) improvement , and in 4 patients (6.2 %) surgery failed. Follow-up ranged from 1 mo nth to 13 years (mean : 4 years and 8 months). Important was that in 9 patients, total relief of spasm occurred only secondarily with a dela y sometimes as long as one year. Post-operative complications were dom inated by : 1) facial nerve deficits in 16 cases (24.6 %), of which 14 were transient and 2 were permanent; 2) hearing decrease in 10 cases (15.4 %), of which 5 were transient and 5 were permanent. These compli cations were encountered at the start of the experience and at a time when monitoring of intraoperative brainstem auditory evoked potentials (BAEP) was not routinely done. Our data proved to be consistent with those published in the literature.