Endoscopically assisted minimally invasive microvascular decompression of hemifacial spasm

Objective: The aim of this study was to assess the use of endoscopy in minimally invasive surgery of the cerebellopontine angle in cases of hemifacial spasm. Materials and Methods: Eighty patients with hemifacial spasm underwent endoscopically assisted microvascular decompression between October 1992 and October 1998, at the Ear, Nose, and Throat Department of Nord Hospital in Marseille, France. The microvascular decompression was performed via a minimally invasive retrosigmoid approach. The cerebellopontine angle was then explored by a 30-degree endoscope to visualize the root exit zone of the facial nerve and the precise location of the site of the conflict. Microvascular decompression was performed under the microscope. If the site was an artery, a Teflon sponge was inserted; if the site was a vein, it was coagulated and then dissected away from the facial nerve. Results: In 80 patients seen regularly for at least 1 year of follow-up, and including patients operated on once or twice, the procedure was successful in 92.5% of patients, brought about improvement in 3.75% (96.25% success plus improvement), and failed in 3.75%. In relation to the type of conflict, success or improvement was experienced by 90.7% of patients with simple conflicts, 86.2% of patients with multiple conflicts, and 87.5% of patients with nutcracker conflicts. No major postoperative complication or mortality occurred in this series. No facial paresis or paralysis occur-red immediately postoperatively. Three patients (3.25%) experienced delayed facial palsy. Postoperative cerebrospinal fluid leak occurred in 2 patients (2.5%) and was treated surgically. Conclusion: The principle of minimally invasive surgery in the cerebellopontine angle is gaining universal acceptance. The use of endoscopy in microvascular decompression for hemifacial spasm has helped tremendously in improving the results. In this study, the use of the endoscope enabled the authors to identify the site of the conflict in all cases, and to confirm the position of the Teflon sponge before closure.