Exoscopic microvascular decompression for trigeminal neuralgia and hemifacial spasm

Introduction: The 4K 3D exoscope system is becoming increasingly used in neurosurgery. Its three-dimensional ultra-high-definition image is valuable in identifying and dissecting the fine neurovascular structures during microvascular decompression (MVD). We described several nuances of exoscopic MVD by presenting several illustrative cases to highlight the benefits of exoscopic surgery.

Methods: The authors retrospectively reviewed the 159 patients who underwent exoscopic MVD. We illustrated surgical nuances and results of exoscopic MVD. by comparing its surgical outcomes and complications with those of 303 patients who underwent conventional operative microscopic MVD.

Results: The exoscope was placed in front of the patient's face to maximize the range of the exoscopic arm. The patients were in the supine position. Of 118 hemifacial spasm patients, 84% of them had excellent, and 10% of them had good results. Of 36 trigeminal neuralgia patients, 82% of them had excellent BNI grade I results, and 8% of them had BNI grade II results. All five glossopharyngeal neuralgia patients had excellent results. The recurrence rate was 1.6% in hemifacial spasm patients, and no recurrence was seen in trigeminal and glossopharyngeal neuralgia patients.
Our exoscopic MVD series showed non-inferior surgical outcomes compared to the operative microscope with no significant increase in surgical risk. The recurrence rates in the present series remain low, but it may reflect the short follow-up period.
Significant pneumocephalus was seen in 15% of exoscopic MVD patients. To avoid pneumocephalus, we need to replace the lost CSF at the end of the procedure.

Conclusion : An exoscope can be an alternative to performing MVD, as it is not inferior to the operative microscope and can provide several clinical and educational benefits. The surgical team needs to optimize the operative layout and patient position to maximize the benefit of the exoscope.