[Contribution of endoscopy of the cerebellopontine angle by retrosigmoid approach. Neuroma and vasculo-nervous compression].

An endoscopic approach to the cerebellopontine angle has been suggested by several authors over the last 20 years but it is only recently that the technical and operative conditions for successful endoscopy could be met. The retrosigmoid approach provides simple and direct access to the cerebellopontine zone. The endoscope, with its distal light source, provides excellent illumination of a wide visual field within an anatomical site particularly rich in neurovascular structures. Endoscopic and microsurgical techniques may be combined for the surgical management of acoustic neuroma with the advantage of assuring better exposure of structures adjacent to the tumor and better control of the quality of dissection of the fundus of the internal auditory canal. The addition of endoscopic techniques, during surgery for trigeminal neuralgia or unilateral facial spasm, makes it possible to accurately locate the site of neurovascular compression without either retraction of the cerebellum or unnecessary dissection.