Anatomic basis of the infratemporal approach of the jugular foramen.

A description of the lateral infratemporal approach of the jugular foramen (JF) was performed according to bone data, anatomico-radiologic relationships and microsurgical and endoscopic dissection: the jugular foramen is an anteromedial fissure of the petro-occipital fissure. The location of the exocranial facial nerve and the skeletonization of the third portion of the facial canal represents the main obstacle. A retro-facial dissection, then a medio-facial sub-labyrinthine dissection, while displacing the sigmoid sinus, should avoid a systematic diversion of the nerve, which is the cause of severe paralysis. The broad approach of the "pars nervosa" of the jugular foramen demands the control of the vertical part of the carotid canal. The lateral infratemporal approach of the jugular foramen is necessary for the treatment of specific lesions of the area (chemodectoma, neurinoma), which is invaded contiguously (carcinoma).