[Anatomic problems involved in the approach to the internal carotid artery]

The portion of the internal carotid artery (ICA) located above the line joining the tip of the mastoid and the angle of the mandible is in close relation with cranial nerves VII, IX, X, XI and XII as well as the middle ear at the beginning of its intrapetrous course. Several procedures have been described for exposure of the ICA at the base of the skull. Extension of the conventional sternocleidomastoid approach by mandibular subluxation associated with division of the posterior belly of the digastric muscle and the styloid apophysis or its attached muscles allows exposure of most of the ICA. To access the last centimeter of the ICA it is necessary ot drill through the mastoid apophysis and the vaginal apophysis of the tympanic bone. This approach preserves the middle ear and the facial nerve.