Facial nerve continuity was restored during cerebellopontine angle tumor removal in nine cases. The distal facial nerve was rerouted from the stylomastoid foramen into the cerebellopontine angle. Direct suture was accomplished in seven cases while two required interposition of a greater auricular nerve graft. There was excellent return of facial function in eight of the nine cases. Overall results are superior to nerve substitution techniques. The facial nerve should be inspected for continuity following tumor removal. If one is not certain the nerve is intact, the proximal facial stump should be identified at the brain stem and facial nerve continuity reestablished. A nerve substitution procedure should be resorted to a later time only when the proximal facial stump is not identifiable.

Adult↗

PubMedDate not supplied

Surgery of the skull base: transcochlear approach to the petrous apex and clivus.

The transcochlear approach is described for resection of lesions arising anterior or medial to the internal auditory canal as well as for those arising directly from the clivus. Through an extended complete mastoidectomy the facial nerve is totally decompressed and re-routed posteriorly from the stylomastoid foramen to the internal auditory canal. The fallopian canal, promontorium, and cochlea are removed anteriorly and medially as far as the internal carotid artery, obtaining exposure to a triangular area limited by the superior petrosal sinus, inferior petrosal sinus, carotid, and internal auditory canal, giving adequate exposure to the structures of the clivus and the midline (basilar artery, vertebral arteries, and the sixth cranial nerves).

Adolescent↗

PubMedDate not supplied

Degenerative changes in the distal stump of the severed human facial nerve.

Specimens of distal segments of the human facial nerve obtained at reinnervation surgery (hypoglossal-facial anastomosis) were studied by light and electron microscopy. Severance of the facial nerve led to the Wallerian degeneration in the distal segment. When the lesion was made at the intracranial level of the nerve, the sensory bundle remained intact. In a specimen 17 days after section, motor fibers either had disappeared or had loss of axons and advanced stage of myelin breakdown. Sensory fibers appeared intact. In two specimens three months after severance, many Schwann cells of degenerated fibers still possessed degraded myelin; most Schwann cells had ingested myelin and formed endoneurial tubes (bands of Büngner). Endoneurium showed proliferation of fibroblasts and increased collagen deposition. A specimen obtained seven months after section showed fibrosis only. The fifth specimen obtained 30 months after severance of the tympanic segment showed only mild collagenization and well formed, not appreciably shrunken Schwann tubes. The distal stump of human facial nerve appears to undergo less denervation atrophy than demonstrated in the peripheral nerves of experimental animals. The collagenization process appears to be essentially completed already after three months denervation with little change after that. The distal stump of the human facial nerve appears to provide a good structural basis for reinnervation even after prolonged denervation.

Adult↗