REPAIR OF THE FACIAL-NERVE IN THE CEREBELLOPONTINE ANGLE USING FREEZE-THAWED SKELETAL-MUSCLE AUTOGRAFTS - AN EXPERIMENTAL SURGICAL STUDY INTHE SHEEP

Six adult blackface sheep underwent repair of the transected facial ne rve in the cerebellopontine angle using short freeze-thawed muscle aut ografts. A typical facial palsy was observed on the side of the interv ention immediately after operation. The sheep were allowed to recover for one year by which time clinical observation showed a complete reco very of the facial palsy in 5 sheep and a partial recovery in the rema ining sheep. Under general anaesthesia function of the repaired VIIth nerve and the normal contra-lateral facial nerve were assessed using e lectrophysiological stimulating and recording techniques. These studie s showed restoration of facial nerve continuity to have taken place wi th functional reinnervation of target facial muscles. Electrophysiolog ical indices of nerve function were consistent with those expected aft er repair of any peripheral nerve. Morphometric study of the nerves af ter their removal showed structural changes which though quantitativel y different from those of normal nerve were consistent with those seen in other sites and studies where nerves have been repaired. This tech nique is discussed as a possible treatment for facial nerves whose con tinuity is disrupted during the removal of cerebellopontine angle tumo urs.