Hypoglossal-facial nerve anastomosis: a review of forty cases caused by facial nerve injuries in the posterior fossa.

Hypoglossal-facial anastomosis has been our procedure of choice in the repair of the permanently injured facial nerve in the cerebellopontine cistern, when the nerve cannot be primarily repaired. Total failures are few and complications are rare. Most results are good to excellent, if assessment is based upon realistic expectations. These include: 1. normal facial symmetry in repose, 2. good midface voluntary motion, 3. no reflex or emotional facial movement, 4. some synkinesis and donor-injected mass facial movement, and 5. surprisingly little functional loss from hypoglossal paralysis. Our experience indicates better results in younger patients and in those repairs completed shortly after injury. These findings correlate well with the experience gained in peripheral nerve repair in the extremities. There appears to be no absolute time period between injury and repair beyond which this anastomosis is definitely contraindicated. Finally, this procedure does not negate adjunctive plastic surgical procedures. Most of our patients have had tarsorrhaphy or physiologic protection of the eye, but few have had corrective cosmetic surgical procedures until the past few years. We have never used cervical sympathectomy to reduce the size of the palpebral fissure. Better surgical procedures to correct both extracranial and intratemporal facial nerve injuries have significantly reduced the indication for anatomosis procedures. Additionally, over the past two decades, the improved diagnostic and surgical techniques for posterior fossa tumors have considerably reduced the incidence of facial paralysis. As these trends continue, the number of patients requiring nerve anastomosis for facial paralysis will continue to decline and what was once the only surgical procedure to repair the paralyzed face will become a rare operation.