[Facial nerve protection during surgery for congenital malformation of the external and middle ear (review of 519 cases)].

The prevention of facial nerve injury in otoplasty for ear malformation is important. This paper analysed 519 cases of ear malformation collected during 10 years from 1985 to 1995. The hearing of 428 cases was improved, of which the hearing of 221 cases did recover to available level. A long-term follow-up of 198 cases showed that 152 cases had kept the same hearing level as that immediately after surgery. In 130 cases with single middle ear malformation the malformation rate of facial nerve was 60.8%(79/130), and that for chorda tympani 5.4% (7/130). In 75 cases of middle ear malformation with stricture of external acoustic meatus the malformation rate of facial nerve was 60.0% (45/75), and that for chorda tympani 13.3%(10/75). In 314 cases of middle ear malformation with atresia of external acoustic meatus the malformation rate of facial nerve was 42.5%(142/314), and that for chorda tympani nerve 100.0%(314/314). Two cases(0.4%) were of surgical facial nerve paralysis. For protection of facial nerve, it was important to master the anatomy of temporal bone and have a high-resolution computed tomographic scanning to identify facial nerve. It was also important to use electroneurographic monitoring when necessary.