How to Avoid Facial Nerve Injury in Mastoidectomy?

Ryu, Nam Gyu; Kim, Jin

Abstract

Unexpected iatrogenic facial nerve paralysis not only affects facial disfiguration, but also imposes a devastating effect on the social, psychological, and economic aspects of an affected person's life at once. The aims of this study were to postulate where surgeons had mistakenly drilled or where obscured by granulations or by fibrous bands and to look for surgical approach with focused on the safety of facial nerve in mastoid surgery. We had found 14 cases of iatrogenic facial nerve injury (IFNI) during mastoid surgery for 5 years in Korea. The medical records of all the patients were obtained and analyzed injured site of facial nerve segment with surgical technique of mastoidectomy. Eleven patients underwent facial nerve exploration and three patients had conservative management. 43% (6 cases) of iatrogenic facial nerve injuries had occurred in tympanic segment, 28.5% (4 cases) of injuries in second genu combined with tympanic segment, and 28.5% (4 cases) of injuries in mastoid segment. Surgeons should try to identify the facial nerve using available landmarks and be kept in mind the anomalies of the facial nerve. With use of intraoperative facial nerve monitoring, the avoidance of in order to avoid IFNI would be possible in more cases. Many authors emphasized the importance of intraoperative facial nerve monitoring, even in primary otologic surgery. However, anatomical understanding of intratemporal landmarks with meticulous dissection could not be emphasized as possible to prevent IFNI.