Facial Nerve Dehiscence and Cholesteatoma

Objectives: We evaluated the incidence of facial nerve dehiscence in a group of patients with cholesteatoma who underwent otologic surgery. Methods: We performed a retrospective study in a tertiary referral hospital of 336 patients (298 adults, 38 children) with cholesteatoma who underwent surgery in the years 1998 to 2008. Using intraoperative findings, we assessed the incidence of facial nerve dehiscence in a group of patients with cholesteatoma. We quantified, in adult versus pediatric patients and in primary versus revision surgeries, the occurrence of facial nerve dehiscence, the predisposed anatomic sites, and the coexistence of semicircular canal fistula. In a selected group of 67 patients, preoperative 0.55-mm collimation computed tomography (CT) scans were compared with the intraoperative findings. Results: The frequency of facial nerve dehiscence in this group of patients was 27.1%. The dehiscence was detected in 29.5% of the adults, but in only 7.8% of the patients 16 years and younger. Dehiscence was present in 42.3% of the patients who underwent revision surgery. The most common site of dehiscence (92.3%) was the tympanic segment. The sensitivity and specificity of CT were 69% and 87%, respectively. Conclusions: Dehiscence of the facial nerve was found in 27.1% of patients with cholesteatoma, with a significant difference between patients of pediatric and adult ages. A dehiscent facial nerve was more commonly seen during revision surgery and more frequent in patients older than 16 years. The site of dehiscence most frequently involved by cholesteatoma was the tympanic segment. The presence of a semicircular canal fistula increases the risk of facial nerve dehiscence. Finally, the results of preoperative CT scans are encouraging for the use of CT in predicting facial nerve dehiscence.