The incidence of facial nerve dehiscence at surgery for cholesteatoma

Objective: Facial paralysis can occur after surgery for cholesteatoma. The risk of facial nerve injury is great when the nerve is not covered by its n ormal bony Fallopian canal. The objective of this study was to identify the incidence of facial nerve dehiscence in patients undergoing surgery for ch olesteatoma. Study Design: Retrospective chart review. Setting: Tertiary referral hospital. Patient Population: An assessment of all cases performed by the senior auth or from 1991 to 1999 revealed 59 patients with adequate data available for analysis. These patients ranged in age from 3 to 92 years. In all, 67 surgi cal procedures. Intervention: Surgery for cholesteatoma, including tympanoplasty and mastoi dectomy. Main Outcome Measure: The presence of facial nerve bony dehiscence after ex enteration of disease, and postoperative facial nerve function. Results: In 33% of the total procedures analyzed, 30% of the initial proced ures, and 35% of the revision procedures, the patients were found to have f acial nerve bony dehiscence. The dehiscence was present in the tympanic por tion of the facial nerve in the vast majority of patients. Of the 97% of pa tients with normal preoperative facial nerve function, all retained normal function postoperatively. Conclusions: Facial nerve dehiscence in our series was far greater than tha t reported in the literature, underscoring the fact that this is an under-a ppreciated condition. These findings suggest that surgeons should be highly vigilant when dissecting near the facial nerve. Intraoperative facial nerv e monitoring has been shown to be of value in facial nerve preservation dur ing acoustic neuroma resections, and may have a role during surgery for cho lesteatoma.