The Incidence Of Facial Nerve Dehiscence Of370Patients With Chronic Suppurative Otitis Media And Cholesteatoma

Objective:To describe the incidence and location of the facial nerve in patients with chronicsuppurative otitis media with cholesteatoma and without cholesteatoma.Methods:370patients who underwent wall–down tympanomastoidectomy due to otitis mediafrom January2011to July2013were analyzed retrospectively. Clinical features (age,disease duration) and intraoperative findings (state of FND and lateral semicircularcanal (LSC) fistula) were analyzed.Preoperative high resolution computedtomography(HRCT) scans were compared with the intraoperative findings.Result: The presence of FND was31.62%of total surgical procedures，the presence offacial nerve prolapse over the oval window was11.35%; Facial nerve dehiscencewas detected in29patients (20%) with non-cholesteatomatous and89(39.11%) withcholesteatomatous otitis media. Dehiscence of the tympanic segment was mostfrequently observed in both groups.The incidence of LSC fistula with FND is5.14%,The dehiscence was detected in28.44%of the adules,but in61.11%of thepatients18years and younger.About disease duration,the dehiscence of morethan5years is37.14%,less than5years is14.44%. The factor as pathologic style(cholesteatoma or chronic otitis media), disease duration were related to FND.Thesensitivity and specificity of HRCT were73%and86%,respectively.Conclusion:1. The incidence of FND was31.62%in this study, the most common location forFND was in the tympanic segment.2. The incidence of facial nerve prolapse over the oval window was12.81%,3. Therefore, the facial nerves should be especially taken care in mastoidectomy forpatients with cholesteatoma, LSC fistula, disease duration.4..Finally,the results of preoperative CT scans are encouraging for the use of CT inpredicting facial nerve dehiscence.