A Study of Intraoperative Incidence of Fallopian Canal Dehiscence in Cases of Cholesteatoma.

Abstract

Our study aimed to find the incidence of fallopian canal dehiscence during surgery for cholesteatoma, to compare this incidence with a homogenous control group (otosclerosis) and to find the incidence of a labyrinthine fistula if fallopian canal dehiscence is present. Prospective case control study design was used in the setting of a tertiary care referral center. Subjects included 60 patients. 30 patients diagnosed with cholesteatoma were taken as cases and 30 patients with conductive or mixed hearing loss suspected of otosclerosis were taken as controls. The method was identification of bony dehiscence under operating microscope. In case of finding of dehiscence of fallopian canal, presence of labyrinthine fistula was searched. The cases underwent modified radical mastoidectomy and controls underwent exploratory tympanotomy after giving a written informed consent. Institutional ethics committee clearance was obtained. Fallopian canal dehiscence was recorded in all subjects. 50% of cases and 3.3% of controls showed presence of fallopian canal dehiscence. This correlation was statistically significant (p < 0.001). Also 26.7% cases with fallopian canal dehiscence had a semicircular canal fistula (4 out of 15),but this finding was not significant (p = 0.100). From our study it was evident that there were very high chances of finding a fallopian canal dehiscence in cases of cholesteatoma than in cases undergoing exploratory tympanotomy. Also, presence of labyrinthine fistula with fallopian canal dehiscence was likely but not significant.