Identification of operculum and surgical results in endolymphatic sac drainage surgery

To increase the accuracy of identification of the endolymphatic sac during endolymphatic sac drainage surgery, we focused on the intra-operative identification of the operculum as a structural marker of the endolymphatic sac and the vestibular aqueduct at the rugose portion. Then, we examined the relationship between identification of the operculum and surgical outcomes. We used 100 cases with intractable Meniere's disease who received endolymphatic sac drainage with local steroid administration, superior to traditional endolymphatic sac drainage surgery and non-surgical medical treatment. According to operation records, we divided these 100 cases into those with intra-operative identification of the operculum (n=72) and those without (n=28) and compared the surgical outcomes. The ratio of intra-operative identification of operculum (OPC(+)) was 72.0%. Better hearing results were observed significantly more often in patients with OPC(+), although there were no significant differences in vertigo results between OPC(+) and OPC(-). We concluded that the endolymphatic sac might be exposed adequately at rugose portion and opened for the drug delivery, resulting in better surgical results.