INTRODUCTION
An attic cholesteatoma is a common disease encountered by otologists because it typically destroys the ossicles, causing several complications.The traditional treatment method for attic cholesteatoma is the transoral or retroauricular approach with microscope.
In 1997, after first reporting 36 successful cases of cholesteatoma removed by endoscope, 1 Tarabichi et al. found an endoscopic case in which the otology department correctly found its own position. The main advantage of endoscope widely used in the world is that it can have a wider and clearer field of vision and destroy less normal tissues, but its disadvantage is localized attic disease, because it has not been investigated and studied whether it can replace microscope treatment in other treatments.2
When studying the subjects in different stages of diseases, the results of comparative experiments under microscope and endoscope are inaccurate, and the correctness of the results cannot be guaranteed. The degree of cholesteatoma can be classified into cholesteatoma of upper tympanum.3 By comparing the traditional microscope treatment with endoscopic treatment for cholesteatoma in different stages, we can evaluate and compare the efficacy of endoscopic ear surgery (EES).4