In our department, 140 ears with middle ear cholesteatoma were treated surgically between 1985 and 1997. The canal wall down method was employed for 107 ears and the canal wall up method for 33 ears. As we changed our surgical policy in 1993, the proportion of canal wall up tympanoplasty increased since then. The mean follow-up periods were 78 and 51 months for canal down and canal up methods, respectively. With respect to hearing acuity, the success rates were 50.0%(canal down) and 78.6%(canal up) when assessed using a guideline for reporting hearing results in middle ear and mastoid surgery (Otology Japan 11, 62-63, 2001). Recurrence of' cholesteatoma was found in 5.6% of canal down cases and in 27.3% of canal up cases, and it could be controlled by second surgery. The major problem after the canal down surgery was the mastoid cavity problem, which occurred in 14.6% of total cases and in 21.7% of cases under 16 of age. The majority of ears with the mastoid problem required additional surgery. We concluded that the canal up method should be employed in the first surgery in view of the better hearing acuity and the preservation of the physiological external canal. It was thought that the higher rate of cholesteatoma recurrence cannot be a reason to reject the canal up method as recurrent cases were well controlled by second surgery. Exceptional cases to which the canal down method is recommended are those with extensive destruction of the external canal wall and dysfunction of Eustachian tube. When the general condition of patients is not likely to allow second surgery, the canal down method should be employed also.
