Abstract
Eighty four ears with middle ear cholesteatoma were operated on using a staged intact canal wall (ICW) tympanoplasty between November 1976 and February 1988. In 17 of the 84 ears, a deep pocket-like epithelial invasion into the antrum or the mastoid cavity was found at the second stage operation. These 17 ears have no relation to age and extent of cholesteatoma noted at the first stage operation, and between these and 67 others no difference except bony defects could be seen with regard to their operative findings, such as inflammation and aeration in the middle ear. A bony defect was recognized in 13 of these in either the lateral wall of the attic or the posterior wall of the external auditory canal, through which the pocket developed. The present findings suggest that the bony defect is critical to form the pocket after the ICW tympanoplasty. A reconstruction of the bony defect with obliteration of the mastoid cavity is concluded to be reasonable to prevent pocket formation.
