Retraction pocket theory is the most acceptable theory for cholesteatoma formation. Canal wall down mastoidectomy is widely performed for cholesteatoma removal. Post-operatively, each patient with canal wall down mastoidectomy has an exteriorised mastoid cavity, exteriorised attic, neo-tympanic membrane and shallow neo-middle ear.
This study aimed to clinically assess the status of the neo-tympanic membrane and the exteriorised attic following canal wall down mastoidectomy.
All post canal wall down mastoidectomy patients were recruited and otoendoscopy was performed to assess the neo-tympanic membrane. A clinical classification of the overall status of middle-ear aeration following canal wall down mastoidectomy was formulated.
Twenty-five ears were included in the study. Ninety-two per cent of cases showed some degree of neo-tympanic membrane retraction, ranging from mild to very severe.
After more than six months following canal wall down mastoidectomy, the degree of retracted neo-tympanic membranes and exteriorised attics was significant. Eustachian tube dysfunction leading to negative middle-ear aeration was present even after the canal wall down procedure. However, there was no development of cholesteatoma, despite persistent retraction.