Anatomic and Functional Long-Term Results of Canal Wall-Down Mastoidectomy

The objective of this study was to evaluate, over the long-term, the anatomic and functional outcome of canal wall-down mastoidectomy performed for chronic otitis media with cholesteatoma and chronic otomastoiditis resistant to all conservative treatment. The study was made through a retrospective review of 338 cases of consecutive primary canal wall-down mastoidectomies performed between 1974 and 1998. Included were 259 cases with sufficient data. In all cases, functional reconstruction was performed at the same time as the mastoidectomy. Demographic and clinical data were collected from each file. From the clinical data, the surgical techniques, complications, the number of follow-up visits necessary to ensure cavity cleanliness, details of care provided over the period 1 to 24 years (mean, 7 years) after the operation, and audiometric data from admission and from the latest postoperative follow-up were retained. Canal wall-down mastoidectomies were followed up an average of 10 times during the first 6 months after operation, twice a year over the 6-year period following surgery, and less than twice a year beyond the 6-year period. Care was dispensed for meatal stenosis, scars, infections, polyps, and beads of cholesteatoma. Surgical revisions were performed because of residual or recurrent cholesteatoma in 6.1% of the cases, because of perforation of the tympanic membrane in 7.3% of the cases, and to improve hearing in 12.2% of the cases. At the last consultation, 1 to 24 years after surgery, cavities were found to be dry and self-cleaning in 95% of the cases, and still humid, with otorrhea, in 5% of the cases. Over the long-term, the hearing threshold remained unchanged in 41.3% of the cases. It was improved after surgery by 10 to 19 dB in 15.4% of the cases, by 20 to 29 dB in 11.5% of the cases, and by more than 29 dB in 3.8% of the cases. The hearing threshold was thus improved or at least remained unchanged in 72.0% of cases. Hearing losses occurred in 28% of the cases: by 10 to 19 dB in 11.9%, by 20 to 29 dB in 6.5%, and by more than 29 dB in 9.2% of the cases. A sensorineural hearing loss of more than 60 dB at all frequencies occurred immediately after the operation in 2 cases (0.7%). There was 1 case of facial paralysis (0.3%). Four patients (1.5%) complained of persistent vertigo. Canal wall-down mastoidectomy is an adequate treatment for chronic otitis with cholesteatoma or chronic otomastoiditis. The anatomic and functional results are satisfactory, and the rate of complications is acceptably low. A tympanoplasty can be performed simultaneously. Thus, for the large majority of patients, only a single intervention is required; however, a small minority can benefit from a revision tympanoplasty. In order to obtain these results, both the patient and the surgeon should engage in a long-term follow-up.