Single stage surgery was used for 174 operations for cholesteatoma. The results were analysed using months at risk (actuarial) statistics. The methods of data collection and of creating a life-table for cholesteatoma follow-up are described. Ninety-one canal-down procedures are compared with 82 canal-up procedures as to the recidivism rate as well as hearing results. The actuarial tables showed a 50 per cent cumulative success rate for canal-up procedures versus a 90 per cent rate for canal-down operations. The successful canal-up procedures, however, demonstrated slightly better hearing results. These success rates seemed to be comparable to those using planned staged surgery.

It was concluded that if single stage canal-up procedures were used with larger mastoids and canal-down procedures with smaller mastoids, 80 per cent of patients could be controlled without either residual or recurrent disease appearing. For the others, it was felt safe to wait for the disease to reappear rather than to do planned two-stage procedures for all patients. It was further urged that actuarial statisties be employed when reporting the results of surgery for cholesteatoma.