What can we learn from precise reporting of residual disease after various types of cholesteatoma surgery using STAM areas?

Purpose: 1. To evaluate current reporting of residual cholesteatoma localisation. 2. To assess prevalent localisations of residual disease following various types of cholesteatoma surgery in our population. Methods: 1. Review of the literature on reported localisation of residual disease following cholesteatoma surgery. 2. Retrospective chart review of patients undergoing cholesteatoma surgery in a tertiary referral centre with a minimum follow-up of two years. Localisation of residual cholesteatoma was noted according to the STAM areas and compared to initial cholesteatoma. Overlapping localisations and multiple pearls were specified. Results: Overall residual disease rate of 14.4% in 1084 surgeries was similar to the pooled data from the literature. In our population, residual disease was most prevalent in A (attic), followed by T (tympanic cavity). The risk of residual disease in M (mastoid) was low. Surgery type influenced the overall risk of residual disease per localisation, as well as the proportion of affected areas. Obliteration reduced the risk of residual disease. Of the residual pearls, 12% were found remote of initial cholesteatoma localisation. Conclusion: Surgery type is a determining factor not only in residual disease rate, but also in localisation of residual disease. Both the efficacy and safety of obliteration is underlined. Standardised reporting of residuals utilising STAM areas, including specification of overlapping areas and remote residuals, will facilitate comparative research on surgical factors influencing residual disease, while providing useful insights for otologic surgeons.