The Safety and Efficacy of Hydroxyapatite Repair of Cholesteatoma Skull Base Defects.

Objective: To investigate the possibility of hydroxyapatite as a safe and effective alternative to currently used bioavailable materials for repair of tegmen defects and labyrinthine fistulas in the setting of cholesteatoma. Study Design: Retrospective study. Setting: Tertiary-level-care hospital. Methods: Electronic medical records of patients 18+ years undergoing cholesteatoma-removal surgery between 2013 and 2022 were reviewed. Results: Twenty-two patients diagnosed with cholesteatoma who underwent repair of either a tegmen defect or labyrinthine fistula using hydroxyapatite were evaluated. There were 17 canal wall up (CWU) and 5 canal wall down (CWD) surgeries. The cholesteatoma recidivism rate was 18.2% (n = 4) and the recurrence rate was 4.5% (n = 1). To ensure that these rates were similar to cholesteatoma-removal surgeries in which hydroxyapatite was not used, a 22 age, gender, and operative technique-matched cohort was evaluated. For patients with CWU surgeries, the rate of recurrence and recidivism were identical between both cohorts (0% and 23.5%, respectively; Conclusion: In our cohort, hydroxyapatite was safe and successful in repairing skull base defects and inner-ear fistulas in the setting of cholesteatoma with a low rate of postoperative infection and no evidence of a higher rate of cholesteatoma recurrence. Further studies are needed to assess population generalizability.