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;  = 1 for both). While in CWD surgeries, there was a nonstatistically significant difference in the recurrence as there was only 1 patient with recurrence in the hydroxyapatite group ( = 1). Three (13.5%) patients in the hydroxyapatite group had a local infection and 1 (4.5%) had a subacute mastoid infection. All patients with semicircular canal fistulas had consistent bone lines on postoperative audiograms, with no worsening sensorineural hearing loss.

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.