Tolerance and safety of 45S5 bioactive glass used in obliteration procedures during middle ear surgery: Preliminary results

Otologists face many disadvantages after extensive mastoid drilling and canal wall down technique in cholesteatoma surgery. Mastoid and epitympanic cavity obliterations or reconstructions after canal wall down procedure using bioactive glass seem to be an interesting solution to overcome some of these disadvantages. Bioactive glass offers many benefits including the availability when there are no sufficient autologous materials for obliteration, its antibacterial activity in chronic infected ear and decreasing the recidivism of cholesteatoma. The objective of this study is to evaluate the tolerance and safety of 45S5 bioactive glass as a filing bone-synthetic material by clinical, audiological and radiological examinations. A retrospective study of 42 patients who had undergone obliteration of mastoid or/and epitympanic cavity with 45S5 bioactive glass between, November 2017 to January 2019. Data from clinical follow-ups, audiological assessment, CT-scan and MRI were analyzed. The patients' mean age was 49.8 years old. Microscopic examinations showed dry well-healed tympanic membranes and external auditory canals for 95.2% of the patients after 1 year. Inner ear injuries after obliteration were not observed by comparing pre and post-operative bone conduction audiometry (p value 0.457). No facial palsy was reported post-operatively. One-year postoperative radiological assessments did not reveal any silent implantation of cholesteatoma or residual disease. Mastoid and epitympanic obliterations with 45S5 bioactive glass seem to be a tolerable and safe option in cholesteatoma surgery with favorable outcomes similar to other member of bioactive glass especially the S53P4.