LAUSR

To evaluate and compare the hearing outcome after the bony obliteration tympanoplasty (BOT), canal wall up (CWU) without mastoid obliteration and canal wall down (CWD) without mastoid obliteration in a large patient cohort. As the aeration of the middle ear is associated with hearing outcome, we hypothesized that the post-operative hearing after the BOT may be better compared to CWU and CWD without obliteration. This is a retrospective cohort study on all adult patients who underwent the BOT, CWU without obliteration or CWD without obliteration for primary or revision cholesteatoma between January 2003 and March 2019 with audiological follow-up at our institution. Pre-operative, short-term post-operative and long-term post-operative hearing tests were analyzed and potential factors influencing post-operative hearing were assessed. 626 ears were included. We found no significant differences between the short-term and long-term post-operative audiometry. The pre-operative air–bone gap (ABG) was the factor with the largest effect size on change in air–bone gap (ABG) between pre- and post-operative. When stratifying for this factor along with the type of ossicular chain reconstruction to account for differences at baseline, no significant differences in post-operative ABG were found between BOT and non-obliteration CWU and CWD. In this large retrospective cohort study, we found no significant differences in post-operative ABG between the BOT and the non-obliteration CWU and CWD. A solid comparison of hearing between groups remains very challenging as hearing outcome seems to be dependent on many different factors. Hearing outcome seems to be no additional argument to choose for BOT over non-obliteration surgery.