To detach or not to detach the umbo in type I tympanoplasty: functional results

Purpose: To compare the audiological outcomes, tympanic membrane (TM) healing rates and complication rates in patients undergoing endoscopic underlay and over-under tympanoplasty type I (TTI). Methods: The study includes 95 patients who underwent endoscopic TTI in the period between 2018 and 2023: 56% of the patients had the underlay technique and 41% had the over-under technique. Data regarding pre- and postoperative hearing, perforation characteristics, surgical procedures, graft types and complications were retrospectively analyzed. Audiometrical assessment included air conduction (AC) and bone conduction (BC) pure tone averages (PTA) and air-bone gap (ABG), pre- and postoperatively. Results: Both underlay and over-under techniques significant improved AC PTA, with a mean ABG improvements of 5.9 dB and 7.2 dB, respectively. There was no significant difference in BC PTA between pre- and post-operative, indicating no inner ear damage in both techniques. The over-under technique showed a significantly higher TM closure rate (94.4%) compared to the underlay technique (80.6%). Complications were rare, with only one case of TM lateralization requiring revision surgery. Conclusions: Endoscopic TTI is an effective treatment in improving auditory function in chronic middle ear diseases. In our cohort, the detachment of the umbo does not negatively influence the postoperative hearing results and does not increase rate of complications. Moreover, the over-under technique demonstrates superior TM closure rates, making it a valuable option for specific cases. However, future prospective studies with larger sample sizes and longer term follow-up are needed to validate these findings and provide more comprehensive insights.