Intratympanic triamcinolone acetonide as a salvage therapy for idiopathic sudden sensorineural hearing loss

Abstract

Introduction Intratympanic steroid (ITS) injections are increasingly used as salvage treatment for idiopathic sudden sensorineural hearing loss (ISSHNL). No consensus exists on the ideal ITS treatment protocol regarding medication, total injection count and interval length. The widely used corticosteroids are dexamethasone and methylprednisolone. There are limited data for triamcinolone acetonide as medication for this treatment modality. Since the initiation of ITS treatment at the Medical University of Graz in 2014, a protocol consisting up to 3x intratympanic triamcinolone acetonide injections at 1-week intervals has been used. In January 2020, the protocol was revised by shortening the interval length and implementation of an additional 4th injection. The present dissertation project included two parts: The primary objective of the first part was to evaluate the efficacy of triamcinolone acetonide as medication for ITS salvage treatment of ISSNHL. The aim of the second part was to compare the revised and initial ITS protocols on hearing outcome. Materials and Methods In the first part (= cohort study), 152 patients diagnosed with ISSNHL between January 2014 and August 2019, who failed to response sufficiently to primary systemic corticosteroid therapy, and who received up to 3x ITS injections at 1-week intervals as a salvage treatment, were retrospectively reviewed. The primary outcome measure was the absolute hearing improvement by ITS salvage treatment. Secondary outcome measures were a clinically significant ITS hearing improvement (>10 dB), grade of hearing recovery, and recovery into a serviceable hearing range (≤50 dB). In the second part (= case-control study), 32 primary-refractory ISSNHL patients who received up to 4x ITS injections every 2-4 days between August 2019 and December 2020, were retrospectively enrolled. These patients (= revised-protocol group), were 1:1 matched to subjects out of the cohort study (= initial-protocol group). Hearing outcomes between the revised and initial ITS salvage treatment protocols were compared by using the same outcome measures as in the cohort study. Results In the cohort study, patients improved in mean hearing function by 15.9 ± 18.9 dB due to salvage treatment with intratympanic triamcinolone acetonide injections. 52.6% of the patients had a clinically significant ITS hearing improvement. A complete and partial hearing recovery were achieved from 9.9% and 48% of the patients, respectively. 23.9% of the patients with an unserviceable hearing level returned by ITS salvage treatment into a serviceable hearing range. In the case-control study, both ITS salvage treatment protocols resulted in a statistically significant decline in hearing thresholds (p0.05). Conclusion Triamcinolone acetonide in ITS salvage treatment of ISSNHL resulted in similar significant hearing outcomes compared to previous studies using commonly applied corticosteroids, namely, dexamethasone and methylprednisolone. Therefore, triamcinolone acetonide constitutes an effective candidate for the ITS treatment of ISSNHL. Both ITS protocols resulted in a similar significant hearing recovery. These results indicate that a shorter injection interval does not lead to better hearing outcomes. Moreover, the usage of fewer ITS injections may reduce costs, physical/mental stress of the patients and lower the risk of persistent tympanic perforations, while maintaining similar treatment efficacy.

Date of Award	2021
Original language	English
Awarding Institution	Medical University Graz
Supervisor	Matthias Koiner-Graupp (Supervisor), Helena Schmidt (Supervisor) & Axel Wolf (Supervisor)