Hearing Changes After Intratympanic Steroids for Secondary (Salvage) Therapy of Sudden Hearing Loss: A Meta-Analysis Using Mathematical Simulations of Drug Delivery Protocols

Abstract

Based on the available data from uncontrolled and controlled randomized and non-randomized studies no clear recommendation can be made so far for a specific application protocol for either primary or secondary (salvage) intratympanic steroid treatment in patients with ISSHL. For meta-analyses, change in pure tone average (PTA) may not be an adequate outcome parameter to assess effectiveness of the intervention especially with inhomogeneity of patient populations. Final PTA might provide a better outcome parameter.

Intratympanic application of triamcinolone in sudden hearing loss—radiologic anatomy in cone beam CT and its’ correlation to clinical outcome

“…Furthermore, factors like starting time after the onset of ISSNHL and comorbidities like diabetes mellitus might play a role in the treatment of ISSNHL. Liebau et al conclude, that solely the degree of initial hearing loss correlates with post-therapeutic improvement while treatment delay does not play a significant role [5,6]. The benefit of IT triamcinolone in our cohort is in the range of 12 and 100% as reported by others [1,3,4,7].…”

“…Multiple non-randomized, randomized and even placebocontrolled studies on the benefit of IT glucocorticoids in the primary and secondary treatment of ISSNHL exist [1][2][3][4][5][6][7][8][9]. Due to the large variances in indication criteria, treatment protocols and the drugs used, no definite recommendations can be drawn and significant hearing improvements can still be questioned.…”

“…Intratympanic (IT) application of glucocorticosteroids for the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL) was introduced into clinical routine not only as a secondary treatment option after failure of systemic steroid treatment but also as a primary therapy in patients with contraindications to systemic treatment [1][2][3][4][5][6][7]. Motivation is found in blinded, placebo-controlled studies, which show significant benefits of IT steroids in comparison to intratympanic normal saline injections [8,9] and in multiple other randomized and non-randomized studies.…”

“…However, published protocols differ in the kind of steroid used, drug concentration and applied volume, number of injections and intervals between injections, total duration of treatment and starting time after the onset of ISSNHL. It becomes difficult to compare the results and subsequently to find clear recommendations for primary or secondary IT steroid treatment [5,6,10,11].…”

“…Rapid clearance of intratympanic glucocorticoid from the middle ear occurs via the Eustachian tube. In addition, drugs might be captured and eliminated by the middle ear mucosa [6,19,20].…”