Intratympanic steroid versus gentamicin for treatment of refractory Meniere's disease: A meta-analysis

Abstract

Purpose: Intratympanic steroid injections (ITSI) have become a promising treatment for refractory Meniere's disease due to less cochleovestibular damage. However, whether ITSI would be a good alternative to intratympanic gentamicin injections (ITGI) for refractory Meniere's disease still remains controversial. Here we intended to compare the therapeutic effect of ITSI and ITGI in patients with Meniere's disease refractory to conservative treatments, in terms of vertigo control and hearing outcomes, via a meta-analysis.

Methods: Using MEDLINE, PubMed, and EMBASE databases, we calculated pooled odds ratio (OR) estimates of vertigo control rate (i.e., class A according to AAO-HNS guideline) and standardized mean differences (SMD) of spell count, pure tone audiometry (PTA) threshold and speech discrimination score (SDS) with a 95% confidence interval (CI). The trim-and-fill method and sensitivity analysis were used as post-hoc analyses to verify the integrity of the quantitative analysis results. Furthermore, subgroup analyses were performed according to steroid type (methylprednisolone versus dexamethasone) and follow-up period (>1-year versus <1-year).

Results: Five studies involving 332 patients with refractory unilateral Meniere's disease were included. In the pooled analysis, those treated with ITGI showed higher ORs than those treated with ITSI in terms of vertigo control rate (OR: 2.39, 95% CI: 0.84-6.79, P = 0.102) and spell counts (SMD: 0.24, 95% CI: -0.12-0.59, P = 0.195), but it did not reach statistical significance. However, a substantial amount of heterogeneity (I² = 71.0%, Q = 13.79, P = 0.008) and publication bias was found, suggesting a significant small-study effect. Additionally, ITSI elicited better hearing outcomes of the mean PTA threshold (SMD: 3.08, 95% CI: -1.18-7.35) and mean SDS (SMD: 11.15, 95% CI: -23.21-0.90) compared with ITGI, although no statistical significance. In subgroup analysis, the difference in vertigo control rate between ITGI and ITSI was not significant, regardless of the follow-up period and steroid type. Further, methylprednisolone appeared to be superior to dexamethasone for vertigo control. No significant complications from either treatment were reported in the literature.

Conclusion: The results of this study further refine the recently proposed efficacy of ITSI for the treatment of refractory Meniere's disease, demonstrating the comparable value of ITGI on vertigo control as well as better hearing preservation. Collectively, ITSI could be a safe and the effective treatment for refractory Meniere's disease. However, the current evidence on efficacy of ITSI for refractory Meniere's disease needs to be further clarified, given the substantial heterogeneity and potential biases.

Keywords: Intratympanic gentamicin injection; Intratympanic steroid injection; Meniere's disease.