Enlarged Vestibular Aqueduct: Disease Characterization and Exploration of Potential Prognostic Factors for Cochlear Implantation

Abstract

Objectives:There is an unmet need to match the anticipated natural history of hearing loss (HL) in enlarged vestibular aqueduct (EVA) with clinical management strategies. The objectives of this study are therefore to provide a detailed case characterization of an EVA cohort and explore the relationship between candidate prognostic factors and timing of cochlear implant (CI) surgery.Study Design:A multicenter retrospective review of patients diagnosed with EVA.Setting:Patient data recruitment across three CI centers in the UK.Patients:One hundred fifty patients with a radiological diagnosis of EVA from January 1995 to January 2021.Main Outcome Measures:Age at audiological candidacy for CI and age at first implant surgery.Results:EVA was predominately a bilateral condition (144/ 150) with increased prevalence in women (M:F, 64:86). 51.7% of patients failed new-born hearing screening, with 65.7% having HL diagnosed by 1 year. Initial moderate to severe and severe to profound HL were reported most frequently. In 123 patients, median age that audiological candidacy for CI was met for at least one ear was 2.75 years. Median age at first CI was 5 years (140/150).Pendred syndrome (confirmed in 73 patients) and ethnicity, were not significantly associated with earlier CI surgery. Multivariate linear regression demonstrated that male patients have first CI surgery significantly earlier than females (coefficient −0.43, 95% CI [−0.82, −0.05), p-value = 0.028).Conclusions:This large UK EVA cohort provides evidence that patients should be closely monitored for CI candidacy within the first 3 years of life. Significantly, male gender is emerging as an independent prognostic factor for earlier assessment and first CI surgery.

Hearing Progression of Children with Enlarged Vestibular Aqueduct (EVA) According toSLC26A4Genetic Mutation Status

“…In other words, before a child with a mutation enters kindergarten, they may have a hearing loss that has progressed sufficiently to warrant conversations and referrals for implantation, but not as many would enter these conversations without a known mutation. Our results are consistent with reports of EVA and monitoring for cochlear implant candidacy in a large cohort study recently conducted in the United Kingdom (Saeed et al 2022). Their study found that EVA patients often qualified as cochlear implant candidates in at least one ear by the age of three years.…”

“…Being proactive is challenging because outcomes are variable, and we know that progression may occur but not when or by how much. Thus, there is an unmet need to improve our understanding of EVA by exploring potential clinical prognostic factors for hearing loss severity and progression (Saeed et al 2022). Understanding the implications of their hearing loss is crucially important as they progress through social and communication developmental periods.…”

Enlarged Vestibular Aqueduct and Associated Inner Ear Malformations: Hearing Loss Prognostic Factors and Data Modeling from an International Cohort

“…This is contrary to previous low risk of bias studies but may be explained by the fact different outcome measures have been used between studies, and an interplay between multiple factors determines timeframes for CI surgery. 3 , 9 , 14 …”

“…We did not categorize variants by a number of mutated alleles as our previous work failed to show an association with HL and conflicting associations are reported in the literature. 3 , 14 …”

“…Choice of covariate was based upon their previous reported role in EVA hearing loss. 8 , 14 However, the endolymphatic duct shapes, sac shapes, and genotype were chosen as novel exploratory covariates (their role in EVA hearing loss has not yet been previously explored). EVA, enlarged vestibular aqueduct.…”