Intraoperative Auditory Brainstem Response (ABR) Measurement During Vibroplasty in Congenital Aural Malformation.

Abstract

Objective: To determine the optimal coupling efficiency by auditory brainstem response (ABR) in patients with aural atresia undergoing vibroplasty to ensure optimal sound transmission and minimize the need for revision surgery.

Study design: Retrospective data analysis.

Setting: Tertiary referral center with an established active middle ear implant program.

Patients: 14 ears of 13 patients with congenital aural malformation receiving active middle ear implant surgery.

Interventions: Therapeutic surgical treatment for hearing rehabilitation in human subjects.

Main outcome measures: Intraoperative coupling efficiency as determined by ABR and postoperative audiologic outcomes (sound-field thresholds, speech perception) after active middle ear implantation in patients with congenital aural malformations.

Results: Intraoperative ABR was performed in all patients and revealed thresholds that were not significantly different from preoperative PTA4 bone-conduction thresholds ( p = 0.67). Pearson correlation coefficient r was 0.57. Speech perception improved by 65.0% at 65 dB SPL and by 60.9% at 80 dB SPL. PTA4 Vibrogram thresholds showed stable long-term coupling outcomes (mean, 28.7 ± 8.3 dB HL eq ).

Conclusion: ABR measurement during vibroplasty is applicable in patients with congenital aural malformation. There are often fewer options for coupling the vibratory element of the VSB (floating mass transducer [FMT]) to the ossicular chain or directly to the cochlea in this patients' collective. Confirmation of a stable and valid coupling efficacy during FMT positioning can be of great benefit in malformed middle ears for efficient hearing restoration and to reduce the risk of revision surgery.