Two different methods to digitally visualize continuous electrocochleography potentials during cochlear implantation: a first description of feasibility.

PURPOSE: The study explores the potential of real-time electrocochleographic potentials (ECochG) visualization during electrode insertion using digital microscopes such as RoboticScope (BHS®). Collaborative software development of the MAESTRO Software (MED-EL®) offers continuous ECochG monitoring during implantation and postoperative hearing evaluation, addressing previous time constraints. The study aims to assess software applicability and the impact of real-time visualization on long-term residual hearing preservation. METHODS: Eight patients with residual hearing underwent cochlear implantation with Flex26 or Flex28 electrode according to the Otoplan evaluation. ECochG responses were measured and visualized during electrode insertion, with insertion times recorded. Two randomized display methods (graph and arrows) tracked ECochG potentials. Postoperative behavioral thresholds determined hearing preservation. Successful real-time intraoperative ECochG visualization was achieved in all cases, enabling surgeon adaptation. Mean electrode insertion time was 114 s, with postoperative thresholds comparable to preoperative values. Visualization did not affect surgeon workload. ECochG amplitudes differed between patients with and without residual hearing. CONCLUSION: The study demonstrates effective implementation of advanced ECochG software combined with real-time visualization, enabling residual hearing preservation during CI. Visualization had no apparent effect on surgeon performance or workload. Future investigation involving a larger population will assess the long-term impact of ECochG on hearing threshold and structure preservation.

Digital live imaging of intraoperative electrocochleography during cochlear implantation: the first 50 patients.

INTRODUCTION: Real-time visualization of intraoperative electrocochleography (ECochG) potentials via a digital microscope during cochlear implantation can provide direct feedback during electrode insertion. The aim of this prospective, randomized study of 50 patients was to obtain long-term data with a focus on residual hearing preservation and speech understanding. MATERIAL AND METHODS: Cochlear implantations were performed in 50 patients (26 female, 24 male) with residual hearing using a digital microscope. Patients were randomized into two groups. Intraoperative ECochG potentials were either displayed directly in the surgeon's field of view (picture-in-picture display, PiP) or not directly in the field of view (without picture-in-picture display, without PiP). Residual hearing preservation and speech comprehension were recorded within a 1-year follow-up period, compared between groups (PiP versus without PiP) and to a control group of 26 patients implanted without ECochG. RESULTS: Mean insertion time was significantly longer in the picture-in-picture group (p = 0.025). Residual hearing preservation after 6 weeks at 250 Hz was significantly better in the picture-in-picture group (p = 0.017). After one year, 76% of patients showed residual hearing in the picture-in-picture group (62% without picture-in-picture technique, p = n.s.). Use of the picture-in-picture technique resulted in better long-term pure tone residual hearing preservation at 250, 500, and 1000 Hz. Speech intelligibility improved by 46% in the picture-in-picture group (38% without picture-in-picture). DISCUSSION: This study is the first to describe long-term results in a large cohort of cochlear implant patients in whom digital visualization of intraoperative ECochG was used. Our results show that visualization of intraoperative ECochG has a positive effect on residual hearing preservation.

Digital Live Imaging of Intraoperative Electrocochleography - First Description of Feasibility and Hearing Preservation During Cochlear Implantation.

INTRODUCTION: Intraoperative electrocochleography (ECochG) during cochlear implantation is a promising tool to preserve residual hearing. However, the time gap between insertion of the electrode and acoustic feedback from the audiologist to the surgeon can cause delay and subsequently irreparable damage to cochlear structures. In this feasibility study, for the first time, real-time visualization of intraoperative ECochG via digital microscope display directly to the surgeon was successfully performed in four patients. MATERIALS AND METHODS: Four patients with residual hearing underwent cochlear implantation. Intraoperative electrocochleography responses were collected and direct visualization during the time of electrode insertion into the surgeon's field of view in the binoculars using augmented real-time digital imaging was realized. The time of electrode insertion was recorded. Hearing preservation was determined by testing postoperative changes in behavioral thresholds. RESULTS: Digital live visualization of intraoperative ECochG using image augmentation in a digital microscope was successfully performed in all cases and enabled direct adaptation of the surgeon's insertion behavior. Mean time of electrode insertion was 129.8 seconds. Postoperative behavioral thresholds were comparable to preoperative taken thresholds. Preservation of residual hearing in the low frequency range was possible. DISCUSSION: This study is the first to describe digital visualization of intraoperative electrocochleography as a new method enabling the surgeon to directly react to changes in amplitude of the cochlea microphonics. Our results show that augmentation of the intraoperative live imaging with electrical potentials could add to hearing preservation during cochlear implantation.