Pilot Clinical Study Using Pre-operative Simulation for Patients Undergoing Cochlear Implant

Hypothesis: Patients undergoing pre-operative CI simulation will have improved outcomes as measured by SL, MD and audiological outcomes.

The goal of this aim is to demonstrate clinical feasibility and to collect preliminary efficacy data for using the pre-operative simulation with active feedback for CI patients. This will be achieved by prospectively using the CI simulation system and evaluating both technical and clinical audiological outcomes.

C.4.1 Pre-operative Simulation: Prior to surgery, a simulation with visualization of cochlear microstructures will be created for each patient, and the surgeon will conduct iterative virtual surgery with active feedback to determine the optimal surgical approach and cochlear implant electrode position. Based on the feedback from the simulation platform, the surgeon will determine the optimal CI electrode and surgical technique using the virtual simulation to plan the actual surgery. Post-implant feedback will be displayed to the surgeon. Once parameters (SL, MD, AID) are optimized, a surgical plan will be recorded and used during the actual surgical procedure. A surgical plan will consist of the implant type, cochleostomy site, and insertion techniques used for optimal placement. This will be added to the patient electronic medical record to be referenced immediately prior to surgery. Additionally, the simulator will save all performances with the optimized performance being made available for review on the simulator at any time (3-dimensional playback).

C.4.2 Clinical Outcomes: Aided speech perception testing in the CI ear will be administered at 6- and 12-months post activation using monosyllabic words (CNC Word test) presented at 60 dB SPL (A-weighted) as well as sentences (AzBio) in quiet and at +10 signal-to-noise ratio. Percent correct will be calculated for each test and will serve as the primary clinical outcomes.

C.4.3 User Evaluation: Simulator evaluation (user interface, usefulness, potential usage in future, and overall satisfactory) and feedback/comments from the surgeon about the simulation platform will continued to be collected pre and post-operatively to provide insight into continued future improvement of the simulation platform.

C.4.5 Reproducibility and Rigor:

Statistical Analysis: Demographic information as well as post-op CI location parameters (SL, MD, AID), pre/post-op CNC and AzBio scores will be summarized with descriptive statistics: mean/SD, median/IQR for continuous variables and count/percentage for categorical data. Changes of the CNC /AzBio scores overtime will be analyzed using linear mixed models to account for the association of measures from the same patient at different time points, and to deal with missing data assuming missing data will occur randomly. Exploratory analysis will be conducted to (1) evaluate the association of the CI location parameters with the post-op CNC scores; (2) compare the post-op CI location parameters with the CI patients without pre-op simulations that are reported in the literature and/or those who have undergone CI insertion in this institution (historical controls at OSU).

Sample Size: For this pilot study, a sample size of 30 patients is proposed to evaluate selected feasibility issues, assess the adequacy of instrumentation, and collect preliminary efficacy data (along with historical data) for the design of a larger prospective, randomized trial. For the improvement of the clinical outcome (CNC) after CI, a sample size of 30 patients produces a one-sided 90% upper confidence limit of variance <1.5 when the sample variance of the improvement of CNC is 1.0. Up to 36 patients will be enrolled to account for potential attrition due to various unexpected reasons during the period from the enrollment to implant surgery, to 6-month follow-up.