Evaluation of Insertion Forces and Cochlea Trauma Following Robotics-Assisted Cochlear Implant Electrode Array Insertion

Abstract

Hypothesis: The objective was to evaluate the effect of cochlear implant (CI) insertion technique on electrode insertion forces and intracochlear trauma. We hypothesize that robotics-assisted insertions will reduce insertion forces and intracochlear trauma compared with manual insertions. Background: Variability in CI outcomes exists across patients, implant centers, surgeons, and electrode types. While surgical techniques that reduce electrode insertion trauma are well established, insertion trauma remains one contributing factor to variability in CI outcomes. Previous work demonstrates that micromechanically controlled insertion tools reduce both maximum insertion forces and insertion variability compared with manual insertions. Methods: CI electrode insertions were performed either by hand (n = 12) or utilizing a robotics-assisted tool (n = 12) in fresh frozen, human cadaveric cochleae using electrodes from four different CI manufacturers. Electrodes array insertion forces were additionally evaluated in benchtop cochlea models. Following cadaveric insertions, samples were imaged via high resolution x-ray microscopy to evaluate electrode position and intracochlear trauma events based on a modified Eshraghi scale. Results: Electrode array insertions performed by robotics-assisted system showed significantly lower insertion forces and variability. Manual electrode array insertions had a significantly higher overall trauma score of 3.1 ± 2.0 compared with 0.9 ± 1.0 for robotics-assisted insertions. Robotics-assisted insertions had higher rate of basilar membrane elevations while manual insertions showed higher rates of severe trauma events. Conclusions: The robotic-assisted insertion system reduced trauma events associated with CI electrode insertions in cadaveric cochleae compared with manual insertions. Surgical devices which help to precisely and more consistently insert electrodes may improve CI outcomes and hearing preservation.

A simple tool to automate the insertion process in cochlear implant surgery

“…However, this is also true in conventional, manually performed electrode insertion and therefore not a specific challenge when using the CHD. In addition, using the surgical retractor, automation of probe insertions goes without additional invasive steps, such as screwing into the skull, as required in the case of the iotaMotion system in order to drive the unit [10].…”

“…More recently, other groups have also developed motorized insertion tools in laboratory experiments [21][22][23] and although they were also not designed for use under sterile conditions, valuable findings have resulted from these works [9,11,21,[24][25][26][27][28][29]. For example, automated EA insertions have shown its capability in reducing critical peak insertion forces [9,10,30]-subsequently promising to reduce insertion trauma. Different insertion velocities have been explored using automated setups, and to date, most data suggest that lower insertion velocities produce lower insertion forces [11].…”

“…Recently, two approaches for robotic surgical systems developed for clinical-, intraoperative use have been described. The robotics-assisted surgical tool proposed by Kaufmann et al has already published promising results in its pre-clinical validation phase [10], but has the drawback of requiring additional drilling and screwing to the patient's head to fixate the tool. In addition, a teleoperated robot (RobOtol, Collin Orl, Bagneux, France) has been used by Nguyen et al to perform EA insertions in first patients [31].…”

“…These include the surgical approach (e.g., angle of insertion trajectory, size and location of the opening into the inner ear, level of surgical skills), the type of EA (e.g., stiffness properties, cross-sectional area, surface smoothness), as well as the insertion technique (e.g., insertion velocity). Automation of the insertion process could minimize intracochlear trauma as it allows for: standardization, independent of EA characteristics or surgical expertise smoothing and optimization, eliminating human tremor and jitter [ 9 , 10 ] deceleration, enabling ultra-slow continuous insertion velocities beyond those which are humanly feasible [ 11 , 12 ]. …”

Acceptance of patients towards task‐autonomous robotic cochlear implantation: An exploratory study

“…To achieve this level of precision between planned and actual trajectory, task‐autonomous robotic platforms have been developed and were recently demonstrated to be feasible and safe 7,8 . Although no robotic platform to date allows for full cochlear implantation (i.e., task‐autonomous robotic drilling and electrode insertion combined), robotic systems for both tasks separately have been developed and have shown superiority compared to manual performance 9–11 . If those tasks could be performed by one robotic platform, the possible benefits, such as optimized placement of the electrode and reduced invasiveness, would be considerable.…”