Grégoire S. Blachon

Percutaneous Cochlear Implant Drilling via Customized Frames: an in vitro study

Objective: Percutaneous cochlear implantation (PCI) surgery uses patient-specific customized microstereotactic frames to achieve a single drill-pass from the lateral skull to the cochlea, avoiding vital anatomy. We demonstrate the use of a specific microstereotactic frame, called a “microtable,” to perform PCI surgery on cadaveric temporal bone specimens. Study Design: Feasibility study using cadaveric temporal bones. Subjects and Methods: PCI drilling was performed on six cadaveric temporal bone specimens. The main steps involved were 1) placing three bone-implanted markers surrounding the ear, 2) obtaining a CT scan, 3) planning a safe surgical path to the cochlea avoiding vital anatomy, 4) constructing a microstereotactic frame to constrain the drill to the planned path, and 5) affixing the frame to the markers and using it to drill to the cochlea. The specimens were CT scanned after drilling to show the achieved path. Deviation of the drilled path from the desired path was computed, and the closest distance of the mid-axis of the drilled path from critical structures was measured. Results: In all six specimens, we drilled successfully to the cochlea, preserving the facial nerve and ossicles. In four of six specimens, the chorda tympani was preserved, and in two of six specimens, it was sacrificed. The mean ± standard deviation error at the target was found to be 0.31 ± 0.10 mm. The closest distances of the mid-axis of the drilled path to structures were 1.28 ± 0.17 mm to the facial nerve, 1.31 ± 0.36 mm to the chorda tympani, and 1.59 ± 0.43 mm to the ossicles. Conclusion: In a cadaveric model, PCI drilling is safe and effective.

Design of a Bone-Attached Parallel Robot for Percutaneous Cochlear Implantation

Access to the cochlea requires drilling in close proximity to bone-embedded nerves, blood vessels, and other structures, the violation of which can result in complications for the patient. It has recently been shown that microstereotactic frames can enable an image-guided percutaneous approach, removing reliance on human experience and hand-eye coordination, and reducing trauma. However, constructing current microstereotactic frames disrupts the clinical workflow, requiring multiday intrasurgical manufacturing delays, or an on-call machine shop in or near the hospital. In this paper, we describe a new kind of microsterotactic frame that obviates these delay and infrastructure issues by being repositionable. Inspired by the prior success of bone-attached parallel robots in knee and spinal procedures, we present an automated image-guided microstereotactic frame. Experiments demonstrate a mean accuracy at the cochlea of 0.20 ± 0.07 mm in phantom testing with trajectories taken from a human clinical dataset. We also describe a cadaver experiment evaluating the entire image-guided surgery pipeline, where we achieved an accuracy of 0.38 mm at the cochlea.

Minimally invasive image-guided cochlear implantation surgery: First report of clinical implementation

Minimally invasive image‐guided approach to cochlear implantation (CI) involves drilling a narrow, linear tunnel to the cochlea. Reported herein is the first clinical implementation of this approach.

Validation of minimally invasive, image-guided cochlear implantation using Advanced Bionics, Cochlear, and Medel electrodes in a cadaver model

PurposeValidation of a novel minimally invasive, image-guided approach to implant electrodes from three FDA-approved manufacturers—Medel, Cochlear, and Advanced Bionics—in the cochlea via a linear tunnel from the lateral cranium through the facial recess to the cochlea.MethodsCustom microstereotactic frames that mount on bone-implanted fiducial markers and constrain the drill along the desired path were utilized on seven cadaver specimens. A linear tunnel was drilled from the lateral skull to the cochlea followed by a marginal, round window cochleostomy and insertion of the electrode array into the cochlea through the drilled tunnel. Post-insertion CT scan and histological analysis were used to analyze the results.ResultsAll specimens (

Minimally Invasive Image-Guided Cochlear Implantation for Pediatric Patients: Clinical Feasibility Study

N=7

Implantation of the completely ossified cochlea: an image-guided approach.

) were successfully implanted without visible injury to the facial nerve. The Medel electrodes (

Measurement of distances between anatomical structures using a translating stage with mounted endoscope

N=3