Intra-operative skull X-ray for misdirection of the cochlear implant array into the vestibular labyrinth

AbstractObjectives:This paper reports five cases of aberrant cochlear implant electrode array insertion into the vestibular labyrinth. A review of the literature was conducted in order to clarify reasonable preventive and detection strategies and endorse the routine use of intra-operative plain skull X-ray.Methods:The study entailed a clinical case series and literature review. The setting was a tertiary academic referral centre. The following data were evaluated: pre-operative temporal bone computed tomography, operative reports, intra-operative imaging, neural response telemetry/imaging and post-operative imaging.Results:There were no consistent pre-operative risk factors found on computed tomography scans and no reliable intra-operative signs of electrode array misdirection. All misdirections in our case series, and those in the literature, were easily detectable on intra-operative plain film X-ray.Conclusion:These reported cases demonstrate implant misdirection without the surgeon's awareness. Aberrant insertion cannot be anticipated, and neural response telemetry/imaging is not a reliable indicator of misdirection. Routine intra-operative anteroposterior plain X-ray of the head is a reliable indicator of misdirection, and is fast and relatively inexpensive.

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An unusual occurrence in cochlear implantation surgery: misplaced electrode

The Journal of Laryngology & Otology ◽

10.1017/s0022215108004064 ◽

2008 ◽

Vol 123 (1) ◽

Cited By ~ 13

Author(s):

R Ramalingam ◽

K K Ramalingam ◽

H S Padmaja

Keyword(s):

Cochlear Implantation ◽

Round Window ◽

Electrode Array ◽

Cost Effective ◽

Conventional Radiography ◽

Neural Response ◽

X Ray ◽

Neural Response Telemetry ◽

Electrode Positioning ◽

Unusual Occurrence

AbstractObjective:To highlight the possibility of misplacement of electrodes during cochlear implantation surgery, to stress the importance of routine neural response telemetry, and also to emphasise the value of conventional radiography in confirming electrode positioning in the immediate post-operative period.Case report:A two-year-old boy presented with bilateral, profound, sensorineural hearing loss and underwent conventional cochlear implantation surgery. During insertion of the implant, there was doubt regarding the direction of passage of the electrode array. Instead of the usual smooth passage of the electrode, some resistance was felt. Neural response telemetry, performed at the end of the procedure, showed absent responses. A confirmatory X-ray in Stenver's view confirmed the extra-cochlear positioning of the electrodes in the superior semicircular canal. The wound was reopened, the electrode array removed and the cochleostomy was positioned a little more antero-inferiorly on the promontory with respect to the round window. Correct insertion of the electrode was then performed without difficulty.Conclusion:The misplacement of electrodes during cochlear implantation surgery is rare but can occur. Neural response telemetry and conventional radiography are invaluable in assessing the placement of the electrode intra-operatively. Conventional radiographs are very cost-effective and aid in confirming the position of the electrode array.

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A study on relationship between Neural Response Telemetry and behavioural Threshold/Comfort levels in children with cochlear implant

Medical Journal Armed Forces India ◽

10.1016/j.mjafi.2020.10.011 ◽

2020 ◽

Author(s):

Indrajeet Chauhan ◽

Himanshu Swami ◽

Rashmi Natraj

Keyword(s):

Cochlear Implant ◽

Neural Response ◽

Comfort Levels ◽

Neural Response Telemetry

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An X-ray fluorescence microscopic analysis of the tissue surrounding the multi-channel cochlear implant electrode array

Cochlear Implants International ◽

10.1080/14670100.2016.1157943 ◽

2016 ◽

Vol 17 (3) ◽

pp. 129-131 ◽

Cited By ~ 11

Author(s):

Kathryn Spiers ◽

Tina Cardamone ◽

John B. Furness ◽

Jonathan C. M. Clark ◽

James F. Patrick ◽

...

Keyword(s):

Cochlear Implant ◽

Electrode Array ◽

Microscopic Analysis ◽

X Ray ◽

Fluorescence Microscopic Analysis

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Precurved Cochlear Implants and Tip Foldover: A Cadaveric Imaging Study

Otolaryngology ◽

10.1177/0194599817738978 ◽

2017 ◽

Vol 158 (2) ◽

pp. 343-349 ◽

Cited By ~ 7

Author(s):

Danielle R. Trakimas ◽

Elliott D. Kozin ◽

Iman Ghanad ◽

Sam R. Barber ◽

Hugh Curtin ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Cochlear Implants ◽

Electrode Array ◽

Imaging Study ◽

Plain Film ◽

Plain Radiography ◽

Electrode Placement ◽

High Resolution Computed Tomography ◽

Plain Film Radiography

Objective This study aims to define a reliable protocol for radiographic identification of placement and tip foldover of newly designed precurved and straight electrodes. Study Design Prospective imaging study. Setting Academic institution. Methods Three models of cochlear implants (Cochlear, MED-EL, and Advanced Bionics) were inserted into fresh cadaveric specimens (n = 2) in 3 configurations (normal positioning in the scala tympani, intracochlear tip foldover, and placement into the vestibular system) for a total of 9 implant scenarios. Specimens were imaged with plain radiography in Stenvers projection, as well as by high-resolution computed tomography. Results Electrode placement and presence or absence of electrode tip foldover were easily identified in all 9 scenarios on plain radiography based on the described technique. Each was confirmed with high-resolution computed tomography. Plain film temporal bone images of new electrode designs with proper and improper placement are provided for reference. Conclusion A defined protocol for intraoperative plain film radiography allowed for reliable imaging of 3 newly designed cochlear implant electrodes and immediate identification of extracochlear placement and tip foldover. Findings may be used for intraoperative confirmation of electrode array placement.

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Neural Response Telemetry With the Nucleus CI24M Cochlear Implant

The Laryngoscope ◽

10.1097/00005537-199911000-00006 ◽

1999 ◽

Vol 109 (11) ◽

pp. 1755-1759 ◽

Cited By ~ 32

Author(s):

Jon K. Shallop ◽

George W. Facer ◽

Ann Peterson

Keyword(s):

Cochlear Implant ◽

Neural Response ◽

Neural Response Telemetry

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Flat-Panel Volume Computed Tomography for Cochlear Implant Electrode Array Examination in Isolated Temporal Bone Specimens

Otology & Neurotology ◽

10.1097/00129492-200606000-00010 ◽

2006 ◽

Vol 27 (4) ◽

pp. 491-498 ◽

Cited By ~ 21

Author(s):

Soenke H. Bartling ◽

Rajiv Gupta ◽

Attila Torkos ◽

Christian Dullin ◽

Grabbe Eckhardt ◽

...

Keyword(s):

Computed Tomography ◽

Cochlear Implant ◽

Temporal Bone ◽

Electrode Array ◽

Flat Panel ◽

Volume Computed Tomography

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Changes in Intraoperative and Postoperative Neural Response Telemetry in Cochlear Implant Users

Sohag Medical Journal ◽

10.21608/smj.2017.39758 ◽

2017 ◽

Vol 21 (3) ◽

pp. 263-271

Author(s):

Shahenda Moussa ◽

Mostafa Aly ◽

Mohamed Abdelrahman

Keyword(s):

Cochlear Implant ◽

Neural Response ◽

Neural Response Telemetry

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Evaluation of the Relationship between the NRT-Ratio, Cochlear Anatomy, and Insertions Depth of Perimodiolar Cochlear Implant Electrodes

BioMed Research International ◽

10.1155/2015/706253 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 6

Author(s):

Philipp Mittmann ◽

Grit Rademacher ◽

Sven Mutze ◽

Frederike Hassepass ◽

Arneborg Ernst ◽

...

Keyword(s):

Cochlear Implant ◽

Electrode Array ◽

Scala Tympani ◽

Flat Panel ◽

Insertion Depth ◽

Tomography System ◽

Neural Response Telemetry ◽

Auditory Performance ◽

The Relationship ◽

Scala Vestibuli

The position of the cochlear implant electrode array within the scala tympani is essential for an optimal postoperative hearing benefit. If the electrode array changes in between the scalae intracochlearly (i.e., from scala tympani to scala vestibuli), a reduced auditory performance can be assumed. We established a neural response telemetry-ratio (NRT-ratio) which corresponds with the scalar position of the electrodes but shows within its limits a variability. The aim of this study was to determine if insertion depth angle or cochlea size influences the NRT-ratio. The intraoperative electrophysiological NRT data of 26 patients were evaluated. Using a flat panel tomography system, the position of the electrode array was evaluated radiologically. The insertion depth angle of the electrode, the cochlea size, and the NRT-ratio were calculated postoperatively. The radiological results were compared with the intraoperatively obtained electrophysiological data (NRT-ratio) and statistically evaluated. In all patients the NRT-ratio, the insertion depth angle, and the cochlea size could be determined. A significant correlation between insertional depth, cochlear size, and the NRT-ratio was not found. The NRT-ratio is a reliable electrophysiological tool to determine the scalar position of a perimodiolar electrode array. The NRT-ratio can be applied independent from insertion depth and cochlear size.

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Radiation Exposure in Patients with Isolated Limb Trauma: Acceptable or Are We Imaging Too Much?

Journal of Clinical Medicine ◽

10.3390/jcm9113609 ◽

2020 ◽

Vol 9 (11) ◽

pp. 3609

Author(s):

James A. Wheeler ◽

Natasha Weaver ◽

Zsolt J. Balogh ◽

Herwig Drobetz ◽

Andrew Kovendy ◽

...

Keyword(s):

Computed Tomography ◽

Effective Dose ◽

Radiation Risk ◽

Plain Film ◽

Study Cohort ◽

X Ray ◽

Cumulative Effective Dose ◽

Orthopaedic Patients ◽

Extremity Trauma ◽

The Mean

The aim of our study was to investigate the cumulative effective dose of radiation resulting from medical imaging in orthopaedic patients with isolated extremity trauma. Deidentified radiology records of consecutive patients without age restriction with isolated extremity trauma requiring operative treatment at a regional hospital were reviewed retrospectively over a 1-year period, and the effective dose per patient for each study type of plain film X-ray, computed tomography, and operative fluoroscopy was used to calculate cumulative effective dose. Values were summarised as mean, ± standard deviation, maximum, and proportion with overdose (>20 mSv). The study cohort included 428 patients (193 male and 235 female) with an average age of 44 years (±28). There were 447 procedures performed, i.e., all involved operative fluoroscopy, 116 involved computed tomography, and 397 involved X-ray. The mean cumulative effective dose per patient was 1.96 mSv (±4.98, 45.12). The mean cumulative effective dose for operative fluoroscopy was 0.32 mSv (±0.73, 5.91), for X-ray was 1.12 mSv (±3.6, 39.23) and for computed tomography was 2.22 mSv (±4.13, 20.14). The mean cumulative effective dose of 1.96 mSv falls below the recommended maximum annual exposure of 20 mSv. This study can serve as a guide for informing clinicians and patients of the acceptable radiation risk in the context of isolated extremity trauma.

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