Electrode Migration: A Review Article (original) (raw)

Management of Cochlear Implant Electrode Migration

Otology & Neurotology, 2016

Objective: The present study reviewed a cochlear implant (CI) patient population after surgery, which received a freefitting electrode carrier designed for hearing preservation. The aim was to determine the rate of electrode migration of the CI electrodes and present clinical and surgical implications. Study Design: Retrospective patient review. Setting: Tertiary referral university hospital. Patients: Two hundred seventy-eight patients implanted unior bilaterally with lateral wall electrodes designed for hearing preservation (358 implants). The control group was 323 patients implanted uni-or bilaterally with preformed perimodiolar electrodes (468 implants). Interventions: Determination of CI electrode migration was conducted according to a clinical test protocol. Revision surgery was offered in confirmed patients of electrode migration. A bone groove was considered to improve the fixation of the electrode. Main Outcome Measures: Audiological testing including speech audiometry, subjective sound quality rating, and bilateral pitch comparison in bilateral patients, as well as radiological examinations, were conducted. Results: Electrode migration was observed solely in patients implanted with lateral wall electrodes; 10 of 358 patients with free-fitting electrodes (2.8%) had electrode migration, which was successfully confirmed by the proposed clinical test protocol. Nine of the 10 confirmed patients underwent reinsertion surgery. Mean perception score decreased from 75.0% to 62.1% after electrode migration and recovered completely after reinsertion surgery. A flowchart to detect electrode migration was designed for clinical practice. Conclusion: Although electrode migration is a rare complication in CI surgery, long-term follow-up diagnostics should include a test protocol to detect electrode shifts of lateral wall electrode arrays. A reinsertion surgery should be conducted in confirmed patients to recover speech perception.

Electrode Migration After Cochlear Implantation

Otology & Neurotology, 2008

Objective: To investigate impedance change of cochlear implant (CI) electrodes from Cochlear TM in patients with straight and precurved electrodes, and to determine if impedance change of the basal electrodes are indicative for cochlear electrode migration. Methods: Retrospective case series at an academic tertiary referral center. Five hundred sixty patients (414 precurved, 146 straight) received a CI from Cochlear TM between January 2010 and August 2018. Electrode impedance measured intraoperatively and during follow-up has been assessed. In case of impedance change of the 3 most basal electrodes a computer tomography (CT) scan has been performed. Cochlear position of the electrode array has been determined and compared to the one day postoperative electrode position (plain radiography). Results: Changes in electrode impedance in the basal electrodes occurred in 2.1% ears (n = 12). CT scan was available in 9 patients and revealed a migration of the electrode array in 6 patients. Straight electrode types showed a significantly higher migration rate than precurved electrode types (4.1% vs 0%). Conclusions: Electrode impedance is a useful tool to investigate electrode array integrity as well as to raise suspicion of possible electrode migration. Patients implanted with a straight electrode from Cochlear TM array might benefit from lead wire fixation.

Migration of the Ball Electrode After Cochlear Implantation

Otology & Neurotology, 2007

Objective: To review the postoperative radiographic investigations of patients implanted with a cochlear implant. Study Design: Retrospective case series. Patients: Thirty-nine patients (22Y77 yrs old) implanted for sensorineural deafness in the cochlear implants program of the Academic Medical Center of Amsterdam. Intervention: Cochlear implantation with Cochlear Nucleus 24 Contour and Cochlear Nucleus Freedom (Cochlear Corp., Lane Cove, New South Wales, Australia) implant.

The Effect of a Bone Groove Against Cochlear Implant Electrode Migration

Otology & Neurotology, 2019

Hypothesis: The risk of electrode migration in cochlear implant (CI) surgery can be reduced by securing the electrode lead in a bone groove in the chorda-facial angle. Background: Electrode migration is an important complication in CI surgery, which affects hearing performance, may induce pain and facial nerve stimulation, and requires surgical revision. A potential method to secure the electrode is to use a bone groove created in the facial recess to fixate the electrode lead. This surgical measure is a standard procedure for lateral wall electrodes (LWE) in our clinic since 2013. Methods: Retrospective analysis of consecutive CI cases of a tertiary referral center from 2006 to 2016 and comparison of incidence rates between group A (without bone groove, years 2006-2012) and group B (with bone groove fixation, years 2013-2016). Clinical cases were reviewed with respect to electrode type, migration length, time interval to migration, and findings during revision surgery. Results: Seventeen cases of electrode migration were found in a total of 1,603 cochlear implantations. Only LWE designs were affected by migration. The cumulative incidence for LWE in group B (0.5%) was significantly lower than in group A (3.7%, p < 0.01). The two migration cases in group B revealed insufficient geometric design of the bone grooves. Only one patient experienced a remigration after revision surgery. Conclusion: The fixation in a bone groove in the chordafacial angle is an effective measure against migration of LWE. Proper surgical execution is mandatory to ensure a tight and enduring fit.

Postoperative complications in cochlear implants: a retrospective analysis of 438 consecutive cases

European Archives of Oto-Rhino-Laryngology, 2012

Our objective is to determine the complication rate in a population of infants, children, adolescents and adults, from a University Hospital Cochlear Implant program and to discuss their causes and treatments. The methods include a retrospective study of 438 consecutive patients in a tertiary referral centre, the Audiology Department of the University Hospital of Ferrara. All patients receiving cochlear implants, between 1 January 2003 and 31 December 2009, have been included. All complications and treatments were systematically reviewed with an average duration of follow-up of 46 months (range 10-84 months). The results reveal that the overall rate of complications in our group was 9.1% (40 of 438), and most of them were minor. Wound swelling and infections represent the most common complication occurred. There were no cases of transient or permanent facial palsy following surgery, and also we did not register any case of postsurgical meningitis. Thirteen patients (3.0%) underwent explantation followed by reimplantation. In conclusion, we find that Cochlear implantation is a safe low-morbility technique with a relatively low complication rate in the presented population.

Complications of Cochlear Implant Surgery: A Public Implant Centre Experience

Pakistan Journal of Medical Sciences, 2021

Objectives: To determine the prevalence of complications of cochlear implant surgery in children with congenital profound sensorineural hearing loss. Methods: This study retrospectively & consecutively reviewed charts of children who underwent cochlear implantation from July 2015 to July 2019 at Cochlear Implant Centre of Otolaryngology Department of Capital Hospital, Islamabad Pakistan. These included cases of both genders aged one to 12 years operated at least one year before the time of data collection. Basic demographic data, complications including major and minor complications and treatment received was noted and statistically analyzed using SPSS-23. Results were presented using descriptive statistics. Results: Current study included a sample of N=251 having a mean age of 4.05±2.15 years including 154(61.4%) males and 97(38.6%) females revealed a prevalence of complications of 16(6.4%) with 4(1.6%) major and 12(4.8%) minor complications. Wound infection and acute otitis media ...

Surgical complications in 550 consecutive cochlear implantation

2012

UNLABELLED Cochlear implantation is a safe and reliable method for auditory restoration in patients with severe to profound hearing loss. OBJECTIVE To describe the surgical complications of cochlear implantation. MATERIALS AND METHODS Information from 591 consecutive multichannel cochlear implant surgeries were retrospectively analyzed. All patients were followed-up for at least one year. Forty-one patients were excluded because of missing data, follow-up loss or middle fossa approach. RESULTS Of 550 cochlear implantation analyzed, 341 were performed in children or adolescents, and 209 in adults. The mean hearing loss time was 6.3 ± 6.7 years for prelingual loss and 12.1 ± 11.6 years for postlingual. Mean follow-up was 3.9 ± 2.8 years. Major complications occurred in 8.9% and minor in 7.8%. Problems during electrode insertion (3.8%) were the most frequent major complication followed by flap dehiscence (1.4%). Temporary facial palsy (2.2%), canal-wall lesion (2.2%) and tympanic membr...

Fixation of cochlear implants: an evidence-based review of literature

B-ENT

There are numerous cochlear implant fixation techniques to prevent soft tissue complications related to device migration. The literature does not provide sufficient evidence to determine the most suitable fixation method. Cochlear implants (CI) are becoming a routine treatment for patients with severe to profound deafness. Steadily growing numbers of implant centres and surgeons worldwide are inevitably leading to higher rates of complications, including device migration. It is currently unknown whether this can be prevented by proper implant fixation during surgery. The low prevalence of this complication makes it challenging to interpret publications regarding CI fixation techniques. An exhaustive literature review reveals a variety of different fixation techniques. Most authors advocate the creation of a bony well for the CI receiver/stimulator (R/S); however, an increasing number of surgeons no longer secure implants at all. Here we give an overview of all published fixation met...

Hearing Loss and Cochlear Implantation

Perspectives in Pragmatics, Philosophy & Psychology, 2017

The aim of this study is to detect the variations in cochlear size which may help in selection of the best cochlear implant electrode length and may also influence the insertion depth angles of the electrode arrays. To achieve this goal, 40 patients (21 females and 19 male) were included, their age ranged from 4 to 57 years (mean 24.63±17.30 years), pre-and postoperative non-contrast CT examination of the petrous bone was performed. It showed that, the cochlear distance (diameter A) ranged between 7.10-10.10mm (mean 8.53 ± 0.56mm) ,The cochlear duct length ranged between 25.50-38.0mm (mean 31.45 ± 2.33mm), postoperative, insertion depth angles ranged between 405 to 500o (mean 450.17±36.77), for advanced bionics, 211.0-420.0o (mean 367.56 ± 71.81o) for cochlear nucleus, 371.0-520.0o (mean 456.14 ± 61.33o) for Flex 28, and 475.0-598.0o (mean 513.06 ± 31.76 o) for Med-El standard electrode, a non-significant correlation was found between the insertion depth angles and the cochlear distance. A statistically significant positive correlation was found between the insertion depth angle and length of the electrode array. Therefore, it is concluded that assessing the cochlear parameters helps to choose the optimal electrode to provide proper cochlear coverage while avoiding insertional trauma.

Cochlear implant electrode array extrusion – is reimplantation feasible? – case report

Medicina Fluminensis

Aim: To present two cases of late complications of cochlear implantation. Case report: In both cases extracochlear extrusion of the implant electrode occurred. More than ten years after successful cochlear implantation, the hearing performance gradually worsened to the point of no intelligibility in both patients. Otomicroscopy revealed chronic otitis media (COM) with an electrode in the external ear canal in implanted ears of both patients. Extracochlear electrode extrusion was noticed on CT scans in both cases. In the first case the device was explanted, the electrode was left in the cochlea and tympanoplasty was performed. Regardless the normal status of the middle ear, extracochlear extrusion occurred again. Conclusion: After extracochlear electrode extrusion, the reimplantation is likely to be unsuccessful.