Alternative Techniques in Cochlear Implantation

European Archives of Oto-Rhino-Laryngology, 2014

The goal of this work was to review the pre-and postsurgical auditory thresholds of two surgical implantation techniques, namely the mastoidectomy with posterior tympanotomy approach (MPTA) and suprameatal approach (SMA), to determine whether there is a difference in the degree of preservation of residual hearing. In a series of 430 consecutive implanted patients 227 patients had measurable pre-operative hearing thresholds at 250, 500, and 1,000 Hz. These patients were divided into two groups according to the surgical technique that was used for implantation. The SMA approach was followed for 84 patients in Amsterdam, whereas the MPTA technique was adhered to 143 patients in Maastricht. The outcome variables of interest were alteration of pre-and postoperative auditory thresholds after cochlear implantation. Complete or partial preservation of residual hearing was obtained in 21.4 and 21.7 % in the SMA and MPTA group, respectively. No statistical differences could be found between the SMA and MPTA group (p = 0.96; Chi-square test). The SMA technique is correlated with a similar degree of hearing loss after cochlear implantation compared to the MPTA technique. However, both techniques were not able to conserve a measurable amount of hearing in patients with a substantial degree of residual hearing. Therefore, both surgical techniques need to be refined for patients in which residual acoustical hearing is pursued.

2009

Our study was designed to compare two surgical approaches that are currently employed in cochlear implantation.

Annals of Otology and Neurotology, 2018

Introduction Different surgical approaches have been adopted for cochlear implantation, with cortical mastoidectomy-posterior tympanotomy being the most commonly followed technique. Method In this article, we describe the surgical technique for cochlear implant followed at our center, which has been successfully implemented in more than 2,500 cochlear implant surgeries. Cochlear implant surgery using the cortical mastoidectomyposterior tympanotomy technique has been performed in more than 2,500 cases with some modifications to the original technique over a period of time. Results In spite of not using tie-down holes and securing down the receiver-stimulator with sutures, no cases of receiver-stimulator displacement or outward electrode migration have been noted with the current technique of creating a snug-fitting subperiosteal pocket along with a hook for the electrode array. Conclusion Adhering to a strict intraoperative surgical protocol plays an extremely important role in carrying out successful cochlear implant surgeries with minimal complications.

Acta Otorrinolaringologica (english Edition), 2012

Introduction: Complications are very sensitive indicators of the usefulness of a surgical technique. In cochlear implant surgery, there are 3 principal approaches: the classic approach uses the facial recess (FR), the suprameatal approach (SMA) does not require mastoidectomy and uses the creation of a tunnel over the facial nerve to enter the middle ear, and the endomeatal approach (EMA) is based on the completion of a groove in the posterior wall of external auditory canal. Material and methods: A multicentre review of 208 patients with cochlear implants was performed for comparing the different techniques. The complications were classified into major and minor. Results: Among the 208 implanted patients, 10.5% (22 of 208) had complications. Of these, 2.88% (6 of 208) were major complications and 7.69% (16 of 208) were minor complications. Comparing the results obtained by the different approaches, the FR technique had the lowest rate of major complications (1.1%), followed by the EMA technique with 2.38% and SMA with 3.75%. As for minor complications, operations in the SMA group had the lowest rate (6.25%), followed by the EMA group (7.14%) and the group operated on using the FR technique presented the highest (10%). Conclusions: The 3 techniques described show very similar rates of complications. Consequently, we can conclude that they are safe and are alternatives.

Cochlear Implants International, 2004

Expanding selection criteria and increasing numbers of cochlear implantations have revealed several challenging cases with regard to surgery and medical point of view. Cochlear implantation of congenitally deaf children with inner-ear malformations may involve difficulties in preoperative evaluation, surgical approach and postoperative follow-up. Cochlear nerve aplasia (as evidence of only one existing nerve in three dimensional magnetic resonance imaging) and hypoplastic cochleas are among the most difficult cases and sometimes children are considered unsuitable for cochlear implantation. However, there is always the possibility that hypoplastic cochleas may include ganglion cells and the only nerve in the internal auditory canal (facial nerve) may contain auditory fibres as well. A positive history of auditory experience and evidence of electrical auditory brainstem response or response to the promontory or round window electrical stimulation may imply that a functioning auditory system is in place. Malformations like common cavity deformity, isolated bilateral vestibular aqueduct enlargement and Mondini dysplasia are usually less challenging, although cerebrospinal fluid leak and postoperative meningitis may be a possibility. In cases of post-meningitic deaf patients, ossification (or obliteration) may be a serious problem even if computed tomography and MRI scan show a patent cochlea or minimal changes. Acoustic neuromas and neurofibromatosis type 2 are other challenging cases, as there is always the possibility that the sensorineural hearing loss is secondary to cochlear damage by interference of the tumour to cochlear blood supply. In conclusion, challenging cases are becoming more common as we are expanding selection criteria, and we should be prepared for alternative cochlear implant devices (straight electrode arrays, dual arrays, compressed arrays, etc.), increased rate of possible complications at, and following, surgery, and functional outcome that may vary considerably among implantees.

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.

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...

Journal of Neurological Surgery Part B: Skull Base, 2018

A cochlear implant (CI) is a surgically implanted device for the treatment of severe to profound sensorineural hearing loss in children and adults. It works by transducing acoustic energy into an electrical signal, which is used to stimulate surviving spiral ganglion cells of the auditory nerve. The past 2 decades have witnessed an exponential rise in the number of CI surgeries performed. Continual developments in programming strategies, device design, and minimally traumatic surgical technique have demonstrated the safety and efficacy of CI surgery. As a result, candidacy guidelines have expanded to include both pre and postlingually deaf children as young as 1 year of age, and those with greater degrees of residual hearing. A growing proportion of patients are undergoing CI for off-label or nontraditional indications including single-sided deafness, retrocochlear hearing loss, asymmetrical sensorineural hearing loss (SNHL) in adults and children with at least 1 ear that is better ...

Acta Oto-Laryngologica, 2006

Conclusion. Partial deafness cochlear implantation (PDCI) is a feasible means of treating individuals who have good low frequency hearing, but a severe to profound hearing loss in the mid to high frequencies. The individuals have benefit in noise and show significant benefit in a number of difficult listening conditions, when compared with their acoustic-only hearing prior to implantation. This benefit is maintained over time. Objectives. PDCI using the round window surgical technique is one means of treating individuals with a 'ski-slope' hearing loss, who gain minimal benefit from amplification with conventional hearing instruments. This paper aims to demonstrate the benefit that PDCI provides these individuals. Patients and methods. Ten subjects received a partial insertion of a standard MED-EL electrode, using the round window approach. Pure tone audiometry and monosyllable testing in quiet and noise were conducted preoperatively, at implant fitting and then at 1, 3, 6 and 12 months after initial device fitting. The APHAB questionnaire was completed by subjects preoperatively and then at 6 and 12 months after receiving their cochlear implant. Results. Hearing was preserved in 9 of 10 cases. One subject uses a hearing aid to amplify low frequency hearing, the remainder use natural low frequency hearing. Improvements in monosyllabic scores over time in both quiet and noise were significant, particularly within the first 3 months of PDCI use.

Acta Oto-Laryngologica, 2005

Conclusions. Hearing may be conserved in adults after implantation with the Nucleus Contour Advance perimodiolar electrode array. The degree of hearing preservation and the maximum insertion depth of the electrode array can vary considerably despite a defined surgical protocol. Residual hearing combined with electrical stimulation in the same ear can provide additional benefits even for conventional candidates for cochlear implantation. Objectives. We present preliminary results from a prospective multicentre study investigating the conservation of residual hearing after implantation with a standard-length Nucleus Contour Advance perimodiolar electrode array and the benefits of combined electrical and acoustic stimulation. Material and methods. The subjects were 12 adult candidates for cochlear implantation recruited according to national selection criteria. A ''soft'' surgery protocol was defined, as follows: 1 Á/1.2-mm cochleostomy hole anterior and inferior to the round window; Nucleus Contour Advance electrode array inserted using the ''Advance-off-stylet'' technique; and insertion depth controlled by means of three square marker ribs left outside the cochleostomy hole. These procedures had been shown to reduce insertion forces in temporal bone preparations. Variations in surgical techniques were monitored using a questionnaire. Pure-tone thresholds were measured pre-and postoperatively. Patients who still retained thresholds B/90 dB HL for frequencies up to 500 Hz were re-fitted with an in-the-ear (ITE) hearing aid. Word recognition was tested in quiet and sentence perception in noise for the cochlear implant alone and in combination with an ipsilateral hearing aid. Results. Hearing threshold level data were available for 12 patients recruited from 6 of the centres. Median increases in hearing threshold levels were 23, 27 and 33 dB for the frequencies 125, 250 and 500 Hz, respectively. These median increases include the data for two patients who had total loss of residual hearing due to difficulties encountered during surgery. ''Cochlear view'' X-ray images indicated that the depth of insertion varied between 300 and 4308, despite modest variations in the length of the electrode inserted (17 Á/19 mm). The insertion angle had some influence on the preservation of residual hearing at frequencies of 250 Á/500 Hz. Six of the 12 patients retained sufficient hearing for effective use of an ipsilateral ITE hearing aid (5/80 dB HL at 125 and 250 Hz; 5/90 dB HL at 500 Hz). Word recognition scores in quiet were improved from 10% to 30% with the cochlear implant plus ipsilateral hearing aid in 3 patients who had at least 3 months postoperative experience. Signal:noise ratio thresholds for sentence recognition were improved by up to 3 dB. Patients reported that they experienced greatly improved sound quality and preferred to use the two devices together.