Supporting cell survival after cochlear implant surgery

Supporting cells (SCs) provide structure and maintain an environment that allows hair cells to receive and transmit signals in the auditory pathway. After insult to hair cells and ganglion cells, SCs respond by marking unsalvageable cells for death and maintain structural integrity. Although the histopathology after cochlear implantation has been described regarding hair cells and neural structures, surviving SCs in the implanted ear have not. We present a patient whose posthumous examination of an implanted cochlea demonstrated SC survival. This finding has implications for SC function in maintaining electrical hearing and candidacy for future hair cell regeneration therapies. Laryngoscope, 129:E36–E40, 2019     

Antibiotic prophylaxis in cochlear implant surgery

OBJECTIVES/HYPOTHESIS: We conducted this study to determine the incidence of infection in cochlear implant surgery after using perioperative antibiotics. STUDY DESIGN: Study design was a retrospective case series. METHODS: There was a retrospective chart review of 95 patients (81 adults, 14 children) undergoing 98 cochlear implants. RESULTS: The incidence of infection following cochlear implant surgery was 1% with the use of perioperative antibiotics. CONCLUSIONS: Perioperative antibiotics, usually administered as a single dose, are sufficient for the prevention of major wound infection after cochlear implant surgery.     

Facial nerve paralysis following cochlear implant surgery

OBJECTIVES: Facial nerve paralysis is a rare but devastating complication of cochlear implant surgery. The aims of the study were to define the incidence of facial nerve paralysis in our series and understand possible mechanisms of injury. STUDY DESIGN: Retrospective chart review and case reports. METHODS: Charts were reviewed of all 705 patients implanted between 1980 and 2002 at the authors' institutions to identify those with postoperative facial nerve weakness and determine incidence. For patients with facial nerve weakness, onset, degree, and timing of paralysis were noted; clinical findings were correlated to operative report findings. The method of treatment was noted, and the final facial nerve function outcome was recorded. RESULTS: Five patients (one child and four adults) were found to have postoperative facial nerve weakness, for an incidence of 0.71%. This complication was delayed in all cases, ranging from 18 hours to 19 days postoperatively. All patients were treated with steroids or steroids combined with antiviral medication, and all ultimately recovered normal facial function. CONCLUSIONS: In the study series, the incidence of facial nerve paralysis following cochlear implant surgery was 0.71%. Possible mechanisms of injury included heating injury and viral reactivation. All patients presented with a delayed facial nerve paralysis and did recover normal facial nerve function.     

Occurrence of major complications after cochlear implant surgery in Ireland

Objectives: Cochlear implantation (CI) is considered an effective and relatively safe procedure for patients with severe-profound hearing loss. However, severe complications are reported in several studies. The purpose of this study was to report the frequency and management of major complications following CI surgery at the National CI Programme (NCIP) in Ireland.

Methods: Major complications were defined according to the classification of Hansen et al. 2010. The medical records of 1017 patients undergoing CI between 1995 and 2016 were analyzed retrospectively for major complications. In addition, radiological and intraoperative findings as well as therapeutic management of all patients with a major complication were reviewed.

Results: Altogether, 1017 patients underwent 1266 CI surgeries. The median follow-up of all CI surgeries was 44 months. The total number of major complications identified was 21 which corresponds to an overall rate of 1.7%. The majority of major complication (71%) occurred at least one week after surgery. The most common major complications were internal receiver/stimulator protrusion and migration (6/21), followed by migration of the electrode array (4/21) and recurrent otitis media requiring re-implantation (4/21). All patients with major complications required additional surgery, with reimplantation necessary in 19 patients (90%).

Discussion: CI surgery is a safe surgical procedure for hearing rehabilitation associated with a low rate of severe complications. However, major complications can occur many years after surgery, making revision surgery necessary.

Conclusion: Long-term follow-up is necessary for the early identification of complications to facilitate appropriate care.     

Patients' involvement in choosing a cochlear implant

Abstract

Objective

The study describes the procedure followed by the South of England Cochlear Implant Centre, Southampton in involving the patients in their choice of device and it also describes the reasons given by patients for choosing a particular device.

Methods

A retrospective service evaluation of 43 adults and 19 children was carried out and the data was analysed.

Results

A wide range of reasons for choosing a particular device were reported. However, it is notable that the single most common reason for choosing a particular device was related to the aesthetics.

Discussion

The data suggest that the main reason for choosing a particular device related more to the aesthetics and comfort of the device irrespective of the technical aspects.     

Validation of a networked virtual reality simulation of temporal bone surgery

Objectives: To assess the content validity and concurrent validity of a haptically (force feedback) rendered, virtual reality simulation of temporal bone surgery. Methods: Eleven naive surgical trainees were given a 1‐hour lesson on the operation, cortical mastoidectomy, in the virtual environment with the trainer on a networked simulator and then asked to perform this procedure on a real temporal bone. Results: The simulator was found to be a convincing representation of temporal bone drilling and could be said to exhibit face validity. The simulator was an effective means of teaching both the surgical anatomy and the surgical approach as judged by oral assessments made before and after the virtual reality training session. The trainees were successful in identifying most surgical landmarks during their first temporal bone dissection, and over two thirds found the landmarks at the correct time during the procedure. Some trainees exhibited acceptable or better technique with the drill despite this being their first temporal bone dissection. Subjective assessments indicated a high level of acceptance of simulated surgery for training, and there was perceived value in specific enhancements of the virtual environment that facilitated learning. Particular enhancements of value were the networked simulation, the option to make the model semitransparent to reveal anatomic relationships, and error reporting when the sigmoid sinus or facial nerve was injured. Conclusions: Virtual reality simulation of temporal bone surgery was an effective method for teaching surgical anatomy and planning and was well accepted by trainees.     

Complications in pediatric cochlear implant surgery

In a retrospective analysis we evaluated the intra- and postoperative complications in children who underwent cochlear implantation between 1984 and 1993 at the Medizinische Hochschule Hannover. The data and records of 366 children were collected and analyzed. Relevant parameters were major complications such as significant infection, intraoperative bleeding, facial nerve injury, implant loss and device failure, as well as lesser complications, including delayed wound healing, chronic pain and vertigo. Late complications such as cholesteatoma or electrode dislocations were also registered. Cases of acute otitis media were managed with conservative treatment. Data presented indicate that cochlear implant surgery in children is a reliable and safe procedure with a low percentage of severe complications. Problems related to ear surgery can occur and should be manageable with standard procedures. Careful operative techniques and sufficient personal experience can help avoid severe postoperative problems. Received: 5 August 1998 / Accepted: 11 August 1998     

Management of cerebrospinal fluid leakage from cochleostomy during cochlear implant surgery

OBJECTIVES: The objectives of this retrospective review were to determine the incidence of cerebrospinal fluid (CSF) otorrhea from the cochleostomy during cochlear implant surgery, to recognize patients at risk, and to determine the appropriate preoperative, postoperative and intraoperative management. METHODS: A chart review from two cochlear implant centers was performed to determine the incidence of CSF otorrhea, patients at risk, and appropriate management. RESULTS: The incidence of CSF gusher is low, encountered in approximately 1% of patients undergoing cochlear implant surgery, and is seen in equal incidence in children and adults in our series. Preoperative imaging was predictive in only 50% of cases. Mechanisms for otorrhea in specific cochlear malformations and in those in which no apparent malformation exists are discussed. Successful implantation is expected in most cases. Intraoperative management may require complete packing of the middle ear space in addition to the cochleostomy to control CSF leak. Lumbar drain is rarely necessary. Outpatient management is possible in the majority of cases. Vaccination and antibiotic prophylaxis is essential. CONCLUSIONS: CSF otorrhea can be encountered in cochlear malformations and in cochleas without apparent malformation. Successful implantation without short-term or long-term complications is expected.     

Vestibular function after cochlear implant surgery

Objective: The aim of this study was to analyze vestibular function in cochlear implant (CI) patients for iatrogenic damage to vestibular function.

Methods: Prospective clinical study. Tertiary care audiological center. Twenty-five subjects receiving surgery for cochlear implantation during 2012 and 2013 were analyzed. Both vestibulo-ocular and vestibulo-spinal responses before and 2 months after CI surgery were evaluated using several tests: analysis of spontaneous nystagmus, head shaking test (HST), and head impulse test recorded by videooculography; caloric stimulation at 44° and 30° in both ears; cervical evoked myogenic potentials and static stabilometry. Residual cochlear function was tested by air-conduction pure-tone audiometry.

Results: Our tests showed damage to vestibular receptors after CI surgery in 12% of the patients; in particular, horizontal semicircular canal function and saccular function had lower responses after surgery. Audiometric results showed poorer thresholds after CI surgery. The static stabilometry results indicate good vestibulo-spinal responses and patients did not report disequilibrium nor postural deficit.

Conclusion: All data suggest an efficient vestibular compensation mechanism in CI patients.     

Audiovisual speech perception in elderly cochlear implant recipients

OBJECTIVES/HYPOTHESIS: This study examined the speech perception skills of a younger and older group of cochlear implant recipients to determine the benefit that auditory and visual information provides for speech understanding. STUDY DESIGN: Retrospective review. METHODS: Pre- and postimplantation speech perception scores from the Consonant-Nucleus-Consonant (CNC), the Hearing In Noise sentence Test (HINT), and the City University of New York (CUNY) tests were analyzed for 34 postlingually deafened adult cochlear implant recipients. Half were elderly (i.e., >65 y old) and other half were middle aged (i.e., 39-53 y old). The CNC and HINT tests were administered using auditory-only presentation; the CUNY test was administered using auditory-only, vision-only, and audiovisual presentation conditions RESULTS: No differences were observed between the two age groups on the CNC and HINT tests. For a subset of individuals tested with the CUNY sentences, we found that the preimplantation speechreading scores of the younger group correlated negatively with auditory-only postimplant performance. Additionally, older individuals demonstrated a greater reliance on the integration of auditory and visual information to understand sentences than did the younger group CONCLUSIONS: On average, the auditory-only speech perception performance of older cochlear implant recipients was similar to the performance of younger adults. However, variability in speech perception abilities was observed within and between both age groups. Differences in speechreading skills between the younger and older individuals suggest that visual speech information is processed in a different manner for elderly individuals than it is for younger adult cochlear implant recipients.     

Identification and revision of a displaced cochlear implant electrode in the internal auditory canal

Abstract

Objective

The aim of the report is to underline the importance of a radiological technique which allows three-dimensional (3D) imaging of the cochlear implant electrode position postoperatively in cases of cochlear malformation, and to show a technique to prevent a repeat of cochlear implant electrode insertion in the internal auditory canal (IAC).

Clinical presentation

This report describes the management of a case of insertion of a cochlear implant electrode into the IAC in a 1.5-year-old patient with an incomplete partition (IP) III cochlear malformation.

Intervention and technique

The commonly used single plain postoperative X-ray is not sufficient to be certain of detecting the incorrect insertion of a cochlear implant electrode in the case of a malformed cochlea. In this case, 3D radiology allowed the incorrect insertion to be detected. The original cochlear implant electrode was temporarily left in place under the assumption that it would block the entrance to the IAC and prevent IAC insertion of the replacement electrode.

Conclusion

Postoperative 3D radiological observation after cochlear implant surgery should be done in cases of malformation. Leaving the original electrode in place can help to prevent a repeat electrode malinsertion.     

Intracochlear assessment of electrode position after cochlear implant surgery by means of multislice computer tomography

The development of electrode arrays, the past years, has focused on modiolus-hugging cochlear implant electrodes. Besides, atraumatic implantation of electrodes is of importance for the use in hearing preservation, in cases of combined electric and acoustic stimulation. Intracochlear positioning of the individual electrodes by means of multislice computer tomography (CT) has not yet been shown. In this study we formulated and tested a CT imaging protocol for postoperative scanning of the temporal bone in cochlear implant subjects. Both a fresh human temporal bone and a fresh human cadaver head were implanted with a cochlear implant. Multislice CT was performed for adequate depiction of the cochlear implant. All scans were analyzed on a viewing workstation. After mid-modiolar reconstruction we were able to identify the intracochlear electrode position relative to the scala tympani and scala vestibuli. This was possible in both the implanted isolated temporal bone and the fresh human cadaver head. The feasibility of imaging the electrode position of the cochlear implant within the intracochlear spaces is shown with multislice CT. An imaging protocol is suggested.     

Follow-up of cochlear implant use in patients who developed bacterial meningitis following cochlear implantation

Objectives/Hypothesis: The present study is a long‐term follow‐up of speech perception outcomes and cochlear implant use in three cases of meningitis that occurred after cochlear implantation. Study Design: Case series study. Methods: Study was performed on three children implanted with different models of Clarion® devices, two of them with positioner. Recognition and comprehension were assessed via the Italian adaptation of GASP (TAP) test, and phonetically balanced bi‐syllabic words in open‐set. High resolution computed tomography scan acquisition was performed to obtain axial coronal and oblique multiplanar reconstructions of the cochlea. Results: Two patients were affected by enlarged cochlear acqueduct and Mondini malformation the first carrying positioner. One patient had a normal cochlea, and the positioner could have been the main cause of bacterial spread. As a consequence of meningitis the child with normal cochlea and the other with enlarged vestibular acqueduct developed cochlear ossification, increased M‐level and worsening of hearing outcomes. The child with Mondini malformation developed facial nerve stimulation. Contralateral implantation was performed in the first two patients. Conclusion: Bacterial meningitis occurring after cochlear implantation may induce cochlear ossification, facial nerve stimulation, and permanent or temporary loss of implant use. Planned follow‐up with high resolution computed tomography and evaluation of M‐levels could be useful prognostic tools in the management of these patients.     

Orientation for cochlear implant surgery in cases with round window obstruction: a computer reconstruction study

In order to improve cochlear implant surgery in patients with obstructed round windows, surgical orientations of the round window and scala tympani relative to the stapes footplate were examined in ten normal temporal bones using a computer-aided, three-dimensional reconstruction and measurement technique. The round window was found to be exactly inferior to the midpoint of the inferior margin of the stapes footplate in most cases. An optimal point on the promontory wall for drilling to reach the bottom of the scala tympani of the basal turn was found to lie approximately 1.5 mm anterolateral or anterolateral inferior to a point 3 mm inferior to the midpoint of the inferior margin of the stapes footplate. A combination of the transmeatal and facial recess approaches made it possible to consistently reach the scala tympani, and demonstrated that this approach was also applicable to patients with obstructed round windows.