Faculty Bibliography

OBJECTIVE:To characterize transimpedance matrix (TIM) heatmap patterns in patients at risk of labyrinthine abnormality to better understand accuracy and possible TIM limitations. STUDY DESIGN/METHODS:Retrospective review of TIM patterns, preoperative, and postoperative imaging. SETTING/METHODS:Tertiary referral center. PATIENTS/METHODS:Patients undergoing cochlear implantation with risk of labyrinthine abnormality. INTERVENTION/METHODS:None. RESULTS:Seventy-seven patients were evaluated. Twenty-five percent (n = 19) of patients had a TIM pattern variant identified. These variants were separated into 10 novel categories. Overall, 9% (n = 6) of electrodes were malpositioned on intraoperative x-ray, of which 50% (n = 3) were underinserted, 17% (n = 1) were overinserted, 17% (n = 1) had a tip foldover, and 17% (n = 1) had a coiled electrode. The number of patients with a variant TIM pattern and normal x-ray was 18% (n = 14), and the number of patients with normal TIM pattern and malposition noted on x-ray was 3% (n = 2; both were electrode underinsertions that were recognized due to open circuits and surgical visualization).A newly defined skip heat pattern was identified in patients with IP2/Mondini malformation and interscalar septum width <0.5 mm at the cochlear pars ascendens of the basal turn. CONCLUSIONS:This study defines novel patterns for TIM heatmap characterization to facilitate collaborative and comparative research moving forward. In doing so, it highlights a new pattern termed skip heat, which corresponds with a deficient interscalar septum of the cochlea pars ascendens of the basal turn in patients with IP2 malformation. Overall, the data assist the surgeon in better understanding the implications and limitations of TIM patterns within groups of patients with risk of labyrinthine abnormalities.

OBJECTIVE/UNASSIGNED:To better characterize the cochlear apex in relation to surgically relevant landmarks to guide surgeons and improve procedural success of apical electrode placement. STUDY DESIGN/UNASSIGNED:Retrospective image analysis. SETTING/UNASSIGNED:Tertiary referral center. PATIENTS/UNASSIGNED:Cochlear implant recipients with available preoperative computed tomography (CT) imaging. INTERVENTION/UNASSIGNED:None. MAIN OUTCOME MEASURE/UNASSIGNED:Cochlear dimensions and cochlear apex distance measures to surgically relevant middle ear landmarks and critical structures. RESULTS/UNASSIGNED:Eighty-two temporal bone CT scans were analyzed utilizing multiplanar reformats. The average lateral width of promontory bone over the cochlear apex was 1.2 mm (standard deviation [SD], 0.3). The anteroposterior distance from the round window (avg, 4.2 mm; SD, 0.5), oval window (avg, 3.3 mm; SD, 0.3), cochleariform process (avg, 2.3; SD, 0.5), and superior-inferior distance from the cochleariform process (avg, -0.9; SD, 0.8) to the cochlear apex were measured. The relationship of the cochlear apex to critical structures was highly variable.A newly developed stapes vector was created and found to mark the posterior/superior boundary of the apex in 94% of patients. When a vector parallel to the stapes vector was drawn through the round window, it marked the anterior/inferior boundary of the cochlear apex in 89% of patients. CONCLUSIONS/UNASSIGNED:This study assists in characterizing cochlear apex anatomy and its relation to surrounding structures as a means of improving procedural accuracy and reducing trauma during apical cochleostomy. Understanding both distance relationships and expected boundaries of the apex could help to inform future surgical approaches.

OBJECTIVES/UNASSIGNED:This study aims to synthesize current knowledge and outcomes related to pediatric auditory brainstem implantation (ABI) in children with severe inner ear malformations (IEMs). It highlights the clinical management practices, challenges, and potential future directions for consensus development in this field. METHODS/UNASSIGNED:A systematic review of findings presented at the Third International Pediatric ABI Symposium organized by the Hacettepe Cochlear Implant team between 3 and 5 September 2020 was conducted, incorporating data from 41 departments across 19 countries. Relevant clinical outcomes, imaging techniques, surgical approaches, and rehabilitation strategies were analyzed to identify key trends and variability in practices. RESULTS/UNASSIGNED:The review indicates that children receiving ABIs exhibit diverse auditory outcomes influenced by individual anatomical variations and developmental factors. Early implantation, particularly before the age of three, positively correlates with better auditory and language development. Multicenter experiences underscore the necessity of tailored decision-making, which considers both surgical candidacy and comprehensive rehabilitation resources. DISCUSSION:/UNASSIGNED:The variability in outcomes emphasizes the need for improved consensus and guidelines regarding eligibility, surgical techniques, and multidisciplinary rehabilitation approaches. Notable complications and the necessity for thorough imaging assessments were also identified as critical components affecting clinical decisions. CONCLUSION/UNASSIGNED:A formal consensus statement is warranted to standardize best practices in ABI management. This will not only enhance patient outcomes but also guide future research efforts to address the remaining challenges in the treatment of children with severe IEMs. Enhanced collaboration among team members will be pivotal in achieving these objectives.

INTRODUCTION/BACKGROUND:The aim of this study was to examine how bimodal stimulation affects quality of life (QOL) during the postoperative period following cochlear implantation (CI). These data could potentially provide evidence to encourage more bimodal candidates to continue hearing aid (HA) use after CI. METHODS:In this prospective study, patients completed preoperative and 1-, 3-, and 6-month post-activation QOL surveys on listening effort, speech perception, sound quality/localization, and hearing handicap. Fifteen HA users who were candidates for contralateral CI completed the study (mean age 65.6 years). RESULTS:Patients used both devices at a median rate of 97%, 97%, and 98% of the time at 1, 3, and 6 months, respectively. On average, patients' hearing handicap scores decreased by 16% at 1 month, 36% at 3 months, and 30% at 6 months. Patients' listening effort scores decreased by a mean of 10.8% at 1 month, 12.6% at 3 months, and 18.7% at 6 months. Localization significantly improved by 24.3% at 1 month and remained steady. There was no significant improvement in sound quality scores. CONCLUSION/CONCLUSIONS:Bimodal listeners should expect QOL to improve, and listening effort and localization are generally optimized using CI and HA compared to CI alone. Some scores improved at earlier time points than others, suggesting bimodal auditory skills may develop at different rates.

OBJECTIVE:Pediatric data regarding treatment via an auditory brainstem implant (ABI) remains sparse. The authors aimed to describe their experience at their institution and to delineate associated demographic data, audiometric outcomes, and surgical parameters. METHODS:An IRB-approved, retrospective chart review was conducted among the authors' pediatric patients who had undergone auditory brainstem implantation between 2012 and 2021. Demographic information including sex, age, race, coexisting syndrome(s), history of cochlear implant placement, average duration of implant use, and follow-up outcomes were collected. Surgical parameters collected included approach, intraoperative findings, number of electrodes activated, and complications. RESULTS:A total of 19 pediatric patients had an ABI placed at the authors' institution, with a mean age at surgery of 4.7 years (range 1.5-17.8 years). A total of 17 patients (89.5%) had bilateral cochlear nerve aplasia/dysplasia, 1 (5.3%) had unilateral cochlear nerve aplasia/dysplasia, and 1 (5.3%) had a hypoplastic cochlea with ossification. A total of 11 patients (57.9%) had a history of cochlear implants that were ineffective and required removal. The mean length of implant use was 5.31 years (0.25-10 years). Two patients (10.5%) experienced CSF-related complications requiring further surgical intervention. The most recent audiometric outcomes demonstrated that 15 patients (78.9%) showed improvement in their hearing ability: 5 with sound/speech awareness, 5 able to discriminate among speech and environmental sounds, and 5 able to understand common phrases/conversation without lip reading. Nine patients (47.4%) are in a school for the deaf and 7 (36.8%) are in a mainstream school with support. CONCLUSIONS:The authors' surgical experience with a multidisciplinary team demonstrates that the retrosigmoid approach for ABI placement in children with inner ear pathologies and severe sensorineural hearing loss is a safe and effective treatment modality. Audiometric outcome data showed that nearly 79% of these patients had an improvement in their environmental and speech awareness. Further multicenter collaborations are necessary to improve these outcomes and potentially standardize/enhance electrode placement.

OBJECTIVE/UNASSIGNED:Evaluate rates of Advanced Bionics Ultra 3D/Ultra cochlear implant failure in the setting of a worldwide device recall and report surgical and auditory outcomes after revision. METHODS/UNASSIGNED:Retrospective chart review was performed for adult and pediatric patients implanted with at risk devices at our center from 2016 to 2020. Device failure rates, surgical, and auditory outcomes were recorded and analyzed. RESULTS/UNASSIGNED: = 0.95). DISCUSSION/UNASSIGNED:Patients with device failure due to this field action performed well after revision implantation. Patients with bilateral at-risk devices but evidence of unilateral failure may elect to undergo simultaneous empiric revision of the contralateral device. Three patients who elected to change device manufacturers on revision have variable results that require further investigation. CONCLUSIONS/UNASSIGNED:Patients requiring revision for a device field action overall perform well. At-risk devices continue to require monitoring as a growing number are likely to fail over time.

The indications for cochlear implantation have expanded to include individuals with profound sensorineural hearing loss in the impaired ear and normal hearing (NH) in the contralateral ear, known as single-sided deafness (SSD). There are additional considerations for the clinical assessment and management of adult cochlear implant candidates and recipients with SSD as compared to conventional cochlear implant candidates with bilateral moderate to profound sensorineural hearing loss. The present report reviews the current evidence relevant to the assessment and management of adults with SSD. A systematic review was also conducted on published studies that investigated outcomes of cochlear implant use on measures of speech recognition in quiet and noise, sound source localization, tinnitus perception, and quality of life for this patient population. Expert consensus and systematic review of the current literature were combined to provide guidance for the clinical assessment and management of adults with SSD.

OBJECTIVE:To evaluate the ability of the transimpedance matrix (TIM) measurement to detect cochlear implant electrode tip foldover by comparing results to a "gold standard," the intraoperative plain film radiograph. STUDY DESIGN/METHODS:Retrospective case series. SETTING/METHODS:Tertiary referral hospital. PATIENTS/METHODS:One hundred three patients who underwent cochlear implantation between June 2020 and August 2021. INTERVENTIONS/METHODS:Intraoperative electrophysiologic monitoring (electrode impedances, neural response telemetry, and TIM measurement) and modified Stenver's view plain film radiographs. MAIN OUTCOME MEASURES/METHODS:Identification of tip foldover on both TIM and plain films. RESULTS:In total, 103 patients (117 ears) had both a TIM measurement and intraoperative X-ray available for review, including 68 adults and 35 children. One hundred patients (85%) received the Cochlear Slim Modiolar electrode. Tip foldovers were noted in three of 117 implants (2.5%). In all cases, TIM was able to detect the foldover, and the electrode arrays were reinserted with the patients still under anesthesia, with repeat X-ray demonstrating a normal configuration. Two other abnormal TIM patterns were identified. One was in a patient with an obstructed cochlea in whom only 10 electrodes could be inserted, the other was in a patient with a common cavity abnormality. One additional patient underwent electrode repositioning intraoperatively because of overinsertion. In this patient, the TIM appeared to be within normal limits, but the over-insertion was apparent on X-ray. Overall, the sensitivity and specificity of TIM measurements in detecting electrode tip foldover were both 100%. CONCLUSION/CONCLUSIONS:TIM measurements were able to accurately identify tip foldovers. More research is needed to define the adjunctive role of TIM as an intraoperative measure.

OBJECTIVE:To evaluate outcomes of auditory implants in children with CHARGE syndrome and describe the evolution in management of hearing loss in this complex population. METHODS:A retrospective case review was performed at a tertiary referral center. Children with CHARGE syndrome who received either a cochlear implant (CI) or auditory brainstem implant (ABI) were included. Clinical records, demographic information, CHARGE features, neuroimaging, audiology, hearing rehabilitation interventions, operative notes, and outcomes were reviewed. RESULTS:Thirteen children with CHARGE syndrome underwent a total of 19 cochlear implants between 2008 and 2020. Among the congenitally deafened children (n = 9), six underwent bilateral implantation (five simultaneous and one sequential). Bilateral implantation was performed even in the presence of diminutive-appearing cochlear nerves. The average age of implantation was 1.1 years, and the mean device use time was 9.4 hours per day. Patients showed improvements in subjective family assessment related to hearing. In this group, two patients use oral communication, five use total communication, and two use sign language exclusively. Among the children with progressive hearing loss, the mean age of hearing deterioration was 4.4 years of age, and the device use time on average was 9.8 hours per day. The highest performer in the cohort was a child who lost hearing in their only hearing ear at age 4 and had normal cochleovestibular anatomy on that side. One child received an auditory brainstem implant at age two after deriving no benefit from a CI and can detect environmental sounds but is currently a nonuser. Over time, we noted that implantation occurred earlier in life and that practice has shifted toward bilateral implantation. CONCLUSIONS:Compared to a previous institutional cohort, children evaluated in this study were often implanted at a younger age and bilaterally with significantly improved outcomes. A CI evaluation should be considered in children with CHARGE syndrome to maximize sensory input and auditory ability.