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Goffi-Gomez MVS, Corrêa FMDS, Magalhães AT, Hoshino AC, Samuel P, Sadowski T, Colalto C, Tsuji RK, Brito Neto R. Is the spread of excitation different between adults and children cochlear implants users? Eur Arch Otorhinolaryngol 2024; 281:3491-3498. [PMID: 38240771 DOI: 10.1007/s00405-024-08451-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 01/02/2024] [Indexed: 06/29/2024]
Abstract
PURPOSE While cochlea is adult size at birth, etiologies and bone density may differ between children and adults. Differences in neural response thresholds (tNRT) and the spread of excitation (SOE) width may impact the use of artificial intelligence algorithms in speech processor fitting. AIM To identify whether neural response telemetry threshold and spread of excitation width are similar in adults and children. METHODS Retrospective cross-sectional study approved by the Ethical Board. Intraoperative tNRT and SOE recordings of consecutive cochlear implant surgeries in adults and children implanted with Cochlear devices (Cochlear™, Australia) were selected. SOE was recorded on electrode 11 (or adjacent, corresponding to the medial region of the cochlea) through the standard forward-masking technique in Custom Sound EP software, which provides SOE width in millimeters. Statistical comparison between adults and children was performed using the Mann-Whitney test (p ≤ 0.05). RESULTS Of 1282 recordings of intraoperative evaluations, 414 measurements were selected from children and adults. Despite the tNRT being similar between adults and children, SOE width was significantly different, with lower values in children with perimodiolar arrays. Besides, it was observed that there is a difference in the electrode where the SOE function peak occurred, more frequently shifted to electrode 12 in adults implanted. In straight arrays, there was no difference in any of the parameters analyzed on electrode 11. CONCLUSION Although eCAP thresholds are similar, SOE measurements differ between adults and children in perimodiolar electrodes.
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Affiliation(s)
- Maria Valéria Schmidt Goffi-Gomez
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil.
| | - Francyelle Machado da Silva Corrêa
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Ana Tereza Magalhães
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Ana Cristina Hoshino
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Paola Samuel
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Tatiana Sadowski
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Claudia Colalto
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Robinson Koji Tsuji
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
| | - Rubens Brito Neto
- ENT Department, Cochlear Implant Group at Clinical Hospital of the Medical School at University of São Paulo, Av. Dr. Eneas de Carvalho Aguiar 255, São Paulo, Brazil
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Jangra A, Das KN, Sharma V, Timmaraju S, Khera P, Tiwari S, Soni K, Choudhury B, Ghatak S, Dixit SG, Nayyar AK, Goyal A. Comparison of depth of electrode insertion between cochleostomy and round window approach: a cadaveric study. Eur Arch Otorhinolaryngol 2024; 281:3547-3555. [PMID: 38294508 DOI: 10.1007/s00405-024-08466-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/08/2024] [Indexed: 02/01/2024]
Abstract
INTRODUCTION Round window approach and cochleostomy approach can have different depth of electrode insertion during cochlear implantation which itself can alter the audiological outcomes in cochlear implant. OBJECTIVE The current study was conducted to determine the difference in the depth of electrode insertion via cochleostomy and round widow approach when done serially in same temporal bone. METHODOLOGY This is a cross-sectional study conducted in the Department of Otorhinolaryngology in conjunction with Department of Anatomy and Department of Diagnostic and Interventional Radiology over a period of 1 year. 12-electrode array insertion was performed via either approach (cochleostomy or round window) in the cadaveric temporal bone. HRCT temporal bone scan of the implanted temporal bone was done and depth of insertion and various cochlear parameters were calculated. RESULT A total of 12 temporal bones were included for imaging analysis. The mean cochlear duct length was 32.892 mm; the alpha and beta angles were 58.175° and 8.350°, respectively. The mean angular depth of electrode insertion via round window was found to be 325.2° (SD = 150.5842) and via cochleostomy 327.350 (SD = 112.79) degree and the mean linear depth of electrode insertion via round window was found to be 18.80 (SD = 4.4962) mm via cochleostomy 19.650 (SD = 3.8087) mm, which was calculated using OTOPLAN 1.5.0 software. There was a statically significant difference in linear depth of insertion between round window and cochleostomy. Although the angular depth of insertion was higher in CS group, there was no statistically significant difference with round window type of insertion. CONCLUSION The depth of electrode insertion is one of the parameters that influences the hearing outcome. Linear depth of electrode insertion was found to be more in case of cochleostomy compared to round window approach (p = 0.075) and difference in case of angular depth of electrode insertion existed but not significant (p = 0.529).
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Affiliation(s)
- Anupriya Jangra
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - K Nidhin Das
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - Vidhu Sharma
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | | | - Pushpinder Khera
- Department of Diagnostic and Interventional, Radiology, All India Institute of Medical Sciences, Jodhpur, India
| | - Sarbesh Tiwari
- Department of Diagnostic and Interventional, Radiology, All India Institute of Medical Sciences, Jodhpur, India
| | - Kapil Soni
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - Bikram Choudhury
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - Surajit Ghatak
- Department of Anatomy, All India Institute of Medical Sciences, Jodhpur, India
| | - Shilpi Gupta Dixit
- Department of Anatomy, All India Institute of Medical Sciences, Jodhpur, India
| | - Ashish Kumar Nayyar
- Department of Anatomy, All India Institute of Medical Sciences, Jodhpur, India
| | - Amit Goyal
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India.
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Malhotra V, Kumar S, Menon GS, Hejjaji Krishnamurthy A, Medikeri S, Dutt SN. Morphometric Analysis of Temporal Bone Radiology for Cochlear Implant Candidacy. Indian J Otolaryngol Head Neck Surg 2024; 76:702-711. [PMID: 38440533 PMCID: PMC10908920 DOI: 10.1007/s12070-023-04257-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 09/28/2023] [Indexed: 03/06/2024] Open
Abstract
Cochlear Implantation (CI) is a well-accepted treatment for severe-to-profound sensorineural hearing loss, refractory to conventional hearing amplification. Pre-operative Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) play pivotal roles in patient selection to rule out findings that preclude surgery or identify conditions that may impact the surgical procedure. A prospective study was carried out in a tertiary care center over three years, from January 2020 to January 2023. One hundred and ninety (380 ears) patients' High-Resolution Computed Tomography (HRCT) studies of the temporal bone and MRI scans of the auditory pathways were analyzed. A reporting format was followed which was devised by a team of senior implant surgeons and senior neuro-radiologists. Our study aims to provide a comprehensive radiologic protocol for CI candidacy including normative data for the essential morphometrics in the Indian setting.
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Sarwar Z, Ahmed J, Saqulain G, Khan MIJ. Cochlear duct length in Pakistani cochlear implant recipients gender, age and side association: A Radiological Measure. Pak J Med Sci 2024; 40:41-45. [PMID: 38196493 PMCID: PMC10772454 DOI: 10.12669/pjms.40.1.7426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/06/2023] [Accepted: 09/19/2023] [Indexed: 01/11/2024] Open
Abstract
Objectives To analyze the gender, age and side association of cochlear duct length in Pakistani-Asian cochlear implant recipient population based on computed tomography imaging study. Methods Current study retrospectively studied charts of cases who underwent cochlear implantation at the Department of Otolaryngology & Auditory Implant Centre, Capital Hospital Islamabad, over a period of two years from 1st May 2017 to 30th April 2019. These included 200 cases of both genders and of any age. In addition to basic demographic data, computed tomography findings of the temporal bone were utilized to measure the cochlear duct length. Data was analyzed using SPSS Version 23. Results Study revealed a mean Cochlear duct length of 29.935±2.173mm (range: 25.12 to 37.60) with significant (p<0.001) association with gender with longer cochlear duct in males compared to females on right (30.50±2.384 vs. 29.36±1.887) and on left side (30.50±2.236 vs.29.32±1.935). However, no significant difference was noted for side with slightly longer cochlear duct on the right side compared to left (29.95±2.224 vs.29.92±2.171). Also, no significant association with age was noted with p=0.578 & p=0.824 for right and left side respectively. Conclusion Pakistani population is characterized by a short mean CDL of 29.935±2.173 mm with significant association (p<0.001) with gender with longer cochlear duct length in males; and side with larger CDL on right side. However, no significant association with age was noted.
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Affiliation(s)
- Zahra Sarwar
- Dr. Zahra Sarwar, MBBS. Post-Graduate FCPS Trainee ENT Department, KRL Hospital, Islamabad, Pakistan
| | - Jawwad Ahmed
- Dr. Jawwad Ahmed, FCPS. Implant Surgeon, Department of Otorhinolaryngology Capital Hospital PGMI, Islamabad, Pakistan
| | - Ghulam Saqulain
- Dr. Ghulam Saqulain, FCPS. Head of Department/ Professor of Otorhinolaryngology Capital Hospital PGMI, Islamabad, Pakistan
| | - Muhammad Iqbal Javed Khan
- Dr. Muhammad Iqbal Javed Khan, FRCS. Consultant Otologist and Skull Base Surgeon, Bradford Teaching Hospitals NHS Foundation Trust, United Kingdom
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Swarup A, Karakkandy V, Chappity P, Naik S, Behera SK, Parida PK, Grover M, Gupta G, Giri PP, Sarkar S, Pradhan P, Samal DK, Kallyadan Veetil A, Adhikari A, Nayak S. Comparing accuracy of cochlear measurements on magnetic resonance imaging and computed tomography: A step towards radiation-free cochlear implantation. J Otol 2023; 18:208-213. [PMID: 37877072 PMCID: PMC10593569 DOI: 10.1016/j.joto.2023.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/20/2023] [Accepted: 08/21/2023] [Indexed: 10/26/2023] Open
Abstract
Objective Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are commonly employed in pre-operative evaluation for cochlear implant surgery. However, with a decrease in the age of implantation, even minor radiation exposure can cause detrimental effects on children over their lifetime. The current study compares different cochlear measurements from CT and MRI scans and evaluates the feasibility of using only an MRI scan for radiological evaluation before cochlear implantation. Methods A longitudinal observational study was conducted on 94 ears/47 children, employing CT and MRI scans. The CT and MRI scan measurements include, A value, B value, Cochlear duct length (CDL), two-turn cochlear length, alpha and beta angles to look for cochlear orientation. Cochlear nerve diameter was measured using MRI. The values were compared. Results The mean difference between measurements from CT and MRI scans for A value, B value, CDL, and two-turn cochlear length values was 0.567 ± 0.413 mm, 0.406 ± 0.368 mm, 2.365 ± 1.675 mm, and 2.063 ± 1.477 mm respectively without any significant difference. The alpha and beta angle measures were comparable, with no statistically significant difference. Conclusion The study suggests that MRI scans can be the only radiological investigation needed with no radiation risk and reduces the cost of cochlear implant program in the paediatric population. There is no significant difference between the measurements obtained from CT and MRI scans. However, observed discrepancies in cochlear measurements across different populations require regionally or race-specific standardized values to ensure accurate diagnosis and precision in cochlear implant surgery. This aspect must be addressed to ensure positive outcomes for patients.
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Affiliation(s)
- Anurita Swarup
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Vinusree Karakkandy
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Preetam Chappity
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Suprava Naik
- Department of Radiodiagnosis, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Sanjay Kumar Behera
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Pradipta Kumar Parida
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Mohnish Grover
- Department of ENT, Sawai Man Singh Medical College, Jaipur, Rajasthan, India
| | - Gaurav Gupta
- Department of ENT, Sardar Patel Medical College, Bikaner, Rajasthan, India
| | - Prajna Paramita Giri
- Department of Community and Family Medicine, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Saurav Sarkar
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Pradeep Pradhan
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Dillip Kumar Samal
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Aswathi Kallyadan Veetil
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Asutosh Adhikari
- Department of ENT and HNS, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
| | - Saurav Nayak
- Department of Biochemistry, All India Institute of Medical Sciences (AIIMS), Bhubaneswar, Odisha, India
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Baguant A, Cole A, Vilotitch A, Quatre R, Schmerber S. Difference in cochlear length between male and female patients. Cochlear Implants Int 2022; 23:326-331. [PMID: 35860840 DOI: 10.1080/14670100.2022.2101534] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Objective: To compare cochlear duct length (CDL) between male and female patients by evaluating the diameter of the basal turn (distance A) on CT scans.Method: All temporal bone CT scans performed between 2014 and 2020 were reviewed in our medical center. Using multiplanar reconstructions, the length A, which is the greatest distance of the basal turn was measured on both sides. We performed an analysis of variance considering two factors: sex and side. Two different physicians carried out the measurements, an otolaryngologist and a neuroradiologist. The patients who had several CT scans allowed us to evaluate the reliability of our procedure.Results: Among the 888 CT scans reviewed, 8 were excluded because of cochlear malformations. The inter-sex difference of length A was found to be 0.29 millimeters(mm) 95% IC [0.26-0.34] and was longer in the male group (p < 0.0001). Using Alexiades' equation, we found that CDL was 34.5mm [34.37-34.61] in the male group and 33.3mm [33.13-33.38] in the female group. When one side was compared to the other, there was no significant difference (p = 0.226). An intra-class correlation found a good absolute agreement between the two screeners of 0.79.Conclusion: Males have a statistically significant longer CDL than females.
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Affiliation(s)
- Ashley Baguant
- Otolaryngology-Head & Neck Surgery Department, Grenoble Alpes University Hospital, Grenoble, France
| | - Anthony Cole
- Neuroradiology and MR Unit, CS 10217- Grenoble University Hospital, Grenoble, France
| | - Antoine Vilotitch
- French National Center for Scientific Research, Department of Public Health, Grenoble University, Grenoble, France
| | - Raphaele Quatre
- Otolaryngology-Head & Neck Surgery Department, Grenoble Alpes University Hospital, Grenoble, France
| | - Sebastien Schmerber
- Otolaryngology-Head & Neck Surgery Department, Grenoble Alpes University Hospital, Grenoble, France.,School of Medicine, Domaine de la Merci, Grenoble Alpes University, Grenoble, France
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Grueninger I, Lippl L, Canis M, Simon F, Spiro JE, Spiegel JL, Hempel JM, Müller J, Volgger V. Anatomical Variations of the Epitympanum and the Usable Space for Middle Ear Implants Analyzed With CT-assisted Imaging Using a Tablet-based Software. Otol Neurotol 2022; 43:e454-e460. [PMID: 35213480 DOI: 10.1097/mao.0000000000003486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate interindividual anatomical variations of the epitympanum and the usable space for implantation of active middle ear implants (AMEI) as well as the usefulness of a tablet-based software to assess individual anatomy on computed tomography (CT) scans. PATIENTS CT scans of 126 patients, scheduled for cochlea implantation (50.8% men; 0.6-90.0 yr) without middle ear malformations or previous middle ear surgery and with slice thickness ≤0.7 mm were analyzed. MAIN OUTCOME MEASURES Since no standardized measurements to assess the size of the epitympanum are available, relevant distances were defined according to anatomical landmarks. Three independent raters measured these distances using a tablet-based software. Interrater correlation was computed to evaluate the quality of the measurement process. Descriptive data were analyzed for validation and for evaluation of interindividual anatomical variations. Influence of age and sex on the taken measurements was assessed. RESULTS No relevant correlation between age or sex and the anatomy of the epitympanum was found. Interrater correlation ranged from Spearman's ρ = 0.3-0.9 and there were significant differences between individual rater results for various combinations. Descriptive data revealed high interindividual anatomical variance of the epitympanum, especially regarding the distance between incus and skull base. CONCLUSION The reported descriptive data regarding the anatomy of the epitympanum emphasizes the importance of preoperative planning, especially since the height of the epitympanum showed great interindividual variance potentially limiting implantation of AMEIs. The herein used tablet-based software seems to be convenient for preoperative assessment of individual anatomy in the hand of otosurgeons.
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Affiliation(s)
- Ivo Grueninger
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - Lisa Lippl
- MED-EL Medical Electronics GmbH, Innsbruck, Austria
| | - Martin Canis
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - Florian Simon
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - Judith E Spiro
- Department of Radiology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - Jennifer L Spiegel
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - John Martin Hempel
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - Joachim Müller
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
| | - Veronika Volgger
- Department of Otorhinolaryngology, University Hospital, Ludwig Maximilian University Munich, Germany
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Dutrieux N, Quatre R, Péan V, Schmerber S. Correlation Between Cochlear Length, Insertion Angle, and Tonotopic Mismatch for MED-EL FLEX28 Electrode Arrays. Otol Neurotol 2022; 43:48-55. [PMID: 34538852 DOI: 10.1097/mao.0000000000003337] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the relationship between cochlear length, insertion angle, and tonotopic mismatch and to compare the tonotopic mismatches with respect to the spiral ganglion and the organ of Corti. STUDY DESIGN Retrospective. SETTING Tertiary referral center with cochlear implant program. PATIENTS Analyses of patients' computed tomography images after cochlear implant surgery. INTERVENTION Cochlear implantation with 28-mm-long straight lateral wall electrode arrays. MAIN OUTCOME MEASURE Cochlear length, insertion angle, and insertion depth were assessed using the OTOPLAN software. Tonotopic mismatch for each electrode contact was estimated using the Greenwood (organ of Corti) and the Stakhovskaya (spiral ganglion) maps and compared. RESULTS 106 cochleae were analyzed. 99% of the electrode arrays were located in the tympanic ramp. The insertion was complete in 96% of cases. The mean cochlear length was 34.5 mm and the mean insertion angle of the apical electrode was 545°. Cochlear length was negatively correlated with the insertion angle of the contacts E1 to E9 (all p < 0.004). The tonotopic mismatch was greater at the organ of Corti than at the spiral ganglion. It was also greater at the organ of Corti in larger cochleae (correlation with mismatch for E1 r = 0.421, p < 0.0001) and in the apical than in the middle and basal regions of the cochlea. CONCLUSION Small cochlea size corresponded to higher insertion angle and reduction of tonotopic mismatch on a 28-mm-long straight lateral wall electrode array. Tonotopic mismatch could be minimized preoperatively by choosing electrode arrays according to the individual cochlear morphology and postoperatively by appropriate frequency fitting.
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Affiliation(s)
- Noémie Dutrieux
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Grenoble Alpes University Hospital, France
- Medical Faculty, University of Grenoble Alpes, Grenoble, France
| | - Raphaële Quatre
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Grenoble Alpes University Hospital, France
- Medical Faculty, University of Grenoble Alpes, Grenoble, France
| | | | - Sébastien Schmerber
- Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Grenoble Alpes University Hospital, France
- Medical Faculty, University of Grenoble Alpes, Grenoble, France
- Brain Tech Inserm Laboratory, UMR 1205, University of Grenoble Alpes, Grenoble, France
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Fan Y, Zhang D, Banalagay R, Wang J, Noble JH, Dawant BM. Hybrid active shape and deep learning method for the accurate and robust segmentation of the intracochlear anatomy in clinical head CT and CBCT images. J Med Imaging (Bellingham) 2021; 8:064002. [PMID: 34853805 DOI: 10.1117/1.jmi.8.6.064002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 11/08/2021] [Indexed: 11/14/2022] Open
Abstract
Purpose: Robust and accurate segmentation methods for the intracochlear anatomy (ICA) are a critical step in the image-guided cochlear implant programming process. We have proposed an active shape model (ASM)-based method and a deep learning (DL)-based method for this task, and we have observed that the DL method tends to be more accurate than the ASM method while the ASM method tends to be more robust. Approach: We propose a DL-based U-Net-like architecture that incorporates ASM segmentation into the network. A quantitative analysis is performed on a dataset that consists of 11 cochlea specimens for which a segmentation ground truth is available. To qualitatively evaluate the robustness of the method, an experienced expert is asked to visually inspect and grade the segmentation results on a clinical dataset made of 138 image volumes acquired with conventional CT scanners and of 39 image volumes acquired with cone beam CT (CBCT) scanners. Finally, we compare training the network (1) first with the ASM results, and then fine-tuning it with the ground truth segmentation and (2) directly with the specimens with ground truth segmentation. Results: Quantitative and qualitative results show that the proposed method increases substantially the robustness of the DL method while having only a minor detrimental effect (though not significant) on its accuracy. Expert evaluation of the clinical dataset shows that by incorporating the ASM segmentation into the DL network, the proportion of good segmentation cases increases from 60/177 to 119/177 when training only with the specimens and increases from 129/177 to 151/177 when pretraining with the ASM results. Conclusions: A hybrid ASM and DL-based segmentation method is proposed to segment the ICA in CT and CBCT images. Our results show that combining DL and ASM methods leads to a solution that is both robust and accurate.
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Affiliation(s)
- Yubo Fan
- Vanderbilt University, Department of Computer Science, Nashville, Tennessee, United States
| | | | - Rueben Banalagay
- Vanderbilt University, Department of Electrical and Computer Engineering, Nashville, Tennessee, United States
| | - Jianing Wang
- Vanderbilt University, Department of Electrical and Computer Engineering, Nashville, Tennessee, United States
| | - Jack H Noble
- Vanderbilt University, Department of Electrical and Computer Engineering, Nashville, Tennessee, United States
| | - Benoit M Dawant
- Vanderbilt University, Department of Electrical and Computer Engineering, Nashville, Tennessee, United States
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Cooperman SP, Aaron KA, Fouad A, Tran E, Blevins NH, Fitzgerald MB. Influence of electrode to cochlear duct length ratio on post-operative speech understanding outcomes. Cochlear Implants Int 2021; 23:59-69. [PMID: 34590531 DOI: 10.1080/14670100.2021.1979289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To assess whether the pre-operative electrode to cochlear duct length ratio (ECDLR), is associated with post-operative speech recognition outcomes. STUDY DESIGN A retrospective chart review study. SETTING Tertiary referral center. PATIENTS The study included sixty-one adult CI recipients with a pre-operative computed tomography scan and a speech recognition test 12 months after implantation. INTERVENTIONS The average of two raters' cochlear duct length (CDL) measurements and the length of the recipient's cochlear implant electrode array formed the basis for the electrode-to-cochlear duct length ratio (ECLDR). Speech recognition tests were compared as a function of ECDLR and electrode array length itself. MAIN OUTCOME MEASURES The relationship between ECDLR and percent correct on speech recognition tests. RESULTS A second order polynomial regression relating ECDLR to percent correct on the CNC words speech recognition test was statistically significant, as was a fourth order polynomial regression for the AzBio Quiet test. In contrast, there was no statistically significant relationship between speech recognition scores and electrode array length. CONCLUSIONS ECDLR values can be statistically associated to speech-recognition outcomes. However, these ECDLR values cannot be predicted by the electrode length alone, and must include a measure of CDL.
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Affiliation(s)
- Shayna P Cooperman
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Ksenia A Aaron
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Ayman Fouad
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA.,Otolaryngology Department, Tanta University, Tanta, Egypt
| | - Emma Tran
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Nikolas H Blevins
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| | - Matthew B Fitzgerald
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
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Neves CA, Tran ED, Cooperman SP, Blevins NH. Fully Automated Measurement of Cochlear Duct Length From Clinical Temporal Bone Computed Tomography. Laryngoscope 2021; 132:449-458. [PMID: 34536238 DOI: 10.1002/lary.29869] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/24/2021] [Accepted: 08/31/2021] [Indexed: 11/06/2022]
Abstract
OBJECTIVES/HYPOTHESIS To present and validate a novel fully automated method to measure cochlear dimensions, including cochlear duct length (CDL). STUDY DESIGN Cross-sectional study. METHODS The computational method combined 1) a deep learning (DL) algorithm to segment the cochlea and otic capsule and 2) geometric analysis to measure anti-modiolar distances from the round window to the apex. The algorithm was trained using 165 manually segmented clinical computed tomography (CT). A Testing group of 159 CTs were then measured for cochlear diameter and width (A- and B-values) and CDL using the automated system and compared against manual measurements. The results were also compared with existing approaches and historical data. In addition, pre- and post-implantation scans from 27 cochlear implant recipients were studied to compare predicted versus actual array insertion depth. RESULTS Measurements were successfully obtained in 98.1% of scans. The mean CDL to 900° was 35.52 mm (SD, 2.06; range, [30.91-40.50]), the mean A-value was 8.88 mm (0.47; [7.67-10.49]), and mean B-value was 6.38 mm (0.42; [5.16-7.38]). The R2 fit of the automated to manual measurements was 0.87 for A-value, 0.70 for B-value, and 0.71 for CDL. For anti-modiolar arrays, the distance between the imaged and predicted array tip location was 0.57 mm (1.25; [0.13-5.28]). CONCLUSION Our method provides a fully automated means of cochlear analysis from clinical CTs. The distribution of CDL, dimensions, and cochlear quadrant lengths is similar to those from historical data. This approach requires no radiographic experience and is free from user-related variation. LEVEL OF EVIDENCE 3 Laryngoscope, 2021.
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Affiliation(s)
- Caio A Neves
- Faculty of Medicine, University of Brasilia, Brasilia, Brazil
| | - Emma D Tran
- Department of Otolaryngology-Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Shayna P Cooperman
- Department of Otolaryngology-Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Nikolas H Blevins
- Department of Otolaryngology-Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
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Chen Y, Chen J, Tan H, Jiang M, Wu Y, Zhang Z, Li Y, Jia H, Wu H. Cochlear Duct Length Calculation: Comparison Between Using Otoplan and Curved Multiplanar Reconstruction in Nonmalformed Cochlea. Otol Neurotol 2021; 42:e875-e880. [PMID: 33710146 DOI: 10.1097/mao.0000000000003119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To describe a new method to measure the cochlear parameters using Otoplan software, and to compare it with the traditional method using curved multiplanar reconstruction (cMPR). STUDY DESIGN Retrospective analysis using internal consistency reliability and paired sample t test. SETTING Tertiary referral center. PATIENTS Thirty-four patients including 68 ears from a clinical trial were retrospectively reviewed. MAIN OUTCOME MEASURES The length, width, height (distances A, B, H), and cochlear duct length of each cochlea were measured independently using two modalities: Otoplan and cMPR. Internal consistency reliability of the two modalities was analyzed. The time spent on each measurement was also recorded. RESULTS Otoplan software was compatible with all radiological data in this series. Distances A, B, and H showed no significant differences between Otoplan (9.33 ± 0.365, 6.61 ± 0.359, and 2.91 ± 0.312 mm) and cMPR (9.32 ± 0.314, 6.59 ± 0.342, and 2.93 ± 0.250 mm). The average cochlear duct length calculated by Otoplan was 34.37 ± 1.481 mm, which was not significantly different from that calculated by cMPR (34.55 ± 1.903mm, p = 0.215). The measurements with Otoplan had better internal consistency reliability compared with those by cMPR, and measurements with a higher peak kilovoltage (140 kVp) CT scan showed further higher internal consistency reliability. Time spent on each cochlea by Otoplan was 5.9 ± 0.69 min, significantly shorter than that by cMPR (9.3 ± 0.72 min). CONCLUSION Otoplan provides more rapid and reliable measurement of the cochlea than cMPR. Furthermore, it can be easily used in the laptop computer.
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Affiliation(s)
- Ying Chen
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
| | - Jianqing Chen
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
| | - Haoyue Tan
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
| | - Mengda Jiang
- Department of Radiology, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yingwei Wu
- Department of Radiology, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhihua Zhang
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
| | - Yun Li
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
| | - Huan Jia
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
| | - Hao Wu
- Department of Otolaryngology-Head and Neck Surgery, Ninth People's Hospital
- Ear Institute, Shanghai Jiaotong University School of Medicine
- Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases
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The Effect of Ultra-slow Velocities on Insertion Forces: A Study Using a Highly Flexible Straight Electrode Array. Otol Neurotol 2021; 42:e1013-e1021. [PMID: 33883518 DOI: 10.1097/mao.0000000000003148] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The present study sought to 1) characterize insertion forces resulting from a flexible straight electrode array (EA) inserted at slow and ultra-slow insertion velocities, and 2) evaluate if ultra-slow velocities decrease insertion forces independent of other variables. BACKGROUND Low insertion forces are desirable in cochlear implant (CI) surgery to reduce trauma and preserve hearing. Recently, ultra-slow insertion velocities (lower than manually feasible) have been shown to produce significantly lower insertion forces using other EAs. METHODS Five flexible straight EAs were used to record insertion forces into an inelastic artificial scala tympani model. Eleven trial recordings were performed for each EA at five predetermined automated, continuous insertion velocities ranging from 0.03 to 1.6 mm/s. RESULTS An ultra-slow insertion velocity of 0.03 mm/s resulted in a median insertion force of 0.010 N at 20 mm of insertion depth, and 0.026 N at 24.3 mm-the final insertion depth. These forces represent only 24 to 29% of those measured using 1.6 mm/s. After controlling for insertion depth of the EA into the artificial scala tympani model and trial insertion number, decreasing the insertion velocity from 0.4 to 0.03 mm/s resulted in a 50% decrease in the insertion forces. CONCLUSION Using the tested EA ultra-slow velocities can decrease insertion forces, independent of variables like insertion depth. Our results suggest ultra-slow velocities can reduce insertion forces at least 60%, compared with humanly feasible continuous velocities (≥0.9 mm/s).
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Cooperman SP, Aaron KA, Fouad A, Tran E, Blevins NH, Fitzgerald MB. Assessment of Inter- and Intra-Rater Reliability of Tablet-Based Software to Measure Cochlear Duct Length. Otol Neurotol 2021; 42:558-565. [PMID: 33492059 DOI: 10.1097/mao.0000000000003015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The objective of this study is to build upon previous work validating a tablet-based software to measure cochlear duct length (CDL). Here, we do so by greatly expanding the number of cochleae (n = 166) analyzed, and examined whether computed tomography (CT) slice thickness influences reliability of CDL measurements. STUDY DESIGN Retrospective chart review study. SETTING Tertiary referral center. PATIENTS Eighty-three adult cochlear implant recipients were included in the study. Both cochleae were measured for each patient (n = 166). INTERVENTIONS Three raters analyzed the scans of 166 cochleae at 2 different time points. Each rater individually identified anatomical landmarks that delineated the basal turn diameter and width. These coordinates were applied to the elliptic approximation method (ECA) to estimate CDL. The effect of CT scan slice thickness on the measurements was explored. MAIN OUTCOME MEASURES The primary outcome measure is the strength of the inter- and intra-rater reliability. RESULTS The mean CDL measured was 32.84 ± 2.03 mm, with a range of 29.03 to 38.07 mm. We observed no significant relationship between slice thickness and CDL measurement (F1,164 = 3.04; p = 0.08). The mean absolute difference in CDL estimations between raters was 1.76 ± 1.24 mm and within raters was 0.263 ± 0.200 mm. The intra-class correlation coefficient (ICC) between raters was 0.54 and ranged from 0.63 to 0.83 within raters. CONCLUSIONS This software produces reliable measurements of CDL between and within raters, regardless of CT scan thickness.
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Affiliation(s)
- Shayna P Cooperman
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Ksenia A Aaron
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Ayman Fouad
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, USA
- Otolaryngology Department, Tanta University, Tanta, Egypt
| | - Emma Tran
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Nikolas H Blevins
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, USA
| | - Matthew B Fitzgerald
- Department of Otolaryngology-Head and Neck Surgery, Stanford University, Stanford, California, USA
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Khurayzi T, Almuhawas F, Alsanosi A, Abdelsamad Y, Doyle Ú, Dhanasingh A. A novel cochlear measurement that predicts inner-ear malformation. Sci Rep 2021; 11:7339. [PMID: 33795738 PMCID: PMC8016924 DOI: 10.1038/s41598-021-86741-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/15/2021] [Indexed: 12/14/2022] Open
Abstract
The A-value used in cochlear duct length (CDL) estimation does not take malformed cochleae into consideration. The objective was to determine the A-value reported in the literature, to assess the accuracy of the A-value measurement and to evaluate a novel cochlear measurement in distinguishing malformed cochlea. High resolution Computer Tomography images in the oblique coronal plane/cochlear view of 74 human temporal bones were analyzed. The A-value and novel C-value measurement were evaluated as predictors of inner ear malformation type. The proximity of the facial nerve to the basal turn was evaluated subjectively. 26 publications report on the A-value; but they do not distinguish normal vs. malformed cochleae. The A-values of the normal cochleae compared to the cochleae with cochlear hypoplasia, incomplete partition (IP) type I, -type II, and -type III were significantly different. The A-value does not predict the C-value. The C-values of the normal cochleae compared to the cochleae with IP type I and IP type III were significantly different. The proximity of the facial nerve to the basal turn did not relate to the type of malformation. The A-value is different in normal vs. malformed cochleae. The novel C-value could be used to predict malformed anatomy, although it does not distinguish all malformation types.
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Affiliation(s)
- Tawfiq Khurayzi
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, 11411, Saudi Arabia. .,King Fahad Central Hospital, Ministry of Health, Jizan, 82666, Saudi Arabia.
| | - Fida Almuhawas
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, 11411, Saudi Arabia
| | - Abdulrahman Alsanosi
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, 11411, Saudi Arabia
| | | | - Úna Doyle
- Research and Development Department, MED-EL GmbH, Innsbruck, Austria
| | - Anandhan Dhanasingh
- Research and Development Department, MED-EL GmbH, Innsbruck, Austria.,Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
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Atalay B, Eser MB, Kalcioglu MT, Ankarali H. Comprehensive Analysis of Factors Affecting Cochlear Size: A Systematic Review and Meta-analysis. Laryngoscope 2021; 132:188-197. [PMID: 33764541 DOI: 10.1002/lary.29532] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 03/09/2021] [Accepted: 03/16/2021] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To determine the cochlea's average size in humans and evaluate the relationships between certain covariates and cochlear size. METHODS A systematic search on articles on cochlear size and published in English was conducted using Cochrane, PubMed, Web of Science, and Scopus databases up to September 15, 2020. Data were pooled using random-effects with three models. The effect of demographic, clinical, and measurement-related parameters was specifically analyzed. Meta-regression and subgroup analyses were conducted. The overall effect estimation was made for outcomes. RESULTS The meta-analysis included 4,708 cochleae from 56 studies. The overall length of the organ of Corti was 32.94 mm (95% confidence interval [CI]: 32.51-33.38). The first and second models revealed that age, gender, country, continent, measurement method (direct, indirect), measured structure ("A" value, cochlear lateral wall), origin (in vivo, in vitro), and type (histology specimens, plastic casts, imaging) of the cochlear material did not affect the cochlear size. However, study populations (general population, patients with a cochlear implant, and patients with congenital sensorineural hearing loss [CSNHL]) were found to affect the outcomes. Compared to the other populations, patients with CSNHL had shorter cochleae. Therefore, we developed a third model and found that the general population and patients with cochlear implants did not differ in cochlear size. CONCLUSION This meta-analysis investigated the factors that could affect the cochlear size and found that patients with CSNHL had significantly shorter cochleae, whereas other covariates had no significant effect. Laryngoscope, 2021.
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Affiliation(s)
- Basak Atalay
- Faculty of Medicine, Department of Radiology, Goztepe Training and Research Hospital, Istanbul Medeniyet University, Istanbul, Turkey
| | - Mehmet Bilgin Eser
- Faculty of Medicine, Department of Radiology, Goztepe Training and Research Hospital, Istanbul Medeniyet University, Istanbul, Turkey
| | - Mahmut Tayyar Kalcioglu
- Faculty of Medicine, Department of Otorhinolaryngology-Head and Neck Surgery, Goztepe Training and Research Hospital, Istanbul Medeniyet University, Istanbul, Turkey
| | - Handan Ankarali
- Faculty of Medicine, Department of Biostatistics and Medical Informatics, Istanbul Medeniyet University, Istanbul, Turkey
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Eisenhut F, Lang S, Taha L, Hoelter P, Wiesmueller M, Uder M, Iro H, Doerfler A, Hornung J. Identification of anatomic risk factors for scalar translocation in cochlear implant patients. Z Med Phys 2021; 31:254-264. [PMID: 33648794 DOI: 10.1016/j.zemedi.2021.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 12/02/2020] [Accepted: 01/05/2021] [Indexed: 10/22/2022]
Abstract
AIM Microanatomical evaluation of cochlear implant (CI) patients to identify anatomical risk factors for a scalar translocation. METHODS CI patients with both a regular scala tympani spiralization (group A) and a scalar translocation (group B) were identified via postoperative flat-detector computed tomography (FD-CT). Then, the corresponding preoperative multislice computed tomography (MS-CT) and postoperative FD-CT datasets were assessed: First, the cochleae were separated in 6 segments of 45° each. Next, quantitative (cochlea height, length, depth, cochlear duct diameter [CD] per segment; percentual tapering of the CD per segment named cochlear geometry index [CGI]) and qualitative (identifiability of the CI model; CI-integrity; intracochlear array position) parameters were evaluated and compared for both groups. Receiver-operating-characteristics (ROC) analysis was performed for the CGI. RESULTS In total, 40 preoperative MS-CT and postoperative FD-CT datasets (nA=20; nB=20) were analysed. Model "CI 512" was successfully identified and CI-integrity has been confirmed in all cases. Quantitative analysis showed a significant difference of both the CD at 0° (CDA0°= 2.06± 0.23mm; CDB0°= 2.19±0.18mm; p0°= 0.04) and the CGI of the first segment (CGIA0°-45°= 18.87±6.04%; CGIB0°-45°= 28.89±8.58%; p0°-45°= 0.0001). For all other 5 cochlear segments there was no significant difference of CD and CGI; there was no significant difference of external cochlea diameters. The area under the curve (AUC) of the CGI0-45° was 0.864 with 24.50° as the optimal cut-off value to discriminate patients with a scala tympani spiralization and a scalar translocation. CGI0-45° of> 24.50° allowed the correct identification of 85% of patients with a scalar translocation. CONCLUSION CI insertion trauma is associated with a significantly higher narrowing of the proximal basal cochlea turn (BCT). The CGI as percentual tapering of the BCT turned out as reliable, clinically applicable parameter for identification of patients with an increased risk for a scalar translocation.
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Affiliation(s)
- Felix Eisenhut
- Department of Neuroradiology, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany.
| | - Stefan Lang
- Department of Neuroradiology, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Lava Taha
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Waldstraße 1, 91054, Erlangen, Germany
| | - Philip Hoelter
- Department of Neuroradiology, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Marco Wiesmueller
- Institute of Radiology, University Hospital Erlangen, Maximiliansplatz 3, 91054, Erlangen, Germany
| | - Michael Uder
- Institute of Radiology, University Hospital Erlangen, Maximiliansplatz 3, 91054, Erlangen, Germany
| | - Heinrich Iro
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Waldstraße 1, 91054, Erlangen, Germany
| | - Arnd Doerfler
- Department of Neuroradiology, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Joachim Hornung
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Erlangen, Waldstraße 1, 91054, Erlangen, Germany
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Radiological evaluation of a new straight electrode array compared to its precursors. Eur Arch Otorhinolaryngol 2020; 278:3707-3714. [PMID: 33090276 PMCID: PMC8382647 DOI: 10.1007/s00405-020-06434-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/10/2020] [Indexed: 11/24/2022]
Abstract
Objective The aim of this study is to examine electrode array coverage, scalar position and dislocation rate in straight electrode arrays with special focus on a new electrode array with 26 mm in lengths. Study design Retrospective study. Setting Tertiary academic center. Patients 201 ears implanted between 2013 and 2019. Main outcome measures We conducted a comparative analysis of patients implanted with lateral wall electrode arrays of different lengths (F24 = MED-EL Flex24, F26 = MED-EL Flex26, F28 = MED-EL Flex28 and F31.5 = MED-EL FlexSoft). Cone beam computed tomography was used to determine electrode array position (scala tympani (ST) versus scala vestibuli (SV), intracochlear dislocation, position of dislocation and insertion angle). Results Study groups show no significant differences regarding cochlear size which excludes influences by cochlear morphology. As expected, the F24 showed significant shorter insertion angles compared to the longer electrode arrays. The F26 electrode array showed no signs of dislocation or SV insertion. The electrode array with the highest rate of ST dislocations was the F31.5 (26.3%). The electrode array with the highest rates of SV insertions was the F28 (5.75%). Most of the included electrode arrays dislocate between 320° and 360° (mean: 346.4°; range from 166° to 502°). Conclusion The shorter F24 and the new straight electrode array F26 show less or no signs of scalar dislocation, neither for round window nor for cochleostomy insertion than the longer F28 and the F31.5 array. As expected, the cochlear coverage is increasing with length of the electrode array itself but with growing risk for scalar dislocation and with the highest rates of dislocation for the longest electrode array F31.5. Position of intracochlear dislocation is in the apical cochlear part in the included lateral wall electrode arrays.
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Modiolar Proximity of Slim Modiolar Electrodes and Cochlear Duct Length: Correlation for Potential Basis of Customized Cochlear Implantation With Perimodiolar Electrodes. Ear Hear 2020; 42:323-333. [PMID: 32826506 DOI: 10.1097/aud.0000000000000920] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVES Recent studies have shown that cochlear duct length (CDL) varies among individuals and could significantly influence the final position of the electrode and its trajectory in the cochlea. Given this, we hypothesized that the degree of modiolar proximity of novel slim modiolar electrodes, such as CI532 and CI632, can also be affected by CDL. To test this hypothesis, we retrospectively evaluated individual CDL to determine if there is any significant correlation of CDL with degree of modiolar proximity. METHODS Fifty-one ears from 38 subjects implanted with slim modiolar electrodes by a single surgeon through the round window approach using the pull-back technique were included. Our cohort was classified according to the deafness onset (congenital versus postlingual) and the degree of modiolar proximity (less versus tight) with reference to the spiral diameter made by the slim modiolar electrodes in situ on transorbital x ray. We then analyzed the CDL and its metrics using a readily available surgical preplanning tool (OTOPLAN) to obtain comparable data. RESULTS Among 30 ears associated with congenital deafness, 9 ears (30%) showed less modiolar proximity, while none of the 21 ears from 19 subjects with postlingual deafness exhibited "less modiolar proximity" based on our criteria. In this study, CDL showed significant variation among subjects. Importantly, a significant inverse correlation between spiral diameter and CDL (ρ = -0.581, p < 0.001) was found, showing that shorter CDLs have longer spiral diameter and less modiolar proximity. Moreover, further pull-back technique characterized by pulling out the electrode a little bit more in cases with shorter CDL, if not always, exhibited tighter modiolar proximity. CONCLUSION A preponderance of less modiolar proximity of the electrode was observed exclusively among congenital deafness cases, demonstrated by a less tight spiral configuration even under the pull-back technique. Our data suggest that shorter CDL is associated with a less tight spiral configuration of slim modiolar electrodes postoperatively. Depending on the insertion technique, the differential degree of modiolar proximity of slim modiolar electrodes can be alleviated in cases with short CDL, which justifies cochlear duct length-based customized insertion of slim modiolar electrodes.
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Khurayzi T, Dhanasingh A, Almuhawas F, Alsanosi A. Shape of the Cochlear Basal Turn: An Indicator for an Optimal Electrode-to-Modiolus Proximity With Precurved Electrode Type. EAR, NOSE & THROAT JOURNAL 2020; 100:38-43. [PMID: 32330070 DOI: 10.1177/0145561320920965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE The objective of this study was to determine the shape of cochlear basal turn through basic cochlear parameters measurement. The secondary aim was to overlay an image of the precurved electrode array on top of the three-dimensional (3D) image of the cochlea to determine which shape of the cochlear basal turn gives optimal electrode-to-modiolus proximity. MATERIALS AND METHODS Computed tomography (CT) preoperative image-data sets of 117 ears were made available for the measurements of cochlear parameters retrospectively. Three-dimensional slicer was used in the visualization and measurement of cochlear parameters from both 3D and 2D (2-dimensional) images of the inner ear. Cochlear parameters including basal turn diameter (A), width of the basal turn (B), and cochlear height (H) were measured from the appropriate planes. B/A ratio was made to investigate which ratios correspond to round and elliptical shape of the cochlear basal turn. RESULTS The cochlear size as measured by A value ranged between 7.4 mm and 10 mm. The B value and the cochlear height (H) showed a weak positive linear relation with A value. The ratio between the B and A values anything above or below 0.75 could be an indicator for a more round- or elliptical shaped cochlear basal turn, respectively. One sized/shaped commercially available precurved electrode array would not offer a tight electrode-to-modiolus in the cochlea that has an elliptical shaped basal turn as identified by the B/A ratio of <0.75. CONCLUSION Accurate measurement of cochlear parameters adds value to the overall understanding of the cochlear geometry before a cochlear implantation procedure. The shape of cochlear basal turn could have clinical implications when comes to electrode-to-modiolus proximity.
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Affiliation(s)
- Tawfiq Khurayzi
- King Abdullah Ear Specialist Center, 37850King Saud University, Riyadh, Saudi Arabia
| | | | - Fida Almuhawas
- King Abdullah Ear Specialist Center, 37850King Saud University, Riyadh, Saudi Arabia
| | - Abdurrahman Alsanosi
- King Abdullah Ear Specialist Center, 37850King Saud University, Riyadh, Saudi Arabia
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