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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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Sharma V, Das K N, Jangra A, Tiwari S, Khera P, Soni K, Dixit SG, Nayyar AK, Goyal A. Dependability of Electrode to Modiolus Distance in Patients Specific Electrode Selection: A Cadaveric Model Study. Laryngoscope 2024. [PMID: 38860484 DOI: 10.1002/lary.31565] [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: 03/02/2024] [Revised: 04/29/2024] [Accepted: 05/28/2024] [Indexed: 06/12/2024]
Abstract
OBJECTIVE This study aims to discern the disparities in the electrode-to-modiolus distance (EMD) between cochleostomy and round window approaches when performed sequentially in the same temporal bone. Additionally, the study seeks to identify the cochlear metrics that contribute to these differences. METHODOLOGY A cross-sectional study was conducted, involving the sequential insertion of a 12-electrode array through both round window and cochleostomy approaches in cadaveric temporal bones. Postimplantation high-resolution CT scans were employed to calculate various parameters. RESULTS A total of 12 temporal bones were included in the imaging analysis, revealing a mean cochlear duct length of 32.892 mm. The EMD demonstrated a gradual increase from electrode 1 (C1) in the apex (1.9 ± 0.07 mm; n = 24) to electrode 12 (C12) in the basal turn (4.6 ± 0.24 mm; n = 12; p < 0.01). Significantly higher EMD values were observed in the cochleostomy group. Correlation analysis indicated a strong positive correlation between EMD and cochlear perimeter (CP) (rs = 0.64; n = 12; p = 0.03) and a strong negative correlation with the depth of insertion (DOI) in both the middle and basal turns (rs = - 0.78; n = 20; p < 0.01). Additionally, EMD showed a strong negative correlation with the DOI-CP ratio (rs = -0.81; n = 12; p < 0.01). CONCLUSION The cochleostomy group exhibited a significantly higher EMD compared with the round window group. The strong negative correlation between EMD and DOI-CP ratio suggests that in larger cochleae with shallower insertions, EMD is greater than in smaller cochleae with deeper insertions. LEVEL OF EVIDENCE N/A Laryngoscope, 2024.
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Affiliation(s)
- Vidhu Sharma
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - Nidhin Das K
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - Anupriya Jangra
- Department of Otorhinolaryngology, All India Institute of Medical Sciences, Jodhpur, India
| | - Sarbesh Tiwari
- Department of Diagnostic and Interventional, Radiology, All India Institute of Medical Sciences, Jodhpur, India
| | - Pushpinder Khera
- 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
| | - Shilpi G Dixit
- Department of Anatomy, All India Institute of Medical Sciences, Jodhpur, India
| | - Ashish K 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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Müller-Graff FT, Spahn B, Herrmann DP, Kurz A, Völker J, Hagen R, Rak K. Comprehensive literature review on the application of the otological surgical planning software OTOPLAN® for cochlear implantation. HNO 2024:10.1007/s00106-023-01417-4. [PMID: 38861031 DOI: 10.1007/s00106-023-01417-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2023] [Indexed: 06/12/2024]
Abstract
BACKGROUND The size of the human cochlear, measured by the diameter of the basal turn, varies between 7 and 11 mm. For hearing rehabilitation with cochlear implants (CI), the size of the cochlear influences the individual frequency map and the choice of electrode length. OTOPLAN® (CAScination AG [Bern, Switzerland] in cooperation with MED-EL [Innsbruck, Austria]) is a software tool with CE marking for clinical applications in CI treatment which allows for precise pre-planning based on cochlear size. This literature review aims to analyze all published data on the application of OTOPLAN®. MATERIALS AND METHODS The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied to identify relevant studies published in the PubMed search engine between January 2015 and February 2023 using the search terms "otoplan" [title/abstract] OR "anatomy-based fitting" [title/abstract] OR "otological software tool" [title/abstract] OR "computed tomography-based software AND cochlear" [title/abstract]. RESULTS The systematic review of the literature identified 32 studies on clinical use of OTOPLAN® in CI treatment. Most studies were reported from Germany (7 out of 32), followed by Italy (5), Saudi Arabia (4), the USA (4), and Belgium (3); 2 studies each were from Austria and China, and 1 study from France, India, Norway, South Korea, and Switzerland. In the majority of studies (22), OTOPLAN® was used to assess cochlear size, followed by visualizing the electrode position using postoperative images (5), three-dimensional segmentation of temporal bone structures (4), planning the electrode insertion trajectory (3), creating a patient-specific frequency map (3), planning of a safe drilling path through the facial recess (3), and measuring of temporal bone structures (1). CONCLUSION To date, OTOPLAN® is the only DICOM viewer with CE marking in the CI field that can process pre-, intra-, and postoperative images in the abovementioned applications.
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Affiliation(s)
- Franz-Tassilo Müller-Graff
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany.
| | - Björn Spahn
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany
| | - David P Herrmann
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany
| | - Anja Kurz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany
| | - Johannes Völker
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Straße 11, 97080, Wuerzburg, Germany
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Müller-Graff FT, Spahn B, Herrmann DP, Kurz A, Voelker J, Hagen R, Rak K. [Comprehensive literature review on the application of the otological-surgical planning software OTOPLAN® for cochlear implantation. German version]. HNO 2024:10.1007/s00106-024-01461-8. [PMID: 38587661 DOI: 10.1007/s00106-024-01461-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2023] [Indexed: 04/09/2024]
Abstract
BACKGROUND The size of the human cochlear, measured by the diameter of the basal turn, varies between 7 and 11 mm. For hearing rehabilitation with cochlear implants (CI), the size of the cochlear influences the individual frequency map and the choice of electrode length. OTOPLAN® (CAScination AG [Bern, Switzerland] in cooperation with MED-EL [Innsbruck, Austria]) is a software tool with CE marking for clinical applications in CI treatment which allows for precise pre-planning based on cochlear size. This literature review aims to analyze all published data on the application of OTOPLAN®. MATERIALS AND METHODS The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied to identify relevant studies published in the PubMed search engine between January 2015 and February 2023 using the search terms "otoplan" [title/abstract] OR "anatomy-based fitting" [title/abstract] OR "otological software tool" [title/abstract] OR "computed tomography-based software AND cochlear" [title/abstract]. RESULTS The systematic review of the literature identified 32 studies on clinical use of OTOPLAN® in CI treatment. Most studies were reported from Germany (7 out of 32), followed by Italy (5), Saudi Arabia (4), the USA (4), and Belgium (3); 2 studies each were from Austria and China, and 1 study from France, India, Norway, South Korea, and Switzerland. In the majority of studies (22), OTOPLAN® was used to assess cochlear size, followed by visualizing the electrode position using postoperative images (5), three-dimensional segmentation of temporal bone structures (4), planning the electrode insertion trajectory (3), creating a patient-specific frequency map (3), planning of a safe drilling path through the facial recess (3), and measuring of temporal bone structures (1). CONCLUSION To date, OTOPLAN® is the only DICOM viewer with CE marking in the CI field that can process pre-, intra-, and postoperative images in the abovementioned applications.
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Affiliation(s)
- Franz-Tassilo Müller-Graff
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland.
| | - Björn Spahn
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland
| | - David P Herrmann
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland
| | - Anja Kurz
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland
| | - Johannes Voelker
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland
| | - Rudolf Hagen
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland
| | - Kristen Rak
- Klinik und Poliklinik für Hals‑, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Josef-Schneider-Straße 11, 97080, Würzburg, Deutschland
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Altamimi FN, AlTheyab F, Al-Amro M, Al Montasheri A, Al Otaibi S, Al Muhawas F. Cochlear Implantation: Small Cochlear Diameter May Indicate Degree of Abnormality. J Int Adv Otol 2024; 20:108-112. [PMID: 39155857 PMCID: PMC11114178 DOI: 10.5152/iao.2024.231191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/08/2023] [Indexed: 08/20/2024] Open
Abstract
Cochlear size variation was first reported in 1884, and since then, there have been various reports confirming the same. Yet, there is no single report that has displayed the wide variations in the cochlear size in a single layout capturing the cochlea in the oblique coronal view/ cochlear view. Basal turn diameter (A-value) was measured in the oblique coronal plane using the OTOPLAN® otological preplanning tool in 104 computed tomography (CT) scans of the temporal bones of cochlear implant (CI) recipients in a tertiary CI center. All CT scans with an image resolution of at least 0.5 mm and identified as having cochleae with normal anatomy were included in this study. A 3-dimensional (3D) segmentation was performed using the 3D slicer and visualized to evaluate the impact of cochlear size on the number of turns studied. The A-value was found to vary between 7.3 mm and 10.4 mm among the studied patients. Three-dimensional segmentation of the inner ear revealed only 2 turns of the cochlea in 4 ears, with A-values of 7.3, 8.8, 7.8, and 7.7 mm. One ear had only 11 /2 turns of the cochlea, with an A-value of 7.9 mm. As a further advancement in the assessment of cochlear size as determined by the A-value, 3D segmentation of the complete inner ear provides a full picture of the number of cochlear turns. Three-dimensional segmentation of the entire inner ear could help improve the preoperative planning of CI surgery and have implications for electrode array selection. Cochlear size could be a predictor of the number of cochlear turns, even in cases that look normal from the radiological findings. The findings of this study could help in improving the preoperative planning for a more successful CI surgery by differentiating between the normal and abnormal cochlea.
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Affiliation(s)
- Fahad N. Altamimi
- Department of Otolaryngology, Al Faisal University, King Saud Medical City, Riyadh, Saudi Arabia
| | - Fatemah AlTheyab
- Department of Otolaryngology, King Saud Medical City, Riyadh, Saudi Arabia
| | - Mariam Al-Amro
- Department of Otolaryngology, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
| | - Ali Al Montasheri
- Department of Radiology, King Saud Medical City, Riyadh, Saudi Arabia
| | - Sara Al Otaibi
- Department of Otolaryngology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fida Al Muhawas
- Department of Otolaryngology, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
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Gautam I, Shaw A, Brickman D, Mahajan A, Jeyakumar A. Creation of a Prototype Cochlear Training Model. Ann Otol Rhinol Laryngol 2024:34894241238868. [PMID: 38491865 DOI: 10.1177/00034894241238868] [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: 03/18/2024]
Abstract
OBJECTIVE Creation of a novel 3D-printed physical cochlear model that demonstrated the feasibility of creating the model, and impact of a Graphical User Interface (GUI) system on training insertion metrics. STUDY DESIGN Feasibility study with a pilot prospective data collection. SETTING Tertiary academic center. METHODS The study was IRB exempt. Five resident trainees (PGY1-PGY5) practiced electrode insertions in cadaveric temporal bones before using the simulator. Nine students were educated on how to hold the electrodes and position them, and then allowed to use the simulator. All trainees were instructed that slower insertions were favorable. One cochlear implant (CI) surgeon used the simulator. The GUI captured the real video feed, but also provided distance, trajectory, and velocity measurements. The program is designed to plot the real-time depth of insertion and speed of insertion of the electrode; the user is also provided real-time occurrence of any kinks and back-outs. RESULTS A total of 14 trainees and 1 CI surgeon inserted the electrode at least 5 times without the use of the GUI (before) and then at least 5 times with the use of the GUI (after). Average Speed before and after (100.84 and 53.23 mm/s); Average minimum speed before and after (59.34 and 9.65 mm/s); and Average maximum speed before and after (416 and 285.81 mm/s). Statistically significant improvements were noted in all the measured speeds of insertion (P < .001). The other variables improved but not to a statistical significance. CONCLUSIONS Real-time training using the 3D-printed model and GUI for cochlear implantation can help improve surgical resident training and comfort levels with electrode insertion for surgical trainees. The advantage of this model is that surgeons/trainees can use it as many times as they like, as the whole set-up is easy, economical, and reusable. The real time graphical user interface enhances training and retention of the practiced skills.
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Affiliation(s)
- Ishwor Gautam
- Biomedical Engineering, Department of Biomedical Engineering, The University of Akron, Akron, OH, USA
| | - Avi Shaw
- Department of Otolaryngology, Mercy Bon Secours, Youngstown, OH, USA
| | - Dhiren Brickman
- Department of Computer Science, Ashland University, Ashland, OH, USA
| | - Ajay Mahajan
- Biomedical Engineering, Department of Biomedical Engineering, The University of Akron, Akron, OH, USA
| | - Anita Jeyakumar
- Department of Otolaryngology, Mercy Bon Secours, Youngstown, OH, USA
- Northeast Ohio Medical University, Rootstown, OH, USA
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Spahn B, Ilgen L, Neun T, Müller-Graff FT, Schendzielorz P, Hagen R, Althoff D, Zabler S, Rak K. Dependence of Cochlear Duct Length Measurement on the Resolution of the Imaging Dataset. Otol Neurotol 2024; 45:e234-e240. [PMID: 38238926 DOI: 10.1097/mao.0000000000004088] [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: 02/17/2024]
Abstract
HYPOTHESIS Measurements of the cochlear duct length (CDL) are dependent on the resolution of the imaging dataset. BACKGROUND Previous research has shown highly precise cochlear measurements using 3D-curved multiplanar reconstruction (MPR) and flat-panel volume computed tomography (fpVCT). Thus far, however, there has been no systematic evaluation of the imaging dataset resolution required for optimal CDL measurement. Therefore, the aim of this study was to evaluate the dependence of CDL measurement on the resolution of the imaging dataset to establish a benchmark for future CDL measurements. METHODS fpVCT scans of 10 human petrous bone specimens were performed. CDL was measured using 3D-curved MPR with secondary reconstruction of the fpVCT scans (fpVCT SECO ) and increasing resolution from 466 to 99 μm. In addition, intraobserver variability was evaluated. A best-fit function for calculation of the CDL was developed to provide a valid tool when there are no measurements done with high-resolution imaging datasets. RESULTS Comparison of different imaging resolution settings showed significant differences for CDL measurement in most of the tested groups ( p < 0.05), except for the two groups with the highest resolution. Imaging datasets with a resolution lower than 200 μm showed lower intraobserver variability than the other resolution settings, although there were no clinically unacceptable errors with respect to the Bland-Altman plots. The developed best-fit function showed high accuracy for CDL calculation using resolution imaging datasets of 300 μm or lower. CONCLUSION 3D-curved MPR in fpVCT with a resolution of the imaging dataset of 200 μm or higher revealed the most precise CDL measurement. There was no benefit of using a resolution higher than 200 μm with regard to the accuracy of the CDL measurement.
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Affiliation(s)
- Bjoern Spahn
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center
| | - Lukas Ilgen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center
| | - Tilmann Neun
- Institute for Diagnostic and Interventional Neuroradiology, University of Wuerzburg
| | - Franz-Tassilo Müller-Graff
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center
| | - Philipp Schendzielorz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center
| | - Daniel Althoff
- Fraunhofer Development Center for X-ray Technology, Wuerzburg
| | - Simon Zabler
- Deggendorf Institute of Technology, Faculty of Applied Computer Science, Deggendorf, Germany
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center
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Weiss NM, Breitsprecher T, Wozniak M, Bächinger D, Völter C, Mlynski R, Van de Heyning P, Van Rompaey V, Dazert S. Comparing linear and non-linear models to estimate the appropriate cochlear implant electrode array length-are current methods precise enough? Eur Arch Otorhinolaryngol 2024; 281:43-49. [PMID: 37466660 PMCID: PMC10764384 DOI: 10.1007/s00405-023-08064-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/09/2023] [Indexed: 07/20/2023]
Abstract
PURPOSE In cochlear implantation with flexible lateral wall electrode arrays, a cochlear coverage (CC) range between 70% and 80% is considered ideal for optimal speech perception. To achieve this CC, the cochlear implant (CI) electrode array has to be chosen according to the individual cochlear duct length (CDL). Here, we mathematically analyzed the suitability of different flexible lateral wall electrode array lengths covering between 70% and 80% of the CDL. METHODS In a retrospective cross-sectional study preoperative high-resolution computed tomography (HRCT) from patients undergoing cochlear implantation was investigated. The CDL was estimated using an otosurgical planning software and the CI electrode array lengths covering 70-80% of the CDL was calculated using (i) linear and (ii) non-linear models. RESULTS The analysis of 120 HRCT data sets showed significantly different model-dependent CDL. Significant differences between the CC of 70% assessed from linear and non-linear models (mean difference: 2.5 mm, p < 0.001) and the CC of 80% assessed from linear and non-linear models (mean difference: 1.5 mm, p < 0.001) were found. In up to 25% of the patients none of the existing flexible lateral wall electrode arrays fit into this range. In 59 cases (49,2%) the models did not agree on the suitable electrode arrays. CONCLUSIONS The CC varies depending on the underlying CDL approximation, which critically influences electrode array choice. Based on the literature, we hypothesize that the non-linear method systematically overestimates the CC and may lead to rather too short electrode array choices. Future studies need to assess the accuracy of the individual mathematical models.
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Affiliation(s)
- Nora M Weiss
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum, Germany.
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
- International Graduate School of Neuroscience (IGSN), Ruhr-University Bochum, Bochum, Germany.
| | - Tabita Breitsprecher
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum, Germany
| | - Martin Wozniak
- MED-EL Elektromedizinische Geräte Deutschland GmbH, Starnberg, Deutschland
| | - David Bächinger
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum, Germany
| | - Christiane Völter
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum, Germany
| | - Robert Mlynski
- Department of Otorhinolaryngology, Head and Neck Surgery, "Otto Körner", University, Rostock, Germany
| | - Paul Van de Heyning
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, Antwerp, Belgium
| | - Vincent Van Rompaey
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp University Hospital, Antwerp, Belgium
| | - Stefan Dazert
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum, Germany
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Creff G, Lambert C, Coudert P, Pean V, Laurent S, Godey B. Comparison of Tonotopic and Default Frequency Fitting for Speech Understanding in Noise in New Cochlear Implantees: A Prospective, Randomized, Double-Blind, Cross-Over Study. Ear Hear 2024; 45:35-52. [PMID: 37823850 DOI: 10.1097/aud.0000000000001423] [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: 10/13/2023]
Abstract
OBJECTIVES While cochlear implants (CIs) have provided benefits for speech recognition in quiet for subjects with severe-to-profound hearing loss, speech recognition in noise remains challenging. A body of evidence suggests that reducing frequency-to-place mismatch may positively affect speech perception. Thus, a fitting method based on a tonotopic map may improve speech perception results in quiet and noise. The aim of our study was to assess the impact of a tonotopic map on speech perception in noise and quiet in new CI users. DESIGN A prospective, randomized, double-blind, two-period cross-over study in 26 new CI users was performed over a 6-month period. New CI users older than 18 years with bilateral severe-to-profound sensorineural hearing loss or complete hearing loss for less than 5 years were selected in the University Hospital Centre of Rennes in France. An anatomical tonotopic map was created using postoperative flat-panel computed tomography and a reconstruction software based on the Greenwood function. Each participant was randomized to receive a conventional map followed by a tonotopic map or vice versa. Each setting was maintained for 6 weeks, at the end of which participants performed speech perception tasks. The primary outcome measure was speech recognition in noise. Participants were allocated to sequences by block randomization of size two with a ratio 1:1 (CONSORT Guidelines). Participants and those assessing the outcomes were blinded to the intervention. RESULTS Thirteen participants were randomized to each sequence. Two of the 26 participants recruited (one in each sequence) had to be excluded due to the COVID-19 pandemic. Twenty-four participants were analyzed. Speech recognition in noise was significantly better with the tonotopic fitting at all signal-to-noise ratio (SNR) levels tested [SNR = +9 dB, p = 0.002, mean effect (ME) = 12.1%, 95% confidence interval (95% CI) = 4.9 to 19.2, standardized effect size (SES) = 0.71; SNR = +6 dB, p < 0.001, ME = 16.3%, 95% CI = 9.8 to 22.7, SES = 1.07; SNR = +3 dB, p < 0.001 ME = 13.8%, 95% CI = 6.9 to 20.6, SES = 0.84; SNR = 0 dB, p = 0.003, ME = 10.8%, 95% CI = 4.1 to 17.6, SES = 0.68]. Neither period nor interaction effects were observed for any signal level. Speech recognition in quiet ( p = 0.66) and tonal audiometry ( p = 0.203) did not significantly differ between the two settings. 92% of the participants kept the tonotopy-based map after the study period. No correlation was found between speech-in-noise perception and age, duration of hearing deprivation, angular insertion depth, or position or width of the frequency filters allocated to the electrodes. CONCLUSION For new CI users, tonotopic fitting appears to be more efficient than the default frequency fitting because it allows for better speech recognition in noise without compromising understanding in quiet.
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Affiliation(s)
- Gwenaelle Creff
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
- MediCIS, LTSI (Image and Signal Processing Laboratory), INSERM, U1099, Rennes, France
| | - Cassandre Lambert
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
| | - Paul Coudert
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
| | | | | | - Benoit Godey
- Department of Otolaryngology-Head and Neck Surgery (HNS), University Hospital, Rennes, France
- MediCIS, LTSI (Image and Signal Processing Laboratory), INSERM, U1099, Rennes, France
- Hearing Aid Academy, Javene, France
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10
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Grzybowski M, Malfeld K, Lenarz T, Scheper V, Schurzig D. Optimization of pharmacological interventions in the guinea pig animal model-a new approach to calculate the perilymph volume of the scala tympani. Front Neurosci 2023; 17:1297046. [PMID: 38161797 PMCID: PMC10754993 DOI: 10.3389/fnins.2023.1297046] [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: 09/19/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024] Open
Abstract
Objective The guinea pig serves as a well-established animal model for inner ear research, offering valuable insights into the anatomy, physiology, and therapeutic interventions of the auditory system. However, the heterogeneity of results observed in both in-vivo experiments and clinical studies poses challenges in understanding and optimizing pharmacotherapy outcomes. This heterogeneity may be due to individual differences in the size of the guinea pig cochlea and thus in the volume of the scala tympani (ST), which can lead to different drug concentrations in the ST, a fact that has been largely overlooked thus far. To address this issue, we aimed to develop an approach for calculating the individual volume of perilymph within the ST before and after cochlear implant insertion. Method In this study, high-resolution μCT images of a total of n = 42 guinea pig temporal bones were used to determine the volume of the ST. We compared fresh, frozen, and fixed tissues from both colored and albino strains to evaluate the potential influence of tissue condition and strain on the results. Results Our findings demonstrate a variability in mean ST volume with a relative standard deviation (RSD) of 14.7%, comparable to studies conducted with humans (range RSD: 5 to 20%). This indicates that the guinea pig cochlea exhibits similar variability to that of the human cochlea. Consequently, it is crucial to consider this variability when designing and conducting studies utilizing the guinea pig as an animal model. Furthermore, we successfully developed a tool capable of estimating ST volume without the need for manual segmentation, employing two geometric parameters, basal diameter (A) and width (B) of the cochlea, corresponding to the cochlear footprint. The tool is available for free download and use on our website. Conclusion This novel approach provides researchers with a valuable tool to calculate individual ST volume in guinea pigs, enabling more precise dosing strategies and optimization of drug concentrations for pharmacotherapy studies. Moreover, our study underscores the importance of acknowledging and accounting for inter-individual variability in animal models to enhance the translational relevance and applicability of research outcomes in the field of inner ear investigations.
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Affiliation(s)
- Marleen Grzybowski
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
- German Hearing Center Hannover, Hannover Medical School, Hannover, Germany
| | - Kathrin Malfeld
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
- Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Hannover, Germany
| | - Thomas Lenarz
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
- German Hearing Center Hannover, Hannover Medical School, Hannover, Germany
- Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Hannover, Germany
| | - Verena Scheper
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
- Center for Biomedical Engineering, Implant Research and Development (NIFE), Hannover Medical School, Hannover, Germany
| | - Daniel Schurzig
- Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany
- MED-EL Research Center, Hannover, Germany
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11
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Alahmadi A, Abdelsamad Y, Dhanasingh A, Almuhawas F, Alsanosi A. Enhancing cochlear duct length estimation by incorporating second-turn parameters. Sci Rep 2023; 13:21496. [PMID: 38057331 PMCID: PMC10700305 DOI: 10.1038/s41598-023-48641-0] [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: 10/19/2022] [Accepted: 11/28/2023] [Indexed: 12/08/2023] Open
Abstract
Estimating insertion depth, cochlear duct length (CDL), and other inner ear parameters is vital to optimizing cochlear implantation outcomes. Most current formulas use only the basal turn dimensions for CDL prediction. In this study, we investigated the importance of the second turn parameters in estimating CDL. Two experienced neuro-otologists blindly used segmentation software to measure (in mm) cochlear parameters, including basal turn diameter (A), basal turn width (B), second-turn diameter (A2), second-turn width (B2), CDL, first-turn length, and second-turn length (STL). These readings were taken from 33 computed tomography (CT) images of temporal bones from anatomically normal ears. We constructed regression models using A, B, A2, and B2 values fitted to CDL, two-turn length, and five-fold cross-validation to ensure model validity. CDL, A value, and STL were longer in males than in females. The mean B2/A2 ratio was 0.91 ± 0.06. Adding A2 and B2 values improved CDL prediction accuracy to 86.11%. Therefore, we propose a new formula for more accurate CDL estimation using A, B, A2, and B2 values. In conclusion, the findings of this study revealed a notable improvement in the prediction of two-turn length (2TL), and CDL by clinically appreciable margins upon adding A2 and B2 values to the prediction formulas.
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Affiliation(s)
- Asma Alahmadi
- King Abdullah Ear Specialist Center (KAESC), King Saud University Medical City (KSUMC), College of Medicine, King Saud University, P.O. Box: 245, 11411, Riyadh, Saudi Arabia.
| | | | | | - Fida Almuhawas
- King Abdullah Ear Specialist Center (KAESC), King Saud University Medical City (KSUMC), College of Medicine, King Saud University, P.O. Box: 245, 11411, Riyadh, Saudi Arabia
| | - Abdulrahman Alsanosi
- King Abdullah Ear Specialist Center (KAESC), King Saud University Medical City (KSUMC), College of Medicine, King Saud University, P.O. Box: 245, 11411, Riyadh, Saudi Arabia
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12
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Aksoy DÖ, Meltem E, Karagöz Y, Yildirim G, Mahmutoğlu Ö, Mahmutoğlu AS. Comprehension of Cochlear Duct Length for Incomplete Partition Types. J Comput Assist Tomogr 2023; 47:982-988. [PMID: 37948375 DOI: 10.1097/rct.0000000000001488] [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: 06/03/2023]
Abstract
OBJECTIVE Preoperative assessment of the cochlear duct length (CDL) and cochlear dimensions allows the selection of optimized implants. We aimed to evaluate the CDL measurements in incomplete partition (IP) defect patients and to create a reference to the literature. METHODS Forty-one patients with IP (13 IP I, 23 IP II, and 5 IP III) and 30 controls were included in the study. The standardized cochlear image showing the basal turn in the most expansive plane was reconstructed from temporal high-resolution computed tomography images. Cochlear duct length measured manually (CDL-M) was measured by points placed consecutively on the lateral wall of the cochlea. The defined equations for estimating CDL (CDL measured according to Schurzig et al formula [CDL-Ɵ], CDL measured according to Escudé et al formula [CDL-E], CDL measured according to Alexiades et al formula [CDL-A]) were calculated from the same images. Cochlear duct length mean values obtained by each method were compared for each IP type. RESULTS The longest CDL value was found in the control group, irrespective of the calculation method. Incomplete partition II cases had the most extended mean CDL among IP types. Incomplete partition III had the shortest CDL among all groups' CDL-M values. However, the mean CDL-M values of IP types I and III showed close results. There was no significant difference between the CDL-E and CDL-M values of the control group. Similarly, no significant difference was found between CDL-Ɵ and CDL-M values in IP type III cases. However, the results of other estimating formulations of all groups differed significantly from CDL-M values. CONCLUSION Cochlear duct length differences were detected between the control group and IP subtypes. These differences should be considered when choosing the appropriate electrode length. Because the results of formulas estimating CDL may differ from CDL-M in both control and IP cases, it would be more appropriate to use manual measurements in clinical practice.
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Affiliation(s)
- Direnç Özlem Aksoy
- From the Department of Radiology, University of Health Sciences Istanbul Training and Research Hospital, Istanbul, Turkey
| | - Emine Meltem
- From the Department of Radiology, University of Health Sciences Istanbul Training and Research Hospital, Istanbul, Turkey
| | - Yeşim Karagöz
- From the Department of Radiology, University of Health Sciences Istanbul Training and Research Hospital, Istanbul, Turkey
| | - Gülşah Yildirim
- From the Department of Radiology, University of Health Sciences Istanbul Training and Research Hospital, Istanbul, Turkey
| | - Özdeş Mahmutoğlu
- Department of Radiology, University of Health Sciences Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Abdullah Soydan Mahmutoğlu
- From the Department of Radiology, University of Health Sciences Istanbul Training and Research Hospital, Istanbul, Turkey
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13
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Gatto A, Tofanelli M, Costariol L, Rizzo S, Borsetto D, Gardenal N, Uderzo F, Boscolo-Rizzo P, Tirelli G. Otological Planning Software-OTOPLAN: A Narrative Literature Review. Audiol Res 2023; 13:791-801. [PMID: 37887851 PMCID: PMC10603892 DOI: 10.3390/audiolres13050070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/10/2023] [Accepted: 10/16/2023] [Indexed: 10/28/2023] Open
Abstract
The cochlear implant (CI) is a widely accepted option in patients with severe to profound hearing loss receiving limited benefit from traditional hearing aids. CI surgery uses a default setting for frequency allocation aiming to reproduce tonotopicity, thus mimicking the normal cochlea. One emerging instrument that may substantially help the surgeon before, during, and after the surgery is a surgical planning software product developed in collaboration by CASCINATION AG (Bern, Switzerland) and MED-EL (Innsbruck Austria). The aim of this narrative review is to present an overview of the main features of this otological planning software, called OTOPLAN®. The literature was searched on the PubMed and Web of Science databases. The search terms used were "OTOPLAN", "cochlear planning software" "three-dimensional imaging", "3D segmentation", and "cochlear implant" combined into different queries. This strategy yielded 52 publications, and a total of 31 studies were included. The review of the literature revealed that OTOPLAN is a useful tool for otologists and audiologists as it improves preoperative surgical planning both in adults and in children, guides the intraoperative procedure and allows postoperative evaluation of the CI.
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Affiliation(s)
- Annalisa Gatto
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Margherita Tofanelli
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Ludovica Costariol
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Serena Rizzo
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Daniele Borsetto
- Department of ENT, Addenbrookes Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Nicoletta Gardenal
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Francesco Uderzo
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Paolo Boscolo-Rizzo
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
| | - Giancarlo Tirelli
- Department of Medical, Surgical and Health Sciences, Section of Otolaryngology, University of Trieste, 34149 Trieste, Italy; (A.G.); (N.G.); (G.T.)
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14
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Sieber D, Timm ME, Weller T, Suhling M, Lenarz T, Schurzig D. The Dependency of Cochlear Lateral Wall Measurements on Observer and Imaging Type. Otol Neurotol 2023; 44:873-880. [PMID: 37641206 DOI: 10.1097/mao.0000000000003991] [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: 08/31/2023]
Abstract
HYPOTHESIS Assessment techniques for the cochlear spatial lateral wall are associated with inter-rater variability, but derived clinical recommendations nonetheless offer value for individualized electrode selection. BACKGROUND Anatomical variations influence the location of cochlear implant electrodes inside the cochlea. Preoperative planning allows individualization of the electrode based on characterization of the bony lateral wall. METHODS The study used publicly available digitized temporal bones based on microslicing and computed tomography. Four experienced observers assessed the lateral wall applying manual tracing, linear regression scaling and elliptic-circular approximation methods in all modalities. Radial and height differences were computed in 90-degree steps from the round window center to the apex. Total length, total angular length, and tonotopic frequencies were computed for each reconstruction. RESULTS Differences were found most pronounced between assessment methods in vertical direction across observers and imaging modalities. One of the five anatomies was consistently found to be of shorter cochlear duct length with estimation techniques yielding more conservative results compared with manual tracings. CONCLUSIONS Assessment techniques for the bony lateral wall yield method, observer, and image modality related deviations. Automation of the anatomical characterization may offer potential in minimizing inaccuracies. Nonetheless, observers were consistently able to detect a smaller inner ear demonstrating the ability of current methods to contribute to an optimized choice of electrodes based on individual patient anatomy.
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Affiliation(s)
- Daniel Sieber
- Department of Medical and Health Technologies, MCI The Entrepreneurial School, Innsbruck, Austria
| | - Max E Timm
- Department of Otolaryngology, Hannover Medical School
| | - Tobias Weller
- Department of Otolaryngology, Hannover Medical School
| | - Marie Suhling
- Department of Otolaryngology, Hannover Medical School
| | - Thomas Lenarz
- Department of Otolaryngology, Hannover Medical School
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15
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Breitsprecher T, Mlynski R, Völter C, Van de Heyning P, Van Rompaey V, Dazert S, Weiss NM. Accuracy of Preoperative Cochlear Duct Length Estimation and Angular Insertion Depth Prediction. Otol Neurotol 2023; 44:e566-e571. [PMID: 37550888 DOI: 10.1097/mao.0000000000003956] [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: 08/09/2023]
Abstract
OBJECTIVE In cochlear implantation with flexible lateral wall electrodes, a cochlear coverage of 70% to 80% is assumed to yield an optimal speech perception. Therefore, fitting the cochlear implant (CI) to the patient's individual anatomy has gained importance in recent years. For these reasons, the optimal angular insertion depth (AID) has to be calculated before cochlear implantation. One CI manufacturer offers a software that allows to visualize the AID of different electrode arrays. Here, it is hypothesized that these preoperative AID models overestimate the postoperatively measured insertion angle. This study aims to investigate the agreement between preoperatively estimated and postoperatively measured AID. STUDY DESIGN Retrospective cross-sectional study. SETTING Single-center tertiary referral center. PATIENTS Patients undergoing cochlear implantation. INTERVENTION Preoperative and postoperative high-resolution computed tomography (HRCT). MAIN OUTCOME MEASURES The cochlear duct length was estimated by determining cochlear parameters ( A value and B value), and the AID for the chosen electrode was (i) estimated by elliptic circular approximation by the software and (ii) measured manually postoperatively by detecting the electrode contacts after insertion. RESULTS A total of 80 HRCT imaging data sets from 69 patients were analyzed. The mean preoperative AID estimation was 662.0° (standard deviation [SD], 61.5°), and the mean postoperatively measured AID was 583.9° (SD, 73.6°). In all cases (100%), preoperative AID estimation significantly overestimated the postoperative determined insertion angle (mean difference, 38.1°). A correcting factor of 5% on preoperative AID estimation dissolves these differences. CONCLUSIONS The use of an electrode visualization tool may lead to shorter electrode array choices because of an overestimation of the insertion angle. Applying a correction factor of 0.95 on preoperative AID estimation is recommended.
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Affiliation(s)
- Tabita Breitsprecher
- Department of Otorhinolaryngology–Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum,
Germany
| | - Robert Mlynski
- Department of Otorhinolaryngology, Head and Neck Surgery, “Otto Körner,” University Rostock, Germany
| | - Christiane Völter
- Department of Otorhinolaryngology–Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum,
Germany
| | - Paul Van de Heyning
- Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Belgium
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Vincent Van Rompaey
- Department of Otorhinolaryngology and Head and Neck Surgery, Antwerp University Hospital, Belgium
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
| | - Stefan Dazert
- Department of Otorhinolaryngology–Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum,
Germany
| | - Nora M Weiss
- Department of Otorhinolaryngology–Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum,
Germany
- Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- International Graduate School of Neuroscience (IGSN), Ruhr-University Bochum, Bochum, Germany
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Paouris D, Kunzo S, Goljerová I. Validation of Automatic Cochlear Measurements Using OTOPLAN ® Software. J Pers Med 2023; 13:jpm13050805. [PMID: 37240975 DOI: 10.3390/jpm13050805] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/02/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
INTRODUCTION Electrode length selection based on case-related cochlear parameters is becoming a standard pre-operative step for cochlear implantation. The manual measurement of the parameters is often time-consuming and may lead to inconsistencies. Our work aimed to evaluate a novel, automatic measurement method. MATERIALS AND METHODS A retrospective evaluation of pre-operative HRCT images of 109 ears (56 patients) was conducted, using a development version of the OTOPLAN® software. Inter-rater (intraclass) reliability and execution time were assessed for manual (surgeons R1 and R2) vs. automatic (AUTO) results. The analysis included A-Value (Diameter), B-Value (Width), H-Value (Height), and CDLOC-length (Cochlear Duct Length at Organ of Corti/Basilar membrane). RESULTS The measurement time was reduced from approximately 7 min ± 2 (min) (manual) to 1 min (AUTO). Cochlear parameters in mm (mean ± SD) for R1, R2 and AUTO, respectively, were A-value: 9.00 ± 0.40, 8.98 ± 0.40 and 9.16 ± 0.36; B-value: 6.81 ± 0.34, 6.71 ± 0.35 and 6.70 ± 0.40; H-value: 3.98 ± 0.25, 3.85 ± 0.25 and 3.76 ± 0.22; and the mean CDLoc-length: 35.64 ± 1.70, 35.20 ± 1.71 and 35.47 ± 1.87. AUTO CDLOC measurements were not significantly different compared to R1 and R2 (H0: Rx CDLOC = AUTO CDLOC: p = 0.831, p = 0.242, respectively), and the calculated intraclass correlation coefficient (ICC) for CDLOC was 0.9 (95% CI: 0.85, 0.932) for R1 vs. AUTO; 0.90 (95% CI: 0.85, 0.932) for R2 vs. AUTO; and 0.893 (95% CI: 0.809, 0.935) for R1 vs. R2. CONCLUSIONS We observed excellent inter-rater reliability, a high agreement of outcomes, and reduced execution time using the AUTO method.
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Affiliation(s)
- Dimitrios Paouris
- Clinic of Pediatric Otorhinolaryngology of the Medical Faculty, National Institute of Children's Diseases, Comenius University, 83340 Bratislava, Slovakia
| | - Samuel Kunzo
- Clinic of Pediatric Otorhinolaryngology of the Medical Faculty, National Institute of Children's Diseases, Comenius University, 83340 Bratislava, Slovakia
| | - Irina Goljerová
- Clinic of Pediatric Otorhinolaryngology of the Medical Faculty, National Institute of Children's Diseases, Comenius University, 83340 Bratislava, Slovakia
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17
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Müller-Graff FT, Voelker J, Kurz A, Hagen R, Neun T, Rak K. Accuracy of radiological prediction of electrode position with otological planning software and implications of high-resolution imaging. Cochlear Implants Int 2023; 24:144-154. [PMID: 36617441 DOI: 10.1080/14670100.2022.2159128] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVES In cochlear implantation, preoperative prediction of electrode position has recently gained increasing attention. Currently, planning is usually done by multislice CT (MSCT). However, flat-panel volume CT (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for more precise visualization of the cochlea. Combined with a newly developed otological planning software, the position of every single contact can be effectively predicted. In this study it was investigated how accurately radiological prediction forecasts the postoperative electrode localization and whether higher image resolution is advantageous. METHODS Utilizing otological planning software (OTOPLAN®) and different clinical imaging modalities (MSCT, fpVCT and fpVCTSECO) the electrode localization [angular insertion depth (AID)] and respective contact frequencies were predicted preoperatively and examined postoperatively. Furthermore, inter-electrode-distance (IED) and inter-electrode-frequency difference (IEFD) were evaluated postoperatively. RESULTS Measurements revealed a preoperative overestimation of AID. Corresponding frequencies were also miscalculated. Determination of IED and IEFD revealed discrepancies at the transition from the basal to the middle turn and round window to the basal turn. All predictions and discrepancies were lowest when using fpVCTSECO. CONCLUSION The postoperative electrode position can be predicted quite accurately using otological planning software. However, because of several potential misjudgments, high-resolution imaging, such as offered by fpVCTSECO, should be used pre- and postoperatively.
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Affiliation(s)
- Franz-Tassilo Müller-Graff
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Johannes Voelker
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Anja Kurz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Tilmann Neun
- Institute for Diagnostic and Interventional Neuroradiology, University of Wuerzburg, Wuerzburg, Germany
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
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18
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Thomas JP, Klein H, Haubitz I, Dazert S, Völter C. Intra- and Interrater Reliability of CT- versus MRI-Based Cochlear Duct Length Measurement in Pediatric Cochlear Implant Candidates and Its Impact on Personalized Electrode Array Selection. J Pers Med 2023; 13:jpm13040633. [PMID: 37109019 PMCID: PMC10142378 DOI: 10.3390/jpm13040633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 03/25/2023] [Accepted: 03/30/2023] [Indexed: 04/09/2023] Open
Abstract
Background: Radiological high-resolution computed tomography-based evaluation of cochlear implant candidates’ cochlear duct length (CDL) has become the method of choice for electrode array selection. The aim of the present study was to evaluate if MRI-based data match CT-based data and if this impacts on electrode array choice. Methods: Participants were 39 children. CDL, length at two turns, diameters, and height of the cochlea were determined via CT and MRI by three raters using tablet-based otosurgical planning software. Personalized electrode array length, angular insertion depth (AID), intra- and interrater differences, and reliability were calculated. Results: Mean intrarater difference of CT- versus MRI-based CDL was 0.528 ± 0.483 mm without significant differences. Individual length at two turns differed between 28.0 mm and 36.6 mm. Intrarater reliability between CT versus MRI measurements was high (intra-class correlation coefficient (ICC): 0.929–0.938). Selection of the optimal electrode array based on CT and MRI matched in 90.1% of cases. Mean AID was 629.5° based on the CT and 634.6° based on the MRI; this is not a significant difference. ICC of the mean interrater reliability was 0.887 for the CT-based evaluation and 0.82 for the MRI-based evaluation. Conclusion: MRI-based CDL measurement shows a low intrarater difference and a high interrater reliability and is therefore suitable for personalized electrode array selection.
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Affiliation(s)
- Jan Peter Thomas
- Department of Otorhinolaryngology, Head and Neck Surgery, St. Johannes Hospital, Cath. St. Paulus Society, Academic Teaching Hospital of the University of Münster, Johannesstr. 9-17, 44137 Dortmund, Germany
| | - Hannah Klein
- Department of Otorhinolaryngology, Head and Neck Surgery, Katholisches Klinikum, Ruhr University Bochum, Bleichstr. 15, 44787 Bochum, Germany
| | - Imme Haubitz
- Department of Otorhinolaryngology, Head and Neck Surgery, Katholisches Klinikum, Ruhr University Bochum, Bleichstr. 15, 44787 Bochum, Germany
| | - Stefan Dazert
- Department of Otorhinolaryngology, Head and Neck Surgery, Katholisches Klinikum, Ruhr University Bochum, Bleichstr. 15, 44787 Bochum, Germany
| | - Christiane Völter
- Department of Otorhinolaryngology, Head and Neck Surgery, Katholisches Klinikum, Ruhr University Bochum, Bleichstr. 15, 44787 Bochum, Germany
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Salamah M, Abdelsamad Y, Alahmadi A, Alsanosi A. Cochlear implantation: Predicting the scala tympani volume of the pediatric recipients. Int J Pediatr Otorhinolaryngol 2023; 165:111432. [PMID: 36640697 DOI: 10.1016/j.ijporl.2022.111432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/26/2022] [Accepted: 12/29/2022] [Indexed: 01/01/2023]
Abstract
OBJECTIVES The main aim of this study was to estimate the volume of the Scala Tympani (ST) of our pediatric cochlear implant (CI) recipients from the computed tomography (CT) images. Then, to study the association between ST volume and both demographic characteristics and cochlear parameters. METHODS A retrospective study on the CT scans of pediatric CI patients at a tertiary referral CI center. Congenital or acquired cochlear defects were excluded. Two reviewers, with the same level of experience, blindly measured the main cochlear parameters and studied its anatomy. Then, the interrater reliability was tested to measure any differences between the two readings. After that, the ST volume of the included patients was calculated and analyzed. Furthermore, the correlations between the main cochlear parameters and ST volume were studied to propose a formula for estimating the ST volume from the cochlear duct length (CDL). RESULTS The mean predicted ST volume among our pediatric CI recipients was 38.51 ± 5.54 μl (range; 24.47-52.57 μl). The statistical analysis revealed that all cochlear parameters (A, B, H, and CDL values) could be significant predictors of the ST volume (p=<0.0001). CONCLUSION The main cochlear parameters along with the CDL are positively linked to the ST volume. There are considerable differences in cochlear size and scala tympani volume among our pediatric population. These findings confirm the importance of pre-operative planning for proper electrode array selection.
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Affiliation(s)
- Marzouqi Salamah
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, Saudi Arabia.
| | | | - Asma Alahmadi
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Abdulrahman Alsanosi
- King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Kurz A, Müller-Graff FT, Hagen R, Rak K. One Click Is Not Enough: Anatomy-Based Fitting in Experienced Cochlear Implant Users. Otol Neurotol 2022; 43:1176-1180. [PMID: 36351223 DOI: 10.1097/mao.0000000000003731] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To evaluate a new methodological approach of applying anatomy-based fitting (ABF) in experienced cochlear implant (CI) users. PARTICIPANTS Three experienced unilateral and bilateral CI users with postlingual hearing loss. INTERVENTION Postoperative imaging, via a high-volume Dyna computed tomography, and exact electrode measurement positions were integrated into the clinical fitting software following a new procedure, which adapted individual frequency bandwidths within the audio processor. MAIN OUTCOME MEASURES Speech perception in quiet and noise, clinical mapping, and self-perceived level of auditory benefit were assessed. RESULTS For each CI user, ABF mapping provided better speech perception in quiet and in noise compared with the original clinical fitting mapping. In addition, ABF mapping was accepted in CI users despite unequal bilateral array insertion depths and lengths; however, acceptance was only established if the point of first electrode contact was less than 230 Hz. CONCLUSIONS ABF mapping increased the acceptance in CI users with longer electrode arrays and in bilateral CI users who were unsatisfied with their device experience. A larger prospective, randomized investigation is currently underway to assess longitudinal outcomes with ABF mapping.
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Affiliation(s)
- Anja Kurz
- Department of Otolaryngology, University Hospital Würzburg, Comprehensive Hearing Center, Würzburg, Germany
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21
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A Web-Based Automated Image Processing Research Platform for Cochlear Implantation-Related Studies. J Clin Med 2022; 11:jcm11226640. [PMID: 36431117 PMCID: PMC9699139 DOI: 10.3390/jcm11226640] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/11/2022] Open
Abstract
The robust delineation of the cochlea and its inner structures combined with the detection of the electrode of a cochlear implant within these structures is essential for envisaging a safer, more individualized, routine image-guided cochlear implant therapy. We present Nautilus-a web-based research platform for automated pre- and post-implantation cochlear analysis. Nautilus delineates cochlear structures from pre-operative clinical CT images by combining deep learning and Bayesian inference approaches. It enables the extraction of electrode locations from a post-operative CT image using convolutional neural networks and geometrical inference. By fusing pre- and post-operative images, Nautilus is able to provide a set of personalized pre- and post-operative metrics that can serve the exploration of clinically relevant questions in cochlear implantation therapy. In addition, Nautilus embeds a self-assessment module providing a confidence rating on the outputs of its pipeline. We present a detailed accuracy and robustness analyses of the tool on a carefully designed dataset. The results of these analyses provide legitimate grounds for envisaging the implementation of image-guided cochlear implant practices into routine clinical workflows.
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22
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Yoon YS, Drew C. Effects of the intensified frequency and time ranges on consonant enhancement in bilateral cochlear implant and hearing aid users. Front Psychol 2022; 13:918914. [PMID: 36051201 PMCID: PMC9426545 DOI: 10.3389/fpsyg.2022.918914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
A previous study demonstrated that consonant recognition improved significantly in normal hearing listeners when useful frequency and time ranges were intensified by 6 dB. The goal of this study was to determine whether bilateral cochlear implant (BCI) and bilateral hearing aid (BHA) users experienced similar enhancement on consonant recognition with these intensified spectral and temporal cues in noise. In total, 10 BCI and 10 BHA users participated in a recognition test using 14 consonants. For each consonant, we used the frequency and time ranges that are critical for its recognition (called “target frequency and time range”), identified from normal hearing listeners. Then, a signal processing tool called the articulation-index gram (AI-Gram) was utilized to add a 6 dB gain to target frequency and time ranges. Consonant recognition was monaurally and binaurally measured under two signal processing conditions, unprocessed and intensified target frequency and time ranges at +5 and +10 dB signal-to-noise ratio and in quiet conditions. We focused on three comparisons between the BCI and BHA groups: (1) AI-Gram benefits (i.e., before and after intensifying target ranges by 6 dB), (2) enhancement in binaural benefits (better performance with bilateral devices compared to the better ear alone) via the AI-Gram processing, and (3) reduction in binaural interferences (poorer performance with bilateral devices compared to the better ear alone) via the AI-Gram processing. The results showed that the mean AI-Gram benefit was significantly improved for the BCI (max 5.9%) and BHA (max 5.2%) groups. However, the mean binaural benefit was not improved after AI-Gram processing. Individual data showed wide ranges of the AI-Gram benefit (max −1 to 23%) and binaural benefit (max −7.6 to 13%) for both groups. Individual data also showed a decrease in binaural interference in both groups after AI-Gram processing. These results suggest that the frequency and time ranges, intensified by the AI-Gram processing, contribute to consonant enhancement for monaural and binaural listening and both BCI and BHA technologies. The intensified frequency and time ranges helped to reduce binaural interference but contributed less to the synergistic binaural benefit in consonant recognition for both groups.
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23
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[Measuring the cochlea using a tablet-based software package: influence of imaging modality and rater background]. HNO 2022; 70:769-777. [PMID: 35970933 PMCID: PMC9512738 DOI: 10.1007/s00106-022-01208-3] [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] [Accepted: 07/20/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Cochlear duct length (CDL) is subject to significant individual variation. In the context of cochlear implantation, adapting the electrode array length to the CDL is of potential interest, as it has been associated with improvements in both speech recognition and sound quality. Using a tablet-based software package, it is possible to measure CDL at the level of the organ of Corti (CDLOC) to select appropriate electrode array lengths based on individual cochlear anatomy. OBJECTIVE To identify effects of imaging modality and rater background on CDL estimates. METHODS Magnetic resonance imaging (MRI) and flat-panel volume CT (fpVCT) scans of 10 patients (20 cochleae) were analyzed using the OTOPLAN software package (MED-EL, Innsbruck, Austria). Raters were an otorhinolaryngology (ORL) specialist, an ORL resident, and an audiologist. To analyze effects of rater background and imaging modality on CDL measurements, linear mixed models were constructed. RESULTS Measurements showed mean CDLOC(fpVCT) = 36.69 ± 1.78 mm and CDLOC(MRI) = 36.81 ± 1.87 mm. Analyses indicated no significant effect of rater background (F(2, 105) = 0.84; p = 0.437) on CDL estimates. Imaging modality, on the other hand, significantly affected CDL (F (1, 105) = 20.70; p < 0.001), whereby estimates obtained using MRI were 0.89 mm larger than those obtained using fpVCT. CONCLUSION No effect of rater background on CDL estimates could be identified, suggesting that comparable measurements could be obtained by personnel other than specially trained neurootologists. While imaging modality (fpVCT vs. MRI) did impact CDL results, the difference was small and of questionable clinical significance.
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24
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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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25
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Müller-Graff FT, Rak K. [Cochlear Implantation: Evaluation of Cochlear Duct Length (CDL)]. Laryngorhinootologie 2022; 101:428-441. [PMID: 35500581 DOI: 10.1055/a-1742-5254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Personalized care in the context of cochlear implantation is becoming increasingly important. Choosing the right electrode could improve speech understanding. The measurement of the cochlear length plays an important role: preoperatively, in order to select a suitable electrode length; postoperatively, on the one hand to check the correct electrode position, on the other hand to enable anatomically based fitting of the electrode contacts. Of the various possible localizations of the CDL measurements within the cochlear turns, the one on the organ of Corti (CDLOC) is the most frequently used and clinically most important. In the CDL measurement, a direct and indirect evaluation can be distinguished. There is also the possibility of reconstructing and measuring the CDL in 3D and calculating it mathematically, e.g. using spiral equations. In this context, measurements based on radiological imaging are gaining increasing importance. Therefore, if there is the possibility of performing higher-resolution imaging, this should be strived preoperatively in order to enable the most precise possible procedure and thus a good outcome. Otological planning software can help to create an interface between new findings regarding CDL measurement and higher-resolution imaging for an individualized cochlear implantation.
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Affiliation(s)
- Franz-Tassilo Müller-Graff
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenkrankheiten, plastische und ästhetische Operationen, Universitätsklinikum Würzburg, Würzburg
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26
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Topsakal V, Heuninck E, Matulic M, Tekin AM, Mertens G, Van Rompaey V, Galeazzi P, Zoka-Assadi M, van de Heyning P. First Study in Men Evaluating a Surgical Robotic Tool Providing Autonomous Inner Ear Access for Cochlear Implantation. Front Neurol 2022; 13:804507. [PMID: 35386404 PMCID: PMC8979022 DOI: 10.3389/fneur.2022.804507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/10/2022] [Indexed: 11/17/2022] Open
Abstract
Image-guided and robot-assisted surgeries have found their applications in skullbase surgery. Technological improvements in terms of accuracy also opened new opportunities for robotically-assisted cochlear implantation surgery (RACIS). The HEARO® robotic system is an otological next-generation surgical robot to assist the surgeon. It first provides software-defined spatial boundaries for orientation and reference information to anatomical structures during otological and neurosurgical procedures. Second, it executes a preplanned drill trajectory through the temporal bone. Here, we report how safe the HEARO procedure can provide an autonomous minimally invasive inner ear access and the efficiency of this access to subsequently insert the electrode array during cochlear implantation. In 22 out of 25 included patients, the surgeon was able to complete the HEARO® procedure. The dedicated planning software (OTOPLAN®) allowed the surgeon to reconstruct a three-dimensional representation of all the relevant anatomical structures, designate the target on the cochlea, i.e., the round window, and plan the safest trajectory to reach it. This trajectory accommodated the safety distance to the critical structures while minimizing the insertion angles. A minimal distance of 0.4 and 0.3 mm was planned to facial nerve and chorda tympani, respectively. Intraoperative cone-beam CT supported safe passage for the 22 HEARO® procedures. The intraoperative accuracy analysis reported the following mean errors: 0.182 mm to target, 0.117 mm to facial nerve, and 0.107 mm to chorda tympani. This study demonstrates that microsurgical robotic technology can be used in different anatomical variations, even including a case of inner ear anomalies, with the geometrically correct keyhole to access to the inner ear. Future perspectives in RACIS may focus on improving intraoperative imaging, automated segmentation and trajectory, robotic insertion with controlled speed, and haptic feedback. This study [Experimental Antwerp robotic research otological surgery (EAR2OS) and Antwerp Robotic cochlear implantation (25 refers to 25 cases) (ARCI25)] was registered at clinicalTrials.gov under identifier NCT03746613 and NCT04102215.
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Affiliation(s)
- Vedat Topsakal
- Department of Otorhinolaryngology Head and Neck Surgery, University Hospital UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium
- *Correspondence: Vedat Topsakal
| | - Emilie Heuninck
- Department of Otorhinolaryngology Head and Neck Surgery, University Hospital UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Ahmet M. Tekin
- Department of Otorhinolaryngology Head and Neck Surgery, University Hospital UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Otorhinolaryngology, Klinikum Bad Salzungen, Bad Salzungen, Germany
| | - Griet Mertens
- Department of Otorhinolaryngology, Head and Neck Surgery, Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | - Vincent Van Rompaey
- Department of Otorhinolaryngology, Head and Neck Surgery, Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
| | | | | | - Paul van de Heyning
- Department of Otorhinolaryngology, Head and Neck Surgery, Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
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Pieper SH, Hamze N, Brill S, Hochmuth S, Exter M, Polak M, Radeloff A, Buschermöhle M, Dietz M. Considerations for Fitting Cochlear Implants Bimodally and to the Single-Sided Deaf. Trends Hear 2022; 26:23312165221108259. [PMID: 35726211 PMCID: PMC9218456 DOI: 10.1177/23312165221108259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 04/28/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022] Open
Abstract
When listening with a cochlear implant through one ear and acoustically through the other, binaural benefits and spatial hearing abilities are generally poorer than in other bilaterally stimulated configurations. With the working hypothesis that binaural neurons require interaurally matched inputs, we review causes for mismatch, their perceptual consequences, and experimental methods for mismatch measurements. The focus is on the three primary interaural dimensions of latency, frequency, and level. Often, the mismatch is not constant, but rather highly stimulus-dependent. We report on mismatch compensation strategies, taking into consideration the specific needs of the respective patient groups. Practical challenges typically faced by audiologists in the proposed fitting procedure are discussed. While improvement in certain areas (e.g., speaker localization) is definitely achievable, a more comprehensive mismatch compensation is a very ambitious endeavor. Even in the hypothetical ideal fitting case, performance is not expected to exceed that of a good bilateral cochlear implant user.
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Affiliation(s)
- Sabrina H. Pieper
- Department of Medical Physics and Acoustic, University of Oldenburg, Oldenburg, Germany
- Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany
| | - Noura Hamze
- MED-EL Medical Electronics GmbH, Innsbruck, Austria
| | - Stefan Brill
- MED-EL Medical Electronics Germany GmbH, Starnberg, Germany
| | - Sabine Hochmuth
- Division of Otorhinolaryngology, University of Oldenburg, Oldenburg, Germany
| | - Mats Exter
- Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany
- Hörzentrum Oldenburg gGmbH, Oldenburg, Germany
| | - Marek Polak
- MED-EL Medical Electronics GmbH, Innsbruck, Austria
| | - Andreas Radeloff
- Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany
- Division of Otorhinolaryngology, University of Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
| | | | - Mathias Dietz
- Department of Medical Physics and Acoustic, University of Oldenburg, Oldenburg, Germany
- Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany
- Research Center Neurosensory Science, University of Oldenburg, Oldenburg, Germany
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Taeger J, Müller-Graff FT, Ilgen L, Schendzielorz P, Hagen R, Neun T, Rak K. Cochlear Duct Length Measurements in Computed Tomography and Magnetic Resonance Imaging Using Newly Developed Techniques. OTO Open 2021; 5:2473974X211045312. [PMID: 34595367 PMCID: PMC8477698 DOI: 10.1177/2473974x211045312] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 08/15/2021] [Indexed: 11/16/2022] Open
Abstract
Objective Growing interest in measuring the cochlear duct length (CDL) has emerged, since it can influence the selection of cochlear implant electrodes. Currently the measurements are performed with ionized radiation imaging. Only a few studies have explored CDL measurements in magnetic resonance imaging (MRI). Therefore, the presented study aims to fill this gap by estimating CDL in MRI and comparing it with multislice computed tomography (CT). Study Design Retrospective data analyses of 42 cochleae. Setting Tertiary care medical center. Methods Diameter (A value) and width (B value) of the cochlea were measured in HOROS software. The CDL and the 2-turn length were determined by the elliptic circular approximation (ECA). In addition, the CDL, the 2-turn length, and the angular length were determined via HOROS software by the multiplanar reconstruction (MPR) method. Results CDL values were significantly shorter in MRI by MPR (d = 1.38 mm, P < .001) but not by ECA. Similar 2-turn length measurements were significantly lower in MRI by MPR (d = 1.67 mm) and ECA (d = 1.19 mm, both P < .001). In contrast, angular length was significantly higher in MRI (d = 26.79°, P < .001). When the values were set in relation to the frequencies of the cochlea, no clinically relevant differences were estimated (58 Hz at 28-mm CDL). Conclusion In the presented study, CDL was investigated in CT and MRI by using different approaches. Since no clinically relevant differences were found, diagnostics with radiation may be omitted prior to cochlear implantation; thus, a concept of radiation-free cochlear implantation could be established.
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Affiliation(s)
- Johannes Taeger
- Department of Oto-rhino-laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Franz Tassilo Müller-Graff
- Department of Oto-rhino-laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Lukas Ilgen
- Department of Oto-rhino-laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Phillip Schendzielorz
- Department of Oto-rhino-laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Rudolf Hagen
- Department of Oto-rhino-laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
| | - Tilman Neun
- Department of Diagnostic and Interventional Neuroradiology, University of Wuerzburg, Wuerzburg, Germany
| | - Kristen Rak
- Department of Oto-rhino-laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Wuerzburg, Germany
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29
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Schendzielorz P, Ilgen L, Müller-Graff FT, Noyalet L, Völker J, Taeger J, Hagen R, Neun T, Zabler S, Althoff D, Rak K. Precise evaluation of the postoperative cochlear duct length by flat-panel volume computed tomography - Application of secondary reconstructions. Cochlear Implants Int 2021; 23:32-42. [PMID: 34519256 DOI: 10.1080/14670100.2021.1973208] [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] [Indexed: 12/17/2022]
Abstract
OBJECTIVE There is still a lack in precise postoperative evaluation of the cochlea because of strong artifacts. This study aimed to improve accuracy of postoperative two-turn (2TL) and cochlear duct length (CDL) measurements by applying flat-panel volume computed tomography (fpVCT), secondary reconstruction (fpVCTSECO) and three-dimensional curved multiplanar reconstruction. METHODS First, 10 temporal bone specimens with or without electrode were measured in multi-slice computed tomography (MSCT), fpVCT and fpVCTSECO and compared to high-resolution micro-CT scans. Later, pre- and postoperative scans of 10 patients were analyzed in a clinical setting. RESULTS Concerning 2TL, no statistically significant difference was observed between implanted fpVCTSECO and nonimplanted micro-CT in 10 temporal bone specimens. In contrast, there was a significant discrepancy for CDL (difference: -0.7 mm, P = 0.004). Nevertheless, there were no clinically unacceptable errors (±1.5 mm). These results could be confirmed in a clinical setting. Using fpVCTSECO, CDL was slightly underestimated postoperatively (difference: -0.5 mm, P = 0.002) but without any clinically unacceptable errors. CONCLUSION fpVCTSECO can be successfully applied for a precise measurement of the cochlear lengths pre- and postoperatively. However, users must be aware of a slight systematic underestimation of CDL postoperatively. These results may help to refine electrode selection and frequency mapping.
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Affiliation(s)
- Philipp Schendzielorz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Lukas Ilgen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Franz-Tassilo Müller-Graff
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Laurent Noyalet
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Johannes Völker
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Johannes Taeger
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
| | - Tilmann Neun
- Department of Diagnostic and Interventional Neuroradiology, University of Würzburg, Würzburg, Germany
| | - Simon Zabler
- Department of X-ray Microscopy, University of Würzburg, Würzburg, Germany
| | - Daniel Althoff
- Fraunhofer Development Center for X-ray Technology, Würzburg, Germany
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Würzburg, Würzburg, Germany
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The Use of Clinically Measurable Cochlear Parameters in Cochlear Implant Surgery as Indicators for Size, Shape, and Orientation of the Scala Tympani. Ear Hear 2021; 42:1034-1041. [PMID: 33480625 DOI: 10.1097/aud.0000000000000998] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES (1) To assess variations of the human intracochlear anatomy and quantify factors which might be relevant for cochlear implantation (CI) regarding surgical technique and electrode design. (2) Search for correlations of these factors with clinically assessable measurements. DESIGN Human temporal bone study with micro computed tomography (μCT) data and analysis of intracochlear geometrical variations: μCT data of 15 fresh human temporal bones was generated, and the intracochlear lumina scala tympani (ST) and scala vestibuli were manually segmented using custom software specifically designed for accurate cochlear segmentation. The corresponding datasets were processed yielding 15 detailed, three-dimensional cochlear models which were investigated in terms of the scalae height, cross-sectional size, and rotation as well as the interrelation of these factors and correlations to others. RESULTS The greatest anatomical variability was observed within the round window region of the cochlea (basal 45°), especially regarding the cross-sectional size of the ST and its orientation relative to the scala vestibuli, which were found to be correlated (p < 0.001). The cross-sectional height of the ST changes substantially for both increasing cochlear angles and lateral wall distances. Even small cochleae were found to contain enough space for all commercially available CI arrays. Significant correlations of individual intracochlear parameters to clinically assessable ones were found despite the small sample size. CONCLUSION While there is generally enough space within the ST for CI, strong intracochlear anatomical variations could be observed highlighting the relevance of both soft surgical technique as well as a highly flexible and self-adapting cochlear implant electrode array design. Cochlear dimensions (especially at the round window) could potentially be used to indicate surgically challenging anatomies.
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Guzman-Perez HG, Guzman-Lopez S, Villarreal-Del Bosque IS, Villarreal-Del Bosque N, Quiroga-Garza A, Treviño-González JL, Pinales-Razo R, Muñoz-Leija MA, Elizondo-Omaña RE. Cochlear morphometry in healthy ears of a mexican population: A comparison of measurement techniques. Morphologie 2021; 106:169-176. [PMID: 34384680 DOI: 10.1016/j.morpho.2021.07.001] [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: 06/24/2021] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This study describes the cochlear morphometry of a mexican population analysed by laterality and sex. The objective is to compare Cochlear Length (CL) evaluation between Alexiades et al. formula and manual method described by Würfel et al. PATIENTS: Hispanic patients from Mexico, with an age of 18 years or older, were included. Morphometric examination was performed retrospectively on 200 subjects who underwent previously temporal bone imaging for clinical purposes. MATERIALS AND METHODS Horos for Mac program was used to measure CL, cochlear height, distance A, and distance B. WorkStation AW Volume Share 2 was used to obtain volume. CL was measured in 400 temporal bones (228 females, 172 males). RESULTS The mean CL was 34.02mm±2.15mm. A significant difference was found in all variables between sex (P=≤0.05) and laterality (P=≤0.05). The Alexiades equation was used for determining CL and compared with the manual formula, with no significant differences (κ=0.71). However, the time consumption was 5 times faster with the calculated method. The Alexiades formula was demonstrated to be a reliable method measurement. CONCLUSION Preoperative Computed Tomography evaluation of the internal ear helps to plan the Cochlear Implants (CI) surgical approach and allows to choose an appropriate electrode length for each necessity. Our findings may be useful to facilitate and adapt preoperative management of CI surgery by considering the characteristics of cochlear morphology of Latin-American populations.
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Affiliation(s)
- H G Guzman-Perez
- Human Anatomy Department, Medicine Faculty, Universidad Autónoma-de-Nuevo-León, avenue Francisco I. Madero y Dr. Aguirre-Pequeño s/n, Mitras-Centro, 64460 Monterrey, (Nuevo León), Mexico.
| | - S Guzman-Lopez
- Human Anatomy Department, Medicine Faculty, Universidad Autónoma-de-Nuevo-León, avenue Francisco I. Madero y Dr. Aguirre-Pequeño s/n, Mitras-Centro, 64460 Monterrey, (Nuevo León), Mexico
| | - I S Villarreal-Del Bosque
- Radiology and Imaging Department, Medicine Faculty, Universidad Autónoma de Nuevo León, University Hospital: "Dr. José-Eleuterio-González", avenue Francisco I.-Madero-y-Gonzalitos s/n, Mitras Centro, 64460 Monterrey, (Nuevo León), Mexico
| | - N Villarreal-Del Bosque
- Radiology and Imaging Department, Medicine Faculty, Universidad Autónoma de Nuevo León, University Hospital: "Dr. José-Eleuterio-González", avenue Francisco I.-Madero-y-Gonzalitos s/n, Mitras Centro, 64460 Monterrey, (Nuevo León), Mexico
| | - A Quiroga-Garza
- Human Anatomy Department, Medicine Faculty, Universidad Autónoma-de-Nuevo-León, avenue Francisco I. Madero y Dr. Aguirre-Pequeño s/n, Mitras-Centro, 64460 Monterrey, (Nuevo León), Mexico
| | - J L Treviño-González
- Otorhinolaryngology and Head and Neck Surgery Department, Medicine Faculty and University Hospital: "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, avenue Francisco I. Madero y Gonzalitos s/n, Mitras Centro, 64460 Monterrey, (Nuevo León), Mexico.
| | - R Pinales-Razo
- Radiology and Imaging Department, Medicine Faculty, Universidad Autónoma de Nuevo León, University Hospital: "Dr. José-Eleuterio-González", avenue Francisco I.-Madero-y-Gonzalitos s/n, Mitras Centro, 64460 Monterrey, (Nuevo León), Mexico
| | - M A Muñoz-Leija
- Human Anatomy Department, Medicine Faculty, Universidad Autónoma-de-Nuevo-León, avenue Francisco I. Madero y Dr. Aguirre-Pequeño s/n, Mitras-Centro, 64460 Monterrey, (Nuevo León), Mexico
| | - R E Elizondo-Omaña
- Human Anatomy Department, Medicine Faculty, Universidad Autónoma-de-Nuevo-León, avenue Francisco I. Madero y Dr. Aguirre-Pequeño s/n, Mitras-Centro, 64460 Monterrey, (Nuevo León), Mexico.
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The smaller the frequency-to-place mismatch the better the hearing outcomes in cochlear implant recipients? Eur Arch Otorhinolaryngol 2021; 279:1875-1883. [PMID: 34131770 DOI: 10.1007/s00405-021-06899-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/20/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To investigate the effect of frequency-to-place mismatch, i.e. the mismatch between the tonotopic frequency map in the cochlea and the frequency band that is assigned to an electrode contact of a cochlear implant (CI) at the same cochlear location on speech perception outcomes, using postoperative CT images. STUDY DESIGN Retrospective observational single-centre study. METHODS Retrospective pre- and postoperative clinical CT data of 39 CI recipients with normal cochlear anatomy were analysed in an otological surgical planning software. The tonotopic frequency at each electrode position was estimated using the Greenwood function. For each patient, frequency-to-place mismatch between the tonotopic frequency and the fitted centre frequency for each electrode contact was calculated. The influence of frequency-to-place mismatch on speech perception in noise at 6 and 12 months after CI activation was studied. RESULTS A significant linear correlation was found between the frequency-to-place mismatch and speech perception in noise 6 months after cochlear implantation (p < 0.05). The smaller the frequency-to-place mismatch, the better the initial speech perception in noise results of the CI recipients. The significant effect disappeared after 12 months CI experience. CONCLUSION The study findings support the idea of minimizing the frequency-to-place mismatch in CI recipients in order to pursue better initial speech perception in noise. Further research is needed to investigate the prospect of tonotopic fitting strategies based upon postoperative CT images of the exact locations of the electrode contacts.
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Müller-Graff FT, Ilgen L, Schendzielorz P, Voelker J, Taeger J, Kurz A, Hagen R, Neun T, Rak K. Implementation of secondary reconstructions of flat-panel volume computed tomography (fpVCT) and otological planning software for anatomically based cochlear implantation. Eur Arch Otorhinolaryngol 2021; 279:2309-2319. [PMID: 34101009 PMCID: PMC8986679 DOI: 10.1007/s00405-021-06924-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/29/2021] [Indexed: 11/28/2022]
Abstract
Purpose For further improvements in cochlear implantation, the measurement of the cochlear duct length (CDL) and the determination of the electrode contact position (ECP) are increasingly in the focus of clinical research. Usually, these items were investigated by multislice computed tomography (MSCT). The determination of ECP was only possible by research programs so far. Flat-panel volume computed tomography (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for high spatial resolution for the visualization of the temporal bone structures. Using a newly developed surgical planning software that enables the evaluation of CDL and the determination of postoperative ECP, this study aimed to investigate the combination of fpVCT and otological planning software to improve the implementation of an anatomically based cochlear implantation. Methods Cochlear measurements were performed utilizing surgical planning software in imaging data (MSCT, fpVCT and fpVCTSECO) of patients with and without implanted electrodes. Results Measurement of the CDL by the use of an otological planning software was highly reliable using fpVCTSECO with a lower variance between the respective measurements compared to MSCT. The determination of the inter-electrode-distance (IED) between the ECP was improved in fpVCTSECO compared to MSCT. Conclusion The combination of fpVCTSECO and otological planning software permits a simplified and more reliable analysis of the cochlea in the pre- and postoperative setting. The combination of both systems will enable further progress in the development of an anatomically based cochlear implantation.
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Affiliation(s)
- Franz-Tassilo Müller-Graff
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Lukas Ilgen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Philipp Schendzielorz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Johannes Voelker
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Johannes Taeger
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Anja Kurz
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Rudolf Hagen
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany
| | - Tilmann Neun
- Insitute for Diagnostic and Interventional Neuroradiology, University of Wuerzburg, Bavaria, Germany
| | - Kristen Rak
- Department of Oto-Rhino-Laryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery and the Comprehensive Hearing Center, University of Wuerzburg, Josef-Schneider-Strasse 11, 97080, Wuerzburg, Germany.
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