1
|
Siebrecht M, Briaire JJ, Verbist BM, Kalkman RK, Frijns JH. Automated segmentation of clinical CT scans of the cochlea and analysis of the cochlea's vertical profile. Heliyon 2024; 10:e35737. [PMID: 39224385 PMCID: PMC11367034 DOI: 10.1016/j.heliyon.2024.e35737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 07/17/2024] [Accepted: 08/02/2024] [Indexed: 09/04/2024] Open
Abstract
Purpose Knowledge of the cochlear anatomy in individual patients is helpful for improving electrode selection and placement during cochlear implantation, as well as in surgical planning. The aim of this study was to develop a model-free automated segmentation algorithm to obtain 3D surfaces from clinical computed tomography (CT) scans that describe an individual's cochlear anatomy and can be used to quantitatively analyze the cochlea's vertical trajectory. Methods Clinical CT scans were re-oriented and re-sliced to obtain mid-modiolar slices. Using these slices, we segmented the cross-section of the cochlea. Results 3D surfaces were obtained for the first 1.5 turns of 648 cochleae. Validation of our algorithm against the manually segmented ground truth obtained from 8 micro-CT scans showed good agreement, with 90 % area overlap and an average distance of 0.11 mm between the segmentation contours. The average cochlear duct length for the basal turn was 16.1 mm along the central path and 22.4 mm along the outer wall. The use of an intrinsic, observer-independent coordinate system and principal component analysis enabled unambiguous quantitative evaluation of the vertical trajectory of the cochlea, revealing only a weak correlation between the symmetry of the commonly used basal turn diameters (B-ratio of A and B diameters) and the profile of the vertical trajectory. Conclusion A model-free segmentation algorithm can achieve similar accuracy as previously published methods relying on statistical shapes. Quantitative analysis of the vertical trajectory can replace the categorization into rollercoaster, sloping, or intermediate vertical trajectory types.
Collapse
Affiliation(s)
- Michael Siebrecht
- Department of Otorhinolaryngology and Head & Neck Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, the Netherlands
| | - Jeroen J. Briaire
- Department of Otorhinolaryngology and Head & Neck Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, PO Box 9600, 2300 RC, Leiden, the Netherlands
| | - Berit M. Verbist
- Department of Radiology, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, the Netherlands
| | - Randy K. Kalkman
- Department of Otorhinolaryngology and Head & Neck Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, the Netherlands
| | - Johan H.M. Frijns
- Department of Otorhinolaryngology and Head & Neck Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC, Leiden, the Netherlands
- Leiden Institute for Brain and Cognition, PO Box 9600, 2300 RC, Leiden, the Netherlands
| |
Collapse
|
2
|
Beck R, Aschendorff A, Arndt S, Hildenbrand T, Rauch AK, Ketterer MC. Evaluation of insertion quality of a slim perimodiolar electrode array. Eur Arch Otorhinolaryngol 2024; 281:1215-1220. [PMID: 37773530 PMCID: PMC10858093 DOI: 10.1007/s00405-023-08212-5] [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: 05/30/2023] [Accepted: 08/25/2023] [Indexed: 10/01/2023]
Abstract
OBJECTIVES The influence of cochlear morphology and electrode array design on scalar position and dislocation rates is of great interest in CI surgery. The aim of this study is to evaluate scalar position and specific points of dislocation in relation to cochlear morphology in patients implanted with a new slim perimodiolar electrode array. MATERIALS AND METHODS Patients were implanted using the slim modiolar electrode array (= SMA) (= 532/632 electrode array of Cochlear™). Postoperative imaging was performed via cone beam computed tomography (CBCT) and the scans were analyzed regarding cochlear morphology (distances A and B and cochlear height), scalar location of the electrode array, basal insertion depth and apical insertion angle. Furthermore, electrode array design and surgical protocols were evaluated. RESULTS 81 ears implanted with the SMA were retrospectively included. We evaluated 3 electrode array tip fold over intraoperatively via X-ray imaging and performed revision during the same surgery. The CBCT scans showed 76 initial scala tympani (ST) insertions without dislocation. Two ears showed a dislocated array, one at 77° and the other at 163°. Three arrays were inserted into scala vestibuli (SV) via cochleostomy. These patients showed no signs of obliteration. Cochlear morphology showed no influence on angular insertion depth and scalar position. CONCLUSIONS The SMA showed a very low rate of scalar dislocations due to its slim electrode array design (2.7%). We could find a learning curve regarding the handling and the risk of dislocation and tip fold over with this electrode array. The rate of intraoperative tip fold over detection via X-ray imaging was 3.7%. Therefore, we highly recommend X-ray imaging and transimpedance matrix measurements within the surgery protocol. Scala vestibuli insertions happened in patients with cochleostomy only. We could identify two specific points of dislocation depending on electrode array design.
Collapse
Affiliation(s)
- R Beck
- Faculty of Medicine, Department of Otorhinolaryngology, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
| | - A Aschendorff
- Faculty of Medicine, Department of Otorhinolaryngology, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
| | - S Arndt
- Faculty of Medicine, Department of Otorhinolaryngology, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
| | - T Hildenbrand
- Faculty of Medicine, Department of Otorhinolaryngology, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
| | - A K Rauch
- Faculty of Medicine, Department of Otorhinolaryngology, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
| | - M C Ketterer
- Faculty of Medicine, Department of Otorhinolaryngology, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany.
- Department of Otorhinolaryngology - Head and Neck Surgery, University of Freiburg, Killianstrasse 5, 79106, Freiburg, Germany.
| |
Collapse
|
3
|
Ketterer MC, Brückerhoff K, Arndt S, Beck R, Aschendorff A. [Insertion of a second electrode array-a rare complication of CI reimplantation. German version]. HNO 2024; 72:113-117. [PMID: 37845537 PMCID: PMC10827957 DOI: 10.1007/s00106-023-01363-1] [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] [Accepted: 08/07/2023] [Indexed: 10/18/2023]
Abstract
Due to a technical defect or a medical indication, it may be necessary to explant a cochlear implant. This case report shows that there is the risk of encountering a nonremovable electrode array-as described here from the scala tympani-during cochlear reimplantation. In the present case, insertion of a second electrode array into the free and nonobstructed scala vestibuli was successful. Nonetheless, the indication for reimplantation must be carefully considered, especially in patients with tolerable limitations with little or no loss of speech understanding. Furthermore, surgery should not be performed solely because an implant upgrade is desired.
Collapse
Affiliation(s)
- M C Ketterer
- Klinik für Hals‑, Nasen‑, Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Deutschland.
| | - K Brückerhoff
- Klinik für Hals‑, Nasen‑, Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Deutschland
| | - S Arndt
- Klinik für Hals‑, Nasen‑, Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Deutschland
| | - R Beck
- Klinik für Hals‑, Nasen‑, Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Deutschland
| | - A Aschendorff
- Klinik für Hals‑, Nasen‑, Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Deutschland
| |
Collapse
|
4
|
Czurda R, Wesarg T, Aschendorff A, Beck RL, Hocke T, Ketterer MC, Arndt S. Investigation of Maximum Monosyllabic Word Recognition as a Predictor of Speech Understanding with Cochlear Implant. J Clin Med 2024; 13:646. [PMID: 38337340 PMCID: PMC10856473 DOI: 10.3390/jcm13030646] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 02/12/2024] Open
Abstract
Background: The cochlear implant (CI) is an established treatment option for patients with inadequate speech understanding and insufficient aided scores. Nevertheless, reliable predictive models and specific therapy goals regarding achievable speech understanding are still lacking. Method: In this retrospective study, 601 cases of CI fittings between 2005 and 2021 at the University Medical Center Freiburg were analyzed. We investigated the preoperative unaided maximum word recognition score (mWRS) as a minimum predictor for post-interventional scores at 65 dB SPL, WRS65(CI). The WRS65(CI) was compared with the preoperative-aided WRS, and a previously published prediction model for the WRS65(CI) was reviewed. Furthermore, the effect of duration of hearing loss, duration of HA fitting, and etiology on WRS65(CI) were investigated. Results: In 95.5% of the cases, a significant improvement in word recognition was observed after CI. WRS65(CI) achieved or exceeded mWRS in 97% of cases. Etiology had a significant impact on WRS65(CI). The predicted score was missed by more than 20 percentage points in 12.8% of cases. Discussion: Our results confirmed the minimum prediction via mWRS. A more precise prediction of the expected WRS65(CI) is possible. The etiology of hearing loss should be considered in the indication and postoperative care to achieve optimal results.
Collapse
Affiliation(s)
- Ronja Czurda
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Thomas Wesarg
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Antje Aschendorff
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Rainer Linus Beck
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Thomas Hocke
- Cochlear Deutschland GmbH & Co., KG, Mailänder Straße 4 a, 30539 Hannover, Germany;
| | - Manuel Christoph Ketterer
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| | - Susan Arndt
- Department of Otorhinolaryngology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany; (T.W.); (A.A.); (R.L.B.); (M.C.K.); (S.A.)
| |
Collapse
|
5
|
Ketterer MC, Brückerhoff K, Arndt S, Beck R, Aschendorff A. Insertion of a second electrode array-a rare complication of CI reimplantation. HNO 2024; 72:63-65. [PMID: 37943372 PMCID: PMC10798908 DOI: 10.1007/s00106-023-01364-0] [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] [Accepted: 08/07/2023] [Indexed: 11/10/2023]
Abstract
Due to a technical defect or a medical indication, it may be necessary to explant a cochlear implant. This case report shows that there is the risk of encountering a nonremovable electrode array-as described here from the scala tympani-during cochlear reimplantation. In the present case, insertion of a second electrode array into the free and nonobstructed scala vestibuli was successful. Nonetheless, the indication for reimplantation must be carefully considered, especially in patients with tolerable limitations with little or no loss of speech understanding. Furthermore, surgery should not be performed solely because an implant upgrade is desired.
Collapse
Affiliation(s)
- M C Ketterer
- Department of Otorhinolaryngology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- Klinik für Hals- Nasen- Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Germany.
| | - K Brückerhoff
- Department of Otorhinolaryngology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - S Arndt
- Department of Otorhinolaryngology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - R Beck
- Department of Otorhinolaryngology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - A Aschendorff
- Department of Otorhinolaryngology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
6
|
The effect of the surgical approach and cochlear implant electrode on the structural integrity of the cochlea in human temporal bones. Sci Rep 2022; 12:17068. [PMID: 36224234 PMCID: PMC9556579 DOI: 10.1038/s41598-022-21399-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 09/27/2022] [Indexed: 12/30/2022] Open
Abstract
Cochlear implants (CI) restore hearing of severely hearing-impaired patients. Although this auditory prosthesis is widely considered to be very successful, structural cochlear trauma during cochlear implantation is an important problem, reductions of which could help to improve hearing outcomes and to broaden selection criteria. The surgical approach in cochlear implantation, i.e. round window (RW) or cochleostomy (CO), and type of electrode-array, perimodiolar (PM) or lateral wall (LW), are variables that might influence the probability of severe trauma. We investigated the effect of these two variables on scalar translocation (STL), a specific type of severe trauma. Thirty-two fresh frozen human cadaveric ears were evenly distributed over four groups receiving either RW or CO approach, and either LW or PM array. Conventional radiological multiplanar reconstruction (MPR) was compared with a reconstruction method that uncoils the spiral shape of the cochlea (UCR). Histological analysis showed that RW with PM array had STL rate of 87% (7/8), CO approach with LW array 75% (6/8), RW approach with LW array 50% (4/8) and CO approach with PM array 29% (2/7). STL assessment using UCR showed a higher inter-observer and histological agreement (91 and 94% respectively), than that using MPR (69 and 74% respectively). In particular, LW array positions were difficult to assess with MPR. In conclusion, the interaction between surgical approach and type of array should be preoperatively considered in cochlear implant surgery. UCR technique is advised for radiological assessment of CI positions, and in general it might be useful for pathologies involving the inner ear or other complex shaped bony tubular structures.
Collapse
|
7
|
Van de Heyning P, Roland P, Lassaletta L, Agrawal S, Atlas M, Baumgartner WD, Brown K, Caversaccio M, Dazert S, Gstoettner W, Hagen R, Hagr A, Jablonski GE, Kameswaran M, Kuzovkov V, Leinung M, Li Y, Loth A, Magele A, Mlynski R, Mueller J, Parnes L, Radeloff A, Raine C, Rajan G, Schmutzhard J, Skarzynski H, Skarzynski PH, Sprinzl G, Staecker H, Stöver T, Tavora-Viera D, Topsakal V, Usami SI, Van Rompaey V, Weiss NM, Wimmer W, Zernotti M, Gavilan J. Suitable Electrode Choice for Robotic-Assisted Cochlear Implant Surgery: A Systematic Literature Review of Manual Electrode Insertion Adverse Events. Front Surg 2022; 9:823219. [PMID: 35402479 PMCID: PMC8987358 DOI: 10.3389/fsurg.2022.823219] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/09/2022] [Indexed: 12/05/2022] Open
Abstract
Background and Objective The cochlear implant (CI) electrode insertion process is a key step in CI surgery. One of the aims of advances in robotic-assisted CI surgery (RACIS) is to realize better cochlear structure preservation and to precisely control insertion. The aim of this literature review is to gain insight into electrode selection for RACIS by acquiring a thorough knowledge of electrode insertion and related complications from classic CI surgery involving a manual electrode insertion process. Methods A systematic electronic search of the literature was carried out using PubMed, Scopus, Cochrane, and Web of Science to find relevant literature on electrode tip fold over (ETFO), electrode scalar deviation (ESD), and electrode migration (EM) from both pre-shaped and straight electrode types. Results A total of 82 studies that include 8,603 ears implanted with a CI, i.e., pre-shaped (4,869) and straight electrodes (3,734), were evaluated. The rate of ETFO (25 studies, 2,335 ears), ESD (39 studies, 3,073 ears), and EM (18 studies, 3,195 ears) was determined. An incidence rate (±95% CI) of 5.38% (4.4-6.6%) of ETFO, 28.6% (26.6-30.6%) of ESD, and 0.53% (0.2-1.1%) of EM is associated with pre-shaped electrodes, whereas with straight electrodes it was 0.51% (0.1-1.3%), 11% (9.2-13.0%), and 3.2% (2.5-3.95%), respectively. The differences between the pre-shaped and straight electrode types are highly significant (p < 0.001). Laboratory experiments show evidence that robotic insertions of electrodes are less traumatic than manual insertions. The influence of round window (RW) vs. cochleostomy (Coch) was not assessed. Conclusion Considering the current electrode designs available and the reported incidence of insertion complications, the use of straight electrodes in RACIS and conventional CI surgery (and manual insertion) appears to be less traumatic to intracochlear structures compared with pre-shaped electrodes. However, EM of straight electrodes should be anticipated. RACIS has the potential to reduce these complications.
Collapse
Affiliation(s)
- Paul Van de Heyning
- Department of Otorhinolaryngology Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Peter Roland
- Department of Otolaryngology, Head & Neck Surgery, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Luis Lassaletta
- Hospital Universitario La Paz, Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Sumit Agrawal
- Department of Otolaryngology-Head and Neck Surgery, Western University, London, ON, Canada
| | - Marcus Atlas
- Ear Sciences Institute Australia, Lions Hearing Clinic, Perth, WA, Australia
| | | | - Kevin Brown
- UNC Ear and Hearing Center at Chapel Hill School of Medicine, Chapel Hill, NC, United States
| | - Marco Caversaccio
- Department for ENT, Head and Neck Surgery, Bern University Hospital, Bern, Switzerland
| | - Stefan Dazert
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth University Hospital Bochum, Bochum, Germany
| | | | - Rudolf Hagen
- Würzburg ENT University Hospital, Würzburg, Germany
| | - Abdulrahman Hagr
- King Abdullah Ear Specialist Center, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
| | - Greg Eigner Jablonski
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Department of Otorhinolaryngology & Head and Neck Surgery, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | | | - Vladislav Kuzovkov
- St. Petersburg ENT and Speech Research Institute, St. Petersburg, Russia
| | - Martin Leinung
- Department of Otolaryngology, Head and Neck Surgery, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Yongxin Li
- Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Key Laboratory of Otolaryngology Head and Neck Surgery (Capital Medical University), Ministry of Education, Beijing, China
| | - Andreas Loth
- Department of Otolaryngology, Head and Neck Surgery, University Hospital Frankfurt, Frankfurt am Main, Germany
| | - Astrid Magele
- Ear, Nose and Throat Department, University Clinic St. Poelten, Karl Landsteiner Private University, St. Poelten, Austria
| | - Robert Mlynski
- Department of Otorhinolaryngology, Head and Neck Surgery, “Otto Körner” Rostock University Medical Center, Rostock, Germany
| | - Joachim Mueller
- Klinik und Poliklinik für Hals-, Nasen- und Ohrenheilkunde, Ludwig-Maximilians-Universitat Munchen, Munchen, Germany
| | - Lorne Parnes
- Department of Otolaryngology-Head and Neck Surgery, Western University, London, ON, Canada
| | - Andreas Radeloff
- Division of Oto-Rhino-Laryngology, Evangelisches Krankenhaus Oldenburg, Research Center of Neurosensory Sciences, University Oldenburg, Oldenburg, Germany
| | - Chris Raine
- Bradford Royal Infirmary Yorkshire Auditory Implant Center, Bradford, United Kingdom
| | - Gunesh Rajan
- Department of Otolaryngology, Head and Neck Surgery, Luzerner Kantonsspital, Luzern, Medical Sciences Department of Health Sciences and Medicine. University of Lucerne, Luzern, Switzerland. Otolaryngology, Head & Neck Surgery, Medical School University of Western Australia, Perth, WA, Australia
| | - Joachim Schmutzhard
- Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Henryk Skarzynski
- Department of Teleaudiology and Screening, World Hearing Center of the Institute of Physiology and Pathology of Hearing, Kajetany, Poland
| | - Piotr H. Skarzynski
- Department of Teleaudiology and Screening, World Hearing Center of the Institute of Physiology and Pathology of Hearing, Kajetany, Poland
| | - Georg Sprinzl
- Ear, Nose and Throat Department, University Clinic St. Poelten, Karl Landsteiner Private University, St. Poelten, Austria
| | - Hinrich Staecker
- Kansas University Center for Hearing and Balance Disorders, Kansas City, KS, United States
| | - Timo Stöver
- Department of Otolaryngology, Head and Neck Surgery, University Hospital Frankfurt, Frankfurt am Main, Germany
| | | | - Vedat Topsakal
- Department of ENT HNS, University Hospital Brussels, Brussels, Belgium
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Nagano, Japan
| | - Vincent Van Rompaey
- Department of Otorhinolaryngology Head and Neck Surgery, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Nora M. Weiss
- Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth University Hospital Bochum, Bochum, Germany
| | - Wilhelm Wimmer
- Department for ENT, Head and Neck Surgery, Bern University Hospital, Bern, Switzerland
| | - Mario Zernotti
- Catholic University of Córdoba and National University of Córdoba, Córdoba, Argentina
| | - Javier Gavilan
- Hospital Universitario La Paz, Institute for Health Research (IdiPAZ), Madrid, Spain
| |
Collapse
|
8
|
Ketterer MC, Aschendorff A, Arndt S, Beck R. Electrode array design determines scalar position, dislocation rate and angle and postoperative speech perception. Eur Arch Otorhinolaryngol 2021; 279:4257-4267. [PMID: 34778920 PMCID: PMC9363302 DOI: 10.1007/s00405-021-07160-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/26/2021] [Indexed: 01/06/2023]
Abstract
Purpose The aim of this study is to examine the scalar dislocation rate in straight and perimodiolar electrode arrays in relation to cochlear morphology. Furthermore, we aim to analyze the specific dislocation point of electrode arrays depending on their design and shape and to correlate these results to postoperative speech perception. Methods We conducted a comparative analysis of patients (ears: n = 495) implanted between 2013 and 2018 with inserted perimodiolar or straight electrode arrays from Cochlear™ or MED-EL. CBCT (cone beam computed tomography) was used to determine electrode array position (scalar insertion, intra-cochlear dislocation, point of dislocation and angular insertion depth). Furthermore, cochlear morphology was measured. The postoperative speech discrimination was compared regarding electrode array dislocation, primary scalar insertion and angular insertion depth. Results The electrode array with the highest rate of primary SV insertions was the CA; the electrode array with the highest rate of dislocations out of ST was the FlexSoft. We did not find significantly higher dislocation rates in cochleostomy-inserted arrays. The angle of dislocation was electrode array design-specific. A multivariate nonparametric analysis revealed that the dislocation of the electrode array has no significant influence on postoperative speech perception. Nevertheless, increasing angular insertion depth significantly reduced postoperative speech perception for monosyllables. Conclusion This study demonstrates the significant influence of electrode array design on scalar location, dislocation and the angle of dislocation itself. Straight and perimodiolar electrode arrays differ from each other regarding both the rate and place of dislocation. Insertion via cochleostomy does not lead to increased dislocation rates in any of the included electrode arrays. Furthermore, speech perception is significantly negatively influenced by angular insertion depth.
Collapse
Affiliation(s)
- Manuel Christoph Ketterer
- Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Killianstrasse 5, 79106, Freiburg, Germany.
| | - Antje Aschendorff
- Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Killianstrasse 5, 79106, Freiburg, Germany
| | - Susan Arndt
- Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Killianstrasse 5, 79106, Freiburg, Germany
| | - Rainer Beck
- Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, Medical Center-University of Freiburg, University of Freiburg, Killianstrasse 5, 79106, Freiburg, Germany
| |
Collapse
|
9
|
Evaluation of cochlear implant electrode scalar position by 3 Tesla magnet resonance imaging. Sci Rep 2021; 11:21298. [PMID: 34716377 PMCID: PMC8556315 DOI: 10.1038/s41598-021-00824-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 10/08/2021] [Indexed: 11/30/2022] Open
Abstract
The estimation of scalar electrode position is a central point of quality control during the cochlear implant procedure. Ionic radiation is a disadvantage of commonly used radiologic estimation of electrode position. Recent developments in the field of cochlear implant magnets, implant receiver magnet position, and MRI sequence usage allow the postoperative evaluation of inner ear changes after cochlear implantation. The aim of the present study was to evaluate the position of lateral wall and modiolar cochlear implant electrodes using 3 T MRI scanning. In a prospective study, we evaluated 20 patients (10× Med-El Flex 28; 5× HFMS AB and 5× SlimJ AB) with a 3 T MRI and a T2 2D Drive MS sequence (voxel size: 0.3 × 0.3 × 0.9 mm) for the estimation of the intracochlear position of the cochlear implant electrode. In all cases, MRI allowed a determination of the electrode position in relation to the basilar membrane. This observation made the estimation of 19 scala tympani electrode positions and a single case of electrode translocation possible. 3 T MRI scanning allows the estimation of lateral wall and modiolar electrode intracochlear scalar positions.
Collapse
|
10
|
Liebscher T, Mewes A, Hoppe U, Hornung J, Brademann G, Hey M. Electrode Translocations in Perimodiolar Cochlear Implant Electrodes: Audiological and Electrophysiological Outcome. Z Med Phys 2021; 31:265-275. [DOI: 10.1016/j.zemedi.2020.05.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/16/2020] [Accepted: 05/05/2020] [Indexed: 10/24/2022]
|
11
|
Jwair S, Prins A, Wegner I, Stokroos RJ, Versnel H, Thomeer HGXM. Scalar Translocation Comparison Between Lateral Wall and Perimodiolar Cochlear Implant Arrays - A Meta-Analysis. Laryngoscope 2020; 131:1358-1368. [PMID: 33159469 PMCID: PMC8246990 DOI: 10.1002/lary.29224] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 12/15/2022]
Abstract
Objectives/Hypothesis Two types of electrode arrays for cochlear implants (CIs) are distinguished: lateral wall and perimodiolar. Scalar translocation of the array can lead to intracochlear trauma by penetrating from the scala tympani into the scala vestibuli or scala media, potentially negatively affecting hearing performance of CI users. This systematic review compares the lateral wall and perimodiolar arrays with respect to scalar translocation. Study Design Systematic review. Methods PubMed, Embase, and Cochrane databases were reviewed for studies published within the last 11 years. No other limitations were set. All studies with original data that evaluated the occurrence of scalar translocation or tip fold‐over (TF) with postoperative computed tomography (CT) following primary cochlear implantation in bilateral sensorineuronal hearing loss patients were considered to be eligible. Data were extracted independently by two reviewers. Results We included 33 studies, of which none were randomized controlled trials. Meta‐analysis of five cohort studies comparing scalar translocation between lateral wall and perimodiolar arrays showed that lateral wall arrays have significantly lower translocation rates (7% vs. 43%; pooled odds ratio = 0.12). Translocation was negatively associated with speech perception scores (weighted mean 41% vs. 55%). Tip fold‐over of the array was more frequent with perimodiolar arrays (X2 = 6.8, P < .01). Conclusions Scalar translocation and tip fold‐overs occurred more frequently with perimodiolar arrays than with lateral wall arrays. In addition, translocation of the array negatively affects hearing with the cochlear implant. Therefore, if one aims to minimize clinically relevant intracochlear trauma, lateral wall arrays would be the preferred option for cochlear implantation. Laryngoscope, 131:1358–1368, 2021
Collapse
Affiliation(s)
- Saad Jwair
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,UMC Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Adrianus Prins
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Inge Wegner
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Robert J Stokroos
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,UMC Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Huib Versnel
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,UMC Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Hans G X M Thomeer
- Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,UMC Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
12
|
The Insertion Results of a Mid-scala Electrode Assessed by MRI and CBCT Image Fusion. Otol Neurotol 2019; 39:e1019-e1025. [PMID: 30444847 DOI: 10.1097/mao.0000000000002045] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To investigate the results of clinical surgical insertions with a Mid-scala array (HIFocus Mid-Scala Electrode, HFms). STUDY DESIGN Consecutive retrospective case study. SETTINGS Tertiary referral center. PATIENTS Analyses of imaging data of 26 consecutive patients (31 insertions) implanted with the HFms. INTERVENTION (S) The evaluation of insertion trauma evoked by a previously validated image fusion technique. Electrode reconstructions from postoperative cone-beam computed tomography (CBCT) were overlaid onto preoperative magnetic resonance imaging (MRI) scans to create artifact-free images. MAIN OUTCOME MEASURES The electrode position was quantified in relation to the basilar membrane. Trauma scaling adopted from Eshraghi was used for evaluating insertion trauma. The results of the visual assessment of the postoperative CBCT were compared to those obtained with the fusion technique. RESULTS Three insertions had to be excluded due to incompatibility of the imaging data with the fusion software. We found consistent peri- to mid-modiolar placement of the HFms with a mean insertion depth angle of 376°. According to the medical records, a visual examination of the postoperative CBCT indicated that there had been no scala dislocations but when assessed by the image fusion technique, five scala dislocations (17.8%) were found. Additionally, one tip fold-over was detected in the postoperative CBCT even though this was not evident in any intraoperative measurements. CONCLUSION HFms showed atraumatic surgical insertion results with consistent mid-modiolar placement. Image fusion enhances the accuracy of the insertion trauma assessment. Routine postoperative imaging is recommended for identifying tip fold-over as well as for quality control and documentation.
Collapse
|
13
|
Dhanasingh A, Jolly C. Review on cochlear implant electrode array tip fold-over and scalar deviation. J Otol 2019; 14:94-100. [PMID: 31467506 PMCID: PMC6712287 DOI: 10.1016/j.joto.2019.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/20/2018] [Accepted: 01/07/2019] [Indexed: 11/26/2022] Open
Abstract
Objective Determine the occurrence rate of cochlear implant (CI) electrode tip fold-over and electrode scalar deviation as reported in patient cases with different commercial electrode types. Data-sources PubMed search for identifying peer-reviewed articles published till 2018 on CI electrode tip fold-over and scalar deviation. Key-words for searching were “Cochlear electrode tip fold-over”, “Cochlear electrode scalar position” and “Cochlear electrode scalar location”. Articles-selection Only if electrode related issues were investigated in patient cases. 38 articles met the inclusion-criteria. Results 13 articles on electrode tip fold-over issue covering 3177 implanted ears, out of which 50 ears were identified with electrode tip fold-over with an occurrence rate of 1.57%. Out of 50 ears, 43 were implanted with pre-curved electrodes and the remaining 7 with lateral-wall electrodes. One article reported on both tip fold-over and scalar deviation. 26 articles reported on the electrode scalar deviation covering an overall number of 2046 ears out of which, 458 were identified with electrode scalar deviation at a rate of 22.38%. After removing the studies that did not report on the number of electrodes per electrode type, it was 1324 ears implanted with pre-curved electrode and 507 ears with lateral-wall electrode. Out of 1324 pre-curved electrode implanted ears, 424 were reported with scalar deviation making an occurrence rate of 32%. Out of 507 lateral-wall electrode implanted ears, 43 were associated with scalar deviation at an occurrence rate of 6.7%. Conclusion This literature review revealing the fact of higher rate of electrode insertion trauma associated with pre-curved electrode type irrespective of CI brand is one step closer to obsolete it from the clinical practice in the interest of patient's cochlear health.
Collapse
Affiliation(s)
| | - Claude Jolly
- MED-EL Medical Electronics GmbH, Innsbruck, Austria
| |
Collapse
|
14
|
The influence of cochlear morphology on the final electrode array position. Eur Arch Otorhinolaryngol 2017; 275:385-394. [DOI: 10.1007/s00405-017-4842-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/05/2017] [Indexed: 11/30/2022]
|
15
|
Dhanasingh A, Jolly C. An overview of cochlear implant electrode array designs. Hear Res 2017; 356:93-103. [DOI: 10.1016/j.heares.2017.10.005] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 07/26/2017] [Accepted: 10/13/2017] [Indexed: 11/28/2022]
|
16
|
Benghalem A, Gazibegovic D, Saadi F, Tazi-Chaoui Z. Use of a mid-scala and a lateral wall electrode in children: insertion depth and hearing preservation. Acta Otolaryngol 2017; 137:1-7. [PMID: 27472299 DOI: 10.1080/00016489.2016.1208367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
CONCLUSIONS Atraumatic insertion of the HiFocusTM Mid-Scala (HFMS) electrode via the round window was successfully achieved in seven children. Residual hearing 6 months post-operatively was preserved to within 10 dB HL of the pre-operative audiogram at 500 Hz for six children, indicating minimal initial insertion trauma to the cochlea. OBJECTIVES The objectives were to document the clinical experience and evaluate differences between HFMS and HiFocusTM 1j (HF1j) by means of insertion depth and hearing preservation results. METHOD Nineteen children were prospectively recruited and consecutively implanted with the HF1j electrode (n = 12) or the HFMS electrode (n = 7) via the round window. Average median angular insertion depths and the amount of residual hearing preserved at 6 months post-operatively were compared between the two electrode groups. RESULTS The median angular insertion depth for the HF1j was 439° and for the HFMS 435°. Preservation of residual hearing at 500 Hz was assessed in seven HFMS subjects and 11 HF1j subjects. Based on the Skarzynski formula, three out of seven subjects (42%) in the HFMS group had their residual hearing completely preserved at 500 Hz. In the control group, no subjects had complete hearing preservation and five subjects had a complete loss of residual hearing.
Collapse
|
17
|
Lathuillière M, Merklen F, Piron JP, Sicard M, Villemus F, Menjot de Champfleur N, Venail F, Uziel A, Mondain M. Cone-beam computed tomography in children with cochlear implants: The effect of electrode array position on ECAP. Int J Pediatr Otorhinolaryngol 2017; 92:27-31. [PMID: 28012529 DOI: 10.1016/j.ijporl.2016.10.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 10/24/2016] [Accepted: 10/26/2016] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To assess the feasibility of using cone-beam computed tomography (CBCT) in young children with cochlear implants (CIs) and study the effect of intracochlear position on electrophysiological and behavioral measurements. METHODS A total of 40 children with either unilateral or bilateral cochlear implants were prospectively included in the study. Electrode placement and insertion angles were studied in 55 Cochlear® implants (16 straight arrays and 39 perimodiolar arrays), using either CBCT or X-ray imaging. CBCT or X-ray imaging were scheduled when the children were leaving the recovery room. We recorded intraoperative and postoperative neural response telemetry threshold (T-NRT) values, intraoperative and postoperative electrode impedance values, as well as behavioral T (threshold) and C (comfort) levels on electrodes 1, 5, 10, 15 and 20. RESULTS CBCT imaging was feasible without any sedation in 24 children (60%). Accidental scala vestibuli insertion was observed in 3 out of 24 implants as assessed by CBCT. The mean insertion angle was 339.7°±35.8°. The use of a perimodiolar array led to higher angles of insertion, lower postoperative T-NRT, as well as decreased behavioral T and C levels. We found no significant effect of either electrode array position or angle of insertion on electrophysiological data. CONCLUSION CBCT appears to be a reliable tool for anatomical assessment of young children with CIs. Intracochlear position had no significant effect on the electrically evoked compound action potential (ECAP) threshold. Our CBCT protocol must be improved to increase the rate of successful investigations.
Collapse
Affiliation(s)
- Marine Lathuillière
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France.
| | - Fanny Merklen
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| | - Jean-Pierre Piron
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| | - Marielle Sicard
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| | - Françoise Villemus
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| | | | - Frédéric Venail
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| | - Alain Uziel
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| | - Michel Mondain
- Cochlear Implant Centre, Ear Nose and Throat Department, University Hospital Gui-de-Chauliac, Montpellier, France
| |
Collapse
|
18
|
Deep electrode insertion and sound coding in cochlear implants. Hear Res 2015; 322:14-23. [DOI: 10.1016/j.heares.2014.10.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 10/08/2014] [Accepted: 10/10/2014] [Indexed: 11/18/2022]
|
19
|
Müller A, Hocke T, Mir-Salim P. Intraoperative findings on ECAP-measurement: Normal or special case? Int J Audiol 2014; 54:257-64. [DOI: 10.3109/14992027.2014.969410] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
20
|
|
21
|
Güldner C, Weiss R, Eivazi B, Bien S, Werner JA, Diogo I. [Intracochlear electrode position: evaluation after deep insertion using cone beam computed tomography]. HNO 2013; 60:817-22. [PMID: 22767189 DOI: 10.1007/s00106-012-2527-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Due to the increasing number of cochlear implantations (CI), postoperative radiological verification of the electrode position, e.g., with respect to quality control, plays a central role. The aim of this study was to evaluate the intracochlear position of deep inserted electrodes by cone beam computed tomography (CBCT). MATERIALS AND METHODS CBCT data sets (Accu-I-tomo, Morita, Kyoto, Japan) of 22 patients (28 ears operated between 2008 and 2011) were retrospectively analyzed. All patients underwent a CI (round window approach) with deep insertion of the electrode (Flex soft or standard electrode from MedEl©). CBCT data were analyzed for intracochlear position of the electrode (scala vestibuli, scala tympani, malposition between the scalae) and the certainty of this evaluation. RESULTS All ears could be evaluated with the status certain or relatively certain in the basal turn of the cochlea. Thereby, the electrode array was inserted into the scala tympani in 93% (n = 26). Primary insertion into the scala vestibuli and the scala media was observed in 3.5% of the ears, respectively. In the apical part of the cochlea, only 32% (n = 9 ears) could be evaluated with relative certainty. The remaining 68% of cases could not be evaluated. Of the 32% interpretable cases in the apical part of the cochlea, 25% (n = 7) were inserted into the scala tympani, 3.5% (n = 1) into the scala vestibuli, and 3.5% (n = 1) were malpositioned between the scalae. CONCLUSION The exact evaluation of the intracochlear position of the electrode by CBCT is only possible in the basal turn of the cochlea. In deep insertion, determination of the position in the medial and apical parts of the cochlea by CBCT is still not possible. Furthermore, the round window approach allows reliable implantation into the scala tympani.
Collapse
Affiliation(s)
- C Güldner
- Univ.-Klinik für HNO-Heilkunde, Kopf- und Halschirurgie, UKGM, Marburg, Deutschland.
| | | | | | | | | | | |
Collapse
|
22
|
Connor SEJ, Holland NJ, Agger A, Leong AC, Varghese RA, Jiang D, Fitzgerald O'Connor A. Round window electrode insertion potentiates retention in the scala tympani. Acta Otolaryngol 2012; 132:932-7. [PMID: 22667826 DOI: 10.3109/00016489.2012.680493] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONCLUSIONS The round window membrane (RWM)-intentioned approach is superior to the traditional bony cochleostomy (BC) approach in obtaining electrode placement within the scala tympani (ST). OBJECTIVE Cochlear implant outcome is influenced by several factors, including optimal placement and retention of the electrode array within the ST. The present study aimed to assess whether the RWM route is superior to a traditional BC for placement and retention of the electrode array in the ST. METHODS This was a prospective consecutive non-randomized comparison study. All patients were implanted with the Advanced Bionics 1J electrode array. The RWM approach (n = 32) was compared with a traditional BC group (n = 33). The outcome measure was the electrode position as judged within the scalar chambers at four points along the basal turn using postoperative computed tomography (CT). RESULTS When the mean position scores were compared, the RWM-intentioned group had significantly more electrodes directed towards the ST compartment than the BC group (p < 0.001). The RWM electrodes achieved 94% ST retention compared with 64% for the BC group (p < 0.05). All electrodes stayed in the ST in the RWM group, whereas in the BC group 9% crossed from the ST to the scala vestibuli.
Collapse
|