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Selected structures of middle ear relevant to cochlear implantation on the basis of computer tomography
- Department of Otolaryngology for Adults and Children and Otolaryngological Oncology, Pomeranian Medical University, Szczecin, Poland
- Department of Normal Anatomy, Pomeranian Medical University, Szczecin, Poland
open access
Abstract
Background: The primary objective of this study was to analyze middle ear structures critical for cochlear implantation using computed tomography.
Materials and methods: Patients who underwent cochlear implantation at the Department of Otolaryngology in Szczecin between 2015 and 2022 were eligible for the study. We analyzed computed tomography images of 57 ears in 52 patients. The following parameters were assessed: mastoid aeration, tegmen tympani height, sigmoid sinus position, posterior tympanotomy width, the distance between the facial nerve and chorda tympani, modified facial recess distance, and the prediction line described by other authors.
Results: In 69% of patients, after the removal of the round window bony overhang, the round window membrane became fully visible. There were no statistically significant correlations found for parameters describing mastoid process anatomy or those rating the width of the posterior tympanotomy concerning round window access. The prediction lines, according to Kashio and Jwair, were found to be relevant. In cases where patients' access to the niche and membrane of the window was rated as good or very good during clinical evaluation, they were more likely to describe the window as being located posteriorly or medially in the radiological evaluation. Using a binary Jwair scale provided a better correlation with the clinical assessment. In cases where the windows were graded as posterior, the clinical assessment indicated better surgical access, especially to the RWM (Round Window Membrane).
Conclusions: Evaluating middle ear anatomy on a computed tomography scan is useful for preparing for middle ear surgery but does not significantly affect the ability to access the round window. For such access, the position of the window in relation to the facial nerve is the most relevant factor, and measurements based on this relationship hold the highest clinical value.
Abstract
Background: The primary objective of this study was to analyze middle ear structures critical for cochlear implantation using computed tomography.
Materials and methods: Patients who underwent cochlear implantation at the Department of Otolaryngology in Szczecin between 2015 and 2022 were eligible for the study. We analyzed computed tomography images of 57 ears in 52 patients. The following parameters were assessed: mastoid aeration, tegmen tympani height, sigmoid sinus position, posterior tympanotomy width, the distance between the facial nerve and chorda tympani, modified facial recess distance, and the prediction line described by other authors.
Results: In 69% of patients, after the removal of the round window bony overhang, the round window membrane became fully visible. There were no statistically significant correlations found for parameters describing mastoid process anatomy or those rating the width of the posterior tympanotomy concerning round window access. The prediction lines, according to Kashio and Jwair, were found to be relevant. In cases where patients' access to the niche and membrane of the window was rated as good or very good during clinical evaluation, they were more likely to describe the window as being located posteriorly or medially in the radiological evaluation. Using a binary Jwair scale provided a better correlation with the clinical assessment. In cases where the windows were graded as posterior, the clinical assessment indicated better surgical access, especially to the RWM (Round Window Membrane).
Conclusions: Evaluating middle ear anatomy on a computed tomography scan is useful for preparing for middle ear surgery but does not significantly affect the ability to access the round window. For such access, the position of the window in relation to the facial nerve is the most relevant factor, and measurements based on this relationship hold the highest clinical value.
Keywords
cochlear implant, posterior tympanotomy, round window, facial nerve, mastoid process
Title
Selected structures of middle ear relevant to cochlear implantation on the basis of computer tomography
Journal
Issue
Article type
Original article
Published online
2023-12-21
Page views
198
Article views/downloads
160
DOI
Pubmed
Keywords
cochlear implant
posterior tympanotomy
round window
facial nerve
mastoid process
Authors
Katarzyna Amernik
Michał Mielnik
Aleksandra Gawlikowska-Sroka
Edyta A. Dzięciołowska-Baran
- Andrew K, Logie S, Hage R. Debating eponyms: History of ear and eye anatomical eponyms. Transl Res Anat. 2023; 32: 100260.
- Badr A, Shabana Y, Mokbel K, et al. Atraumatic scala tympani cochleostomy; resolution of the dilemma. J Int Adv Otol. 2018; 14(2): 190–196.
- Chen J, Wu Y, Shi J, et al. Predictors of round window membrane visibility in pediatric cochlear implant surgery using temporal bone HRCT: a retrospective study. Int J Pediatr Otorhinolaryngol. 2019; 121: 150–153.
- Elzayat S, Mandour M, Lotfy R, et al. Predicting round window visibility during cochlear implantation using high resolution CT scan. J Int Adv Otol. 2018; 14(1): 15–17.
- Elzayat S, Soltan I, Talaat M, et al. The role of high-resolution Computer Tomography in prediction of the round window membrane visibility and the feasibility of the round window electrode insertion. Eur Arch Otorhinolaryngol. 2021; 278(9): 3283–3290.
- Fouad YA, Elaassar AS, El-Anwar MW, et al. Role of multislice CT imaging in predicting the visibility of the round window in pediatric cochlear implantation. Otol Neurotol. 2017; 38(8): 1097–1103.
- Haber K, Konopka W, Amernik K, et al. Inner ear malformations — overview, current classifications, challenges in the management. Pol Otorhino Rev. 2020; 9(3): 1–11.
- Jain S, Gaurkar S, Deshmukh PT, et al. Applied anatomy of round window and adjacent structures of tympanum related to cochlear implantation. Braz J Otorhinolaryngol. 2019; 85(4): 435–446.
- Jwair S, van Eijden JJM, Blijleven EE, et al. Radiological and surgical aspects of round window visibility during cochlear implantation: a retrospective analysis. Eur Arch Otorhinolaryngol. 2022; 279(1): 67–74.
- Kashio A, Sakamoto T, Karino S, et al. Predicting round window niche visibility via the facial recess using high-resolution computed tomography. Otol Neurotol. 2015; 36(1): e18–e23.
- Krause E, Louza JPR, Wechtenbruch J, et al. Influence of cochlear implantation on peripheral vestibular receptor function. Otolaryngol Head Neck Surg. 2010; 142(6): 809–813.
- Lee DH, Kim JK, Seo JH, et al. Anatomic limitations of posterior tympanotomy: what is the major radiologic determinant for the view field through posterior tympanotomy? J Craniofac Surg. 2012; 23(3): 817–820.
- Mehanna AM, Abdelnaby MM, Eid M. The anatomy and anatomical variations of the round window prechamber and their implications on cochlear implantation: an anatomical, imaging, and surgical study. Int Arch Otorhinolaryngol. 2020; 24(3): e288–e298.
- Mostafa BE, Fiky LM. Radiologic evaluation of the round window niche configuration: a one-stop approach. J Int Adv Otol. 2021; 17(6): 478–481.
- Nguy PL, Saidha S, Jay A, et al. Radiologic anatomy of the round window relevant to cochlear implantation and inner ear drug delivery. World J Otorhinolaryngol Head Neck Surg. 2021; 7(1): 9–16.
- Park E, Amoodi H, Kuthubutheen J, et al. Predictors of round window accessibility for adult cochlear implantation based on pre-operative CT scan: a prospective observational study. J Otolaryngol Head Neck Surg. 2015; 44(1): 20.
- Pringle MB, Konieczny KM. Anatomy of the round window region with relation to selection of entry site into the scala tympani. Laryngoscope. 2021; 131(2): E598–E604.
- Rajati M, Afzalzadeh MR, Nourizadeh N, et al. Predicting round window visibility by HRCT during cochlear implantation in children. Cochlear Implants Int. 2020; 21(5): 269–274.
- Sarafraz M, Heidari M, Bayat A, et al. Role of HRCT imaging in predicting the visibility of Round window (RW) on patients underwent cochlear implant surgery. Clin Epidemiol Glob Health. 2020; 8(2): 432–436.
- Topsakal V, Kachlik D, Bahşi I, et al. Relevant temporal bone anatomy for robotic cochlear implantation: an updated terminology combined with anatomical and clinical terms. Transl Res Anat. 2021; 25: 100138.
- Wang J, Liu H, Ke J, et al. Image-guided cochlear access by non-invasive registration: a cadaveric feasibility study. Sci Rep. 2020; 10(1): 18318.
- Xie LH, Tang J, Miao WJ, et al. Preoperative evaluation of cochlear implantation through the round window membrane in the facial recess using high-resolution computed tomography. Surg Radiol Anat. 2018; 40(6): 705–711.