Dimensions of the Posterior Tympanotomy and Round Window Visibility Through the Facial Recess: Cadaveric Temporal Bone Study Using a Novel Digital Microscope

2021 ◽  
Author(s):  
Habie Thomas Samuel ◽  
Anjali Lepcha ◽  
Ajay Philip ◽  
Mary John ◽  
Ann Mary Augustine
Keyword(s):  
Temporal Bone ◽  
Round Window ◽  
Facial Recess ◽  
Digital Microscope ◽  
Posterior Tympanotomy

Surgical considerations during cochlear implantation: the utility of temporal bone computed tomography

2021 ◽  
pp. 1-8
Author(s):  
Beomcho Jun ◽  
Sunwha Song
Keyword(s):  
Computed Tomography ◽  
Temporal Bone ◽  
Cochlear Implantation ◽  
Round Window ◽  
Three Dimensional ◽  
Electrode Placement ◽  
Posterior Tympanotomy ◽  
Electrode Insertion ◽  
Window Approach ◽  
Bone Structures

Abstract Objective This paper describes the construction of portals for electrode placement during cochlear implantation and emphasises the utility of pre-operative temporal bone three-dimensional computed tomography. Methods Temporal bone three-dimensional computed tomography was used to plan portal creation for electrode insertion. Results Pre-operative temporal bone three-dimensional computed tomography can be used to determine the orientation of temporal bone structures, which is important for mastoidectomy, posterior tympanotomy and cochleostomy, and when using the round window approach. Conclusion It is essential to create appropriate portals (from the mastoid cortex to the cochlea) in a step-by-step manner, to ensure the safe insertion of electrodes into the scala tympani. Pre-operative three-dimensional temporal bone computed tomography is invaluable in this respect.

scholarly journals HRCT Correlation with Round Window Identification during Cochlear Implantation in Children

2014 ◽  
Vol 4 ◽  
pp. 70 ◽  
Author(s):  
Sai Kiran Pendem ◽  
Rajeswaran Rangasami ◽  
Ravi Kumar Arunachalam ◽  
Venkata Sai Pulivadulu Mohanarangam ◽  
Paarthipan Natarajan
Keyword(s):  
Temporal Bone ◽  
Cochlear Implantation ◽  
Round Window ◽  
Oval Window ◽  
Significant Difference ◽  
Posterior Tympanotomy ◽  
Hrct Temporal Bone ◽  
Round Window Niche ◽  
The Right ◽  
A Prospective Study

Objective: To determine the accuracy of High Resolution Computer Tomography (HRCT) temporal bone measurements in predicting the actual visualization of round window niche as viewed through posterior tympanotomy (i.e. facial recess). Materials and Methods: This is a prospective study of 37 cochlear implant candidates, aged between 1and 6 years, who were referred for HRCT temporal bone during the period December 2013 to July 2014. Cochlear implantation was done in 37 children (25 in the right ear and 12 in the left ear). The distance between the short process of incus and the round window niche and the distance between the oval window and the round window niche were measured preoperatively on sub-millimeter (0.7 mm) HRCT images. We classified the visibility of round window niche based on the surgical view (i.e. through posterior tympanotomy) during surgery into three types: 1) Type 1- fully visible, 2) Type 2- partially visible, and 3) Type 3- difficult to visualize. The preoperative HRCT measurements were used to predict the type of visualization of round window niche before surgery and correlated with the findings during surgery. Results: The mean and standard deviation for the distance between the short process of incus and the round window niche and for the distance between the oval window and the round window niche for Types 1, 2, and 3 were 8.5 ± 0.2 mm and 3.2 ± 0.2 mm, 8.0 ± 0.4 mm and 3.8 ± 0.2 mm, 7.5 ± 0.2 mm and 4.4 ± 0.2 mm respectively, and showed statistically significant difference (P < 0.01) between them. The preoperative HRCT measurements had a sensitivity and specificity of 92.3% and 96.2%, respectively, in determining the actual visualization of round window niche. Conclusion: This study shows preoperative HRCT temporal bone measurements are useful in predicting the actual visualization of round window niche as viewed through posterior tympanotomy.

scholarly journals Az emberi halántékcsontnak a csecsemő- és kisgyermekkori cochlearis implantáció szempontjából kiemelkedően fontos dimenziói. Klinikoradiológiai vizsgálat

2019 ◽  
Vol 160 (24) ◽  
pp. 936-943 ◽  
Author(s):  
Ádám Perényi ◽  
József Jóri ◽  
Miklós Csanády ◽  
László Rovó
Keyword(s):  
Temporal Bone ◽  
Cochlear Implantation ◽  
Soft Tissues ◽  
Round Window ◽  
Young Age ◽  
Mastoid Cavity ◽  
Tomographic Images ◽  
Computed Tomographic ◽  
Facial Recess ◽  
Young Subjects

Abstract: Introduction: Early cochlear implantation enables prelingual deaf individuals to become full members of the hearing society. Although early diagnostics are widely accessible and enable early rehabilitation, implant surgery often may be delayed due to a candidate’s young age. Aim: The authors’ objectives were to determine the anatomical parameters of the pediatric and adult temporal bone that are relevant to cochlear implantation and to ascertain the differences between them in order to assess whether the anatomical differences could influence the surgical technique and the timing of surgery. Method: Along with a survey of the literature, findings from the authors own cochlear implantees were assessed with respect to the most relevant dimensions of the internal electronic package, including the stimulating electrode of the cochlear implant, by measuring the squama of the temporal bone, the mastoid cavity and the facial recess on high resolution computed tomographic images. Results: The skull and the overlying soft tissues proved to be thinner and the mastoid cavity was less developed in children than in adults, while no significant changes were noted in the size of the facial recess. Conclusions: It is recommended to choose modern, thin implants that do not require sinking the implant package into a bone bed. Less bone work in infants and children enables excellent visualization of the round window through the underdeveloped mastoid cavity, which makes the procedure less time-consuming and minimally invasive. Indeed, a young age should alert ear surgeons to be cautious, but no higher risk of injury to important structures is predicted for young subjects than those that might occur in adults. Orv Hetil. 2019; 160(24): 936–943.

Circumferential Tympano - Mastoid Access the Sinus Tympani Area

1973 ◽  
Vol 82 (4) ◽  
pp. 547-554 ◽  
Author(s):  
Victor Goodhill
Keyword(s):  
Temporal Bone ◽  
Surgical Approach ◽  
Cellular System ◽  
Posterior View ◽  
Anterior View ◽  
Sinus Tympani ◽  
Surgical Access ◽  
Facial Recess ◽  
Posterior Tympanotomy

Primary emphasis is on the juxtaposition of the antero-posterior view of the surgeon as a complement to the standard postero-anterior view. This antero-posterior view permits greater latitude in dealing with lesions of the sinus tympani cellular system. Although this new visualization approach may entirely obviate the surgical-anatomical necessity for the posterior tympanotomy-facial recess bone dissections in many cases, it may be useful to combine both in some cases. A circumferential 270° surgical approach to the temporal bone is described. It allows for circumnavigation of the tympano-mastoid area, for specific surgical access requirements.

Comparative evaluation of round window niche accessibility pre-operatively on high-resolution computed tomography of the temporal bone with intra-operative findings

2019 ◽  
Vol 133 (7) ◽  
pp. 575-579 ◽  
Author(s):  
R Sharma ◽  
R Meher ◽  
J C Passey ◽  
J Kumar ◽  
A Gupta ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Temporal Bone ◽  
Round Window ◽  
Type I ◽  
Significant Finding ◽  
High Resolution Computed Tomography ◽  
Posterior Tympanotomy ◽  
Round Window Niche ◽  
Operative Findings

AbstractObjectiveTo compare round window niche visibility as seen endoscopically during cochlear implant surgery with pre-operative high-resolution computed tomography of the temporal bone.MethodsNineteen patients scheduled for cochlear implantation, aged 2–20 years, were referred for computed tomography from October 2016 to March 2018. Angles were measured between the lines passing through the mid-sagittal plane and cochlear basal turn on the scans. Endoscopic round window niche visibility during posterior tympanotomy was categorised as: type I = 100 per cent, type IIa = more than 50 per cent, type IIb = less than 50 per cent or type III = 0 per cent. Pre-operative computed tomography measurements were used to predict round window niche visibility before surgery and correlated with intra-operative findings.ResultsThe mean (range) of pre-operative angles on computed tomography for endoscopic visibility types I, IIa and IIb, were 64.06° (61.16–69.37°), 63.81° (58.61–71.35°) and 56.48° (50.37–59.05°), respectively, a statistically significant finding (one-way analysis of variance test, p = 0.016).ConclusionPre-operative high-resolution temporal bone computed tomography measurements are useful in predicting round window niche visualisation as viewed endoscopically during posterior tympanotomy. The angle was more acute in type IIb compared to type I.

Feasibility study of round window stimulation with the MET-V implantable middle ear device: A temporal bone study

2010 ◽  
Vol 263 (1-2) ◽  
pp. 251
Author(s):  
N. Julian Holland ◽  
Kanthaiah Koka ◽  
J. Eric Lupo ◽  
Daniel J. Tollin ◽  
Herman A. Jenkins
Keyword(s):  
Temporal Bone ◽  
Feasibility Study ◽  
Middle Ear ◽  
Round Window

scholarly journals Comparison of Round Window Anatomy between Pediatric and Adult Population: A Perspective from Cochlear Implantation Surgery

2020 ◽  
Vol 42 (3) ◽  
pp. 23-25
Author(s):  
Rabindra B Pradhananga ◽  
Bigyan R Gyawali ◽  
Pabina Rayamajhi
Keyword(s):  
Cochlear Implantation ◽  
Adult Population ◽  
Round Window ◽  
Round Window Membrane ◽  
Institute Of Medicine ◽  
Statistical Association ◽  
Complex Anatomy ◽  
Wide Range ◽  
Posterior Tympanotomy ◽  
Round Window Niche

Introduction The round window is thought to be an ideal port for inserting electrodes during cochlear implantation. Considering its complex anatomy with an individual variation, this study aims to review the anatomy of round window based on the visibility of round window niche and round window membrane via posterior tympanotomy in pediatric and adult population who underwent cochlear implantation. MethodsThis was a retrospective observational study conducted at the Department of ENT-HNS, Institute of Medicine, Kathmandu, Nepal. Surgical notes of adult (>15 years) and pediatric cases (<15years) who underwent primary cochlear implantation from January 2015 to January 2018 were assessed for different grading of round window niche and round window membrane visibility via posterior tympanotomy. Cases with revision surgery and with incomplete documentation of intra-operative findings were excluded from the study. Statistical analysis was done using SPSS software version 25. We used Chi-square and Fisher’s exact tests to analyze the statistical association. ResultsType B round window niche (partially visible) was the most common variant seen in the pediatric group while in adults, both Type B (partially visible) and Type C (fully visible) round window niche were common. Compared to the adults, the pediatric group had good visibility of RWM. However, there was no statistical association between these observations. ConclusionThe round window has a wide range of anatomical variations with different levels of visibility of RWN and RWM in the different age groups. Although statistically insignificant, RWM visibility seemed to be better in pediatric cases compared to adults.

scholarly journals Analysis of tympanic sinus shape for purposes of intraoperative hearing monitoring: a microCT study

2021 ◽  
Author(s):  
Małgorzata Bilińska ◽  
Tomasz Wojciechowski ◽  
Jacek Sokołowski ◽  
Kazimierz Niemczyk
Keyword(s):  
Computed Tomography ◽  
Round Window ◽  
Optimal Placement ◽  
Facial Canal ◽  
Average Width ◽  
Sinus Tympani ◽  
Stapedius Muscle ◽  
Electrode Shape ◽  
Posterior Tympanotomy ◽  
Temporal Bones

Abstract Purpose Sinus tympani is the space in the retrotympanum, with variable morphology. Computed tomography is a common tool to investigate sinus tympani anatomy. During cochlear implantation or tympanoplasty, electrocochleography can be used for hearing monitoring. In such a surgical strategy the electrode is placed in the round window’s region throughout posterior tympanotomy. Common accessible needle-shaped electrodes using is difficult in achieving intraoperative stabilization. The aim of the study is to assess the dimensions and shape of sinus tympani, basing on the micro computed tomography scans for purposes of establishing the possible new electrocochleography electrode shape. Materials and methods Sixteen fresh frozen cadaveric temporal bones were dissected. MicroCT measurements included the depth and the width of sinus tympani, width of facial canal with stapedius muscle chamber. Obtained data were analyzed statistically with the use of RStudio 1.3.959 software. Results The highest average width of sinus tympani amounted for 2.68 mm, depth measured at the round window plane for 3.19 mm. Width of facial canal with stapedius muscle chamber highest average values at the round window plane- 3.32 mm. The lowest average minimum and maximum values were calculated at the 1 mm above the round window plane. The highest average posterior tympanotomy width was 2.91 mm. Conclusions The shape of the tympanic sinus is like a trough with the narrowest and deepest dimensions in the middle part. The ST shape and dimensions should be taken into account in constructing the ECochG electrode, designed for optimal placement through posterior tympanotomy approach.

scholarly journals Herniation of the Mastoid Segment of the Facial Nerve During Cochlear Implantation Surgery

2021 ◽  
pp. 014556132110516
Author(s):  
Mohammad Almohammad ◽  
Tala Tasabehji ◽  
Abdulrahman Awad ◽  
Ibrahem Hanafi
Keyword(s):  
Facial Nerve ◽  
Hearing Aids ◽  
Cochlear Implantation ◽  
Round Window ◽  
Posterior Wall ◽  
Case Presentation ◽  
Posterior Tympanotomy ◽  
Bilateral Sensorineural Hearing Loss ◽  
The Right ◽  
Electrical Stimuli

Background: We aim to report a rare case of a herniated mastoid segment of the facial nerve that was accidently discovered during cochlear implantation surgery and how altering the surgery plan could achieve the implantation while preserving the nerve. Case presentation: A four-year-old girl presented with profound bilateral sensorineural hearing loss that did not completely resolve after 2 years of using hearing aids was scheduled for cochlear implantation surgery in the right ear. During surgery, a herniated mastoid segment of the facial nerve took an anterior course and obstructed the access to the round window. Conclusion: When a traditional posterior tympanotomy approach in cochlear implantation surgery is limited in cases of a herniated facial nerve, a tunnel created near the inferior part of the posterior wall of the auditory canal provided safe insertion of the electrode. It also permitted placement of a piece of fascia between the electrode and the facial nerve, therefore, protecting the facial nerve from electrical stimuli.

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