scholarly journals Surgeon Oriented Preoperative Radiologic Evaluation in Cochlear Implantation - Our experience with a Proposed Checklist

2018 ◽  
Vol 23 (02) ◽  
pp. 137-141 ◽  
Author(s):  
Mahmoud Mandour ◽  
Mohammed Tomoum ◽  
Saad El Zayat ◽  
Hisham Hamad ◽  
Mohamed Amer
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Cochlear Implantation ◽  
Round Window ◽  
Special Focus ◽  
Radiologic Evaluation ◽  
Cortical Mastoidectomy ◽  
Temporal Bone Ct ◽  
Operative Findings ◽  
Key Steps

Introduction Preoperative temporal bone imaging studies have been routinely performed prior to cochlear implantation. Radiologists need to report these examinations with special focus on the surgeon's expectations. Objectives To provide a basic structured format, in the form of a checklist, for reporting preoperative computed tomography (CT) and to its clinical impact on operative findings. Methods The preoperative temporal bone CT scans of 47 patients were analyzed and reported according to the proposed checklist. Intraoperative assessment of mastoidectomy, posterior tympanotomy and round window access was done by the surgeon in a blinded fashion and were correlated with the radiological findings to assess its significance. Results The proposed radiological checklist was reliable in assessing operative difficulty during cochlear implantation. Contracted mastoid and lower tegmen position were associated with a greater difficulty of the cortical mastoidectomy. Presence of an air cell around the facial nerve (FN) was predictive of easier facial recess access exposure. Facial nerve location and posterior external auditory canal (EAC) wall inclination were predictive of difficult round window (RW) accessibility. Conclusion Certain parameters on the preoperative temporal bone CT scan may be useful in predicting potential difficulties encountered during the key steps involved in cochlear implant surgery.

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 Congenital unilateral facial palsy revealing a facial nerve agenesis: a case report and review of the literature

2019 ◽  
Vol 5 (1) ◽  
pp. 20180029
Author(s):  
Yaotse Elikplim Nordjoe ◽  
Ouidad Azdad ◽  
Mohamed Lahkim ◽  
Laila Jroundi ◽  
Fatima Zahrae Laamrani
Keyword(s):  
Case Report ◽  
Facial Nerve ◽  
Temporal Bone ◽  
Facial Paralysis ◽  
Facial Palsy ◽  
Rare Condition ◽  
Review Of The Literature ◽  
Moebius Syndrome ◽  
Temporal Bone Ct

Facial nerve aplasia is an extremely rare condition that is usually syndromic, namely, in Moebius syndrome. The occurrence of isolated agenesis of facial nerve is even rarer, with only few cases reported in the literature. We report a case of congenital facial paralysis due to facial nerve aplasia diagnosed on MRI, while no noticeable abnormality was detected on the temporal bone CT.

scholarly journals The depth of the facial nerve in the mastoid bone

2018 ◽  
Vol 4 (3) ◽  
pp. 666
Author(s):  
B. Y. Praveen Kumar ◽  
K. T. Chandrashekhar ◽  
M. K. Veena Pani ◽  
Sunil K. C. ◽  
Anand Kumar S. ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Significant Variation ◽  
Canal Wall ◽  
Stylomastoid Foramen ◽  
Cortical Mastoidectomy ◽  
Canal Wall Down ◽  
Canal Wall Down Mastoidectomy ◽  
The Mean ◽  
Temporal Bones

<p class="abstract"><strong>Background:</strong> The hallmark of the temporal bone is variation. Various important structures like the facial nerve run in the temporal bone at various depths which can be injured during mastoidectomy.</p><p class="abstract"><strong>Methods:</strong> Twenty wet cadaveric temporal bones were dissected. A cortical mastoidectomy was performed followed by a canal wall down mastoidectomy and the depth of the vertical segment of the facial nerve in the mastoid was determined.  </p><p class="abstract"><strong>Results:</strong> The mean depth of the second genu was 13.82 mm. The mean depth of the stylomastoid foramen was 12.75 mm and the mean distance from the annulus at 6’0 clock to the stylomastoid foramen was 10.22 mm.</p><p><strong>Conclusions:</strong> There is significant variation in the average depth of the facial nerve in the mastoid. </p>

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.

Benefit of Preoperative Temporal Bone CT for Atraumatic Cochlear Implantation

2018 ◽  
Vol 39 (3) ◽  
pp. e186-e194
Author(s):  
Alexandre Karkas ◽  
Nicolas Menjot de Champfleur ◽  
Alain Uziel ◽  
Michel Mondain ◽  
Jean-Luc Puel ◽  
...  
Keyword(s):  
Temporal Bone ◽  
Cochlear Implantation ◽  
Temporal Bone Ct

scholarly journals Preoperative Evaluation and Surgical Outcome of Cochlear Implantation in NIENT

2020 ◽  
Vol 26 (2) ◽  
pp. 128-135
Author(s):  
Md Zakaria Sarker ◽  
Muhammad Rafiqul Islam ◽  
Utpal Kumar Dutta ◽  
Debabrota Roy ◽  
AHM Ferdows Nur ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Facial Nerve ◽  
Psychosocial Development ◽  
Cochlear Implantation ◽  
Preoperative Evaluation ◽  
Round Window ◽  
Round Window Membrane ◽  
Safe Procedure ◽  
Female Ratio ◽  
Facial Recess

Background: Sensory neural hearing loss (SNHL) is the most common congenital sensory deficit, with an incidence of one to three per 1000 live births. Acoustic deprivation during the first 3 years of life can hinder speech and language acquisition with significant negative consequences on a child’s educational and psychosocial development. The gold standard intervention for permanent severe to profound hearing loss is cochlear implantation. Cochlear implant (CI); is a semi implantable electronic device that bypass the cochlea. Objectives: An observational study was carried out on 40 cases of pre-lingual deaf to find out the causes of pre-lingual deaf, to evaluate the preoperative procedures to set ideal criteria for pre -lingual cochlear implantation and to evaluate surgical procedure and outcome of cochlear implantations. Methods: Evaluation of the candidates included patient medical history, general health checkup, ENT examination, audiometric evaluation, CT and MRI scans, psychological profile of the candidate. A limited cortical mastoidectomy was performed. The facial recess was opened using the fossa of incudis as an initial landmark. The round window niche was visualized through the facial recess about 2 mm inferior to the stapes. A cochleostomy created by drilling over the basal turn of the cochlea anterior and inferior to the annulus of the round window membrane. The electrode array was then carefully inserted through the fenestra into the scala tympani of the cochlea. Electrophysiological testing (Neural Response Telemetry: NRT) was performed to verify the correct placement of active electrodes. Resulst: Among them 22 (55%) were male and 18 (45%) were female. Male female ratio was 1.2:1. Age distribution at implantation was 3.3±1.054(SD). Average hearing loss was 96.4±5.3(SD) dB and in aided audiogram was 63.7±4.6(SD) dB. Overall complications occurred in 10 (25%) cases. Transient facial nerve paresis in 2 (5%), injury of tympanic membrane in 1(2.5%), seroma 4(10%) and delayed otitis media in 1(2.5%) were observed. Major postoperative complications occurred in 2 cases including facial nerve palsy in 1(2.5%) case and spontaneous device failure in 1(2.5%) case. Conclusion: The result of this survey was find out the risk factor of congenital hearing loss. With a thorough preoperative evaluation, we can select proper candidates for CI which is a reliable and safe procedure with a low percentage of severe complication. Bangladesh J Otorhinolaryngol; October 2020; 26(2): 128-135

scholarly journals Unilateral internal auditory canal stenosis with progressive facial weakness

2012 ◽  
Vol 18 (2) ◽  
pp. 179-182
Author(s):  
Sathiya Murali ◽  
Arpana Shekhar ◽  
S Shyam Sudhakar ◽  
Kiran Natarajan ◽  
Mohan Kameswaran
Keyword(s):  
Hearing Loss ◽  
High Resolution ◽  
Facial Nerve ◽  
Temporal Bone ◽  
Internal Auditory Canal ◽  
Facial Weakness ◽  
Profound Hearing Loss ◽  
Canal Stenosis ◽  
Temporal Bone Ct ◽  
Magnetic Resonance Imaging Mri

Internal auditory canal (IAC) stenosis is a rare cause of sensorineural hearing loss. Patient may present with symptoms of progressive facial nerve palsy, hearing loss, tinnitus and giddiness. High resolution temporal bone CT-scan and magnetic resonance imaging (MRI) are the important tools for diagnosis. No specific management has been devised. Here is presentation of a case of unilateral (left) IAC stenosis with profound hearing loss and progressive House Brackmann Grade III-IV facial weakness. The diameter of the IAC was less than 2 mm on high resolution temporal bone computed tomography (HRCT) scan. It was managed by facial nerve decompression by translabyrinthine approach in an attempt to prevent further deterioration of facial palsy. DOI: http://dx.doi.org/10.3329/bjo.v18i2.12014 Bangladesh J Otorhinolaryngol 2012; 18(2): 179-182

scholarly journals Fully automated segmentation in temporal bone CT with neural network: a preliminary assessment study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jiang Wang ◽  
Yi Lv ◽  
Junchen Wang ◽  
Furong Ma ◽  
Yali Du ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Normal Group ◽  
Automated Segmentation ◽  
Mean Values ◽  
Generalization Ability ◽  
Image Guided ◽  
Temporal Bone Ct ◽  
The Mean ◽  
Abnormal Group

Abstract Background Segmentation of important structures in temporal bone CT is the basis of image-guided otologic surgery. Manual segmentation of temporal bone CT is time- consuming and laborious. We assessed the feasibility and generalization ability of a proposed deep learning model for automated segmentation of critical structures in temporal bone CT scans. Methods Thirty-nine temporal bone CT volumes including 58 ears were divided into normal (n = 20) and abnormal groups (n = 38). Ossicular chain disruption (n = 10), facial nerve covering vestibular window (n = 10), and Mondini dysplasia (n = 18) were included in abnormal group. All facial nerves, auditory ossicles, and labyrinths of the normal group were manually segmented. For the abnormal group, aberrant structures were manually segmented. Temporal bone CT data were imported into the network in unmarked form. The Dice coefficient (DC) and average symmetric surface distance (ASSD) were used to evaluate the accuracy of automatic segmentation. Results In the normal group, the mean values of DC and ASSD were respectively 0.703, and 0.250 mm for the facial nerve; 0.910, and 0.081 mm for the labyrinth; and 0.855, and 0.107 mm for the ossicles. In the abnormal group, the mean values of DC and ASSD were respectively 0.506, and 1.049 mm for the malformed facial nerve; 0.775, and 0.298 mm for the deformed labyrinth; and 0.698, and 1.385 mm for the aberrant ossicles. Conclusions The proposed model has good generalization ability, which highlights the promise of this approach for otologist education, disease diagnosis, and preoperative planning for image-guided otology surgery.

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.

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