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.

R435 – Stapedius Muscle Relations to the Facial Canal

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P190-P190
Author(s):  
Alaa A. Abou-Bieh ◽  
Thomas J Haberkamp ◽  
Jarah Ali Al-Tubaikh
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Anatomical Variations ◽  
Surgical Anatomy ◽  
Facial Canal ◽  
Sinus Tympani ◽  
Stapedius Muscle ◽  
Facial Nerve Canal ◽  
Tendon Insertion ◽  
Temporal Bones

Problem The gross anatomical variations of the stapedius muscle and its relations to the facial nerve canal. Methods Thirty-five temporal bones were dissected, and the anatomic details were studied utilizing an operating microscope and otoendoscopes with 0o, 30o and 70o angles and 2.7 and 3 mm diameters. The muscle origin, its course in its bony sulcus with its relation to the facial nerve canal, the tendon and its insertion were studied. Results Marked variations in the origin, size, and course of the muscle in its bony sulcus were detected. The shape of the sulcus itself and its relation to the facial nerve canal varied also, both mainly influenced by the sinus tympani development. These variations affected the shape and length of the tendon and the pyramidal eminence. In addition, they influenced the site of tendon insertion into the stapes. The presence of ectopic muscle bundles was confirmed in one specimen. Conclusion The stapedius muscle anatomy can vary significantly from one temporal bone to another. In some situations these variations can be of surgical importance worse enough to be recognized. Significance To add important unrecognized data to the surgical anatomy of the temporal bone.

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.

Marrow-Mesenchyme Connections in the Fetal and Newborn Tympanum

1997 ◽  
Vol 106 (6) ◽  
pp. 466-470 ◽  
Author(s):  
Fred H. Linthicum ◽  
Qing Tian ◽  
William Slattery
Keyword(s):  
Middle Ear ◽  
Immunohistochemical Staining ◽  
Fibrous Tissue ◽  
Postnatal Period ◽  
Bacterial Invasion ◽  
Sinus Tympani ◽  
Stapedius Muscle ◽  
Microscopic Evaluation ◽  
Temporal Bones ◽  
Hematopoietic Bone Marrow

Examinations of 41 human fetal, 8 infant, and 8 juvenile temporal bones prepared for light microscopic evaluation revealed direct connections between the hematopoietic bone marrow and the unresolved mesenchyme in the middle ear. The connections first appeared at 15 weeks of gestation and became bridged by fibrous tissue, in most cases, by the postpartum age of 10 months. Between 16 and 18 months after birth, the marrow-mesenchyme connections gradually disappeared. The areas in which the connections were most numerous were the anterior epitympanum, the sinus tympani medial to the stapedius muscle, and transitory bone that occupies the area that will become the aditus of the antrum. Immunohistochemical staining demonstrated the existence of mature leukocytes in these connections. These connections may help protect the middle ear against bacterial invasion during the postnatal period.

Mesenchyme Remaining in Human Temporal Bones

1986 ◽  
Vol 95 (3_part_1) ◽  
pp. 349-357 ◽  
Author(s):  
Tetsuo Takahara ◽  
Isamu Sando ◽  
Yoshie Hashida ◽  
Yoshihiro Shibahara
Keyword(s):  
Middle Ear ◽  
Round Window ◽  
Oval Window ◽  
The Body ◽  
First Year ◽  
Sinus Tympani ◽  
Hematoxylin And Eosin ◽  
Round Window Niche ◽  
Temporal Bones ◽  
Middle Ear Cleft

This study was conducted in order to gain basic information about mesenchyme remaining in the middle ear cleft in normal infants. Because no previous report has objectively described the quantity or quality of such postnatal remnants in normal infants, it has not been possible to accurately evaluate the significance of mesenchyme remaining in the middle ears of infants with pathologic conditions, such as otitis media and congenital anomalies. Thus, 53 temporal bones obtained from 41 individuals reported upon here—from 26 weeks' gestation to 8 years of age—will be controls for future studies of pathologic conditions. The children from whom these temporal bones were obtained had no anomalies of the ear (or any other known part of the body); nor did they have any pathologic conditions in the ear. The temporal bones were prepared for histologic study with hematoxylin and eosin staining and were examined under the light microscope. After areas of the mesenchyme in the histologic sections were projected and illustrated for each of 19 portions in the middle ear cleft under the microprojector, those areas were measured by compensating polar planimetry. The findings obtained in this study were as follows: (1) The amount of mesenchyme remaining in the days after birth seemed to gradually decrease in volume with increased maturity and had nearly disappeared within the first year in normal infants. Where mesenchyme was noted in the temporal bones of infants over 1 year of age, it was usually present only in small niches. (2) Most mesenchyme found in temporal bones of normal infants was seen in the mastoid antrum; it was also found in the aditus ad antrum, the epitympanum, the hypotympanum, the sinus tympani, the round window niche, the oval window niche, and the mesotympanum.

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.

R434 – The Round Window

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P189-P190
Author(s):  
Alaa A Abou-Bieh ◽  
Thomas J Haberkamp ◽  
Jarah Ali Al-Tubaikh
Keyword(s):  
Middle Ear ◽  
Anatomical Variation ◽  
Round Window ◽  
Anatomical Variations ◽  
Main Target ◽  
Main Observation ◽  
Posterior Tympanotomy ◽  
Temporal Bones ◽  
Mucosal Folds

Problem Round window is the main target in many modern otologic procedures. Unfortunately it is approached either blindly or indirectly in most of these procedures. Others necessitate a complex technique in order to be directly approached. Many failures have been shown to be due to difficulties in the approach and/or anatomical variations. This study was undertaken to review the role of endoscopes to facilitate and ensure safe and controlled different approaches to the round window. Methods Thirty-five temporal bones were dissected. Anatomic details and different approaches (mainly the transcanal transtympanic and the posterior tympanotomy approaches) were studied utilizing an operating microscope and otoendoscopes with 0o, 30o and 70o angles and 2.7 and 3 mm diameters. Results Marked anatomical variation in the surgical pathways to the round window was observed. Mucosal folds variation was the main observation with complete isolation of the window in 3 bones (8.6%). Bony overhangs, unusual secondary tympanic membrane, and variations in site, shape, and window direction were also detected. Conclusion The approach to the round window is influenced by the development and arrangement of the middle ear contents especially mucosal tracks and folds. This is especially clear in cases with no or limited middle ear pathology. The incorporation of otoendoscopes during the middle ear procedures helps to ensure safe and complete exposure of the window regardless of these anatomical variations. Significance To address the minimally invasive approaches to the round window.

scholarly journals Supratubal recess and sinus tympani: CT analysis of middle ear hidden areas

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Mohammad Waheed El-Anwar ◽  
Diaa Bakry Eldib ◽  
Ashraf Elmalt ◽  
Alaa Omar Khazbak
Keyword(s):  
Middle Ear ◽  
Preoperative Imaging ◽  
High Resolution Computed Tomography ◽  
Sinus Tympani ◽  
Ct Analysis ◽  
Length Width ◽  
Middle Ear Anatomy ◽  
Grade 3 ◽  
Temporal Bones ◽  
Ct Classification

Abstract Background High-resolution computed tomography (HRCT) magnifies the role of preoperative imaging for detailed middle ear anatomy particularly its hidden area. The purpose of the current study was to assess the sinus tympani (ST) and supratubal recess (STR) by HRCT, to create CT classification of the STR depth, and to study the relationship between ST types and the new STR grades. Results In HRCT of non-pathological temporal bones of 100 subjects (200 ears), measurements of the STR and ST were calculated, registered, and analyzed. The depth of the STR was classified into grade 1 with depth less than 3 mm, grade 2 with depth ranged between 3 and 5 mm, and grade 3 with depth more than 5 mm. The mean STR length, width, and height were 4.17 ± 0.86, 3.55 ± 0.65, and 3.64 ± 0.7 mm, respectively, while the ST mean length and width of were 2.52 ± 0.5 and 1.82 ± 0.78 mm, respectively, without significant differences between either sexes or sided. The ST types were found to be type A in 56 ears (28%), type B in 142 ears (71%), and type C in 2 ears (1%). The STR grading was grade 1 in 12 ears (6%), grade 2 in 160 ears (80%), and grade 3 in 28 ears (14%) without significant relationship between ST types and STR grading (P = 0.3). Conclusion The current study provided reliable and applicable methods of CT assessment of STR and ST that can help to predict the degree of surgical visibility of the ST and STR during ear surgery.

Facial Canal Anatomy in Patients with Microtia: Evaluation of the Temporal Bones with Thin-Section CT

Radiology ◽  
2002 ◽  
Vol 225 (3) ◽  
pp. 852-858 ◽  
Author(s):  
Hideki Takegoshi ◽  
Kimitaka Kaga ◽  
Shigeru Kikuchi ◽  
Ken Ito
Keyword(s):  
Thin Section ◽  
Facial Canal ◽  
Temporal Bones
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