R434 – The Round Window

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.

Download Full-text

Role of the Round Window Membrane in Middle Ear Immune Responses

Acta Oto-Laryngologica ◽

10.3109/00016488809138897 ◽

1988 ◽

Vol 105 (sup457) ◽

pp. 139-143 ◽

Cited By ~ 3

Author(s):

E. M. Keithley ◽

A. F. Ryan ◽

J. P. Harris

Keyword(s):

Immune Responses ◽

Middle Ear ◽

Round Window ◽

Round Window Membrane

Download Full-text

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

Surgical and Radiologic Anatomy ◽

10.1007/s00276-021-02859-7 ◽

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.

Download Full-text

Transcanal Endoscopic Antrostomy Hole : Its Utility in Restoring Ventilation Pathway to Epitympanum and Mastoid Antrum During Tympanoplasty

Bangladesh Journal of Endosurgery ◽

10.3329/bje.v2i1.19588 ◽

2014 ◽

Vol 2 (1) ◽

pp. 9-14

Author(s):

Sheikh Shawkat Kamal

Keyword(s):

Middle Ear ◽

Tertiary Care ◽

Case Series ◽

Care Hospital ◽

Retrospective Case ◽

Middle Ear Mucosa ◽

Case Series Study ◽

Temporal Bones ◽

Mastoid Antrum

Aim: To evaluate the role of newly created transcanal endoscopic antrostomy hole as a passage in restoring the aeration of epitympanum and mastoid antrum.Materials & Methods: Study design: Retrospective case series study. Study duration: From January 2013 to January 2014. Study place: Private tertiary care hospital. Patients: 27 ears of 23 adult patients (age ranging from 15years to 54years) underwent transcanal endoscopic tympanoplasty for their chronic middle ear diseases in presence of inflamed middle ear mucosa along with radiological shadows of stagnant fluid in their epitympanum and mastoid antrum. Structured three months follow-up was ensured in every case. Intervention: A hole was created at a selected site of posterior meatal wall purely through transcanal endoscopic approach that established direct communication between mastoid antrum and external auditory canal. Thereafter this newly created passage was used for three purposes- assessment of the condition of mastoid antrum, performing the water test for checking epitympanic patency and in few cases placement of temporary tube for postoperative ventilation and drainage of middle ear. Main out come measures: The feasibility, performance and management of transcanal endoscopic antrostomy hole as passage for reestablishing the aeration of epitympanum and mastoid antrum.Results: The chosen site for antrostomy hole was found effective and safe in providing convenient entrance into the mastoid antrum in every case in this study with out facing technical complexity and failure. Postoperative healing of skin over antrostomy hole was found complete in all ears without any inward growth of skin in to mastoid antrum. Available post operative CT scan imaging of temporal bones showed improved aeration in their epitympanum and mastoid antrum.Conclusions: The role of transcanal antrostomy hole has been proved worthy in restoring ventilation pathway to epitympanum and mastoid antrum during tympanoplasty. This antrostomy hole has the potentiality to be considered in future for placement of long term mastoid ventilation tube in order to treat persistent atelectatic middle ear.

Download Full-text

Comparative study of efficiency and characteristics of FMT and DRT installed in human cadavers for round-window stimulation

Scientific Reports ◽

10.1038/s41598-021-95456-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dong Ho Shin ◽

Jong Hoon Kim ◽

Peter Gottlieb ◽

Yona Vaisbuch ◽

Sunil Puria ◽

...

Keyword(s):

Middle Ear ◽

Hearing Aids ◽

Round Window ◽

Standard Of Care ◽

Acoustic Hearing ◽

Middle Ear Implants ◽

Human Cadavers ◽

Limited Frequency ◽

Output Characteristics ◽

Temporal Bones

AbstractAcoustic hearing aids generate amplified sound in the ear canal, and they are the standard of care for patients with mild to moderate sensorineural hearing loss. However, because of their limited frequency bandwidth, gain, and feedback, there is substantial room for improvement. Active middle ear implants, which directly vibrate the middle ear and cochlea, are an alternative approach to conventional acoustic hearing aids. They provide an opportunity to improve sound quality and speech understanding with amplification rehabilitation. For floating-mass type and direct-rod type (DRT) middle ear transducers, a differential floating-mass transducer (DFMT) and a tri-coil bellows transducer (TCBT), respectively, were fabricated to measure the output characteristics in four human temporal bones. Both were fabricated to have similar output forces per unit input and were placed in four human temporal bones to measure their output performances. The TCBT resulted in higher output than did the DFMT throughout the audible frequency range, and the output was more prominent at lower frequency ranges. In this study, we showed that DRT was a more effective method for round window stimulation. Because of its frequency characteristics and vibration efficiency, this implantation method can be utilized as a driving solution for middle ear implants.

Download Full-text

Temporal Bone Findings in Cases of Salt Water Drowning

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348948309200207 ◽

1983 ◽

Vol 92 (2) ◽

pp. 134-136 ◽

Cited By ~ 12

Author(s):

George Kelemen

Keyword(s):

Inner Ear ◽

Temporal Bone ◽

Middle Ear ◽

Salt Water ◽

Round Window ◽

Scuba Diving ◽

Serial Sections ◽

Histopathological Findings ◽

Histopathological Features ◽

Temporal Bones

The otologic literature contains no description of the histopathological features of temporal bones of persons who perished in drowning accidents. Three temporal bones from two fatal cases of drowning were studied in serial sections. Two temporal bones were from a man aged 31 years who collapsed after scuba diving and died three days later. One temporal bone was from a 32-year-old man, serving in the navy, who drove his car, probably accidentally, into the sea and drowned in it. Histopathological findings appeared to be similar in the two cases. Diffuse hemorrhage was evident throughout the middle ear and inner ear. The tympanic and round window membranes appeared to be intact although hemorrhage had occurred within the tissue layers of the membranes. This finding contrasts with observations of ruptured membranes by other investigators.

Download Full-text

The Role of Pars Flaccida in Human Middle Ear Sound Transmission

Otolaryngology ◽

10.1177/019459988809800407 ◽

1988 ◽

Vol 98 (4) ◽

pp. 310-314 ◽

Cited By ~ 12

Author(s):

Hiroshi Aritomo ◽

Richard L. Goode ◽

James Gonzalez

Keyword(s):

Middle Ear ◽

Sound Transmission ◽

Measuring System ◽

Human Beings ◽

Pars Flaccida ◽

Acoustic Insulation ◽

Before And After ◽

Temporal Bones ◽

A Minor

The role of the pars flaccida in middle ear sound transmission was studied with the use of twelve otoscopically normal, fresh, human temporal bones. Peak-to-peak umbo displacement in response to a constant sound pressure level at the tympanic membrane was measured with a noncontacting video measuring system capable of repeatable measurements down to 0.2 micron. Measurements were made before and after pars flaccida modifications at 18 frequencies between 100 and 4000 Hz. Four pars flaccida modifications were studied: (1) acoustic insulation of the pars flaccida to the ear canal with a silicone rubber baffle, (2) stiffening the pars flaccida with cyanoacrylate cement, (3) decreasing the tension of the pars flaccida with a nonperforating incision, and (4) perforation of the pars flaccida. All of the modifications (except the perforation) had a minimal effect on umbo displacement; this seems to imply that the pars flaccida has a minor acoustic role in human beings.

Download Full-text

The Location and Diameter of the Primary Maxillary Sinus Ostium in Malaysians: A Cone-Beam Computerized Tomography Study

Journal of Big Data Research ◽

10.14302/issn.2768-0207.jbr-20-3194 ◽

2020 ◽

Vol 1 (1) ◽

pp. 20-26

Author(s):

Sanual S. Peter ◽

Phrabhakaran Nambiar ◽

Subramaniam Krishnan ◽

Nisreen Mohammed AL-Namnam

Keyword(s):

Anatomical Variation ◽

Anatomical Variations ◽

Clinical Effects ◽

Bilateral Asymmetry ◽

Chinese Populations ◽

Cone Beam Computerized Tomography ◽

The Mean ◽

The Right ◽

Sinus Ostium

Rhinosinusitis is one of widely spread diseases in the region and the role of the anatomical variations in its pathogenesis remains unresolved. A retrospective study using CBCT scan was employed to locate and measure the diameter of 320 primary maxillary ostium (PMO) (n = 160 subjects) among the Malay and Chinese populations (Mongoloid race) in Malaysia. Image analysis was performed using the i-CAT Vision Software, employing the multiplanar reconstruction window in which axial, coronal and sagittal planes were visualized in 0.3 mm intervals. The mean diameter of the PMO was significantly larger in the Chinese than the Malay. Females had larger size than the male and bilateral asymmetry was noticed, where the right side PMO was larger than the left side (p < 0.05). In addition, PMO opened more in the posterior third position of the hiatus semilunaris (61.9%) than anterior and middle third. The PMO showed a statistically significant posteriorly placed position in the Chinese than the Malays and this was more evident in the right side PMO (p < 0.01). In conclusion, the PMO commonly opens in the posterior third of the hiatus semilunaris and its diameter is significantly greater in the Chinese female with evidence of bilateral asymmetry. Awareness the anatomical variation of the Ostium diameter and location among the Malay and Chinese populations potentially has important clinical effects during surgical procedures.

Download Full-text

Role of CT-PNS in non-neoplastic sino-nasal diseases: an observational study at tertiary care center in South Gujarat

International Journal of Otorhinolaryngology and Head and Neck Surgery ◽

10.18203/issn.2454-5929.ijohns20190045 ◽

2019 ◽

Vol 5 (2) ◽

pp. 345

Author(s):

Rahul B. Patel ◽

Nidhi R. Nair ◽

Jaymin A. Contractor ◽

Jalpadevi A. Patel ◽

Ankita M. Vasani

Keyword(s):

Sample Size ◽

Anatomical Variation ◽

Care Center ◽

Tertiary Care ◽

Anatomical Variations ◽

Small Sample ◽

Type I ◽

Frontal Recess ◽

Nasal Diseases

Background: Role of CT scan in sinonasal disease is proved by many published articles. Most of them are having small sample size, poorly defined protocol of CT reporting and does not mention the window width and window level of the software. We did this study to include these points and tried to have sample size of at least 200.Methods: 231 patients included in the study. After clinical examination CT PNS was done. A strict protocol was maintained for the timing of CT, window settings (to get highest bony definition) and for the reporting of CT. Results: Few common anatomical variations were agger nasi (61.9%), DNS in 50.6%; concha bullosa (18.6%), paradoxical MT (20.3%), Onodi Cells (21.6%) and Haller cells (11.3%). Most common subtypes amongst some anatomical variations include middle meatal drainage of frontal recess (58.8%), type I frontal cell (7.1%), type I ethmoid roof (48.9%), type I attachment of UP (58.8%) and sellar type of sphenoid pneumatization (68%). CT has 100% sensitivity and specificity in detecting the diseased sinuses correctly. Except from 11.8% cases in which frontal recess drainage could not be assessed, all other anatomical variation were same intra-op as shown by CT. In fungal rhinosinusitis anatomical variations were difficult to detect by CT.Conclusions: This study proves that CT-PNS gives us the detailed and near exact picture of the disease with its extent as well as of existing anatomical variations in non-neoplastic sino-nasal diseases except in FRS cases where in anatomical variations are difficult to analyze.

Download Full-text

Middle-ear endoscopy and trans-tympanic drug delivery using an interventional sialendoscope: feasibility study in human cadaveric temporal bones

The Journal of Laryngology & Otology ◽

10.1017/s0022215110001155 ◽

2010 ◽

Vol 124 (12) ◽

pp. 1263-1267 ◽

Cited By ~ 4

Author(s):

G Peters ◽

J Lin ◽

M A Arriaga ◽

D W Nuss ◽

B Schaitkin ◽

...

Keyword(s):

Drug Delivery ◽

Eustachian Tube ◽

Middle Ear ◽

Guide Wire ◽

Round Window ◽

Human Cadavers ◽

Incudostapedial Joint ◽

Round Window Niche ◽

Temporal Bones ◽

Inferior Quadrant

AbstractObjective:This study aimed to assess the feasibility of using a 1.3 mm, semi-rigid, interventional salivary endoscope for middle-ear endoscopy, and as a trans-tympanic route for delivery of medication, in human cadaveric temporal bones.Study design:Human cadaveric study.Methods:Five temporal bones harvested from human cadavers were examined. A 1.3 mm, interventional sialendoscope was used to make endoscopy-assisted myringotomy incisions in the postero-inferior quadrant (n = 5) and the antero-inferior quadrant (n = 3).Results:Middle-ear examination was successful in all specimens (n = 5). Access to the round window niche and adequate visualisation of the round window were achieved in all five temporal bones (100 per cent). A guide wire could be navigated to the round window niche without difficulty. Other structures identified in all specimens included the incudostapedial joint, stapedius tendon, pyramidal eminence and facial nerve via an extended myringotomy incision. The anterior middle-ear space was also successfully examined through an endoscope-guided anterior myringotomy. The opening to the eustachian tube was visualised and cannulated with a guide wire in all preparations in which this was attempted (n = 3).Conclusions:The 1.3 mm, interventional sialendoscope allowed adequate visualisation of the eustachian tube, middle-ear space and round window niche, with interventional capabilities, in a cadaveric model. Our result validates the feasibility of its use for trans-tympanic drug delivery.

Download Full-text

Goblet Cell Population in the Normal Middle Ear and Eustachian Tube of Children and Adults

Annals of Otology Rhinology & Laryngology ◽

10.1177/00034894760850s210 ◽

1976 ◽

Vol 85 (2_suppl) ◽

pp. 44-50 ◽

Cited By ~ 31

Author(s):

Mirko Tos ◽

K. Bak-Pedersen

Keyword(s):

Eustachian Tube ◽

Middle Ear ◽

Round Window ◽

Newborn Infants ◽

Lateral Wall ◽

Goblet Cells ◽

Oval Window ◽

Mastoid Process ◽

Temporal Bones ◽

Age Range

On 54 temporal bones from entirely normal prematures and newborn infants, children, and adults, 30,000 to 90,000 counts of goblet cells were done in different parts of the Eustachian tube and middle ear. In the Eustachian tube, normal prematures showed a very low density of goblet cells in all localities, increasing in the pharyngeal parts gradually through childhood and reaching in the normal adult a very high density in the pharyngeal orifice. There are no differences in density between the medial and lateral wall, but in some parts a decrease of density towards the tubal roof. In the middle ear the density is low in normal prematures, increasing slightly in infants, and decreasing again during the age range 7–14 years and in adults. Goblet cells are present in all middle-ear localities, but in markedly decreasing density in this sequence: hypotympanum anteriorly, posteriorly, promontory anteriorly, in the middle, epitympanum, niche of oval window, antrum, niche of round window, mastoid process, incus, and promontory posteriorly.

Download Full-text