Comparative Anatomical and Morphometric Analysis of Eustachian Tube Across Species

Otitis media with effusion is one of the most common diseases in children and infants, which is a major cause of childhood morbidity increasing the risk for hearing lossand the delay in language development. Eustachian tube dysfunction is one of the clear causes of the disease. The eustachian tube mucosa under normal conditions is an important part of the eustachian tube function, which is essential for maintaining a good microenvironment in the middle ear cavity and maintaining its normal function. Ultrastructural and molecular biological abnormalities of the eustachian tube mucosa are closely related to the occurrence of otitis media with effusion. Therefore, this article reviews the ultrastructural and molecular biological differences between normal and otitis media with effusion eustachian tube mucosa in recent years, and further explores the pathogenesis of secretory otitis media, in order to help guide clinical treatment. Key words: Otitis Media with Effusion; Eustachian Tube; eustachian tube dysfunction; Cilia

Reflux is thought to be a risk factor for middle ear disease, but the mechanism underlying this relationship is unclear. In this study, we evaluated the effects of reflux on the eustachian tube (ET) mucosa. Twenty-two healthy 150 to 220 g Wistar rats with normal middle ears were used. The animals were divided into three groups according to exposure time: 1-, 3-, and 12-week exposures. Four rats were used as a control group. An experimental model of gastroesophageal reflux was induced under general anesthesia. After exposure, the animals were sacrificed, and cross sections of the ETs were prepared. The histologic changes in the ET mucosa were observed under a light microscope. The density of goblet cells, numbers of lymphocytes, polymorphonuclear leukocytes, and eosinophils, subepithelial edema, subepithelial vasodilatation, subepithelial gland formation, and intraepithelial gland formation were compared among the groups. The goblet cell density and numbers of lymphocytes and polymorphonuclear leukocytes were significantly higher in the three exposure groups compared with the control group. Nasopharyngeal exposure to experimental reflux alters the ET mucosa histopathology, which suggests that gastroesophageal reflux has a role in ET dysfunction.

Symptoms: Clogged Ears and Muffled Hearing

To evaluate histologic changes in middle ear and eustachian tube (ET) mucosa of mice after exposure to tobacco or electronic cigarette (e-cigarette) smoke. To determine whether there were any mitigating effects of middle ear application of anti-IL-13 or the epidermal growth factor receptor antagonist AG1478 on noted changes within ET mucosa. Controlled animal study. Fifty BALB/cJ mice were randomly assigned to one of five groups: A control group with no smoke exposure, two groups exposed to tobacco smoke, and two groups exposed to e-cigarette vapor. Within the exposed groups after 4 weeks of exposure, one ear was infiltrated with a saline hydrogel and the other ear with hydrogel of either Anti-IL-13 or AG1478. After four more weeks of exposure, the animals were euthanized and the ETs were evaluated for mucosal changes. Compared to control animals with no smoke exposure, there were significant decreases in the numbers of goblet cells within the ET mucosa of mice exposed to tobacco smoke and e-cigarette vapor. No significant differences in cilia, mucin, or squamous metaplasia were noted. Neither anti-IL-13 nor AG178 significantly altered goblet cell count in the ET mucosa of mice exposed to tobacco smoke; however, both agents significantly increased goblet cells within the ET mucosa of mice exposed to e-cigarette vapor. Short-term tobacco smoke and e-cigarette vapor significantly decrease goblet cell count in mouse ET mucosa. Middle ear application of both anti-IL-13 and AG1478 resulted in an increase in goblet cell count among mice exposed to e-cigarette vapor, but not to tobacco smoke. NA Laryngoscope, 132:648-654, 2022.

ObjectivesParticulate matter (PM) is a risk factor for various diseases. Recent studies have established an association between otitis media (OM) and PM exposure. To confirm this relationship, we developed a novel exposure model designed to control the concentration of PM, and we observed the effects of PM exposure on the Eustachian tube (ET) and middle ear mucosa of rats.MethodsForty healthy, 10-week-old, male Sprague-Dawley rats were divided into 3-day, 7-day, 14-day exposure, and control groups (each, n=10). The rats were exposed to incense smoke as the PM source for 3 hours per day. After exposure, bilateral ETs and mastoid bullae were harvested, and histopathological findings were compared using microscopy and transmission electron microscopy (TEM). The expression levels of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor (VEGF) in the middle ear mucosa of each group were compared using real-time reverse transcription polymerase chain reaction (RT-PCR).ResultsIn the ET mucosa of the exposure group, the goblet cell count significantly increased after PM exposure (P=0.032). In the middle ear mucosa, subepithelial space thickening, increased angio-capillary tissue, and inflammatory cell infiltration were observed. Moreover, the thickness of the middle ear mucosa in the exposure groups increased compared to the control group (P<0.01). The TEM findings showed PM particles on the surface of the ET and middle ear mucosa, and RT-PCR revealed that messenger RNA (mRNA) expression of IL-1β significantly increased in the 3-day and 7-day exposure groups compared to the control group (P=0.035). VEGF expression significantly increased in the 7-day exposure group compared to the control and 3-day exposure groups (P<0.01).ConclusionThe ET and middle ear mucosa of rats showed histopathologic changes after acute exposure to PM that directly reached the ET and middle ear mucosa. Therefore, acute exposure to PM may play a role in the development of OM.

Obstructive eustachian tube (ET) dysfunction is a common condition associated with various otologic symptoms. The current lack of a diagnostic gold standard makes diagnosis and evaluation at follow-up difficult. The aim of the study was to determine the value and discriminative power of the seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7) in patients with obstructive ET dysfunction and patulous ET. Diagnostic test study. The ETDQ-7 was completed by 39 patients with obstructive ET dysfunction, eight patients with patulous ET, and 22 healthy controls. The internal consistency was evaluated using the Cronbach α coefficient. Receiver operating characteristic (ROC) was determined as an accuracy measure. The mean ETDQ-7 total score was 9.91 in the control group, 25.77 in the patients with obstructive ET dysfunction, and 27 in the patulous ET group. The Cronbach α coefficient was 0.795 in the obstructive ET group and 0.72 in the patulous ET group, demonstrating adequate reliability. The area under the curve in ROC analysis for the obstructive ET group was 95% and 96% for the patulous ET dysfunction group, which confirms its excellent discriminant validity toward the healthy control group. However, the ETDQ-7 cannot discriminate between obstructive ET dysfunction and patulous ET. The ETDQ-7 can be a useful disease-specific rating scale for ET dysfunction but is unable to discriminate between patients with obstructive ET dysfunction and patulous ET. 3b.

Enhanced allergic Eustachian tube response in surfactant protein D knockout mice induced by ovalbumin

Eustachian tube (ET) dysfunction is known to be a cause for various middle ear diseases. Dynamic slow motion videoendoscopy (DSVE) and impedance audiometry (IA) can both be employed to evaluate ET dysfunction. To assess the role of DSVE and IA for diagnosing ET dysfunction in cases of middle ear disorders. It is a prospective case control study. 102 ears with chronic otitis media were taken as cases and 102 healthy ears as controls. IA and DSVE were performed to assess ET function in both the groups. Sensitivity/ specificity of both the diagnostic tests were evaluated in case and control groups. Out of 102 ET of case group exposed to both tests, 87 were found to have ET dysfunction by DSVE and 80 by IA. Among 102 ET of control group 78 were identified as normal by DSVE while 87 by IA. On applying chi square test in both these groups, the associations were significant. (p value < 0.0001). Patients with grade 2B or higher on DSVE endoscopy had abnormal IA findings, indicating that higher the grade on DSVE, higher the chance of abnormal IA. DSVE and IA are potentially useful tools in evaluation of cases of COM and which provide information regarding functional and pathological factors responsible for ET dysfunction.

Conclusion: The present study demonstrates a mouse model of chronic Eustachian tube (ET) dysfunction using a surgical technique that is reproducible and effective with low mortality and morbidity.Objective: To create a reproducible and effective mouse model of ET obstruction with a low operative morbidity.Methods: Forty healthy, male CBA/CaJ mice underwent the procedure. ET obstruction was performed on one side under general anesthesia; A small piece of dental material (Gutta Percha Points, Meta Biomed, Chungbuk, Korea) was placed via the tympanic orifice of the ET to occlude the entire ET. The contralateral ears of animals served as a control. One month after the operation, all ears were inspected under an operating microscope for signs of ET dysfunction. Primary outcome measures were the signs of ET dysfunction inspected through tympanic membrane (TM) 4 weeks after the operation and confirmation of ET occlusion by post-mortem dissection.Results: Forty (100%) of the treated mice ears developed ET dysfunction, as confirmed by the middle ear appearance on otoscopy and dissection post-mortem and 0% of the control ears at 4 weeks. The most common otoscopic signs were thickened TMs and middle ear effusions. No mortality or morbidity occurred either from anesthesia or surgery.

&lt;b&gt; Introduction:&lt;/b&gt; The Eustachian tube (ET) is the anatomical structure that connects the middle ear with the nasopharynx. It is part of a system that, in addition to the already mentioned elements, also includes the soft palate. The functions of ET are pressure equalization, clearance of secretions and protection of the middle ear from sounds and reflux of secretions from the nasopharynx. Dysfunctions of ET are multifactorial, and the diagnostics is difficult due to lack of defined standards for assessing its function prior and post treatment. &lt;/br&gt;&lt;/br&gt; &lt;b&gt;Aim:&lt;/b&gt; The aim of the study is the review of the publications concerning actual definitions and classification of ET dysfunctions, efforts of adopting unified criteria and methods of assessing its functions and ways of treatment. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Material and methods:&lt;/b&gt; In the year 2015 classification was adopted which distinguish three subtypes of ET dysfunction: (1) dilatory ET dysfunction, (2) baro-challenge-induced, (3) patulous ET. Dilatory ET dysfunctions were further divided as follows: functional obstruction (most common), dynamic dysfunction and anatomical obstruction. The Eustachian Tube Dysfunction Questionnaire (ETDQ-7) enables the systematization of symptoms. Clinical assessment of the patient with ET dysfunction should include otoscopy or otomicroscopy, tympanometry, Rinnes and Webers tuning fork tests or pure tone audiometry, nasopharyngoscopy with visualization of ET orifice and opening. Other tests of assessment of ET functions like tubomanometry, sonotubomanometry and pressure chamber tests are useful research tools. Endoscopic evaluation of ET orifice should encompass the assessment of mucosa of the torus tubarius and ET as well as dynamic process of ET opening. In surgical treatment of functional obstructions of ET, the most common method is balloon dilatation tuboplasty. Several studies showed that this is safe and in high percentage of cases successful method of treatment, however the indications for this type of surgery are not yet universally accepted.

Introduction Eustachian tube (ET) dysfunction plays an important role not only in the pathophysiology of various middle ear disorders, but also in predicting the outcome of the treatment. As there is no single test that assesses both the anatomic and physiological functions of the ET, a combination of tympanometry and dynamic slow motion video endoscopy may improve the sensitivity of ET function assessment.Objective To find out if there is any correlation between dynamic slow motion nasal video endoscopy and impedance audiometry in assessing ET function in patients with middle ear diseases.Methods Ours was a descriptive study performed with 106 patients attending the Ear, Nose and Throat (ENT) Outpatient Department of a tertiary care center in South India with features suggestive of middle ear disease. All patients underwent impedance audiometry and dynamic slow motion nasal video endoscopy, and were graded based on the severity of the ET pathology.Results A total of 47 out of 97 patients with abnormal endoscopy findings also had abnormal impedance audiometry. The correlation was greater among the patients with higher grades of ET dysfunction. The endoscopy findings of 106 cases, when correlated with middle ear manometry, revealed that 56 cases showed complete agreement, and 50 cases showed disagreement. The nasal endoscopy results, when correlated with middle ear manometry studies by using McNemar's chi-squared (χ2) test, showed a significant association between the 2 tests (p = 0.017).Conclusion There is a significant alteration in middle ear pressure as the severity of the ET tube dysfunction increases. Impedance audiometry and nasal endoscopy provide a better measure of ET function.

Is middle ear pressure affected by continuous positive airway pressure use?

Objective:Through analysis of the tympanic membrane perforation rate and hearing improvement rate with chronic suppurative otitis media (CSOM) by myringoplasty,to observe the effect of different preoperative conditions such as middle ear lesion,eustachian tube (ET) function and infection status on the postoperative curative effect.Method:Retrospective analysis of EENT Hospital of Fudan University from January 2012 to November 2016 during the 203 cases (203 ears) with clinical data of myringoplasty: according to intraoperative exploration of the presence of purulent secretions in the tympanic cavity,divided into infection active group and infection quiescence group; according to the preoperative results of the function of ET with acoustic impedance test divided into dysfunction or good group; according to the preoperative temporal bone HRCT suggested that the middle ear (mastoid cells,tympanic antrum and tympanic cavity) with or without soft tissue density,divided into the group with no focal lesion and the group with focal lesion. Review endoscopy and pure tone audiometry after 3 to 6 months. Using SPSS 19.0 statistical software to compare the differences among them of tympanic membrane perforation rate and hearing improvement rate.Result:Single factor analysis: ①The infection quiescence group of tympanic membrane perforation rate was 11.93%(13/109),higher than the infection active group ［8.51%(8/94)］; the infection quiescence group of hearing improvement rate was 75.23%(82/109),below the infection active group ［79.79%(75/94)］,no statistically significant differences of them (P>0.05).②The group with dysfunction of ET of tympanic membrane perforation rate was 14.06%(9/64),significantly higher than the group［4.04%(4/99)］with good function ET,with statistical difference of them (P<0.05); the group with dysfunction of ET of hearing improvement rate was 76.56% (49/64),lower than the group［81.82%(81/99)］with good function of ET,no significant difference of them (P>0.05).③The group with no obvious lesion of tympanic membrane perforation rate was 9.09% (10/110),lower than the group ［11.83%(11/93)］with focal lesion; the group with no obvious lesion of hearing improvement rate was 78.18% (86/110),higher than the group with focal lesion ［76.34%(71/93)］,no significant difference of them (P>0.05).Multivariate analysis: ①There was a significant correlation of postop-erative tympanic membrane perforation rate with preoperative ET functi-on (P<0.05).There was no significant correlation of the postoperative tympanic membrane perforation rate with the infection status and the temporal bone HRCT images in the middle ear lesions (P>0.05).②There was no significant correlation of the postoperative hearing improvement rate with the infection status,the ET function and the temporal bone HRCT images in the middle ear lesions (P>0.05).Conclusion:Dysfunction of ET and localized lesions of the ear were more common in infection active;the accumulation of purulent exudate on the surface of the tympanic mucosa and localized lesions of the middle ear did not affect the healing rate of the tympanic membrane and the hearing improvement rate; ET function is one of the most important factors that affect the healing rate of tympanic membrane after operation,the patients with ET dysfunction are more likely to affect tympanic membrane perforation,but does not affect the hearing improvement rate.

HintergrundEine klaffende Tube kann insbesondere durch Autophonie, Druckgefühl und gestörten Höreindruck zu einer Einschränkung der Lebensqualität führen. Bei fehlenden spezifischen Symptomen kann die Diagnose der klaffenden Tube schwierig sein. Insbesondere die Abgrenzung zur chronisch obstruktiven Tubenfunktionsstörung stellt eine Herausforderung dar. Da derzeit kaum standardisierte Diagnostik- und Therapieoptionen zur Verfügung stehen, ist eine strukturierte Untersuchung zur sicheren Diagnostik und wissenschaftlichen Aufarbeitung dieser Erkrankung erforderlich. Für die Diagnostik der chronisch obstruktiven Tubenfunktionsstörung wurde 2012 bereits der „Eustachian Tube Dysfunction Questionnaire“ (ETDQ-7-Fragebogen) nach McCoul entwickelt. Für die klaffende Tube existiert seit 2017 der PHI-10-Fragebogen („patulous Eustachian tube handicap inventory“) nach Kobayashi.Material und MethodenDer PHI-10-Fragebogen wurde ins Deutsche übersetzt und an 41 Gesunden, 13 Patienten mit Tinnitus auris, 11 Patienten mit klaffender Tube und 18 Patienten mit chronisch obstruktiver Tubenventilationsstörung getestet. Zusätzlich erfolgte im Vergleich die Auswertung des ETDQ‑7 nach McCoul.ErgebnisseEs erfolgt die Präsentation der deutschen Übersetzung des PHI-10 und der Ergebnisse von PHI-10 und ETDQ‑7 in allen Patientengruppen. Der ETDQ‑7 hat das Risiko falsch-positiver Ergebnisse bei Patienten mit klaffender Tube und der PHI-10 bei Patienten mit obstruktiver Tubenfunktionsstörung. Beide untersuchten Fragebögen sind falsch-positiv bei Tinnituspatienten.SchlussfolgerungDer PHI-10 (deutsch) und ETDQ‑7 (deutsch) sind eine nützliche Unterstützung der Anamnese bezüglich Tubenfunktionsstörungen. Sie unterscheiden jedoch nur unzureichend zwischen klaffenden und obstruktiven Tubenfunktionsstörungen und eignen sich nicht für Patienten mit Tinnitus. Die Stärke der Fragebögen ist in der Verlaufskontrolle und dem Monitoring von Therapieergebnissen zu sehen.

Otitis Media (OM) is the most commonly diagnosed childhood illness and has health care related cost of four billion dollars annually. [1] The onset of OM has been directly related to Eustachian Tube (ET) dysfunction. The ET has three main physiological functions, and when these functions are compromised, middle ear (ME) disorders arise. It is also known that specific populations of patients, such as those with cranio-facial abnormalities, such as a cleft palate, have a 100% onset rate of OM. Even though ET dysfunction has been related to OM, the underlying reasons for ET dysfunction in certain populations remains unknown. To gain an understanding of this system, we use fully coupled fluid-structure interaction (FSI) models of the ET based on geometries reconstructed from histological images. Using these models in systematic parameter variation studies allows us to identify which parameters of the ET can cause dysfunction. Using healthy adult subjects as a model for a well-functioning ET, we determined ET function to be sensitive to changes in TVP muscle force.