Update on eustachian tube dysfunction and the patulous eustachian tube

PURPOSE OF REVIEW: The purpose of this review is to summarize the recent knowledge on eustachian tube dysfunction and the patulous eustachian tube. RECENT FINDINGS: A clinically useful test for eustachian tube function is still lacking. Narrowing of the isthmus alone was demonstrated to be an insufficient cause of otitis media. Inflammatory mediators identified within the eustachian tube and middle ear cells were causally linked with otitis media with effusion. Increasing evidence was found that allergic disease and reflux may be two of the most important contributors of tubal inflammation causing otitis media with effusion. The adenoid size and proximity to the torus tubaris may also be important in considering which patients with persistent otitis media with effusion may benefit from adenoidectomy. Computed tomography scan has documented loss of soft tissue within the cartilaginous eustachian tube in patients with patulous eustachian tubes. An endoscopic approach to seal the tubal lumen has been found to be effective in relieving patulous symptoms. SUMMARY: These studies suggest that allergic rhinitis and gastroesophageal reflux should be investigated in patients with eustachian tube dysfunction. Adenoidectomy should also be considered in patients who have adenoids that obstruct the torus tubaris. Patients with a patulous eustachian tube may benefit from an endoscopic closure. Further research is needed to identify a clinically useful test for eustachian tube dysfunction.     

Growth of the foetal eustachian tube and its dimensions

Summary In a study of the growth and dimensions of the Eustachian tube, 47 tubes from 33 foetuses varying in age from the 12th to the 27th menstrual week were removed in toto, stained with PAS, PAS-alcian blue, and the osmium tetroxide whole-mount method. At the beginning of the 12th menstrual week the tube is 2.4 mm in length, at the beginning of the 27th week 12.5 mm. The rate of increase in tubal length is at a maximum from the 20th to the 27th week, amounting to 0.8 mm per week. Later, the weekly increment is presumably only 0.6 mm. The mean inner circumference of the tube is 1.0 mm at the beginning of the 12th week and 4.4 mm at the beginning of the 27th week. The mean diameter of the tube is 0.32 mm at the beginning of the 12th week and 1.38 mm at the beginning of the 27th week. Up to the 15th week the tube is almost round in cross section, but as cartilage develops it becomes first oval and, in the 27th week, slit-shaped.The development of the tubal cartilage starts towards the end of the 12th week, first in the pharyngeal part of the internal lamina. By the 16th week the newly-formed cartilage attains contact with the tympanic cartilage, and then the development of cartilage starts oin the external lamina. Differentiation of the epithelium and formation of goblet cells in the rhinopharynx starts in the 12th week. Hence, the differentiation spreads towards the tubal orifice, along the tubal floor to the tympanic part and the middle ear.

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Zusammzenfassung Bei Untersuchungen über Wachstum und Dimensionen der Eustachischen Tube wurden 47 Tuben von 33 Foeten der 12.–27. Menstrualwoche in toto herauspräpariert und mit PAS, PAS-alcian-Blau und Osmium Tetroxid in toto gefärbt. Läge und innere Zirkumferenz der Tube wurde gemessen. 12,5 mm lang. Das stäkste Läugenwachstum findet in der 20.–27. Woche statt und beträgt bis zu 0.8 mm wöhentlich. Später beträgt das wöchentliche Wachstum wahrscheinlich our 0,6 mm. Der durchschnittliche innere Umfang der Tube ist am Beginn der 12. Woche 1,0 mm, bei Beginn der 27. Woche 4,4 mm. Der entsprechende mittlere Durchmesser beträgt bei Beginn der 12. Woche 0,32 mm and 1.38 mm am Beginn der 27. Woche. Bis zur 15. Woche ist der Querschnitt der Tube fast rund, aber mit Beginn der Knorpel-Entwicklung wird or oval and in der 27. Woche schlitzfög.Die Entwicklung des Tubenknorpels beginnt gegen Ende der 12. Woche, zuerst im pharyngealen Teil der inneren Wand. In der 16. Woche bekommt der Tubenknorpel Kontakt mit dem tympanalen Knorpel, und zu dieser Zeit beginnt auch die Entwicklung der Lamina externa. Die Differenzierung des Epithels und die Ausbildung von Becher-Zellen beginnt in der 12. Woche im Rhinopharynx. Von bier breitet sich die Differenzierung zur Tubenmündung und entlang des Bodens zum tympanalen Teil and zum Mittelohr aus.

     

Does the silastic eustachian tube prosthesis improve eustachian tube function?

This clinical study attempts to evaluate the effectiveness of Eustachian tube function in 30 ears, 11–29 months after insertion of the Silastic® Eustachian tube prosthesis (SETP). Indications for the SETP were limited to persistent Eustachian tube dysfunction. Preoperatively, 13 patients had intact tympanic membranes with persistent serous otitis media. Seventeen patients underwent tympanoplasty and demonstrated persistent serous otitis media in the opposite ear. Postoperatively, aeration of the middle ear was evaluated by tympanometry, microscopic examination, and myringostomy. Microphotographs demonstrate the state of the middle ear. Histology of the middle ear mucosa was obtained in a few cases. Ninety-six percent of the ears with an SETP demonstrated confirmed persistent Eustachian tube dysfunction beginning an average of six months after insertion. Complications were common.     

Mucociliary function of the eustachian tube in the eustachian tube dysfunction

Background: Most of the tests to evaluate the eustachian tube (ET) function are focused on the ventilation function of the ET.

Aim: Here we evaluate mucociliary function of the ET in patients with ET dysfunction.

Materials and methods: Ten patients with ET dysfunction were enrolled into the study. Six patients had chronic tympanic membrane retraction and four patients had chronic middle ear effusion (MEE). All patients had intact tympanic membranes. Tympanometry and clinical examinations were done to all patients. Mucociliary function was evaluated with technetium labeled albumin and blue dye. Tympanometry and clinical examinations were done to six patients with chronic tympanic membrane retraction and four patients with chronic middle ear effusion (MEE). Mucociliary function of the ET was evaluated with technetium labeled albumin and blue dye placed into middle ear through an intact tympanic membrane and followed from nasopharynx ET orifice (blue dye) and with gamma camera (technetium).

Results: Blue dye was observed in tubal orifice in six (6 of 10) patients during 30?min observation. Five of those patients (5 of 6) had tympanic membrane retraction and one patient (1 of 6) had MEE. Tracer activity decreased from middle ear in six (6 of 10) patients. Four of those patients had tympanic membrane retraction and two had MEE.

Conclusion: Mucociliary function of the ET seems to be better in patients with tympanic membrane retraction than patients with middle ear effusion.

Significance: Mucociliary function of the ET is an important function for middle ear aeration, blue dye test is easily available to be used also in clinical practice.     

Ligation of eustachian tube for intractable patulous eustachian tube: a preliminary report

Pharyngeal orifice of the eustachian tube was ligated on ten patients, 15 ears with intractable patulous eustachian tube. While the eustachian tube orifice was observed by an endoscope inserted through the contralateral nostril, the orifice was ligated transnasally and/or transorally using instruments usually used in the endoscopic nasal surgery. Now 13–27 months after the surgery, the outcome was excellent (both symptoms and sonotubometry were normalized) in two ears, good (either symptoms or sonotubometry was improved) in seven ears, and unchanged in the remaining six ears. In one of the ears with an outcome of unchanged, the ligation was found to be spontaneously released soon after surgery, but the symptom was improved after the second operation 2.5 months after the first operation. Temporary otitis media with effusion was seen in one ear, mild inflammation around the ligated site also in one ear, but no other serious complication has been observed. Although further improvement in the surgical procedure and further discussion about its long-term outcome should be required, this procedure appeared to be one of the therapeutic options for intractable patulous eustachian tube.     

Flexible endoscopy and radiologic evaluation of the eustachian tube in adults with eustachian tube dysfunction

This study was conducted on 20 adult patients presenting with eustachian tube dysfunction of about 6 months' duration. It included endoscopy of the pharyngeal end of the eustachian tube and contrast radiologic study. Both methods are now available because of technical progress and practical improvements. By these methods, physiologic movements of the soft palate, tubal torus, and tubal orifice can be observed and studied and anatomic variations and pathologic abnormalities can be detected. This study shows that eustachian tube dysfunction may be caused by salpingitis (acute or chronic) or adenoid or nasopharyngeal carcinoma. Scleroma affecting the lumen of the eustachian tube was reported in one case.     

Autophony and the patulous eustachian tube

Autophony and the patulous Eustachian tube is a real but rare clinical entity often misdiagnosed because the symptoms so mimic those of middle ear effusion. The diagnosis is made by the history of fullness or blockage and hearing ones own voice and breath sounds in the ear. The drum is usually atrophic and moves with respiration but this may not be visible. The usual past history is of weight loss. The diagnostic test is to observe a regular increase or decrease in middle ear pressure when increasing or decreasing the ambient pressure while measuring the impedance in a pressure chamber. The usual variations in pressure with opening and closing of the tube are not seen because the tube remains open all the time. Few patients need operative intervention and explanation is all that is usually required. When surgical treatment is necessary the application of 20% silver nitrate to the lumen of the tube on a wire covered by cotton has given results with few complications. Injection of Teflon® paste anterior to the mouth of the Eustachian tube has been stopped by the manufacturer of the paste because of serious complications caused by the Teflon® paste being accidently injected into the internal carotid artery. Why some patients with a patulous tube and movement of the drum with respiration have no symptoms and other patients with very bothersome symptoms have so few objective signs and no movement of the drum, that can be observed with respiration, remains a mystery that needs further study.     

Physiologic eustachian tube inflation.

A new maneuver (oral positive pressure) of voluntary middle ear inflation is described. The efficacy of this new maneuver over the Valsalva maneuver was established by conducting an experiment in 50 normal volunteers and a clinical trial in 75 patients with Eustachian tube obstruction and in 25 patients with chronic serous otitis media. The lower opening pressure and higher available head of pressure, characteristic of this new maneuver, is hoped to be of definite therapeutic value in the management of the previously mentioned conditions. This maneuver has a potential for use in aviation medicine.     

Myringotomy and tube for relief of patulous eustachian tube symptoms

Reports on the effectiveness of myringotomy and tube for treatment of symptoms of the patulous eustachian tube are discouraging, even though there are no large series substantiating its ineffectiveness. To further investigate this problem, we have reviewed the charts of all patients at the Otologic Medical Group (OMG) from 1974 to 1981 with the diagnosis of patulous eustachian tube who underwent myringotomy and tube for their symptoms. We identified 60 ears of 46 patients with complaints consistent with patulous eustachian tube symptoms. The treatment either eliminated or substantially reduced symptoms in 32 ears (53%). For the other 28 ears, myringotomy and tube were of no benefit. Nine of 13 (70%) ears with a definitive diagnosis based on movement of the tympanic membrane with respiration or tympanometry showed relief of symptoms with myringotomy and tube. Myringotomy and tube will remain part of the treatment regimen because it is relatively simple to perform, reversible, and effective in the majority of patients.     

Middle ear pressures and the eustachian tube

Objective. To evaluate changes in positive and negative middle ear pressures and eustachian tube function in the rat. Materials and methods. A permanently introduced canula was used to measure the middle ear pressure in the rat. Positive and negative pressures were induced by an infusor system in alert Wistar rats but also under an anaesthetic. Results. Positive pressure is diminished step by step to atmospheric or to a slightly positive pressure. Negative pressure is equalized step by step to atmospheric or to a slightly negative pressure. When the negative pressure becomes too low amiddle ear effusion will occur. The mean opening pressures in alert animals are 23.64 cm H₂O and in animals during narcosis 25.50 cm H₂O. The closing pressures are respectively 15.83 and 14.04 cm H₂O. The scatter of opening and closing pressures in animals under an anaesthetic is much smaller than in alert animals (P = 0.003 versusP = 0.032). Conclusions. (1) Opening and closing pressures in rats under narcosis are not significantly different in comparison to alert animals. (2) The larger scatter of values in alert rats is probably due to muscle activity in the tubopharyngeal area. (3) The reaction of the rat eustachian tube to applied positive and negative pressures are comparable to the human situation.