EUSTACHIAN TUBE DISORDERS (EVERYTHING YOU NEED TO KNOW).pptx

Presentation on Eustachian Tube Disorders
By Dr. Akhil Kumar
Junior Resident in JIPMER

1. EUSTACHIAN TUBE DISORDERS DR AKHIL KUMAR JUNIOR RESIDENT JIPMER, PUDUCHERRY

2. NASOPHARYNX AND EUSTACHIAN TUBE ANATOMY AND FUNCTION

3. NASOPHARYNX The nasopharynx is the upper part of the pharynx, located behind the nasal cavities and above the soft palate Communication with the oral cavity occurs via the velopharyngeal port . Key features of the nasopharynx include: Torus Tubarius : Nasopharyngeal Orifice Salpingopharyngeal Fold Pharyngeal Tonsil (Adenoids) Fossa of Rosenmüller  

4. EUSTACHIAN TUBE E qualize ear pressure and draining middle ear fluids V aries in structure and orientation between adults and infants: Adult Eustachian Tube: Angled at 45 degrees to the horizontal plane and typically 31 to 38 mm long. Infant Eustachian Tube: Less inclined, at about 10 degrees, and shorter than in adults. Structural Details: Osseous Eustachian Tube: Open at all times. It has a roughly triangular lumen, 2-3 mm vertically and 3-4 mm horizontally. Fibrocartilaginous Portion: Closed at rest, it opens during swallowing or forced maneuvers like the Valsalva maneuver .

5. DEVELOPMENTAL AND FUNCTIONAL ASPECTS: The eustachian tube's cartilage increases in mass from birth to puberty , affecting its function. The cartilaginous portion follows a curved path in adults, aligning closely with the cranial base Muscle Attachments: The cartilaginous tube's lateral and inferior walls, composed of a veiled membrane, serve as attachment sites for the tensor veli palatini muscle, which helps open the tube. Torus Tubarius : The thickened anterior fibrous investment of the medial cartilage forms a prominent fold, measuring 10-15 mm in thickness. This fold is the origin point for the salpingopalatine and salpingopharyngeal muscles, aiding in tube opening and airway maintenance.

6. MUSCLES ASSOCIATED WITH THE EUSTACHIAN TUBE Tensor velli palitini Lateral Bundle (Tensor Veli Palatini Proper): Medial Bundle (Dilator Tubae ): Tensor tympani Levator Veli Palitini Salphingopharyngeous

7. PHYSIOLOGY OF EUSTACHIAN TUBE

8. The eustachian tube serves three main physiological functions for the middle ear : Protection : Shields the middle ear from nasopharyngeal sound pressure and secretions. Drainage : Facilitates drainage of middle ear secretions into the nasopharynx. Ventilation : Equalizes air pressure in the middle ear with atmospheric pressure and replenishes oxygen absorbed by the middle ear mucosa.

9. PROTECTION AND DRAINAGE FUNCTIONS Flask Model : The eustachian tube, middle ear, and mastoid air cell system can be modeled as a flask with a long, narrow neck. The mouth of the flask represents the nasopharyngeal end. The neck represents the eustachian tube isthmus . The bulbous portion represents the middle ear and mastoid air chambers.

10. Factors Affecting Fluid Flow : Neck Diameter and Length : Fluid flow through the neck is influenced by pressure, radius and length of the neck, and liquid viscosity. Positive Air Pressure : Stops liquid flow due to capillarity within the neck and positive pressure in the chamber. Flask Position : Supine position enhances liquid flow into the middle ear, making infants more prone to reflux otitis media. Perforation : A hole in the flask (like a tympanic membrane perforation) can lead to reflux by losing the air cushion in the middle ear.

11. Reflux Mechanisms : Positive Nasopharyngeal Pressure : Activities like nose blowing, crying, and swallowing can create positive pressure, leading to fluid insufflation into the middle ear. Negative Middle-Ear Pressure : Aspiration of nasopharyngeal secretions can occur if high negative pressure develops in the middle ear. Compliance of the Tube : The human eustachian tube is compliant, meaning it can distend under pressure, making it easier for secretions to enter the middle ear.

12. FLUID FLOW MECHANICS Positive Pressure Effects : Compliant Neck : Less positive pressure is needed to insufflate liquid into a flask with a compliant neck. Clinical Implications : Abnormally distensible eustachian tubes facilitate easier entry of nasopharyngeal secretions into the middle ear. Negative Pressure Effects : Slow Application : Negative pressure applied slowly to the bottom of the flask allows fluid flow even if the neck is collapsed. Sudden Application : Sudden negative pressure locks the compliant neck, preventing fluid flow. Clinical Implications : Negative middle-ear pressure from gas absorption leads to gradual gas aspiration, whereas sudden pressure changes (e.g., descent in an airplane) can lock the eustachian tube, preventing air flow.

13. Fluid Drainage : Inverted Flask : Demonstrates that liquid trapped in the bulbous portion does not flow out due to negative pressure, but creating a hole relieves this pressure. Clinical Application : Myringotomy or tympanic membrane rupture can relieve pressure in cases of middle-ear effusion.

14. TESTS OF EUSTACHIAN TUBE FUNCTION OTOSCOPY Description : Visual inspection of the tympanic membrane using an otoscope. Purpose : To identify middle-ear effusion or high negative middle-ear pressure, indicating potential eustachian tube dysfunction. Limitations : Cannot determine the type or degree of dysfunction.

15. NASOPHARYNGOSCOPY Description : Indirect mirror examination or endoscopic examination of the nasopharyngeal end of the eustachian tube. Purpose : Useful for diagnosing conditions such as neoplasms in the fossa of Rosenmüller . Limitations : Current instruments do not allow for assessment of eustachian tube function.

16. TYMPANOMETRY Description : Uses an electroacoustic impedance instrument to obtain a tympanogram. Purpose : To objectively determine the status of the tympanic membrane and middle-ear system. Indicates impaired eustachian tube function if middle-ear effusion or high negative pressure is present. Limitations : Normal middle-ear pressure does not necessarily indicate normal eustachian tube function.

17. MANOMETRY Description : Assesses eustachian tube function using a pump-manometer system of the electroacoustic impedance bridge or a controlled syringe and manometer. Purpose : Clinically assesses eustachian tube function, especially when the tympanic membrane is not intact. Limitations : Commercial manometric systems may be inadequate for pressures exceeding +400 to +600 mm H₂O, requiring additional equipment like a water manometer.

18. CLASSICAL TESTS OF TUBAL PATENCY VALSALVA MANEUVER Description : The patient attempts to exhale forcefully with a closed mouth and nose. Purpose : To check for mechanical obstruction of the eustachian tube by observing middle ear inflation. Application : When the tympanic membrane is intact, inflation indicates patency. With an intact membrane, this is confirmed via tympanogram, and without, via manometric observation. Limitations : Indicates patency but not full function. Some patients, especially young children or those with certain ear conditions, may struggle to perform the maneuver correctly.

19. POLITZER MANEUVER Description : Air is insufflated into the nasal cavity while the patient swallows, typically using a device called a Politzer bag. Purpose : To assess the eustachian tube's ability to allow air passage. Application : Similar to Valsalva, it confirms patency if air passes into the middle ear. Limitations : Can only assess patency rather than full function.

20. TOYNBEE TEST Description : The patient pinches their nose and swallows. Purpose : To create negative pressure in the middle ear, which helps to assess eustachian tube function. Application : Positive results are indicated by an alteration in middle ear pressure, which can be determined through otoscopy or tympanometry. Limitations : More effective in adults than in children. Negative results do not necessarily rule out normal function and other tests might be needed for confirmation.

21. PATULOUS EUSTACHIAN TUBE TEST Description : Performed through otoscopy or tympanometry to detect a patulous (abnormally open) eustachian tube. Purpose : To diagnose a patulous eustachian tube by observing tympanometric trace fluctuations that coincide with breathing. Application : Fluctuations are observed during normal breathing and breath-holding. Enhanced by occluding one nostril during forced inspiration and expiration or using the Toynbee maneuver. Limitations : Should not be performed while the patient is reclined as this may close the patulous tube.

22. NINE-STEP INFLATION-DEFLATION TYMPANOMETRIC TEST

23. MODIFIED INFLATION-DEFLATION TEST (NON-INTACT TYMPANIC MEMBRANE) Procedure: Preparation Passive Function Assessment: Opening Pressure Closing Pressure Active Function Assessment: Equilibration Overpressure and Underpressure

24. Interpretation: Normal Function : The tube opens and closes within the normal pressure range. Residual positive and negative pressures are equilibrated by swallowing. The mean opening pressure for normal subjects is around 330 mm H2O. Abnormal Function : Failure to open at pressures above 400-600 mm H2O may indicate severe mechanical obstruction. Higher opening pressures (e.g., >500-600 mm H2O) suggest partial obstruction. Very low opening pressures (e.g., <100 mm H2O) suggest a semipatulous tube. Inability to maintain modest positive pressure indicates a patulous tube (open at rest). Partial equilibration or failure to reduce applied negative pressure may indicate increased compliance or a "floppy" eustachian tube.

25. EUSTACHIAN TUBE DYSFUNCTION

26. FUNCTIONAL OBSTRUCTION Persistent high negative ear pressure, which may result in tympanic membrane atelectasis. This condition can further complicate into acute bacterial otitis media if nasopharyngeal secretions are aspirated due to improper ventilation. If ventilation is completely absent, sterile otitis media with effusion can develop. Infants with unrepaired palatal clefts and many children with repaired cleft palates often suffer from otitis media due to functional obstruction of the eustachian tube.

27. INTRINSIC MECHANICAL OBSTRUCTION Intrinsic mechanical obstruction usually results from inflammation within the bony or ear portion of the eustachian tube, which can be caused by polyps, cholesteatoma, or chronic mucosal inflammation. This type of obstruction is less common but significant. Inflammatory Causes : Acute or chronic inflammation due to upper respiratory infections can lead to significant eustachian tube dysfunction, causing conditions like atelectasis of the tympanic membrane, acute otitis media, or otitis media with effusion. Allergic Reactions : Although not commonly seen in children, eustachian tube obstruction due to nasal antigen challenges has been demonstrated in adult volunteers.

28. EXTRINSIC MECHANICAL OBSTRUCTION External compression of the eustachian tube, often by enlarged adenoids or, less commonly, tumors. The inflation-deflation manometric technique further confirmed that adenoidectomy improved eustachian tube function in some children with recurrent or chronic otitis media with effusion. Severity and Consequences : Partial obstruction might cause atelectasis or bacterial otitis media with effusion, while More severe obstruction can lead to sterile otitis media with effusion.

29. PATULOUS EUSTACHIAN TUBE Airflow and Ventilation : Air flow freely from the nasopharynx into the middle ear, but this can result in reflux otitis media. Semi-Patulous Eustachian Tube : Increased tubal compliance may lead to functional obstruction. This condition can cause negative pressure, effusion, or both in the middle ear. Factors Influencing Tubal Function Active Tubal Opening : When the tensor veli palatini muscle contracts and actively opens the tube, the risk of reflux or insufflation of nasopharyngeal secretions increases. Lower Resistance : If resistance is low but functional obstruction during active opening attempts, nasopharyngeal secretions may enter the ear more readily than air.

30. EUSTACHIAN TUBE FUNCTION RELATED TO CLEFT PALATE Studies suggest functional obstruction of the eustachian tube in children with cleft palates, leading to persistent or recurrent high negative ear pressure and effusion. Even after repair, children may experience persistent failure of the eustachian tube to open actively or increased tube distensibility, or both. Inflation-deflation manometric tests show that these children often struggle to equilibrate increased ear pressure and cannot equilibrate negative pressure through active swallowing.

31. OTHER CAUSES OF EUSTACHIAN TUBE DYSFUNCTION Cleft Palate : Craniofacial malformations associated with cleft palate, such as Pierre Robin syndrome, increase the risk of ear disease. Down's Syndrome : Eustachian tubes with low resistance that fail to dilate during swallowing, contributing to recurrent otitis media with effusion. Deviated Nasal Septum : This condition can impair eustachian tube function, especially during barometric pressure changes such as during flying or diving. Palatal and Pterygoid Trauma : Injury to the palate, pterygoid bone, tensor veli palatini muscle, or eustachian tube itself can result in ETD. Trauma to the trigeminal nerve: Particularly the mandibular branch, can cause functional obstruction or patulous eustachian

32. MANAGEMENT OF EUSTACHIAN TUBE DYSFUNCTION Eustachian tube dysfunction (ETD) can manifest as Obstruction Abnormal patency

33. OBSTRUCTION Obstruction of the eustachian tube can lead to conditions like otitis media and atelectasis This can result in high negative pressure in the middle ear, leading to symptoms such as: Otalgia Feeling of fullness Hearing loss Popping and snapping sounds Tinnitus Vertigo

34. Management Strategies: Medical Treatment : Relief of nasal congestion during episodes of acute upper respiratory infection. For chronic symptoms, search for underlying causes such as allergies or chronic sinusitis. Use of decongestants or antihistamines may be beneficial. Eustachian tube-middle ear inflation techniques can be tried. Surgical Treatment : Myringotomy and insertion of a tympanostomy tube if non-surgical methods are ineffective.

35. ABNORMALLY PATENT EUSTACHIAN TUBE An abnormally patent eustachian tube, or patulous tube, remains open when it should be closed. Symptoms often include: Autophony (hearing one’s own voice or breathing loudly) A tympanic membrane that moves with respiration (medially on inspiration and laterally on expiration).

36. Management Strategies: Non-Surgical Treatment : Self resolving, especially in children and teenagers. Conservative measures include recumbent positioning to increase extramural pressure. Surgical and Interventional Treatment : Myringotomy with tympanostomy tube insertion may be performed, but results are mixed. Historical treatments include insufflation of boric and salicylic acid powder, infusion of absorbable gelatin sponge, and polytetrafluoroethylene (Teflon) injections.

37. Innovative Procedures : An anterior tympanotomy approach with insertion of an indwelling intravenous catheter into the protympanic portion of the eustachian. The catheter can be removed if necessary, providing a reversible option.

38. MANAGEMENT OF ATELECTASIS Atelectasis of the tympanic membrane involves the collapse of the membrane due to eustachian tube dysfunction, leading to high negative middle ear pressure and the formation of retraction pockets. The condition varies in severity and can be either acute or chronic. Causes and Symptoms Causes : Obstruction of the eustachian tube (functional, mechanical, or both) rather than abnormal patency. Symptoms : Can include ear pain (otalgia), hearing loss, tinnitus, vertigo, and a feeling of fullness or pressure in the ear.

39. ACUTE ATELECTASIS : Transient High Negative Pressure : Often secondary to acute upper respiratory infections or barotrauma. Management : Usually self-limited and resolves with the infection. Treatment focuses on relief of nasal symptoms using decongestants. Severe Symptoms : If otalgia, hearing loss, tinnitus, or vertigo is severe, myringotomy may be necessary to equalize ear pressure.

40. CHRONIC ATELECTASIS WITHOUT DEEP RETRACTION POCKETS : Persistent Symptoms : If symptoms like otalgia, hearing loss, vertigo, or tinnitus persist, consider: Myringotomy with Tympanostomy Tube Insertion : This can prevent high negative pressure and manage chronic retraction. Tympanoplasty : If the tympanic membrane does not return to a normal position post-tympanostomy tube insertion, or if suitable aerated space is lacking, surgery might be required.

41. CHRONIC ATELECTASIS AND RETRACTION POCKETS : Concurrent Ear Effusion : Treat similarly to otitis media with effusion. If severe retraction pockets are present, perform myringotomy and insert a tympanostomy tube to prevent irreversible changes. Severe Retraction Pockets : Consider tympanoplasty to prevent complications like ossicular discontinuity or cholesteatoma. Less Severe Cases : For chronic atelectasis without a severe retraction pocket, consider: Watchful Waiting Nasal Decongestants and Antihistamines Eustachian Tube Inflation

42. SEVERELY ATELECTATIC TYMPANIC MEMBRANE WITHOUT HIGH NEGATIVE PRESSURE : Management : Non-surgical and surgical options may be ineffective. Symptoms often do not necessitate treatment. Adhesive Otitis Media : If present, portions of the tympanic membrane may adhere to the ear, leading to separate management strategies for ventilation and aeration of affected areas. Options : Consider tympanoplasty or periodic observation (once or twice a year) to monitor the condition.

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