1. Anatomy & Physiology of Eustachian Tube
Dr. Vishal Sharma

2. History & Embryology
Bartolomeus Eustachius first described it as pharyngo-tympanic tube in 1562.
Antonio Valsalva named it Eustachian tube.
Develops from tubo-tympanic recess, derived from endoderm of 1st pharyngeal pouch.

3. Bartolomeus Eustachius

4. Antonio Maria Valsalva

5. Embryology

7. Anatomy

8. Anatomy 36 mm long in adults.
Directed anteriorly, inferiorly & medially from anterior wall of M.E., forming angle of 450 with horizontal & sagittal planes.
Enters naso-pharynx 1.25 cm behind posterior end of inferior turbinate.

9. Angulation

10. Pharyngeal opening

11. Parts Lateral 1/3 is bony Medial 2/3 is fibro-cartilaginous.
Junction b/w 2 parts is isthmus, narrowest part of Eustachian Tube.

12. Anatomy of medial 2/3rd
Cartilage plate lies postero-medially & consists of medial + lateral laminae separated by elastin hinge. Fibrous tissue + Ostmann’s fat pad lie antero-laterally.

13. Anatomy Muscle attachments: 1. tensor veli palatini or dilator tubae
2. levator veli palatini
3. salpingopharyngeus
4. tensor tympani
Nerve supply: 1. Sphenopalatine ganglion
2. Mandibular nv 3. Tympanic plexus

14. Anatomy Lining epithelium: respiratory epithelium
Arterial supply: ascending pharyngeal &
middle meningeal arteries
Venous drainage: pharyngeal & pterygoid
venous plexus
Lymphatic drainage: retropharyngeal node

15. Endoscopic Anatomy Medial end forms tubal elevation / torus tubarius
Lymphoid collection over torus is called Gerlach’s tubal tonsil.
Postero-superior to torus is fossa of Rosenmüller.

16. Adult vs. Child (< 7 yr)

17. Adult vs. Child (< 7 yr)
INFANT
Length
36 mm
18 mm
Angle with horizontal
45 0
10 0
Lumen
Narrower
Wider
Angulation at isthmus
Present
Absent
Cartilage
Rigid
Flaccid
Elastic recoil
Effective
Ineffective
Ostmann’s fat
More
Less

18. Physiology Bony part is always open.
Fibro-cartilaginous part is closed at rest.
Opens on:
1. swallowing yawning sneezing forceful inflation

19. Physiology
Opens actively by contraction of tensor veli palatini & passively by contraction of levator veli palatini (it releases the tension on tubal cartilage).
Closes by elastic recoil of elastin hinge + deforming force of Ostmann’s fat pad.

20. E.T. opening

21. Functions 1. Ventilation & maintenance of atmospheric
pressure in middle ear for normal hearing
2. Drainage of middle ear secretions into
nasopharynx by muco-ciliary clearance,
pumping action of Eustachian tube &
presence of intra-luminal surface tension

22. Functions 3. Protection of middle ear from:
Ascending nasopharyngeal secretions due to narrow isthmus & angulation between 2 parts of E.T. at isthmus
Pressure fluctuations
Loud sound coming through pharynx

23. Functions

24. Conditions of Dysfunction

25. Bluestone’s Flask Model

26. Adult vs. Pediatric

27. TM perforation & nose blowing

28. O.M.E. & Barotrauma

29. Grommet insertion in O.M.E.

30. Tests for E.T. function

31. 1. Valsalva Maneuver Forced expiration with mouth & nose closed.
Otoscopy shows
lateral bulging of
Tympanic membrane

32. 2. Frenzel Maneuver Hands free Valsalva for pilots
Compression of nasopharyngeal air by muscles of tongue
Otoscopy shows lateral bulging of tympanic membrane

33. 2. Frenzel Maneuver

34. 3. Toynbee Maneuver More physiological Swallowing with
mouth & nose closed
Otoscopy shows
retraction of tympanic
membrane

35. 4. Pneumatic otoscopy & Siegelization
Air pressure is alternately increased & decreased within external auditory canal
Mobility of tympanic membrane is observed
Normal mobility indicates good patency of Eustachian tube

36. Siegelization

37. Pneumatic Otoscope

38. Normal Tympanic Membrane

39. Eustachian Tube dysfunction

40. Early otitis media with effusion

41. Late otitis media with effusion

42. Acute suppurative otitis media

43. Ear drum perforation

45. 5. Politzerization

46. Politzer Bag

47. 5. Politzerization
Rubber tube attached to a Politzer bag put into one nostril & both nostrils pinched
Patient asked to swallow or repeat “k”
Politzer bag is squeezed simultaneously
Otoscopy shows lateral bulging of ear drum in patent Eustachian tube

48. 6. E.T. catheterization

49. Eustachian tube catheter

50. 6. E.T. catheterization
E.T. catheter passed along nasal floor till it touches posterior wall of naso-pharynx.
Catheter rotated 90° medially & pulled forward till it impinges on posterior nasal septum.
Catheter rotated 180° laterally, & its tip inserted into opening of E.T.
Politzer bag attached to outer end of catheter

51. 6. E.T. catheterization
Air pushed into E.T. catheter by squeezing Politzer bag. Examiner hears by Toynbee auscultation tube put in pt's ear.
Blowing sound = normal E.T. patency
Bubbling sound = middle ear fluid
Whistling sound = partial E.T. obstruction
No sound = complete obstruction of E.T.

52. 7. Tymapanometry

53. 7. Tymapanometry Type C = E.T. dysfunction
Type B = fluid in middle ear

54. 8. William’s pressure equalization test
200 mm H2O pressure is created in patient’s external auditory canal
Patient asked to swallow 10 times
Residual pressure in patient’s external auditory canal after 10th swallow is noted
Test repeated with -ve 200 mm H2O pressure created in patient’s external auditory canal

55. William’s Test Residual Pressure Result Up to + 50 mm H2O
normal E.T. function
+ 51 to mm H2O
mild dysfunction
+ 101 to mm H2O
moderate dysfunction
+ 200 mm H2O
severe dysfunction

56. 9. Sono-tubometry
Sound made in pt’s nasal cavity & detected with stethoscope in patient’s external auditory canal
Loud sound = patent Eustachian tube
10. Eustachian tube Salpingogram
Dye instilled through E.T. catheter & X-ray taken
11. C.T. scan & M.R.I. of skull

57. 12. Trans-nasal E.T. video-endoscopy
13. Test for E.T. patency in T.M. perforation
Saccharine crystal / antibiotic ear drop / methylene blue placed in middle ear via ear drum perforation.
Sweet taste / bitter taste / blue staining of secretions indicates patent Eustachian tube

58. Patulous Eustachian Tube

59. Clinical Features
Aural fullness, humming tinnitus, hearing their own voice (autophony), hearing their own breath sounds (tympanophonia).
Symptoms resolve in supine position, in forward bending with head between knees, in U.R.T.I. Aggravated by mastication.

60. Otoscopy: T.M. moves during breathing.
Associated conditions: radiation therapy, hormonal therapy, nasal decongestants, 3rd trimester pregnancy, stress, sudden weight loss, multiple sclerosis.
Treatment: Reassurance, weight gain, oral potassium iodide.

61. Surgical interventions
Electro-cauterization of E.T. orifice
Peri-tubal injection with Teflon paste
Transposition of tensor veli palatini muscle medial to pterygoid hamulus
Plugging of E.T. orifice in Middle ear + myringotomy & grommet insertion

62. Thank You