Introduction and Overview

All otitis media is middle-ear disease, but middle-ear disease includes more than otitis media, such as Eustachian tube (ET) dysfunction, myringosclerosis, tympanosclerosis, ossicular congenital and acquired disorders, otosclerosis, and congenital and acquired cholesteatoma.

The chapter includes

• Key advances in the study of the ET in the past 11 years.

• Glossary of terms.

• Historical perspective, including contributions of Eusthachius, Valsalva, Toynbee, Politzer, Rich, Perlman, and Ingelstedt.

• Other etiologic and pathogenic factors in the pathogenesis of middle-ear diseases.

Knowledge of the structure and function of the Eustachian tube (ET) system is necessary to understand the pathogenesis of otitis media, which will result in rational management decisions. The contents of this book have been divided into chapters that relate to the structure, function, and dysfunction of the ET system (i.e., the nasal cavities, nasopharynx, and palate, proximal to the ET, and middle ear cavity and mastoid gas cells distally); its role in the pathogenesis and management of middle-ear disease; and related diseases and disorders. Also presented are contributing factors other than the ET in the etiology and pathogenesis of otitis media, including infection owing to viruses and bacteria, the immunology of the host, the role of allergy, and social and environmental factors. This perspective is important at the outset so that the reader does not think that the only factor in the pathogenesis of middle-ear disease is dysfunction of the ET.

New to This Edition

This edition includes the many advances in the study of the ET over the past 11 years and contributions from several colleagues. (The first edition was solely written by Charles Bluestone.) Each chapter has been updated with important peer-reviewed articles published from 2004 to 2016.

Key New Advances

• Impact of human evolution on the structure and function of the ET, as well as pathogenesis and epidemiology of otitis media. Chapter 6: Pathogenesis

• An apparently unique case of alternobaric vertigo, not from the usual activities of scuba diving and airplane flying, but at ground level due to nasal obstruction, ET dysfunction, and a unilaterally functioning tympanostomy tube, which created a “Toynbee phenomenon.” Chapter 6: Pathogensis

• Pressure chamber evaluation of ET function. Chapter 8: Diagnosis and Tests of Function

• Balloon dilation of the ET. Chapter 9: Role in Management

Glossary of Terms

Some differences remain among health care professionals regarding the meanings of these terms. No organized professional body has agreed on the definitions used, but we have used these terms in our current texts on otitis media^1–5 and to some extent at the International Symposia on Recent Advances in Otitis Media,^6,7 with the most recent being the 18th symposium held in June 7–11, 2015.

Middle-ear disease is a term that not only includes otitis media and its related conditions but also ET dysfunction, traumatic and infectious perforation of the tympanic membrane, tympanosclerosis, myringosclerosis, congenital and acquired disorders of the ossicules, congenital and acquired cholesteatoma, otosclerosis, and benign and malignant tumors.

Otitis media is an inflammation of the middle ear, without reference to etiology or pathogenesis. (NOTE: All otitis media is middle-ear disease but not all middle-ear disease is otitis media.

Acute otitis media is the rapid onset of signs and symptoms of acute infection in the middle ear.

Otitis media with effusion is an inflammation of the middle ear in which a collection of liquid is present in the middle-ear space and the tympanic membrane is intact.

Middle-ear effusion is the liquid resulting from otitis media or from ET dysfunction. The effusion may be

• Serous—thin, watery liquid

• Mucoid—thick, viscid, mucus-like liquid

• Purulent—pus-like liquid

Persistent middle-ear effusion is an effusion that persists in the middle ear after an episode of acute otitis media.

Eustachian tube dysfunction is an abnormal function of the ET but does not imply the type of dysfunction. The type of dysfunction must be specified because there are several ways in which the tube functions abnormally; it can be obstructed (too closed) or patulous (too open).

Atelectasis of the tympanic membrane–middle ear is the collapse or retraction of the tympanic membrane. Negative middle-ear pressure may or may not be present. It may be generalized or localized, the latter usually being a retraction pocket.

Retraction pocket is a localized area of atelectasis of the tympanic membrane.

Otorrhea is a discharge from the ear that can emanate from the external auditory canal, middle ear, mastoid, or brain. Discharge can be blood or cerebral spinal fluid. The consistency can be described as

• Serous—thin, watery liquid

• Mucoid—thick, viscid, mucus-like liquid

• Purulent—pus-like liquid

Chronic suppurative otitis media is a stage of ear disease in which there is chronic inflammation of the middle ear and mastoid gas cells and in which a nonintact tympanic membrane (perforation or tympanostomy tube) and otorrhea are present. Chronic otitis media is an incorrect term as chronic suppurative otitis media is preferred.

Cholesteatoma is keratinizing stratified squamous epithelium and an accumulation of desquamating epithelium of keratin within the middle ear or other pneumatized portions of the temporal bone, but it may also occur in other portions the skull. Chronic suppurative otitis media may or may not be present. Cholesteatoma that is associated with middle-ear disease and disorders and related conditions is acquired as opposed to congenital.

Eustachian tube (ET) is an organ consisting of a lumen with its mucosa, cartilage, surrounding soft tissue, peritubal muscles (tensor veli palatini, levator veli palatini, salpingopharyngeus, and tensor tympani), and its superior bony support, the sphenoid sulcus.

Eustachian tube system is contiguous organs, including the nose, palate, nasopharynx, ET, middle ear, and mastoid gas cells (see Figure 1–1).

FIGURE 1–1. The ET as part of a system in which the pharynx, palate, and nasal cavities are at its proximal end, and the middle ear and mastoid gas cells are at its distal end.

Auditory tube is synonymous with ET, but the latter is correct.

Pharyngotympanic tube is synonymous with ET. This is a new term proposed by the International Federation of Anatomists to replace ET.

Pressure regulation is the physiologic function of the ET to regulate atmospheric pressure and gas pressure between the nasopharynx and the middle ear.

Ventilation is used synonymously with the physiologic function of pressure regulation, which is the more correct term for this function of the ET.

Protection is the physiologic function of the ET in which unwanted nasopharyngeal secretions and sound pressures are prevented from entering the middle ear by the unique structural and functional aspects of the tubal system.

Clearance is the physiologic function of the ET in which liquid is drained toward the nasopharynx by the mucociliary system of the tubal lumen and the pumping action of the tube during passive closing.

Drainage is used synonymously with clearance, but clearance is the more precise term.

Prograde is the flow of liquid down the ET tube and is synonymous with clearance.

Opening pressure is the pressure at which the ET opens to applied positive pressure.

Forced-opening pressure is used synonymously with opening pressure.

Closing pressure is the pressure that remaining in the middle ear following forced opening.

Residual pressure is the pressure remaining in the middle ear following applied positive or negative pressure and after swallowing.

Forced-response test is a test of ET function in which the middle ear is inflated with a constant airflow rate until the tube is opened.

Passive resistance is the resistance of the ET to airflow when active opening (i.e., dilation) of the tubal lumen is absent.

Active resistance is the resistance of the ET to airflow during active opening (i.e., dilation) of the tubal lumen.

Sonotubometry is a test of the ET opening during swallowing in which a sound generated within the nose and nasopharynx is recorded in the external auditory canal.

Compliance is the quality of yielding to pressure or force without disruption. When related to the ET as an organ, it is the distensibility of the walls of the lumen of the tube. The reciprocal of compliance is stiffness of the tube. We have used the expression floppy to describe increased compliance of the tube (decreased stiffness).

Failure of the opening mechanism is used to describe the pathophysiologic condition in which the ET does not actively open during swallowing activity owing to contraction of the tensor veli palatini muscle.

Functional obstruction is due to failure of the opening mechanism of the ET as opposed to anatomic (mechanical) obstruction.

Anatomic obstruction refers to obstruction of the ET, which can be intraluminal, intramural, or extramural.

Mechanical obstruction is used synonymously with anatomic obstruction.

Intrinsic obstruction is synonymous with intraluminal or intramural anatomic obstruction of the ET.

Extrinsic obstruction is synonymous with extramural anatomic obstruction of the ET.

Patulous Eustachian tube is a tube in which the lumen is too open, usually at rest, when the normal tubal lumen should be collapsed.

Semipatulous Eustachian tube is open at intervals at rest or is almost patulous and has abnormally low opening pressures on tests of function.

Valsalva’s maneuver is a method to force air into the ET and inflate the middle ear by applying positive pressure to the nasopharyngeal end of the tube by a forced expiration with the nose closed (autoinflation). This normally results in positive middle-ear pressure.

Valsalva’s test is a test of patency of the ET that normally should result in positive middle-ear pressure. It is not a test of ET function.

Politzer’s test is similar to Valsalva’s maneuver, but a bag filled with air is used to apply positive pressure to the nose, nasopharynx, and ET.

Politzerization is the method of Politzer to inflate the ET and middle ear either for testing tubal function or for treating middle-ear diseases and disorders.

Toynbee maneuver is swallowing with both nares held closed by the thumb and fore finger.

Toynbee test is used to assess ET function in which the subject swallows with the nose obstructed by pinching off the ala (nostrils) of the nose with the finger and thumb; the pressures in the middle ear are evaluated following the test. Compared with the other classic tests and maneuvers, this is a better, albeit crude, test of function.

Toynbee phenomenon (first introduced by Charles Bluestone) describes the effect on the ET system when there is nasal or postnasal obstruction and swallowing occurs.

Aspiration is the indrawing of fluid (i.e., gas or liquid) from the nasopharynx into the ET and middle ear owing to negative middle-ear pressure (under pressure).

Insufflation is forcing fluid (i.e., gas or liquid) into the ET–middle ear by the application of positive pressure into the nasopharynx; it occurs when the nose or nasopharynx is obstructed during a Valsalva maneuver, Toynbee test or phenomenon, or when blowing the nose.

Reflux is backward flow that, in the context of the pathophysiology of the ET, is abnormal flow of liquid (secretions) from the nasopharynx through the tube into the middle ear.

Retrograde is abnormal backward flow of liquid into the ET–middle ear and is synonymous with reflux.

Reflux otitis media refers to middle-ear disease caused by the reflux of nasopharyngeal secretions through the ET into the middle ear.

Historical Perspective

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