BACKGROUND

Referring toFIG. 1, the ear (10) is divided into three parts: an external ear (12), a middle ear (14) and an inner ear (16). The external ear (12) consists of an auricle (18) and ear canal (20) that gather sound and direct it toward a tympanic membrane (22) (also referred to as the eardrum) located at an inner end (24) of the ear canal (20). The middle ear (14) lies between the external and inner ears (12,16) and is connected to the back of the throat by a Eustachian tube (ET) (26), which serves as a pressure equalizing valve between the ear (10) and the sinuses. The ET (26) terminates in a pharyngeal ostium (28) in the nasopharynx region (30) of the throat (32). In addition to the eardrum (22), the middle ear (14) also consists of three small ear bones (ossicles): the malleus (34) (hammer), incus (36) (anvil) and stapes (38) (stirrup). These bones (34,36,38) transmit sound vibrations to the inner ear (16) and thereby act as a transformer, converting sound vibrations in the canal (20) of the external ear (12) into fluid waves in the inner ear (16). These fluid waves stimulate several nerve endings (40) that, in turn, transmit sound energy to the brain where it is interpreted.

The ET (26) is a narrow, one-and-a-half inch long channel connecting the middle ear (14) with the nasopharynx (30), the upper throat area just above the palate, in back of the nose. A narrowed region known as the isthmus (29) of the ET (26) provides a transition between the remainder of the ET (26) and the middle ear (14). The isthmus (29) is the narrowest part of the ET (26) at the junction of the bony and cartilaginous parts of the ET (26) (i.e., where the bony canal meets the cartilaginous tube). The isthmus (29) thus has a reduced inner diameter compared to the remaining portion of the ET (26) that extends between the isthmus (29) and the pharyngeal ostium (28); and provides a density that is substantially greater than the density of the tissue of the remaining portion of the ET (26) that extends between the isthmus (29) and the pharyngeal ostium (28).

The ET (26) functions as a pressure equalizing valve for the middle ear (14), which is normally filled with air. When functioning properly, the ET (26) opens for a fraction of a second periodically (about once every three minutes) in response to swallowing or yawning. In so doing, it allows air into the middle ear (14) to replace air that has been absorbed by the middle ear lining (mucous membrane) or to equalize pressure changes occurring on altitude changes. Anything that interferes with this periodic opening and closing of the ET (26) may result in hearing impairment or other ear symptoms.

Obstruction or blockage of the ET (26) results in a negative middle ear (14) pressure, with retraction (sucking in) of the eardrum (22). In adults, this is usually accompanied by some ear discomfort, a fullness or pressure feeling and may result in a mild hearing impairment and head noise (tinnitus). There may be no symptoms in children. If the obstruction is prolonged, fluid may be drawn from the mucous membrane of the middle ear (14), creating a condition referred to as serous otitis media (fluid in the middle ear). This may occur frequently in children in connection with an upper respiratory infection and account for hearing impairment associated with this condition.

When the ET (26) is blocked, the body may absorb the air from the middle ear (14), causing a vacuum to form that tends to pull the lining membrane and ear drum (22) inwardly, causing pain. Next, the body may replace the vacuum with more fluid which tends to relieve the pain, but the patient can experience a fullness sensation in the ear (10). Finally, the fluid can become infected, which can lead to pain, illness, and temporary hearing loss. If the inner ear (16) is affected, the patient may feel a spinning or turning sensation (vertigo).

Methods for treating the middle ear (14) and restriction or blockage of the ET (26) include those disclosed in U.S. Patent Pub. No. 2010/0274188, entitled “Method and System for Treating Target Tissue within the ET,” published on Oct. 28, 2010, now abandoned, the disclosure of which is incorporated by reference herein; U.S. Patent Pub. No. 2013/0274715, entitled “Method and System for Eustachian Tube Dilation,” published on Oct. 17, 2013, now abandoned, the disclosure of which is incorporated by reference herein; and U.S. Pub. No. 2015/0374963, entitled “Vent Cap for a Eustachian Tube Dilation System,” published Dec. 31, 2015, issued as U.S. Pat. No. 10,350,396 on Jul. 16, 2019, the disclosure of which is incorporated by reference herein.

In some cases, rather than being restricted or blocked, the ET (26) may fail to close properly, or such that the ET (26) takes an inordinately prolonged amount of time to close after being opened, such that the ET (26) substantially remains in a patulous state. This may adversely affect the patient by causing variations in the upper airway pressure around the ET (26) and the middle ear (14). In some patients, a patulous ET (26) may create a feeling of dry sinus, an increased breathing rate with physical activity, higher than usual perceived volumes of sound, and/or other undesirable consequences. It may therefore be desirable to provide a form of treatment for a patulous ET (26). It may further be desirable for such a treatment to still provide some degree of ventilation and drainage for the ET (26), without completely closing the ET (26).

While a variety of surgical instruments have been made and used, it is believed that no one prior to the inventors has made or used the invention described in the appended claims.

