WO2006049131A1 - Artificial eustachian tube - Google Patents

Abstract

An artificial Eustachian tube fitted in patient’s Eustachian tube that is effective in the basic remedy of Eustachian tube dysfunction diseases and enables closing of eardrum perforation, which artificial Eustachian tube can be widely applied to patient’s Eustachian tube isthmus of variable size. There is provided an artificial Eustachian tube fitted in patient’s Eustachian tube in the state of engaging with the isthmus of Eustachian tube so as to make its forefront face the cartilage part of Eustachian tube, characterized in that one or more circular protrusions of 0.6 to 3.6 mm outer diameter are provided within the range from the forefront to 16 mm lengthwise, and that the cavity of the tube opens outward through a forefront side aperture at the forefront, or front of one most close to the forefront among the circular protrusions, or therebetween, while in the rear of the circular protrusions, the tube cavity opens outward through a rear aperture.

Description

 Specification

 Artificial ear canal

 Technical field

 [0001] The present invention relates to an artificial ear canal that can restore the function of a patient's ear canal by being embedded in the ear canal of a patient.

 Background art

 [0002] The ear includes an outer ear, a middle ear, and an inner ear. The outer ear and the middle ear are separated by the eardrum located at the inner edge of the ear canal. The middle ear consists of the tympanic chamber (middle ear cavity), which is the space that houses the ear ossicles (tut bone, quinuta bone, and stapes) that connect the eardrum to the vestibular window (which leads to the vestibule of the inner ear) and the pharynx. The ear canal is open to the The eustachian tube begins in the tympanic vestibule (the tympanic ear canal), and extends obliquely from the upper posterior outer side to the lower anterior inner side and opens at the pharyngeal side wall (the tubal pharyngeal mouth). The eustachian tube is about 33 mm long, about 1/3 of the upper part passes through the temporal bone, and about 2/3 of the lower part is wrapped with cartilage. The bone ear canal passes through the narrowed tympanic ear canal and then gradually narrows and becomes the thinnest at the cartilage entrance (the canal area).

) Normally closed at this position. Below the eustachian tube, the eustachian tube gradually thickens and opens into the pharyngeal mouth in a rapper shape. One of the functions of the eustachian tube is the ventilation function. This is because the lower wall of the cartilage part is pulled downward due to contraction of the palatal levee muscle during swallowing, and the lumen of the canal is temporarily opened, and air flows from the pharynx into the tympanic chamber. It is divided into active ones and passive ones that passively ventilate as the external pressure changes. In healthy ears, the intratympanic pressure is kept equal to the external pressure due to the ventilatory function of the eustachian tube, especially the active ventilation function. The eustachian tube also has the function of excreting middle ear secretions into the pharynx. The state in which these functions are impaired, i.e., ear canal dysfunction, include ear canal stenosis (ear canal obstruction), ear canal opening, ear canal insufficiency, exudative otitis media, cholesteatic otitis media, Adhesive otitis media and the like can be mentioned.

[0003] Eustachian stenosis is a condition in which the enlargement of the harmful ear canal caused by swallowing or other reasons is impaired for some reason, and ventilation of the middle ear through the ear canal is impaired. The cause of this is due to organic stenosis of the eustachian tube due to inflammation of the nasopharynx, etc. There is functional stenosis due to dysfunction. If the middle ear is prevented from ventilating due to a constriction of the eustachian tube, oxygen in the tympanic chamber is absorbed by the surrounding mucosal force, resulting in a negative pressure in the tympanic chamber and the tympanic membrane. As a result, symptoms such as ear-closed feeling, hearing loss, and hearing loss are caused. If tubal stenosis persists, it may shift to exudative otitis media. This is a disease in which exudate leaks into the middle ear cavity as a result of persistent negative pressure in the tympanic chamber, which fills the tympanic chamber with exudate and causes hearing loss and ear obstruction, as well as recurrent acute otitis media. It becomes easy to suffer from. In addition, if the tympanic chamber is placed in a chronic and irreversible negative pressure state, it may occur in adhesive otitis media, an extremely refractory disease in which the tympanic membrane adheres to the middle ear wall, or in the mucous membrane of the middle ear cavity, which is not essentially epithelial The keratinized squamous epithelium of the tympanic membrane proliferates and destroys the surrounding bone in the process, causing cholesteatic otitis media.

For the treatment of ear canal stenosis, so-called ear canal ventilation therapy, in which a catheter is inserted into the pharyngeal mouth and ventilated, is frequently used. Other treatments include the ability to inject steroid hormones into the ear canal from the pharynx side or the tympanic chamber side, and the method of injecting steroid hormones submucosally around the ear canal pharyngeal mouth. It has not been established in the past. In conservative treatment by medication, anti-inflammatory enzyme preparations are administered systemically with antiallergic drugs and nasal drops of steroids, but they require long-term medication and are effective in patients with moderate or higher severity. There is a problem that there are many cases where it cannot be obtained sufficiently. In cases where drug therapy is not effective, tympanic tube placement is also performed to ensure ventricular ventilation. The eardrum tube is a tube that can be fitted into a perforation provided in the eardrum, and various sizes and shapes are commercially available. One of the most commonly used is a central tube with a length of about 3mm. With some tympanic tubes, ventricular ventilation can be obtained, but the stenosis of the ear canal itself is not sufficiently improved, and ventilation and excretion through the ear canal are not necessarily restored. In addition, the eardrum tube naturally falls off within a few months to a year with the repair of the perforation of the eardrum. If ear canal stenosis has not been improved, the eardrum tube must be re-applied to ensure ventilation. Yuve detention is also required. Recently, a treatment method has been developed to cauterize the mucous membrane in the ear canal from the pharyngeal mouth side with a laser (carbon dioxide laser, KTP laser) for cases that resist drug treatment. While shouting, cauterize the inner part near the canal It is essential to master sufficient anatomical knowledge and advanced surgical techniques in order to perform ablation of the canal, which has many unclear points about the effects on the surrounding tissue. I haven't been told.

 [0005] In addition, eustachian tube is a condition in which the eustachian tube is always open, and the patient's subjective symptoms include self-hearing due to the fact that his / her voice reaches the middle ear via the eustachian tube. Some people complain of dizziness because they can hear their breathing sounds and have a feeling of ear closure. The patient's tympanic membrane is normal but is observed to move back and forth with breathing. Causes of eustachian tube include atrophy of the nasal mucosa due to aging and neurological disease, atrophy of the peritubular mucosa due to weight loss, {HYPERLIN K http://homepagel.nifty.com/jibiaka50/adesyujyutu.htm, Fattenoid cattle After surgery; fe scarring, etc., but the cause is unknown.

 [0006] Pharmacotherapy for Eustachian tube disease includes the Bezold method in which a mixed powder of boric acid and salicylic acid is sprayed into the ear canal with an ear canal catheter, injection of gelatin sponge solution into the ear canal lumen, etc. Surgical treatment includes injection of liquid silicone, cauterization of the mucosa of the ear, patella scapular muscle movement, injection of collagen or cartilage around the ear canal, and collagen injection. Pharmacotherapy required continuous treatment over a long period of time, and surgical treatment was ineffective. In addition, as a device for treatment of eustachian tube and intubation atresia, a flattened eustachian pin with a taper that is placed in the middle ear canal lumen from the eardrum to about 5 to 15 mm deep is used. Although it has been proposed (see Patent Document 1), it works to block the cross section of the ear canal and is not applicable to ear canal stenosis.

 [0007] Further, so-called floppy tubes have recently attracted attention from the viewpoint of the function of the eustachian tube. A floppy tube is an ear canal that is easy to block and easily open, and when it is swallowed, the ear canal is opened, resulting in self-hearing and a feeling of ear closure. In order to resolve these discomforts, patients often unconsciously sniff their nose (this causes negative pressure in the tympanic chamber and closes the ear canal), but this is habitual and the tympanic chamber is chronic. In addition, exposure to irreversible negative pressure can cause exudative otitis media, adhesive otitis media, and cholesteatoma, as described above in connection with ear canal stenosis.

[0008] As described above, abnormalities of the eustachian tube function cause various diseases of the middle ear. However, it is effective to use a floppy tube that causes both eustachian stenosis, eustachian tube opening, and both occlusion and opening. There is a need for a reliable treatment method that can be easily treated and that can be used for the treatment of adhesive otitis media, prevention of tympanic membrane adhesion after surgery for exudative otitis media, prevention of recurrence of pearl species, and the like.

 [0009] For this purpose, the present inventor has previously developed a tube having a predetermined shape having an opening for ventilation on the tube wall. This is inserted into the ear canal from the eardrum side through the eardrum and the tip is located in the cartilage ear canal, while the opening of the tube wall is located in the eardrum and the rear end of the tube is attached to the eardrum. By fixing the tube through the tube, the nasal cavity and the tympanic chamber are connected to the auditory canal stenosis (tubal obstruction), and the ventilation function and excretion function through the ear canal are brought into a physiologically close state. Recoverable and appropriate communication between the nasal cavity and the tympanic chamber through the lumen of the tube, covering at least part of the cross-section of the tubal canal that is overspread, even in cases of eustachian tube or intubation failure It was found that it can be secured. Focusing on the fact that such a tube is extremely effective in the treatment of ear canal dysfunction and can be an “artificial ear canal”, based on this, an artificial ear canal consisting of a tube of a predetermined form was developed. (See Patent Document 2).

 [0010] Further, the present inventor does not need to fix the rear end to the eardrum, and thus enables the perforation of the eardrum to be closed, and has the same therapeutic effect while restoring the intratympanic environment closer to a more physiological state. We have developed a fully-embedded artificial ear canal, which has been filed for a patent (see Patent Document 3).

[0011] However, although the full containment type artificial eustachian tube has a remarkable therapeutic effect, it requires an advanced micro-molding technique, and there is a problem that the manufacturing cost for that is not negligible at present. In addition, it is desirable from the industrial point of view that an artificial eustachian tube of wide applicability to the Eustachianis part of various dimensions that is not greatly affected by the difference in the dimensions of the Eustachian part of each patient. There was room for further improvement.

 Patent Document 1: JP 2002-224157

 Patent Document 2: # 112003-375097

 Patent Document 3: Japanese Patent Application 2004-052323

 Disclosure of the invention

Problems to be solved by the invention [0012] Under the above background, the present invention is effective for the fundamental treatment of ear canal stenosis (ear canal obstruction), ear canal opening, ear canal insufficiency, and ear canal dysfunction including floppy tubes. An artificial ear canal that can be inserted into the patient's ear canal, and that can eventually close the perforation of the tympanic membrane, which can be fixed in the ear canal and is relatively easy to manufacture. And Z or

Another object of the present invention is to provide an artificial eustachian tube that can be widely applied to the eustachian tube of various thicknesses.

 Means for solving the problem

 [0013] In the course of the study aimed at solving the above problems, the present inventor, when placed in the patient's ear canal, has an annular shape on the side wall at a position where it will come into contact with the ear canal or the tissue in the vicinity thereof. As a result of producing and testing a tubular article having one or more protrusions, it was found that the above problems could be solved, and the present invention was completed. That is, the present invention provides the following.

 [0014] (1) An artificial eustachian tube that is inserted into a patient's ear canal in a state in which the tip of the cartilage canal portion is engaged with the canal isthmus,

 Having a tip, a rear end and a lumen;

 One or a plurality of annular projections having an outer diameter of 0.6 to 3.6 mm are provided within a range of 16 mm in the longitudinal direction from the distal end of the artificial ear canal,

 The lumen is open to the outside through at least one distal opening at the front end of the prosthetic ear canal or the front surface of the annular projection closest to the front end or any force therebetween.

 Behind the one or more annular projections, the lumen is open to the outside through at least one rear opening.

 An artificial eustachian tube characterized by the above.

 (2) The artificial ear canal according to the above 1, which has a plurality of the annular protrusions.

 (3) providing a flow path having at least an inner diameter of 0.2 mm or more through which the distal end side opening, the lumen, and the rear opening communicate with the inside and outside of the artificial ear canal; The artificial ear canal according to 1 or 2 above, wherein the flow path provides a portion having an inner diameter of 0.9 mm or less.

(4) Each of the annular projections has an outer diameter and an outer diameter of the starting portion near the rear end or the front end. The artificial ear canal according to any one of 1 to 3 above, which has a difference of 0.1 mm or more between

(5) The artificial ear canal according to any one of the above 1 to 4, wherein at least one of the rear openings is provided on a side wall of the lumen.

 (6) The artificial ear canal according to any one of 1 to 5 above, which includes a distal end side axial portion that extends forward in the longitudinal direction from the annular protrusion closest to the distal end.

 (7) The artificial ear canal according to 6 above, wherein an outer diameter of the shaft portion on the distal end side is 0.4 mm or more.

 (8) The artificial shaft according to 6 or 7 above, wherein the distal end side shaft portion includes an annular constricted portion having a width of 0.2 to 2.5 mm in the longitudinal direction adjacent to the most distal end side annular protrusion. Eustachian tube.

 (9) The artificial ear canal according to 8 above, wherein the annular constricted portion has an outer diameter of 0.1 to: 1. Omm smaller than an outer diameter of a portion near the tip and adjacent thereto.

 (10) The distal end side opening is open in the longitudinal direction at the distal end of the artificial ear canal, and has a portion where the inner diameter of the flow path is narrow within a range of 14 mm from the distal end. 10. The artificial ear canal according to any one of the above items 1 and 9, wherein the inner diameter is smaller by 0.2 mm or more than the inner diameter of the lumen behind it.

 (11) The above 1 to 10 in which the lumen is open to the outside through an opening extending in the longitudinal direction or arranged in the longitudinal direction by longitudinally cutting the one or more annular protrusions Any of the artificial eustachian tubes.

 (12) The artificial ear canal according to any one of 1 or 11 above, wherein the front surface and / or the rear surface of the annular protrusion has a conical surface.

 (13) The artificial ear canal according to any one of 1 to 11 above, wherein the front surface or the rear surface of the annular protrusion has a conical surface, and the opposite surface has a steeper surface.

 (14) The artificial ear canal according to any one of 1 to 13 above, having an overall length of 22 mm or more.

 (15) The artificial ear canal according to any one of 1 to 14 above, which is made of a flexible material.

 (16) The artificial ear canal according to any one of 1 to 15 above, wherein a plurality of annular protrusions are arranged adjacent to each other.

The invention's effect

The artificial ear canal of the present invention is inserted into the patient's ear canal, thereby allowing the artificial ear canal to flow. Moderate communication between the patient's cartilage ear canal (and thus the nasal cavity) and the tympanic chamber can be achieved through the tract. That is, (1) In a patient with ear canal stenosis (ear tube obstruction), ventilation between the nasal cavity and the tympanic chamber can be ensured (ventilation function), and the pressure difference between the tympanic chamber and the outside can be eliminated. In addition, when there is secretion in the tympanic chamber, it can also function to flow through the lumen to the nasal cavity side (excretion function). Even when exudate remains in the artificial ear canal, the exudate moves up and down in response to pressure fluctuations between the tympanic chamber and the nasal cavity, so there is virtually no difference in pressure between the tympanic chamber and the nasal cavity (i.e., the arousal function). Is kept). In addition to passing through the lumen, the flat canal mucosa can be pushed and expanded to form a slight gap, thereby further promoting the excretion of exudate into the nasal cavity of the tympanic cavity. (2) Also, in patients with Eustachian tube or Eustachian canal insufficiency, correct the excessive ventilation between the nasal cavity and the tympanic chamber and make it physiologically appropriate via the lumen of the artificial eustachian tube. Ventilation conditions can be brought about. (3) Furthermore, even for a patient having a floppy tube, it is possible to remove the open or closed state of the ear canal and restore a physiologically appropriate ventilation state.

Therefore, according to the artificial ear canal of the present invention, various middle ear diseases caused by these ear canal dysfunctions can be fundamentally treated. Moreover, the artificial ear canal of the present invention can be completely embedded in the range from the ear canal to the tympanic chamber where the rear end does not need to be fixed to the eardrum, and does not need to be removed at a later date. In addition, during the follow-up after surgery, it is possible to see the long-term progress as it is, even if the rear end part protrudes from the eardrum. Thereafter, when completely embedding, the rear end may be disposed inside the eardrum (eg, by cutting off the excess length of the rear end if necessary). Therefore, if the artificial ear canal of the present invention is used, it is possible to leave the tympanic membrane perforation created at the time of surgery to be repaired and closed after the operation. After the perforation is closed, there is no risk of infection of the middle ear or foreign matter from the outer ear side, and the tympanic chamber is blocked from direct communication with the outside air, restoring the physiological atmosphere in the tympanic chamber. Thus, the patient treated by the placement of the artificial ear canal of the present invention can live daily life with the eardrum healed and restored to a physiological state, and there are no restrictions on life. That is, the artificial eustachian tube of the present invention has excellent effects in both the treatment of the target disease and the quality of life of the patient after treatment. In addition to these effects, the artificial ear canal of the present invention is relatively easy to manufacture, and can be applied to the ear canal of various thicknesses when a plurality of annular projections are provided. It is excellent in practicality in that it requires only a small number of sizes and it can be easily inserted into the ear canal, and enables treatment of a wide range of patients.

Brief Description of Drawings

 [Fig. 1] Side view of the artificial ear canal of Example 1

 [Fig. 2] Longitudinal sectional view of the artificial eustachian tube of Example 1

 FIG. 3 is a side view of a variation of the artificial ear canal of Example 1.

4] Side view of the artificial ear canal of Example 2

5] Side view of the artificial ear canal of Example 3

 [Fig. 6] Side view of the artificial eustachian tube of Example 4

 FIG. 7: Side view of the artificial ear canal of Example 5

 [Fig.8] Anatomy of the ear

9] Anatomy of the ear with an artificial eustachian tube inserted

10] Chart showing results of preoperative acoustic eustachian tube examination in case 1

11] A chart showing the results of postoperative acoustic eustachian examination in case 1

12] Chart showing results of preoperative Valsalva ventilation in case 1 [13] Chart 13 showing results of postoperative Valsalva ventilation in case 1 [14] Garden 14] Preoperative deep nose breathing in case 1 Chart 15: Chart showing results of preoperative Toinbee swallowing in Case 1 Chart 16: Chart showing results of postoperative Toinbee swallowing in Case 1 Garden 17] Preoperative nose in Case 1 Chart showing test results by scouring test method 18] Chart showing results of pressure reduction test by reverse aeration after surgery in case 1

[Figure 19] Chart showing results of preoperative acoustic eustachian examination in case 2 [20] Chart showing results of postoperative acoustic eustachian examination in case 2 [21] Preoperative in 21 Chart showing the results of pressure / decompression test by reverse aeration method

[Figure 22] Chart showing the results of post-operative pressure reduction test by reverse ventilation method in Case 2 [23] Chart showing results of preoperative Valsalva ventilation test in Case 2 [24] Garden 24] Post-operative results in Case 2 Chart showing test results by Valsalva ventilation method

[Fig.25] Conceptual diagram showing the principle of eustachian tube function testing by pressure reduction method [Fig.26] Conceptual diagram showing the principle of acoustic ear canal function testing

1 = artificial ear canal

 2 = Tip side shaft

 3 = Front end opening

 4 = Lumen

 5 = Shaft

6, 7 = opening

8a ~ e = annular protrusion ''

 9 = Front

 10 = rear

11 = Artificial eustachian tube

 12 = Tip side shaft

 13 = Front opening

 14 = Neck part

 15 = Shaft

16, 17 = Open Π

18a-d = annular projection

21 = Artificial eustachian tube

 22 = Tip side shaft

 23 = Front opening

25 = Shaft

 26, 27 = opening

 8a-c = annular projection

 1 = artificial ear canal

 3 = Front end opening

 5 = Shaft

6, 37 = opening 38a-e = annular projection

 41 = Artificial eustachian tube

 42 = Tip side shaft

 43 = Tip side opening

 45 = Shaft

 46, 47 = open P

 48a ~ 3 = annular projection

 50 = Minoh

 51 = rear

 141 = Pressure transducer

 142 = Amplifier

 143 = Recorder

 151 = Sound inspection function analyzer

 BEST MODE FOR CARRYING OUT THE INVENTION

[0019] The artificial ear canal of the present invention is inserted into a patient's ear canal from the side of the tympanic cavity, the tip is made to face the cartilage ear canal, and the rear end is in principle located in the tympanic chamber (ie, It ends inside the eardrum) and is kept in the patient's ear canal. Considering ease of handling, the human ear canal of the present invention is preferably 22 mm or more in total length. Usually, it can be used for most patients with a total length of 30 mm or more. On the other hand, the artificial ear canal of the present invention can be used by appropriately excising the rear end side so as to have a length suitable for the size of the middle ear of the patient. Absent. About 45 mm is sufficient for most patients, but it may be set to 50 mm, 70 mm, etc. as desired, taking into account the convenience of handling, including the part to be excised.

[0020] The artificial ear canal of the present invention has an elongated shape as a whole because it is inserted into the ear canal of a patient from the eardrum side. The outer diameter of the portion behind the annular protrusion may or may not be constant, but it is usually preferable to stop it at about 3 mm. However, since the portion behind the annular projection is placed in the bone ear canal that expands toward the front side, and in the wider tympanic chamber, the outer diameter is slightly larger than 3 mm as long as the overall shape is elongated. Can be Permissible.

 [0021] The cross-sectional shape of the artificial ear canal of the present invention is not particularly limited. Usually, it may be circular, but since the cross section of the canal is flat, it may be a flat cross section like an ellipse. The cross-sectional shape may be the same over the entire length of the artificial eustachian tube, but it may not be, for example, even if it is circular in the majority of the total length and partially elliptical (eg, tip to annular protrusion), Further, it may be elliptical in most of the entire length and circular in part (for example, the tip to the annular protrusion). Since the cross-section of the canal is a flat shape extending in the front-rear direction from the left and right, if the artificial canal has an elliptical cross-section, it is easy to fit the inner peripheral surface of the canal canal easily. It is advantageous for opening up to effectively block the extra lumen of the canal. On the other hand, in the case of ear canal stenosis, when an artificial ear canal having a roughly circular cross section is inserted into the canal canal, the inner periphery of the flat canal canal directly on the outer periphery of the tip of the artificial canal Since the untouched area will be expanded somewhat, a slight gap will be formed between the outer wall of the end of the artificial ear canal and the inner wall of the canal canal, and the discharge channel of the secretory fluid in the tympanic chamber will be artificially formed. It can be secured also around the ear canal, which is further advantageous. For various types of patients, the major axis / minor axis ratio should be limited to 5 even in the case of a flat cross-sectional shape such as an ellipse, in order to be able to cope with artificial ear tubes with the fewest dimensional standards possible. Is preferred. For example, it can be 5, 4, 3, 2, etc. The cross-sectional shape and size of the prosthetic ear canal of the present invention are individually determined by the attending physician in accordance with the shape and state of the ear canal of the patient to be treated. In the case of a flat cross-sectional shape such as an ellipse, the “diameter” when referring to the “outer diameter” and “inner diameter” of the artificial ear canal of the present invention means the shorter diameter (short axis).

[0022] The annular protrusion is a portion that is sandwiched between surrounding tissues at or near the canal part of the patient and works to fix the artificial ear canal of the present invention. As long as it is such a size, there may be only one annular protrusion. Only one annular protrusion may be provided at the forefront of the artificial ear canal of the present invention. In this case, an artificial eustachian tube having an annular projection with an outer diameter that matches the dimensions of the eustachian portion of a specific patient to be treated and has the ability to engage with the canal canal portion is used. However, in order to handle patients with various canal dimensions in advance, and to be able to respond accurately with a relatively small number of artificial ear canals, there are multiple annular protrusions. Is more preferably provided. When providing a plurality of annular projections, it is usually preferable to provide 2 to 10 in the range from the distal end of the artificial ear canal to 16 mm in the longitudinal direction. This is because the tip of the artificial ear canal remains at a preferred position in the ear canal of the cartilage if it is fixed to the tissue of the ear canal or its vicinity anywhere in the range of 16 mm from the front end. In addition, as long as one or more annular projections with an outer diameter of 0.6 to 3.6 mm are provided in the range from the tip to 16 mm, the annular projection is supplementarily moved from the tip to the inside and outside of this range. It is permissible to add an annular protrusion. The outer diameter of each annular projection may be the same or different, but is usually in the range of 0.6 to 3.6 mm as it is convenient to fit the patient's various dimensions of the tubal canal. A plurality of annular protrusions having different outer diameters are set. For example, the leading edge J force, etc. 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm, or even f, 0.9 mm, 1.5 mm and 2.5 mm, or f 1. 0, 1.5 mm, 2. Omm, 2.5 mm and 3. Omm, 2.5 mm, 2. Omm, 1.5 mm, 1. Omm etc. When a plurality of annular protrusions are provided, the annular protrusions may be separated from each other, but it is more preferable that the annular protrusions be adjacent to each other. This is because the ability to fix the ear canal becomes higher if there is no useless middle part.

 [0023] When a plurality of annular protrusions are provided, the arrangement of the outer diameters of the annular protrusions may be appropriately determined. For example, the outer diameter of the annular protrusion located at the center may be the largest. In this case, it is preferable that the rearmost annular protrusion has a larger outer diameter than the most distal annular protrusion. Further, the outer diameter of the annular protrusion located in the middle of them can be set to the intermediate size between the outer diameter of the most annular protrusion and the outer diameter of the most rear annular protrusion. By doing so, it is easy to adapt to the canal part of various dimensions, which is convenient. However, when the canal portion fits between adjacent annular projections, the outer diameter of those annular projections may be the same or slightly larger at the annular projection near the tip. It can also be the same that the outside diameter of the adjacent annular projections is reversed from one to the other.

[0024] It is preferable that the difference between the outer diameter of each of the annular protrusions and the outer diameter of the starting portion near the rear end or the front end is 0.1 mm or more. This is because if there is a difference of 0.1 mm or more, the effect of fixing the artificial ear canal by engaging with the tissue in or near the canal canal is high. Also, annular protrusion In each of the above, it is also preferable that the difference between the outer diameter and the outer diameter of the starting portion before and after the outer diameter is within 1.2 mm. It is not necessary to provide a difference of more than 1.2 mm when engaging with the orbital canal or its adjacent tissue.If there is a too large difference, the insertion and removal of the artificial eustachian tube to adjust the insertion position during insertion This is because it becomes difficult.

 [0025] The shape of the annular protrusion may be appropriate as long as it does not hinder insertion and fixation of the artificial ear canal. A preferred example is one in which the front surface of the annular protrusion (the surface on the front side from the maximum outer diameter portion) and the Z or rear surface (the surface on the rear side from the maximum outer diameter portion) coincide with the conical surface. However, “coincidence with conical surface” includes not only exact coincidence with exact conical surface but also approximate coincidence. Further, the gradient of the front surface or the rear surface of the annular protrusion may be the same or different. A preferred example is that the front surface (or rear surface) of the annular protrusion coincides with the conical surface, and the rear surface (or front surface) has a steeper surface (for example, a surface substantially perpendicular to the longitudinal axis).

 [0026] The artificial ear canal of the present invention can include a shaft portion (referred to as "tip-side shaft portion") extending forward from the annular protrusion. Since the distal end side shaft portion serves as a guide during insertion, it is usually preferable to have the distal end side shaft portion. If the tip side shaft is provided, the tip of the human ear canal can be positioned on the side of the cartilage ear canal in any case, and the tip of the cartilage ear canal and the prosthetic ear canal to face it. There is also an advantage that the positional relationship is certain. Considering the strength and the inner diameter of the lumen, the outer diameter of the distal side shaft is usually preferably 0.6 mm or more, but it can be reduced to about 0.4 mm for patients with a particularly narrow canal area. Is possible. Except for these points, the outer diameter of the tip side shaft portion may be determined as appropriate in relation to the outer diameter of the most distal end side annular projection adjacent thereto. Further, the length of the distal end side shaft portion may be appropriately determined so that one or a plurality of annular protrusions are located within a range of 16 mm from the distal end.

[0027] When the prosthetic ear canal of the present invention includes a distal end side shaft portion, the distal end side shaft portion is adjacent to the most distal end side of the annular protrusions, that is, an annular constricted portion, that is, an outer diameter is reduced. Can be included. The annular constriction is preferably 0.2 to 2.5 mm wide in the longitudinal direction. Depending on the size of the patient's canal, the annular constriction can be used to engage the canal. The annular constricted part should be 0.1 mm smaller than the outer diameter of the tip side shaft adjacent to the part. [0028] The distal opening at the distal end of the artificial ear canal of the present invention may be opened in the axial direction of the lumen, but the distal opening is a blind end in the axial direction, and the distal opening is on the side of the distal end. May be provided. If the distal end is blind, when the artificial ear canal is inserted into the ear canal using a guide wire passed through the lumen, the distal end may hit the blind end of the artificial ear canal and stop moving forward. Surgery is simplified because it is easy to remove only the guide wire after insertion of an artificial eustachian tube. However, even when the distal opening is provided at the distal end of the artificial ear canal in the same axial direction as the lumen, the distal end or the vicinity thereof (for example, the diameter of the distal opening is narrowed by 0.2 mm or more from the lumen diameter, for example) In the range of 5 or 10 mm or less), the guide with a diameter larger than the opening on the tip side can be provided by narrowing the inner diameter of the flow path and providing a portion 0.2 mm or more narrower than the inner diameter of the lumen behind it. By using a wire, it is possible to prevent the guide wire from slipping forward, so there is no problem. Further, when the distal end side opening is provided on the side of the distal end portion, the number of openings may be one, but a plurality of openings may be provided. For example, a pair of openings may be provided on both sides of the lumen. When the distal end opening is provided on the side wall other than the distal end of the artificial ear canal, the position of the opening should be selected appropriately from the distal end of the artificial ear canal to the most distal annular protrusion. It can be installed somewhere.

[0029] In addition to the distal end opening, the artificial ear canal of the present invention has at least one opening (in this specification, "back opening") behind the annular protrusion that engages with the tissue of the ear canal or its vicinity. It is open to the outside through. The posterior opening may simply be the end of an axially open lumen, but may be provided on the side wall of the lumen instead of or in conjunction with the open end of the lumen. Providing an opening in the side wall of the lumen has the advantage of facilitating the drainage of the exudate into the nasal cavity through the lumen when there is exudate in the tympanic chamber. When an opening is provided in the side wall of the lumen, the position may be appropriate as long as the position is behind the annular projection that engages with the tissue of the ear canal or its vicinity. It can be just behind or around 20-25mm from the tip of the artificial ear canal. One opening may be provided on the side wall, but a plurality of openings may be provided. For example, a pair of openings may be provided on both sides of the lumen. In addition, the artificial ear canal of the present invention can be provided with openings extending in the longitudinal direction (for example, in the form of slits) or arranged in the longitudinal direction so as to longitudinally cut the annular projection or the annular projection group. . If such openings are added, exudate flow and aeration may be It will be further promoted in conjunction with exercise, and a more favorable effect will be obtained. Such an additional opening can be provided separately from the rear opening. However, when the rear opening is provided adjacent to the annular protrusion, it may be integrated with the annular protrusion.

 [0030] It should be noted that the insertion of the artificial ear canal into the patient of the present invention typically involves passing a guide wire from the rear end side to the lumen and supporting it thereby, and is inserted into the ear canal while being supported by the guide wire. After passing the head part through the ear canal part and the tip facing the cartilage part ear canal, only the guide wire was removed, and the artificial ear canal was placed at the rear end part in the tympanic chamber or in the bone ear canal Left in. Therefore, typically, it is preferable that the lumen penetrates and opens at the rear end of the artificial ear canal during insertion. However, if the artificial ear canal is made of a sufficiently strong material, the use of a guide wire is not necessary and the rear end can be closed.

 [0031] The distal opening, lumen and posterior opening perform the function of the patient's original ear canal by allowing air and exudate to flow between the cartilage ear canal (ie, the nasal cavity) and the tympanic chamber. Configure the flow path. This flow path preferably has an inner diameter of at least 0.20 mm. This is because if the diameter of the lumen is too narrow, resistance to the flow of air (and possibly exudate) in the lumen may occur, but if it is 0.20 mm or more, there is substantially less concern. On the other hand, if the inner diameter of the flow path is too large over the entire length, there is a risk that the voice will be conducted into the tympanic chamber. In order to prevent this, the inner diameter force of at least any part of the flow path of the artificial ear canal inserted in the ear canal is preferably 0.9 mm or less, more preferably 0.8 mm or less. Good. By providing such a part, even if the diameter of the remaining part of the flow path is larger, the voice is surely prevented from being conducted to the tympanic chamber.

 When the artificial ear canal is formed of a non-flexible or poorly flexible material, the inner diameter of at least any part of the flow path is preferably 0.9 mm or less, more preferably 0.8 mm or less. When an artificial eustachian tube is formed of a flexible material that is easy to use, it is deformed by being pressed and deformed by the inner wall of the eustachian tube in the vicinity of the eustachian tube while being placed in the eustachian tube. The inner diameter is preferably 0.9 mm or less, more preferably 0.8 mm or less.

[0032] The artificial ear canal of the present invention achieves communication between the patient's tympanic chamber and the cartilage ear canal via the lumen of the artificial ear canal, and ensures ventilation between the tympanic chamber and the nasal cavity. One purpose. Therefore, the patient The artificial ear canal is inserted into a person by engaging the artificial ear canal with tissue in or near the canal of the ear tube, the tip of the artificial ear canal facing the ear canal of the cartilage, and the opening on the tip side in the ear canal of the cartilage. Or it opens to this. The artificial ear canal inserted into the patient's ear canal is excised if there is an excess in the length of the rear end, and typically the rear end is located inside the eardrum and within the tympanic chamber. And stay in the patient.

 [0033] The material constituting the artificial ear canal of the present invention is biocompatible, that is, has no possibility of inducing a foreign body reaction harmful to the living body, and is unlikely to be decomposed or deteriorated in the living body. Is used. While flexible materials are generally preferred, non-flexible materials can also be used, combining both flexible and non-flexible materials, for example, non-flexible tubing and flexible materials. It can also be used by combining the annular projection. As such materials, various materials that can be used for indwelling in vivo in medical applications can be appropriately used for producing an artificial ear canal. For example, the force S includes, but is not limited to, a flexible synthetic resin, such as salt vinyl, silicone, polyethylene, polypropylene, polypentene, polyurethane resin, and the like. Examples of non-flexible materials include, but are not limited to, metals such as titanium, ceramics, and bone tissue as a biomaterial. It is preferable that the annular protrusion is flexible and can be elastically deformed. This is because the elastically deformable ring-shaped projections have high adhesion to the canal part and increase the frictional force to secure the fixation of the artificial ear canal, and also to the bone part of the ear canal before reaching the canal part. This is because even if there is a stenosis, the diameter can be once reduced, so that it easily passes. Resin designed to increase softness when heated to body temperature is easy to handle because it can maintain moderate hardness during insertion, but it becomes softer at body temperature after insertion, giving the patient a feeling of strangeness. Since there is no possibility of giving, it is more preferable. Further, by using autologous cartilage formed by culturing as a biomaterial, it is possible to obtain an artificial ear canal having superior safety.

 Hereinafter, the present invention will be described more specifically with reference to typical examples. However, the present invention is not intended to be limited to the examples.

[Example 1] FIG. 1 is a side view of the artificial ear canal 1 of Example 1, and FIG. 2 is a longitudinal sectional view thereof. In these drawings, the artificial eustachian tube 1 is a cylindrical structure with a circular section having a total length of 30 mm made of polyurethane resin. The artificial ear canal 1 is provided with an opening 3 (distal opening) in the distal end side shaft portion (distal end side shaft portion 2), and the distal end side opening 3 communicates with the lumen 4 of the artificial ear canal 1 Yes. In addition, an opening 6 provided on the side wall of the shaft portion 5 and an opening 7 at the rear end (both “rear opening”) communicate with the lumen 4 respectively. The artificial ear canal 1 is provided with five annular protrusions 8a, 8b, 8c, 8d and 8e in the range of 4.5 to 12. Om m from the tip, and these annular protrusions are closer to the tip. The outer diameter is expanding from near to the rear end. Each annular projection is formed by a front surface 9 which is a relatively gentle conical surface and a rear surface 10 which is relatively steep. The outer diameter of each annular projection is 1.4mm for 8a, 8b force .65mm, 8c 1.85mm, 8d force S2. 10mm, 8e 2.50mm. The outer diameter of the front shaft 2 is 0.95 mm, and the outer diameter of the rear shaft 5 is 1.80 mm. The lumen 4 has a narrow inner diameter at the front part, the outer diameter of this part is 0.6 mm, the inner diameter of the rear part is 1.05 mm, excluding the rear end region, and the inner diameter near the rear end is 1.30 mm. is there. The enlarged inner diameter near the rear end is for convenience when fitting the end of the extension tube that protrudes from the eardrum, and is not essential. Further, instead of using the extension tube, the rear end portion may be extended from that shown in FIG. 2 so as to protrude from the eardrum. In this case, it is preferable to reduce the outer diameter of this extension (see Figure 3). The artificial eustachian tube 1 is linear in the figure, but can be bent by hand so as to follow the curve of the eustachian tube if desired during surgery.

Example 2

FIG. 4 shows a side view of the artificial ear canal 11 according to the second embodiment. The artificial eustachian tube of this embodiment is made of polyurethane resin and has a circular cross-sectional structure with a total length of 30 mm. In this embodiment, there are four annular projections 18a, 18b, 18c, 18d forces S in the range of tip force, etc. 4.5 to 12. Omm. The outer diameter expands toward the rear end. The outer diameter f of each annular protrusion is 18a force Si. 50mm, 18b force Si. 80mm, 18c force 2.20mm, 18d is 2.50mm. In the present embodiment, the distal end side shaft portion 12 has an outer diameter of 9.5 mm, and includes an annular constricted portion 14 whose outer diameter is narrowed at a position adjacent to the root side and the annular protrusion. The constricted part 14 has a width of 0.90 mm in the longitudinal direction, and its outer diameter is at the tip. It is 0.75mm, 0.20mm thinner than the outer diameter of the side shaft. In the present embodiment, the shaft portion 15 is provided with an opening 19 at a position corresponding to the opening 6 of the first embodiment, and an opening 16 (one of the “rear openings”) immediately after the annular protrusion 18d. It has been. Reference numeral 13 denotes a front end opening, and reference numeral 17 denotes a rear end opening. Other configurations of the present embodiment are the same as those of the first embodiment.

FIG. 5 shows a side view of the artificial ear canal 21 of the third embodiment. The artificial ear canal of this example has a total length of 30 mm, which is almost the same as that of Example 1, but differs from Example 1 in that the number of annular protrusions is three. In the present embodiment, the annular protrusions 28a, 28b, 28c are provided in the range of 5.0 to 10. Omm from the distal end of the artificial ear canal 21, and each outer diameter f, 28a force S i. , 28b force 2. 05mm, 28c force 2. 40mm. 22 ^; the leading wheel of the vehicle, 23 is a front end opening communicating with the lumen, 25 is a shaft portion, 26 is an opening communicating with the lumen, and 27 is an opening at the rear end.

 FIG. 6 is a side view of the artificial ear canal 31 according to the fourth embodiment. This example has a total length of 30 mm, and unlike the previous example, it does not include the tip side shaft, and includes five annular projections 38a, 38b, 38c, 38d, 38e within the range from 0 to 0.5 mm from the tip. Is provided. 38a force S i. 45mm, 38b force 1. 70mm, 38c force 1. 90mm, 38d force 2. 10mm, 38e are 2.40mm. In the present embodiment, the distal end opening 33 is opened axially at the distal end of the artificial ear canal 31, and the inner diameter thereof is 0.4 mm, which is smaller than the inner diameter of the lumen 0.6 mm. 36 is an opening provided on the side wall of the shaft portion 35, and 37 is an opening at the rear end. Other configurations of the present embodiment are the same as those of the first embodiment.

 FIG. 7 shows a side view of the artificial ear canal 41 of the fifth embodiment. The present invention has a total length of 30 mm, and unlike the first embodiment, each annular projection 48a, 48b, 48c, 48d, 48e is a rear surface that is a relatively steep front surface 50 and a relatively gentle conical surface. 51 and formed. These ring-shaped protrusions are provided in the range of 4.5. The outer diameter of each annular projection is 48a force S i .65, 48b force S18.5mm, 48c force 2.05mm, 48d force 2.25mm, 48e force 2.45mm. 46 is an opening provided in the side wall of the shaft 45, and 47 is an opening at the rear end. 42 is a front end side shaft portion, and 43 is a front end side opening. Other configurations of the present embodiment are the same as those of the first embodiment.

[0040] [Clinical trial] Some of the results of clinical trials treated by inserting the artificial ear canal of the present invention into a patient are described below.

 FIG. 8 is an anatomical diagram of the ear, and FIG. 9 is an anatomical diagram of the ear just after the artificial ear canal of the present invention is inserted. In Fig. 9, the posterior end of the artificial ear canal extends and protrudes through the eardrum into the external auditory canal, but after postoperative follow-up (for example, several weeks), if there is an extra length on the posterior end side, it will be removed. The rear end can be stored in the eardrum. In such a case, the perforation of the eardrum is usually healed and blocked, and the inside of the middle ear can return to the physiological environment. However, the rear end may be left protruding into the ear canal depending on the patient's condition and other circumstances.

 [0042] (Test method)

 Eustachian tube function test: Eustachian tube function test was performed by the pressure-reduced pressure method and the acoustic eartube method. In the pressure-depressurization method, air pressure is applied at a constant speed from the ear canal side to the ear canal through the tympanic membrane, and the pressure at which the ear canal opens naturally (referred to as passive open pressure or reverse ventilation pressure) is examined. There are a static test and a dynamic test in which a constant positive or negative pressure is applied to the middle ear from the external auditory canal side, and the extent of the eustachian tube can be opened by swallowing. According to the pressurization and decompression method, in the case of a healthy ear canal, even if the pressure of the tympanic chamber is increased from the outer ear side, the ear canal is opened by swallowing movement, so that recovery by rapid decompression can be seen. Also, even if the applied air pressure is gradually increased, if the air pressure exceeds a certain level, the ear canal is passively expanded and opened (passive expansion), and the air flows out. . In contrast, in ear canal stenosis, the ear canal remains closed during swallowing, so the tympanic air pressure does not decrease even after repeated swallowing, and the tympanic pressure is quite high. Otherwise, the passive expansion of the ear canal will not occur. Passive open pressure is normal when the average of normal ears is about 355 daPa, and the standard deviation X 2 is considered normal, and when it exceeds 545 daPa, it can be judged as abnormal.

[0043] For the examination by the pressure reduction method, an eustachian function test apparatus ET-1000 manufactured by Nagashima Medical Instrument Co., Ltd. was used (conceptually shown in FIG. 25). When air pressure (positive pressure or negative pressure) is applied from the outer ear side of a tympanic membrane perforated patient and the ear canal is released (by swallowing or applied air pressure), the channel of the device is adjusted to the plot diagram of the pressure reduction method. Pressure change due to increase in pressure) is measured with pressure transducer 141, amplified with amplifier 142, and recorded on recorder 143 And evaluated.

 [0044] The acoustic eustachian tube method examines the open / closed state of the eustachian tube by projecting the sound from the load sound source into the nasal cavity and monitoring the change in sound pressure during swallowing using a microphone attached to the ear canal. It is a method. If the eustachian tube is enlarged during swallowing, sound in the nasal cavity conducts air through the eustachian tube and reaches the outer ear, so the presence or absence and degree of ear canal stenosis are evaluated based on changes in sound pressure captured by the microphone on the ear canal side. can do.

 [0045] For the examination by the acoustic eustachian tube method, an eustachian function inspection apparatus ET-1000 manufactured by Nagashima Medical Instrument Co., Ltd. was used (conceptually shown in FIG. 26). The channel of the device 151 was adjusted to the acoustic eustachian function test, and the swallowing movement and the sound pressure of the ear canal were simultaneously monitored to evaluate the presence or absence of the eustachian tube during swallowing.

[Case 1] A 37-year-old male patient. An incision was made in front of the right eardrum for a case of right ear canal insufficiency (broad open ear canal), and the artificial ear canal of the present invention was placed. The artificial eustachian tube used is almost the same as that of Example 3. After the operation, the feeling of occlusion of the ear disappeared, and the vocalization was only mildly retained. Objectively, the eustachian function test revealed that the eustachian tube pattern disappeared. Figures 10 and 11 show the results of preoperative and postoperative acoustic eustachian examination, respectively. In the acoustic eustachian examination, an increase in sound pressure and a ski slope-like waveform were observed preoperatively, and this was a peculiar finding to eustachian tube (Fig. 10). On the other hand, after the operation, the increase in sound pressure due to swallowing ceased, and it was confirmed that the eustachian tube was not released (Fig. 11). Figures 12 and 13 show the preoperative and postoperative results of Valsalva ventilation (determined by TTAG (Eustachian Tympanic Flow Dynamics)), respectively. Before surgery, a slight increase in nasopharyngeal pressure (below 50 daPa) showed an increase in middle ear pressure and a low open pressure in the ear canal (Figure 12). On the other hand, after surgery, the middle ear pressure did not change even when the nasopharyngeal pressure exceeded 300 daPa (Fig. 13), indicating that the open state of the eustachian tube was corrected. Figure 14 shows the results of preoperative tests by deep nasal breathing (determined by TTAG). An easy change in middle ear pressure due to deep nasal breathing was observed, indicating that the ear canal was open prior to surgery. In a post-operative study using the same method, no changes in middle ear pressure due to deep nasal breathing were observed, confirming that the open state of the eustachian tube was resolved (not shown). Figure 15 shows the preoperative test results by the Toinbee swallowing method (determined by TTAG), which shows an easy change in middle ear pressure. Against this However, in the post-operative test by the same method, the change in middle ear pressure was clearly reduced (Fig. 16), confirming that the open state of the ear canal was corrected. Figure 17 shows the results of the preoperative nasal slide test (determined by TTAG), which also confirms easy fluctuations in middle ear pressure. In post-surgery studies using the same method, no change in middle ear pressure was seen (not shown). Figure 18 shows the force of the post-operative pressure-decompression test. According to this, the back pressure from the middle ear to the pharynx was 381 daPa, confirming that the normal ear canal function was achieved ( The normal value of the passive opening pressure of the eustachian tube during reverse ventilation from the middle ear to the pharynx is 355 ± 190 daPa (average ± 2SD)). Thus, by setting the artificial eustachian tube of the present invention, recovery of the eustachian tube function was confirmed as a subjective symptom and objectively.

[Case 2] A 74-year-old female patient. She had a sense of occlusion of the right ear and her voice was strongly heard. She received medical care at another location but did not improve, and she visited the inventor for more than a year. The right ear canal was diagnosed, and the artificial ear canal of the present invention was placed in the right ear canal under local anesthesia. The artificial eustachian tube used is almost the same as that of Example 3. After the operation, the following day, subjective symptoms such as sensation of ear occlusion disappeared. Objectively, the pattern of eustachian tube disappeared with the Eustachian Function Test. Figures 19 and 20 show the results of pre- and post-operative acoustic eustachian examination, respectively. Before the operation, the increase in sound pressure was recognized as an S ski slope, and the baseline sound pressure (sound pressure during non-swallowing) was slightly lower (Fig. 19). After the operation, there was no increase in the sound pressure like a ski slope, and the sound pressure at the baseline was normalized (Fig. 20). Figures 21 and 22 show the results of pre- and post-operative pressure and pressure reduction tests, respectively. The reverse aeration pressure, which indicates the air permeability from the middle ear to the pharynx, was almost normalized to a force S that was less than lOOdaPa before the operation (Fig. 21) and 442 daPa after the operation (Fig. 22). Figures 23 and 24 show the results of pre- and post-operative Valsalva ventilation (determined by TTAG) in Figures 23 and 24, respectively. Before the operation, it was mostly OdaPa (Fig. 23), but after the operation it improved to 150-200 daPa (Fig. 24). The residual pressure in the middle ear after Valsalva ventilation was slightly negative before the operation (Fig. 23), but was almost normal after the operation (Fig. 24). Thus, by placing the artificial eustachian tube of the present invention, recovery of the eustachian tube function was confirmed as a subjective symptom and objectively.

[Case 3] A 44-year-old female patient. The right side of the head was bruised by a traffic accident about 3 months ago. From then on, a right ear obstruction and self-hearing occurred, and the present invention was inserted into the right ear canal by diagnosis of right ear canal opening. The eustachian tube was placed. The artificial eustachian tube used is of the type of Example 3. Preoperative ear canal function test showed that the reverse aeration pressure from the middle ear to the pharynx was lOOdaPa. (Graph not shown). However, although the hearing loss almost disappeared, but the ear occlusion remained, the artificial ear canal was removed over time, and the new artificial ear canal of the present invention was placed. The newly placed artificial ear canal is of the same type as that of Example 3, but the position and shape of the opening 26 are changed, and the width of the opening is about 10 mm and the width is about 0. The slit shape was 5mm. This artificial eustachian tube was placed so that the slit-shaped opening was positioned to straddle the patient's eustachian tube. As a result, the symptoms of the remaining ear canal stenosis disappeared, and the drainage of physiological saline injected from the eardrum side into the pharynx side became smoother and the ventilation function improved. (Graph not shown).

Industrial applicability

 The artificial ear canal of the present invention can be used for the treatment of ear canal dysfunction including ear canal stenosis (ear canal obstruction), ear canal opening, ear canal insufficiency, and floppy tubes.

Claims

The scope of the claims  [1] An artificial eustachian tube that is placed in the patient's ear canal with the tip of the cartilage ear canal engaged with the ear canal,  Having a tip, a rear end and a lumen;  One or a plurality of annular projections having an outer diameter of 0.6 to 3.6 mm are provided within a range of 16 mm in the longitudinal direction from the distal end of the artificial ear canal,  The lumen is open to the outside through at least one distal-side opening at the front end of the prosthetic ear tube or the front surface of the annular projection closest to the front end or any position therebetween.  Behind the one or more annular projections, the lumen is open to the outside through at least one rear opening.  An artificial eustachian tube characterized by the above. [2] The artificial ear canal according to claim 1, which has a plurality of the annular protrusions.  [3] The front end side opening, the lumen, and the rear opening provide a flow path having at least an inner diameter of 0.2 mm or more, through which the inside and the outside of the artificial ear canal communicate. The artificial ear canal according to claim 1 or 2, which provides a portion having an inner diameter of 0.9 mm or less. [4] Each of the annular protrusions has a difference of 0.1 mm or more between the outer diameter of the annular protrusion and the outer diameter of the starting portion near the rear end or the tip. An artificial eustachian tube. 5. The artificial ear canal according to any one of claims 1 to 4, wherein at least one of the rear openings is provided on a side wall of the lumen. [6] Includes a tip side shaft portion extending forward in the longitudinal direction from the annular protrusion closest to the tip The artificial eustachian tube according to any one of claims 1 to 5. 7. The artificial ear canal according to claim 6, wherein the distal end side shaft portion has an outer diameter of 0.4 mm or more. [8] The artificial shaft according to claim 6 or 7, wherein the distal end side shaft portion includes an annular constriction portion having a width of 0.2 to 2.5 mm in the longitudinal direction adjacent to the most annular protrusion on the distal end side. Eustachian tube. [9] The outer diameter of the ring-shaped constricted portion is 0.:! 1. The prosthetic ear canal of claim 8 that is Omm small. [10] The distal opening is open in the longitudinal direction at the distal end of the artificial ear canal, and the distal end 2. The region having a narrowed inner diameter of the flow path within a range up to a force of 14 mm, wherein the inner diameter of the portion is smaller than the inner diameter of the lumen behind it by 0.2 mm or more. Or any of 9 artificial eustachian tubes. [11] The lumen is open to the outside through an opening extending in the longitudinal direction or arranged in the longitudinal direction by longitudinally cutting the one or more annular protrusions. 1 to 10 artificial eustachian tubes.  12. The front surface and the Z or rear surface of the annular projection have a conical surface. Any one of 11 artificial eustachian tubes. 13. The artificial ear canal according to any one of claims 1 to 11, wherein a front surface or a rear surface of the annular protrusion has a conical surface, and an opposite surface is a steeper surface. 14. The artificial ear canal according to any one of claims 1 to 13, wherein the total length is 22 mm or more. 15. The artificial ear canal according to any one of claims 1 to 14, which is made of a flexible material. [16] The artificial ear canal according to any one of claims 1 to 15, wherein there are a plurality of annular projections and they are arranged adjacent to each other.