Middle ear prosthesis

3,473,170

Oct. 21, 1969

F. R. HAASE ET AL

MIDDLE EAR PROSTHESIS

Filed July 5, 1967

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INVENTORS.

EREOER/CK /? ERASE t/UL/O T NOGUERA

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ATTORNEY3,473,170

Patented Oct. 21, 1969

United States Patent Office

3,473,170

MIDDLE EAR PROSTHESIS

Frederick R. Haase, Brielle, and Julio T. Noguera, Interlaken, N.J., assignors to Dow Corning Corporation, Midland, Mich., a corporation of Michigan

Filed July 5,1967, Ser. No. 651,181

Ini. Cl. A61f 1/00

U.S. CI. 3—1 10 Claims

ABSTRACT OF THE DISCLOSURE

A prosthesis for insertion into the middle ear cavity to replace the ossicles comprising an arcuate frame member having a front and back, a film extending across the front of said frame member adapted to fit against the ear drum and an elongated member extending from said film, in the direction of the back of said frame member, adapted to contact the footplate of the stapes.

This invention relates to a novel prosthesis for the middle ear, and more particularly, it relates to a prosthesis for replacing the ossicles of the middle ear.

Tn the ear of a normal human, vibrations which pass through the external auditory canal strike the tympanic membrane or ear drum and are conducted across the middle ear cavity by means of three small bones, the ossicles. These bones are identified as the malleus, incus and stapes. The malleus is in contact with the tympanic membrane and picks up the vibrations therefrom and passes them along to the incus and in turn to the stapes and the mobile footplate of the stapes, which is located in the oval window, an opening in the bony wall of the inner ear.

In certain pathological conditions of the middle ear, it becomes necessary to remove the ossicles in order to correct the disease condition. In such instances, quite often only the footplate of the stapes, and the middle ear cavity remain intact, and thus all practical hearing is lost. In some cases, the footplate of the stapes is also removed.

It is therefore an object of this invention to provide a novel prosthesis to replace the ossicles of the middle ear so that hearing can be restored.

It is a further object of the present invention to provide a novel prosthesis to replace the ossicles of the middle ear and also provide a frame for occupying the middle ear space adjacent to the ear drum and to provide a supporting means and form for the ear drum.

A further object is to provide a prosthesis for replacing the bones of the middle ear which will be well tolerated by the surrounding bone and tissue contained therein.

These and other objects which will become apparent on a reading of the following disclosure are realized by the utilization of a prosthesis for insertion into the middle ear cavity comprising an arcuate frame member having a front and a back, a film extending across the front of said frame member, and an elongated member extending from said film in the direction of the back of said frame member.

The subject prosthesis is novel in that it forms a middle ear space which is necessary to hearing and in that in one integral structure, it provides a device which forms a middle ear space and effectively conducts sound from the ear drum to the inner ear. The present prosthesis can be used in instances where the stapes footplate remains in the inner ear and also in cases where the stapes footplate has been removed and replaced by a graft or bed of gelfoam. In general, middle ear prosthesis representing the prior art are used in ears not affected with infection and principally in one disease, otosclerosis. However, the present prosthesis has been successfully used in cases where there has been infection and disease breaking down the structures of the middle ear and mastoid. Additionally, but most important, clinical results indicate that the use of the present prosthesis in proper cases, in general, results in sustained restoration of hearing.

The arcuate frame member is designed to fit in the middle ear cavity in the area adjacent to the tympanic membrane, whereby the film or diaphragm, which is mounted in relatively taut engagement across and to the front of said frame member, will be in contact with most of the medial surface of the tympanic membrane when both the tympanic membrane and the present prosthesis are in proper position, so as to provide support for the tympanic membrane and a large area of contact. The elongated member or columella, which extends from and is bonded to the film, is of such length and construction so that the distal or free end thereof will be in contact with the mobile footplate of the stapes or oval window of the middle ear when the present prosthesis is placed in proper position in the middle ear cavity. The distal end of the columella is held in proper position by friction fit or by wire sutures embedded in the footplate of the stapes or in the oval window.

The present prosthesis, both as to its construction and the method of its use, will be further illustrated by the following description of preferred embodiments when read in connection with the accompanying drawings. It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not intended as a definition of the limits of the present invention.

In the drawings wherein like reference characteristics refer to like parts throughout the several views:

FIGURE 1 is an enlarged side elevation of a prosthesis of this invention.

FIGURE 2 is an enlarged back or bottom view of the prosthesis of FIGURE 1.

FIGURE 3 is an enlarged cross-sectional view of the prosthesis of FIGURE 2 taken along the line A-B of FIGURE 2.

FIGURE 4 is an enlarged side elevation of another embodiment of the present invention.

FIGURE 5 is an enlarged front or top view of the prosthesis of FIGURE 4.

FIGURE 6 is a diagrammatic view showing a prosthesis of the present invention in operative position in a human ear.

Referring now to the embodiments of the present invention shown in FIGURES 1 to 6, a prosthesis generally designated 1 is illustrated in FIGURES 1, 2 and 3. It is provided with a C-shaped arcuate frame member 2, as illustrated in FIGURE 2. Columella or elongated solid member 5 extends generally perpendicular from substantially circular film or diaphragm 3, which extends across the front of frame member 2 where it is attached over the entire front surface of frame member 2, as shown in FIGURES 1 to 3. The front or top surface of film 3 can be suitably smooth or ridged. Columella 5 is attached to the under-surface of film 3 at a point off-set from the center of film 3 and in line with a point in the center of void 6 in frame 2. Frame member 2, film 3 and columella 5 together form one integral structure. The C-shaped frame member 2, shown in FIGURES 2 and 3, is constructed so that opening or void 6 will fit over the ridge of the facial nerve in the middle ear when prosthesis 1 is placed in proper position in the middle ear cavity.

In FIGURES 4 and 5, prosthesis 7 is provided with a physiologically inert thread 9 woven through film 8 so that small loops or stitches thereof are exposed slightly upwardly from the front side or top of film 8, which is extending across and bonded to frame member 10. The slightly upwardly projecting loops or stitches provide sites on which membrane from the ear drum can eventually anchor and thereby form an integral unit with the subject

3,473,170 prosthesis and, in turn, the inner ear. It is not necessary that thread 9 be woven through film 8 in any particular pattern, as long as one or more series of stitches are located across substantially the entire diameter of film 8. In FIGURE 4, columella 11 is shown extending beneath _ frame member 10 from film 8. °

FIGURE 6 is a diagrammatic view of prosthesis 12 positioned in the middle ear cavity 14 of a human ear. Tympanic membrane 16 is shown at the internal end of external auditory canal 18. Positioned in kissing contact ₁₀with tympanic membrane 16 is film 20, which is bonded or integral with arcuate frame 22. Columella 24 is seen extending out from under frame 22. Shown by dotted lines inside columella 24 is wire cord 25, which extends out of the distal end of columella 24 forming wire loop 45 28, which is looped through stapes footplate 26, located in oval window 27.

In other embodiments of the present invention, the columella can be hollow. Further, the columella, whether solid or hollow, can be provided with a wire core which, 20 among other things, provides increased rigidity. This wire core suitably can be a portion of the same filament of wire which is looped and anchored across the top surface of the film member.

Further, in other embodiments, a suitable wire loop 25 extending from the distal end of the columella is positioned or anchored in a groove formed in the stapes footplate or the wire loop is embedded in gelfoam positione din the oval window in cases where the stapes foottioned in the oval removed. In another embodiment, the 30 wire core does not extend out of the distal end of the columella and the columella is placed in position by friction fit against the stapes footplate.

Obviously, the dimensions of the prosthesis of the present invention must be such that it will fit in the middle 35 ear cavity in relationship to the tympanic membrane facial ridge and mobile footplate of the stapes, as disclosed above. Therefore, the dimensions of the present prothesis must necessarily be varied to a small degree in order to accommodate the specific anatomical character- 40 istics of different individuals in order to fit properly into their middle ear cavity. However, in most instances, it has been found that a prosthesis of the present invention, as shown in FIGURES 1 to 6, having the following dimensions, is suitable for most individuals: 45

Frame member.—Approximately 1.5 mm. (front to back) x 1 mm.

Diameter of frame member.—Approximately 9 mm.

Film or diaphram.—Approximately 9 mm. in diameter x 0.005 mm. ^δυ

Length of columella.—Approximately 6 mm. Diameter of columella.—Approximately 1 mm. Location of columella.—Approximately 1.5 mm. from the center of columella to a point substantially in the cen- ₅₅ter of the void (6 in the drawing) on the outer periphery of the film or diaphram 3 in FIGURES 1-3.

The prosthesis of the present invention can be made from any suitable material which exhibits minimal or no tissue reaction and which is capable of being fabricated ⁰⁰into the subject device. For example, the frame member, film or diaphram and columella of the present prosthesis can be made from a physiologically inert plastic. Among those plastics which are particularly suitable are silicone rubber, polyester, and polyolefins such as polyethylene ⁰⁵and polypropylene. Silicone rubber sold commercially as “Silastic #372” medical elastomer by the Dow-Coming Corporation proved highly satisfactory in this use.

The thread used in several embodiments of the present invention must also be physiologically inert so as to ex- ⁷⁰ hibit minimal tissue reaction. Therefore, any thin thread that exhibits such behavior in tissue can be utilized. For example, thread made from stainless steel, platinum, and polyester resin can be used. The thread should be of such diameter and flexibility so that several loops or stitches can be made or anchored across the top surface of the film or diaphram member. Very small, substantially oval loops made from thread can be anchored to the top surface of the diaphram member by means of a suitable adhesive or by directly molding the loops of thread in the top surface of the thermoplastic film or diaphram member. Among suitable commercially available thread is #000 surgical stainless steel single filament wire, manufactured by the Ethicon Corporation, N.J., and 15 denier “Dacron” polyester fiber, manufactured by the E. I. du Pont Company, Wilmington, Del.

While the present invention has been described with particular reference to several preferred embodiments, it will be understood by those skilled in the subject art that various changes and modifications in form and detail may be made.