1. A cornual plug adapted to engage and be retained in the cornual area within the human uterus and formed of an inert material compatible with retention therein, comprising a tapered, plug-shaped device having, at one end thereof a cone-shaped end portion that cooperates with the surrounding uterine tissue as the cornual plug is inserted; a means for retaining the plug in removable contact with said cornual area and the surrounding tissue comprising a cavity within the central portion of said device and opening at the end opposite said cone-shaped portion; at least one anchoring wire contained substantially within said cavity; a plurality of apertures between said cavity and the outside surface of said plug, said apertures providing channels for guiding said anchoring wire from said cavity through the wall of said device, said anchoring wire, in its retracted or insertion position, extending no further than the outside circumference of said plug, and, in its extended or engaging position, extending beyond the outside circumference of said plug, thereby when extended securing and engaging said plug to the surrounding uterine tissue to retain said plug in proper position.
2. The cornual plug of claim 1 having an annular groove adjacent said cone-shaped end portion, said apertures positioned within said annular groove.
3. The cornual plug of claim 2 further including a tapered portion opposite said cone-shaped end portion for cooperation and seating upon the insertion tool used to position said cornual plug.
4. The cornual plug of claim 3 wherein said apertures are opposite each other and directed away from the outside surface of the inside cavity from the forward cone-shaped end portion, and said anchoring wire is a spring-shaped wire having its two end portions extending thru said apertures and the loop portion thereof extending at least partially beyond said cavity opening in a direction away from the taper of said cone-shaped end portion.
5. The cornual plug of claim 1 wherein said anchoring wire is provided with a pendant inert removal cord.
6. A method of temporarily blocking access to the Fallopian tubes of the human female by securing a cornual plug device to the cornual area of the uterus of said female, said method including the steps of:
BACKGROUND OF THE INVENTION
In the past there have been several proposals in the patent literature for a body passageway insert and more specifically a contraceptive cervical obturator, pessary, intrauterine contraceptive device or the like. While intrauterine contraceptive devices, the so-called IUDs, have enjoyed some measure of acceptance and reliability, others have not.
In U.S. Pat. No. 3,042,030, Read describes a spherical device that is inserted into the Fallopian tube to plug the passageway and prevent the passage of an egg or ovum from the Fallopian tubes into the uterus. Read also discloses a magnetic-type insertion tool that is provided with magnets on the insertion end that attract the ferrous-containing spherical body inserted into the tub. This process has a number of drawbacks, however, the most apparent one being that while the placement of the spherical object into the Fallopian tube itself appears, in theory at least, to be possible, in practice this is exceedingly difficult to achieve. Even the most skilled operator would have great trouble in properly positioning the sphere.
U.S. Pat. No. 3,405,711 to Bacunin describes an intrauterine contraceptive device that is generally V-shaped having a pair of slender divergent arms formed with bulbous extremities that are said to tend to become located in the Fallopian region of the uterus when the stem portion of the device is in the os. This is said to facilitate placement of the IUD and aids in its retention as the device itself is "yieldable" and the bulbous portions tend to conform to the uterus configuration. The device does not specifically act to block access to the Fallopian tubes by itself, as described, but rather acts as a contraceptive device owing to the presence of a foreign structure (the device itself) in the uterus; this, as recognized in the art, is known to have the effect of preventing conception.
Retention of IUD devices in the uterus itself has been and continues to be a problem; frequently these devices are expelled from the uterus. There have been several suggestions in the art to facilitate IUD retention; one such suggestion is described in the Bacunin patent, mentioned above. Horne, in U.S. Pat. No. 3,598,115, suggests a barb that penetrates the muscular wall of the uterus in combination with a shaft having a flexible vane which, after insertion, engages the uterine walls.
THE CORNUAL PLUG ACCORDING TO MY INVENTION AND AS DESCRIBED HEREIN IS DIFFERENT FROM THESE AND OTHER PREVIOUS PROPOSALS IN THAT A CONICAL OR BULLET-SHAPED INERT PLUG IS POSITIONED IN THE CORNUAL AREA OF THE UTERUS, RATHER THAN THE Fallopian tube itself as in Read, and, once in position, is secured to the surrounding uterine wall by anchoring wires. The technique used to insert my cornual plug is relatively straight-forward, requires no anesthesia and is conveniently inserted or removed in the physician's office without the need for special or sophisticated equipment. My cornual plug is preferably provided with a pendant string or cord which is used to remove the plug and while intended primarily for non-surgical sterilization, it may also be used for contraception, as indicated under the circumstances. These and other objects of my invention will be more apparent in the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
I have now found an effective yet convenient-to-insert cornual plug and method to insert such a plug to achieve either permanent sterilization or temporary sterilization (contraception). The plug of my invention is generally characterized as having an overall "bullet" or conical shape that is inserted in the cornual area of the uterus where the Fallopian tube enters the uterine cavity. The cornual plug is conveniently inserted, without the need for anesthesia, in the physician's office following appropriate cervical dialation procedures. The cornual plug itself is of a bullet configuration, tapered at one end and conically increasing to a cross-sectional area of larger diameter. Included with the plug are fastening means which are adjusted, either extended or retracted, to engage the plug with the surrounding uterine muscle.
The cornual plug as described above is fabricated from a material that is itself inert to reaction with the human body or is provided with a coating that renders it inert to the body tissues. In theory a host of such materials can be used, such as nylon, low density polyethylene, polypropylene, 4-methylpentene-1, `Dacron and polyesters in general; in short nearly all thermoplastic synthetic polymers. I prefer to use a material for fabrication that is not only inert to the body tissues but also opaque to X-rays sources. The reason for this is that it is customary, according to one insertion procedure, to X-ray the patient prior to and following insertion of the cornual plug. Thus, when using X-ray techniques opacity of the cornual plug to radiographic sources is an important indication to proper placement. Accordingly, even though metalized or polymeric inserts may be used, I prefer to use a solid metal such as a high-quality stainless steel. Of course, while other metals more precious and hence more costly can also be used, such as gold, silver and platnium, I have found that favorable and indeed highly acceptable results are achieved using a high quality stainless steel material.
The wire contained within the plug and acting, when properly positioned, as the anchoring means can be of a material different from or the same as the cornual plug itself. In one preferred embodiment the wire is of the same material as the plug itself, that is high-quality stainless steel.
Another radiographic technique used to determine proper placement of the cornual plug according to my invention is the hysterosalpingogram in which a dye or radio opaque fluid is injected into the cervix. The uterus is filled with the fluid and, when the plugs are properly placed, no fluid enters either Fallopian tube. When using this technique it is possible to check proper placement of the plug by the distance and outline of penetration of the dye, so that the plug may be made from a material that is not opaque to X-rays.
The cornual plug according to my invention is quickly and conveniently inserted into position according to the following illustrative procedure, it being understood that other techniques and approaches may also be used: the patient is first examined; the cervix of the uterus is dialated by the insertion of a Laminaria tent into the cervix, preferably at least four hours before proceeding, providing for substantially painless dialation of the cervix; using an inserter device of the type illustrated in the drawings and described below, the plug is pressed against the lateral sides of the uterine walls and using firm, constant pressure applied against the lateral uterine wall, the plug is pushed upward until it stops. It is at this point that the skilled physician will determine that the cornual region of the uterus has been reached.
Once the plug is appropriately positioned the inserter tool is adjusted such that the fastening means are extended from their stored or transport position to their attachment or securing position, fastening the plug to the uterine walls. The insertion instrument is withdrawn, a hysterosalpingogram is given to confirm proper plug placement and tubal occlusion, and the procedure is complete. As the plug itself is fabricated from an inert material it is reasonable to expect that it will remain in place indefinitely, thus providing a permanent form of sterilization for the female.
A temporary sterilization technique (contraception) may also be provided by attaching a nylon string or thread to the loop portion of the cornual plug and allowing the string to extend thru the cervix just into the vaginal area as in the manner presently used in intrauterine (IUD) devices. When it is desired to remove the plug, the physician merely locates the nylon string and urges it outward from the cornual area by first disengaging the fastening means for the cornual wall then, causing constant pressure, releasing the cornual plug from the uterus, past the cervix and out of the body. Of course, the same withdrawal means and techniques may also be used to remove the plug from its position should the need arise. The string or removal means is made of a material inert to the surrounding tissues; illustrative is nylon -- and preferably of a color to contrast with that of the surrounding tissue for ease of visual recognition on removal.
Insertion, positioning and later removal of the plug require a certain degree of skill on the part of the physician, and techniques similar to those used in the insertion of intrauterine (IUD) devices are employed according to my invention. Following a reasonable amount of experience using the devices and procedures described herein proper placement of the cornual plug will be appreciated by touch and this will be confirmed with appropriate radiographic procedures.
My invention will be further illustrated with reference to the attached sheet of drawings in which:
FIG. 1 is an elevated perspective view of one embodiment of a cornual plug according to my invention showing the securing wires in the retracted position in solid lines and in the extended position in dashed lines;
FIG. 2 is an elevated perspective view with the bottom portion broken away of another embodiment of a cornual plug according to my invention;
FIG. 3 is a sectional view of a fragmental nature illustrating the cornual plug being urged into position into the cornual region of the uterus;
FIG. 4 is a further detailed view of FIG. 3 showing the cornual plug in position and the attachment wires extending into the tissue of the uterus; and
FIG. 5 is a partial cross-sectional view of the insertion tool with portions being shown in elevation.
Referring now to FIGS. 1 and 2, a cornual plug designated generally as 10 is shown having a cone-shaped upper or forward portion 12, an intermediate portion provided with an annular groove 14, and several channels or apertures 16 communicating from the inner cavity of the cornual plug to the outside surface. The several channels are shown in FIG. 1 so that the plug may accommodate a number of attachment or anchor wires 18, for the sake of illustration only one attachment loop or wire 18 is illustrated in FIG. 1. The attachment wire 18 is bent in a spring-shaped loop, as shown in detail in FIG. 2, and has both ends of the wire extending through the channels 16, but in opposite directions. In the fully retracted position the wires 18 do not extend beyond the point where the channels 16 open to the surface of the plug; this is shown in solid lines in FIG. 1 and is the position of the wires 18 when the cornual plug is inserted. In their fully extended position the wires 18 extend beyond the outer surface of the cornual plug 10 and into the surrounding uterine tissue, as shown in more detail in FIGS. 3 and 4 and as described below.
The bottom or base portion of the plug includes a deep annular ring or groove 20 and a tapered conical section 22 that cooperates with the insertion instrument as shown in more detail in FIG. 5 and described below. Wires 18 are provided with a pendant nylon removal string 24 which, for the sake of convenience, is illustrated only in FIG. 4.
FIGS. 3 and 4 show a sectional view of the cornual portion of the uterus 30 and the manner in which the cornual plug 10 is inserted. The plug 10 is attached to the end of the insertion tool 32 and passed into the uterus and urged against the cornual portion of the uterus 30 by the physician. The conical taper of the plug 10 cooperates with the uterine wall and assists in the proper placement of the plug. Once the plug is urged into position the insertion tool 32 is manipulated by pushing plunger 34 to separate the plug 10 from the cavity 36 at the tip of insertion tool 32 in which it is received while, at the same time, pushing against the wire loop and extending wires 18 into the tissue of the cornual area of the uterus. The tool 32 is then withdrawn from the uterus and a nylon string 24 remains attached to the wire loop and extending through the uterus past the cervix.
The insertion tool or instrument 32 is shown in detail in FIG. 5 and is defined by a hollow outer cylinder 36 having one end adapter to receive the tapered base portion 22 of the cornual plug 10, the deep annular groove 20 seating the plug onto the tip of the instrument. Inside cylindrical member 36 is a moveable plunger 34 which travels virtually the entire length of the cylinder. When pressure is applied to the plunger 34 and there exists pressure in the opposite direction acting on the plug 10, as when the plug 10 is in the proper position, the end of the plunger 34 urges the wire loop forward and forces the wires 18 to extend from the plug and into the surrounding tissue. The particular configuration and mechanical arrangement of the insertion tool in general is not important so long as the cornual plug is properly inserted and secured to the cornual area of the uterus. The insertion tool may be of any particular configuration -- usually it is slightly curved, of the order of about 20°-35° -- and is constructed of materials customarily used in surgical instruments. This includes various plastics, stainless steel, chrome or silver plated metal or the like. The tool is conveniently sterilizable and, if made of plastic, may be disposable after use.