Abortifacient

Abstract

An intrauterine device for use as an abortifacient, a method of making the device, and method of inducing an abortion. The device is a strip or ribbon of plastic material set in a coiled configuration. The coiled strip retains a memory of its generally circular form and tends to maintain a coiled planar configuration after insertion into the uterus.

Description

BACKGROUND OF THE INVENTION

This invention relates to abortifacients and in particular to a device for insertion into the uterus for inducing an abortion, and to a method for making such a device, and to a method for inducing an abortion.

Intrauterine devices have been used in the past for preventing conception. These devices consist of metal or plastic wires and other shapes of small cross-sectional area and various configurations, including open and closed loops and helices. The devices are flexible so that they can be pushed through an inserter, and they are readily deflected in all directions to conform to voids in the uterus.

SUMMARY OF THE INVENTION

The intrauterine device is a strip or ribbon of plastic material of generally rectangular cross section and set in a multiturn coil. The strip is self-stressed to remain coiled and tends to maintain a planar configuration, opposing any tendency of the strip to meander through a void.

The device may be made by winding a strip of plastic material into a multiturn coil, restraining the strip in the coiled condition, and then heating the coiled strip for a period of time such that the strip remains coiled after cooling and retains a memory of the coiled condition so that it will return to the coiled configuration after passing through an inserter.

The device is used in inducing an abortion by inserting the device into the uterus through an inserter, permitting the device to remain in the uterus for a substantial period of time, such as 6 to 24 hours, and then removing the strip. Often several of the devices will be used in the treatment, being inserted one at a time, and removed one at a time. The uterus is evacuated spontaneously shortly after device removal. With this method, the scheduling of the procedure may be controlled by the physician.

It appears that the effectiveness of the device is due at least in part to its presence as a foreign body and to its inherent tendency to maintain a coiled configuration and its resistance to deformation from the plane of the coil, i.e., from the plane perpendicular to the axis of the coil.

It is an object of the invention to provide such a new and improved intrauterine device and an inserter therefor. Other objects, advantages, features and results will more fully appear in the course of the following description. The drawings merely show and the description merely describes a preferred embodiment of the present invention which is given by way of illustration or example.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an intrauterine device incorporating the presently preferred embodiment of the invention;

FIG. 2 is a view similar to that of FIG. 1 showing the device in a retainer;

FIG. 3 is a view similar to that of FIG. 1 showing the device partly uncoiled;

FIG. 4 is a side view of the device and retainer of FIG. 2 with an insertion tube suitable for placing the device;

FIG. 5 is a view of the inserter of FIG. 4, partly in section, with the device of FIG. 1 ready for use;

FIG. 6 is an enlarged partial sectional view taken along the line 6--6 of FIG. 5;

FIG. 7 is a side view of one end of the device of FIG. 1 showing the suture and serrations;

FIG. 8 is a view similar to that of FIG. 7 showing an alternate form for the strip;

FIG. 9 is a view similar to that of FIG. 5 illustrating the use of a rod for moving the strip through the inserter;

FIG. 10 is an enlarged perspective view of the rod of FIG. 9;

FIG. 11 is an enlarged partial sectional view taken along the line 11--11 of FIG. 9;

FIG. 12 is an enlarged sectional view taken along the line 12--12 of FIG. 9; and

FIG. 13 is an enlarged sectional view of a portion of the inserter and strip of FIG. 5 showing the tip of the strip.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The intrauterine device is a strip, preferably in ribbon form, of a flexible plastic material. The strip is relatively large, typically in the order of 1/32 inch thick, 5/32 inch wide and 14 inches long. The strip, designated by the reference numeral 20, preferably has a tapered and rounded tip 21 (see FIGS. 6 and 13), which tip is very flexible. The strip may be serrated along one side, as seen in FIGS. 7 and 13. The serrations 22, which may be produced by embossing or molding, are applied to the side of the strip which becomes the outer side of the coil. The serrations appear to enhance the presence and effectiveness of the device in the uterus and also may be utilized to retain material in liquid or gel or cream form. A suture or string 24 may be attached to the end 25 of the strip for removing the strip. Serrations may also be provided at the inner face of the tip 21, as seen in FIG. 13, for enhancing the tip flexibility and its tendency to curl.

An alternate configuration for the strip is shown in FIG. 8, with a series of perforations 27 through the strip. The cavities formed by the perforations are particularly suited for carrying medications and other substances into the uterine cavity.

In one process, the strip 20 is initially straight and may be formed by extrusion or by slitting from sheet stock or by other conventional processes. The strip is wound into a tight coil, typically in the order of 1 to 11/4 inch diameter, as seen in FIG. 1. The coiled strip is heated to set it in the coiled configuration. The coil is restrained during the heating and this may be accomplished by placing the coil in a cup-shaped retainer 26 which may also be used for subsequent storage and packaging of the coil. The temperature and duration of the heating operation will depend upon the size and type of material utilized for the strip and can readily be determined. Nylon is a preferred material for the strip. By way of example, a strip of Zytel 101 nylon of the specific dimensions previously given, may be heated at 212.degree. F. for 5 to 10 seconds, as by placing it in boiling water, to provide the desired set.

In an alternate process, the device may be initially formed in the coiled configuration, as by injection molding.

After cooling, the coiled strip should tend to remain in the coiled configuration, although some unwinding as seen in FIG. 3 does not detract from the use of the device. The plastic material of the coiled strip should retain the generally circular configuration and should return to the circular form after being pushed through a length of tubing. Desirably the strip should return to a coil in the order of 2 inch diameter after passing through a length of tubing.

The coil with its ribbon or rectangular cross section is a stable structure which tends to remain coiled and in a planar configuration. The device resists twist and meandering, and while the utilimate size and shape it assumes when inserted is a function of the space available, the inherent tendency to assume the planar coil form appears to be a significant factor in the effectiveness of the device.

The strip 20 may be introduced into the uterus through a tube and a preferred inserter 30 is illustrated in FIG. 4. The inserter is a tube with an interior cross section corresponding to that of the strip 20, typically elliptical or rectangular with rounded corners, and preferably is formed of a flexible plastic material in a generally arcuate shape. The inserter 30 has a tapered and very flexible tip 31 with a closed side to the convex side of the inserter and an open side to the concave side thereof, as best seen in FIGS. 5 and 6. A flange 32 may be provided at the other end of the inserter to provide a gripping means.

The device may be packaged for use in the form shown in FIG. 4. The strip 20 is in the retainer 26 with the end 25 of the strip passing through a slot 34 in the circumferential wall of the retainer. The strip end 25 is positioned in the tip end of the inserter 30, with the string 24 passing through the inserter to the other end.

To use the device the retainer 26 is removed and the strip is pulled into the inserter to a position with the strip tip 21 at or within the inserter tip and with the strip end projecting from the inserter.

Next the inserter is guided through the cervical canal into the uterus and may be manipulated as a sound to locate a void. The arcuate shape of the inserter facilitates the sounding action. The feather tapered, flexible tip 31 readily bends as seen in FIG. 9, substantially reducing the likelihood of perforation of the wall of the uterus. After a void is located, the strip may be advanced through the inserter by manually grasping the end 25. If no obstruction is encountered, the strip may be pushed through the inserter, as by a push rod 40, with the strip emerging from the inner end at the tip 31, as seen in FIG. 9. The inserter preferably is shorter than the strip so that the initial exiting of the tip end 21 can be manually controlled by grasping the other end of the strip.

In the preferred configuration of the tip 31 as illustrated in the drawings, the extreme end is flat and quite flexible so that it will readily bend on encountering the wall of the uterus to avoid damage to the wall, and also to serve as a guide for the tip of the strip 20, as seen in FIG. 9. The tip 21 of the strip also is quite flexible so as to avoid damage. With the inherent coil configuration, the emerging strip tends to assume the coiled form, further reducing the likelihood of damage. The tip 21, while being flexible, retains its curvature and avoids any spearing action during insertion.

The push rod 40 typically is a length of plastic with enlarged ends 41 to act as a piston for pushing the strip 20 through the inserter 30 into the uterus. After the strip has been pushed out of the inserter, the rod and inserter may be removed.

As the strip emerges from the inserter it tends to return to its initial multiturn coil configuration such as is shown in FIGS. 1 and 3. In the moist, warm environment, the strip may assume a larger diameter such as 3 to 4 inches, or even larger, but there is very little force in this expansion. In a typical treatment several of the devices may be inserted, one after another, depending upon the interuterine space available.

The device or devices are left in place in the uterus for a substantial period of time, typically 6 to 24 hours and may be removed at a scheduled time in the conventional manner by means of the string 24. It has been found that contractions generally do not occur while the device is in place but may commence shortly after removal. This delay and its predictability is of great aid in scheduling the final stage of the procedure.

Although an exemplary embodiment of the invention has been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiment disclosed may be subjected to various changes, modifications and substitutions without necessarily departing from the spirit of the invention.

Claims

I claim:

1. An intrauterine device for use as an abortifacient, comprising in combination:

a retainer having a bottom and a circumferential rim fixed to said bottom, said rim having a slot therein;

a strip of plastic material of generally rectangular cross section and set in a multiturn coil with free inner and outer ends, with said coil positioned in said retainer with the outer turn urged outwards engaging said rim in coil restraining relation; and

a string affixed to said strip outer end and projecting through said slot for withdrawing said strip from said retainer through said slot.

2. An intrauterine device for use as an abortifacient, including in combination:

a flexible tube having an outer end and an inner end, with said inner end having a tapered flexible tip;

a retainer having a bottom and a circumferential rim, with a slot in said rim;

a strip of plastic material set in a multiturn coil within said retainer, with the outer end of said coiled strip projecting through said retainer slot into said tube inner end, with said tube tip overlying said retainer slot; and

a string affixed to said strip outer end and extending through said tube and out said tube outer end.

3. A device as defined in claim 2 wherein said tube has an arcuate configuration with an open side of the tapered tip on the concave side of said tube, and wherein said strip has a tapered flexible tip at its inner end.