WO2007075086A1

WO2007075086A1 - Intrauterine device and applicator for introducing the same into the uterus

Info

Publication number: WO2007075086A1
Application number: PCT/NL2006/050330
Authority: WO
Inventors: Willem Arthur Adriaan Van Os
Original assignee: Willem Arthur Adriaan Van Os
Priority date: 2005-12-27
Filing date: 2006-12-22
Publication date: 2007-07-05
Also published as: NL1030795C2

Abstract

The invention relates to an intrauterine device for inserting into and retaining in the uterus of an active substance, the device being provided with at least two flexible arms (1, 1´) extending symmetrically from a central point (2), wherein the two ends (3, 3´) of the arms are each lodged in a utero-tubal corner (5, 5´), and when in use point towards the fundus (4), the central point being provided with at least one flexible wire (6) surrounded by the active substance, while the wire is provided with a retention means (9) for the active substance; the ends of the flexible arms are bulbous and curved such that in use they maintain a predetermined minimum distance to the fundus, and near the end are curved towards the fundus to rest against the fundus. The invention also relates to a method and applicator for inserting an intrauterine device.

Description

Intrauterine device and applicator for introducing the same into the uterus

The invention relates to an intrauterine device for inserting into and retaining in the uterus an active substance, wherein the device is provided with at least two arms extending from a central point, wherein the ends of the flexible arms are lodged in the utero-tubal corners (Caldeiro Barcia) , and point towards the fundus, and the central point is provided with at least one flexible wire surrounded by the active substance, while the wire is provided with a retention means for the active substance. The invention also relates to an applicator for inserting the intrauterine device into the uterus .

There are many variations on the theme of mechanical methods for fertility control and for the prevention of pregnancy. The fact that a foreign object in the uterine cavity is capable of preventing conception has been known for decades .

Departing from the basic thought, a large number of different intrauterine devices, also referred to as IUDs, have been proposed and applied in practice. Although these IUDs are effective with respect to planning or preventing pregnancy, they also have a number of important drawbacks. It has been shown that approximately 85% of the complaints or side effects from such IUDs relate to bleeding and pain and in many cases this results in infec- tions .

For this reason there is an ever-growing demand for IUDs with which the above-mentioned drawbacks are limited to a minimum or are eliminated completely. This would provide the important advantage that the IUDs can remain in the uterus considerably longer, with increased comfort for the patient.

As the birth rate in many countries in the world reaches a critical stage, there is a growing interest in IUDs with improved properties. It is pointed out that IUDs have been in use for 30 years already, and in the course of these 30 years they have been modified many times. The most significant development was the use of copper, since it has been shown that the cop- per ions are very effective against fertility. Another significant development is the reduction in size of the IUD' s plastic body, due to the copper taking over the anti- fertility effect.

The first IUDs that became generally used, for exam- pie the Lippes Loop (without copper), were large and extended the uterus. A frequently occurring drawback of these large IUDs was that they caused bleeding and pain and this, moreover, was often accompanied by infections. As a result, they often had to be removed prematurely. Research carried out in the sixties and seventies by, among others, the Population Council and the F.H.I, showed that the induction of bleeding and pain was associated with the size of the IUD with the consequence that in many cases, these large IUDs had to be removed prematurely, partly because of the risk of perfora- tion.

The discovery of copper as anti-fertility agent made it possible to produce much smaller IUDs without reducing the contraceptive effect.

Recent IUD developments point in the direction of producing smaller IUDs in order to further reduce or eliminate bleeding and pain, so as to promote the acceptability of the IUDs.

Some of these developments involve IUDs that are fixed in the fundus, with the IUD being fastened to the uter- ine fundus. These IUDs, which are usually fastened to the fundus by means of a needle, may cause pain, bleeding and perforations of the fundus.

The use of copper as intrauterine contraceptive resulted in a unique approach with respect to reducing the size of the IUD, with the result that bleeding and pain (the two most prevalent reasons for having to remove the IUD prematurely) are reduced to a minimum, while at the same time maintaining a high level of protection against pregnancy. The European patent EP 0 673 629 discloses an intrauterine contraceptive with a device as described in the preamble of claim 1. Although an intrauterine device in accordance with EP 0 673 629 already reduces the above- mentioned problems relating to bleeding and pain considerably, a further improvement regarding these points is very desirable and welcome.

DE 29 25 993 discloses a IUD with a central body that holds a copper spiral and that extends into flexible arms that are bending outwards. The arms are at their free end provided with a lump of copper material.

A particular object of the present invention is to provide an intrauterine device that affords an improvement concerning the stability of the position of the intrauterine device when the uterus returns to the anteversal or retrover- sal position, without damaging the uterus. This in contrast to all classical IUD' s, that do cause damage to the uterus by embedding of their stiff vertical stem.

This object is attained by an intrauterine device according to claim 1. Hysteroscopic studies and three- dimensional imaging with ultrasound have shown that the flexible curved arms with the bulbous ends remain firmly lodged in the fundus, also during contractions of the uterus. When the IUD is put in the proper position, such that the ends of the flexible arms are each lodged in a utero-tubal corner, the arms are shaped such that they are following the shape of the fundus and are thus generally spaced apart from the fundus (at its rest position) at a short distance. The bulbous ends of the flexible arms will thus be the first and principal contact points of the IUD with the uterus and these contact points are each situated in a utero-tubal corner, which ensures a stable position of the IUD. When during a contraction of the uterus the utero-tubal corners are approaching each other, the flexible arms can accommodate such movement and ensure that IUD will return to its original shape and position the moment the contraction is over. The main interaction, and thus the main transfer of forces, between uterus and the IUD is taking place via the bulbous ends of the flexible arms. Because the ends of the flexible arms are bulbous, this interaction will cause no harm to the uterine wall.

In a preferred embodiment of the invention, near the ends the arms are curved towards the fundus, so that the bulbous ends are the principle contact with the fundus. Due to this the uterus will push the IUD towards the fundus, and this phenomenon even further reduces the chance of downwards displacement of the IUD in case of uterine activity. Owing to this effect the IUD according to the invention provides maximum protection against becoming expelled, which is especially important during contractions of the uterus. The arched shape allows the arms to adapt more easily to the fundus, which is convex in all directions. The arched flexible arms with bul- bous ends ensure proper lodging in the utero-tubal corners (Caldeiro Barcia) at an anteversal or retroversal position. Especially the bulbous ends will lodge firmly in the fundus, keeping the UID in position. Due to the rounded shape of the ends they however do not damage the uterine wall. It is fur- ther emphasised that the IUD according to the invention, similar to the IUD according to EP 0 673 629, is not provided with a stiff solid vertical stem, which the classical IUDs needed in order to keep the IUD in situ. The IUD according to the invention gives no embedment of the endometrium of the uterus.

The arms of the IUD disclosed in DE 29 25 993 are bent outwards to point at the utero-tubal corners. Their shape is determined by that they also should be folded together when in the device is entered into the uterus in a single tube. They are thus bent for a totally different purpose as compared to the IUD of the present invention. Consequently their shape is also different. The lump of copper at the free end of the arms serves to provide copper at the far end of the uterus. This is entirely different of the purpose of the bulbous ends of the arms of the present invention. The lumps disclosed in DE 29 25 993 will not be in contact with the fundus. Providing the arms of the intrauterine device from the central point to approximately the bulbous ends with a groove, promotes the stability of the intrauterine device' s position. During uterine activity, the uterine wall may come into contact with the flexible arms and may partially or completely fill these grooves, which then creates a kind of suction effect with the result that the arms, as it were, adhere to the uterine wall, fixing the IUD in the uterus.

In a favourable embodiment, the retention means is spherical. The retention means forms an end of the IUD and if this is spherical, this end will have no sharp edges and thus will not cause any injuries and/or bleeding and perforations. If, in addition, the diameter of the retention means is approximately 3 mm, there is a good balance between a smallest possible dimension on the one hand, and on the other hand, sufficient space for the active substance, whose dimensions are preferably as similar as possible to the dimension of the retention means.

In practice, the arms and the retention means are made of plastic, in particular LDPE/BaSC>4.

In a preferred embodiment of the invention, the active substance is copper acting as contraceptive, which is provided around the wire in the form of rings.

More preferably, the copper is provided as a spi- rally wound copper wire. This spiral is flexible in practically all directions, allowing it to follow the movements of the uterus. A relatively large surface area of contraceptive is obtained with a short copper spiral, which reduces the risk of injuries and bleeding. In a preferred embodiment, the copper wire of the spiral has a diameter of approximately 0.3-0.8 mm, preferably approximately 0.5 mm, and the spiral has a diameter of approximately 2.8-4.0 mm, preferably 3.2 mm. An adequate length for the spiral is approximately 12-20 mm, preferably 16 mm, which is significantly shorter than the IUDs according to the prior art, i.e. approximately 36 mm. The shorter vertical length of the cooper spiral is compensated by a larger diameter of the spiral, which maintains the amount of copper needed for contraceptive action. The larger diameter of wire avoids disintegration, e.g. through corrosion, of the copper wire that might happen in thinner wires in a classical IUD.

Good results are also obtained when the active sub- stance is contained in a flexible tube provided with openings, made of a uterus-safe plastic. With respect to flexibility, and thus following the movements of the uterus, the advantages are similar to those obtained with the above- mentioned spirally wound wire. This makes it possible to re- lease the active substance into the uterine cavity slowly dosed over an extended period of time.

In one preferred embodiment, the active substance is a contraceptive. It has been shown that good results are also obtained when such a plastic tube is filled with a standard contraceptive hormone preparation, while the disadvantages of the known preparations are eliminated.

In another preferred embodiment, such a plastic tube contains a drug. This may, for example, be a drug that needs to be effective locally, e.g. for a local treatment of infec- tions (Chlamydia, gonorrhoea, and the like) , fungal infections, or cytostatics and the like. This may also be a medication for treatment of abnormal uterine bleeding, whether containing hormonal or non hormonal pharmacological agents. Such a drug is then introduced directly in situ and thus does not need to pass through the intestinal tract, thereby sparing the liver and avoiding systemic side effects. According to the invention, such a plastic tube containing a drug may also be attached to an IUD according to the invention, wherein the active substance is copper acting as contracep- tive, wound around the wire in the form of rings or a spiral. The plastic tube is then located, for example, inside the spiral .

It is also an object of the present invention to provide a method to insert a IUD, ensuring a simple and proper positioning of the IUD.

This object is attained by the method from claim 16. In particular the fact that the flexible arms are in a fixed predetermined direction allows that the IUD is positioned such that the arms will be placed in the utero-tubal corners.

It is also an object of the present invention to provide an applicator for the IUD that ensures that the IUD is brought in into the desired stable position.

This object is attained by an applicator according to claim 16. At one end, said applicator is provided with recesses for receiving the flexible arms. By means of these recesses, the arms of the IUD are fixed during insertion, pre- venting them from rotating in relation to the applicator.

This ensures that in the anteversal and retroversal position, the arms with bulbous ends are reliably lodged in the utero- tubal corners (Caldeiro-Barcia) .

The invention will now be further elucidated by way of describing some preferred exemplary embodiments, referring also to the appended drawing, which:

In Fig. 1 shows a cross-sectional view of the device according to the invention, without the active substance,

In Fig. 2A shows a cross-sectional view of the de- vice according to the invention in a first embodiment, with a first active substance,

In Fig. 2B shows a cross-sectional view of the device according to the invention in a second embodiment, with the active substance of fig. 2A, In Fig. 3 shows a cross-sectional view of the device according to the invention in the embodiment of fig. 1 and fig. 2A, with a second active substance,

In Fig. 4 shows a schematic view of an embodiment of the device according to the invention positioned in the uterus,

In Fig. 5 shows the flexibility of the device according to the invention, and

In Figs. 6a and 6b, respectively, shows an enlarged distal part of an applicator for the intrauterine device ac- cording to the invention, and an applicator holding the device .

Fig. 1 shows an embodiment of an intrauterine device, wherein the device is provided with at least two arms 1, 1' extending from a central point 2. In Fig. 1, the ends 3, 3' of the flexible arms 1, 1' point upward. Fig. 4 is a schematic view of the device according to the invention, positioned in the uterus. Fig. 4 shows that the flexible arms 1, 1' are lodged in the utero-tubal corners 5, 5' and that the ends 3, 3' of the flexible arms 1, 1' point towards the fundus 4. The central point 2 is provided with at least one flexible wire 6. Fig. 2A, Fig. 2B and Fig. 3 show that the active substance 7, 8 is provided around the flexible wire 6. The wire 6 is provided with a retention means 9 for attaching the active substance 7 , 8 to the flexible wire 6. The ends 3, 3' of the flexible arms 1, 1' are bulbous, while from the central point 2 to approximately the ends 3, 3', the arms 1, 1' are arched. The fact that the flexible arms 1, 1' are arched, enables them to follow the convex shape of the fundus 4 very well. The uterus contracts continually. The contractions are initiated from the tubular corners 5, 5' . Due to the bulbous ends 3, 3' pointing towards the fundus 4, these bulbous ends 3, 3' of the device according to the invention will, for example during uterine contractions, be pushed into the fundus 4 and will thus stay firmly in position. The bulbous ends prevent the fundus 4 from being damaged. The arms 1, 1' being arched and flexible, ensure that the device according to the invention is well able to follow the shape of the fundus 4, and in that way strengthens the firm positioning of the device according to the invention against the fundus 4 in the uterus, without damaging the uterus.

Fig. 2A shows the embodiment of the IUD according to the invention of fig. 1, but with a first active substance. In this case the active substance is a copper wire, wound into a helical spring 7. The copper serves as contraceptive. The helical spring 7 is particularly flexible and, for example during contractions, is able to adapt remarkably well to the changes in the uterine cavity. The copper wire of the helical spring 7 has a thickness of 0.5 mm. The helical spring itself has an outside diameter of 3.2 mm and a length of a mere 16 mm. The retention means 9, retaining the active substance around wire 6, has a diameter of approximately 3 mm.

Because of the small dimensions of the device according to the invention, the forces exerted on the device during contractions will be relatively small. The slightness of these forces in combination with the above-mentioned properties provides the device with excellent anchoring, without damaging or injuring the uterine wall. This allows the device to remain in the uterus for an extensive period of time with- out any harmful consequences. Fig. 5 illustrates the small dimension of this embodiment, as well as its great flexibility.

Fig. 2B shows a second embodiment of a IUD according to the invention. In this embodiment the flexible arms 1, 1' are each provided with a groove 10, 10' , respectively, extending from the central point to approximately the solid ends. When during contractions the arms get in contact with the uterine wall, the grooves 10, 10' create a kind of suction effect, with the result that the arms, as it were, ad- here through suction to the uterine walls, thereby fixing the device in the uterus. Also the arms are arched somewhat different so that the central point 2 lies closer to the fundus. Even if the central point may touch the fundus in this embodiment the bulbous ends remain the principal contact of the IUD with the uterus.

Fig. 3 shows another embodiment of a device according to the invention. In Fig. 3 the active substance is contained in a flexible tube 8 provided with openings, made of a uterus-safe plastic. This plastic tube 8 has approximately the same external dimensions as the helical spring 7 and is about equally flexible. This embodiment of the invention therefore exhibits the same favourable characteristics described above with regard to the embodiment of Fig. 2. The active substance in the plastic tube 8 may be a contracep- tive, but the device in this embodiment according to the invention may also contain an active substance with a therapeutic effect. This active substance may be locally released via the openings in the tube over a long period of time. This makes it possible, for example, to use the device according to the invention for local treatment of infections (Chlamydia, gonorrhoea, and the like) , fungal infections, or cytostatics and the like. Such an active substance is directly administered in situ so that it does not need to pass through the intestinal tract, sparing the liver and avoiding systemic side effects, which is a significant advantage of this embodiment of the invention.

Fig. 6a and Fig. βa, respectively, show an enlarged distal part of an applicator 11 for the intrauterine device according to the invention, and an applicator 11 holding the device. At one end, the applicator 11 is provided with recesses 12, 12' for receiving the flexible arms 1, 1', respectively. By means of these recesses 12, 12', the arms 1, 1' of the IUD are fixed during insertion, and they are prevented from rotating in relation to the applicator 11. This ensures that in the anteversal and retroversal position the bulbous ends 3, 3' of the arms 1, 1' are reliably positioned in the utero-tubal corners (Caldeiro-Barcia) 5, 5' . In addition, fitting a IUD according to the invention correctly this way is considerably simplified compared with the existing devices .

In most existing applicators during insertion, the IUD is completely contained in the applicator. Then when the applicator with the IUD is positioned in the uterus, then the IUD must be pushed out of the applicator by means of an inserter. The inserter is brought in the proximal end of the applicator and pushes against the proximal end of the IUD, pushing the IUD out of the applicator. This activity requires coordinated action of two hands in opposite directions. One hand pushes the inserter against the IUD, while the other hand is withdrawing with the applicator. This is a delicate movement, which is complicated and prone to damage the uterine wall. With the applicator according to the invention, and the method of inserting the IUD in the uterus according to the invention, the IUD is mounted on the applicator, with the flexible arms extending from the distal end of the applicator .

When the applicator is inserted into the uterus, the flexible arms will fold alongside the external of the applicator and directly after passing through the opening of the uterus, the flexible arms start to move back to their original position. When the flexible arms are lodged in the utero-tubal corners, positioned by means of the fixed predetermined direction of the IUD in the applicator, then only the applicator needs to be withdrawn. No additional tool is required. Thus simplifying the process of insertion of the IUD and reducing the probability to damage the uterine wall.

Claims

1. An intrauterine device for inserting into and retaining in the uterus of an active substance (7, 8), wherein the device is provided with at least two flexible arms (1, 1') extending symmetrically from a central point (2), wherein the two ends (3, 3') of the flexible arms (1, 1') are each lodged in a utero-tubal corner (5, 5' ) , and when in use point towards the fundus (4), and the central point (2) is provided with at least one flexible wire (6) surrounded by the active substance (7, 8), while the wire (6) is provided with a re- tention means (9) for the active substance (7, 8), characterised in that the ends (3, 3') of the flexible arms (1, 1') are bulbous and that the arms (1, 1') from the central point (2) to approximately the ends (3, 3' ) , are curved such that in use they maintain a predetermined maximum distance to the fundus in a position at rest.

2. An intrauterine device according to claim 1, characterised in that the arms (1, 1' ) near the ends are curved towards the fundus so that the bulbous ends rest against the fundus. 3. An intrauterine device according to claim 1 or 2, characterised in that the arms (1, 1') from the central point (2) to approximately the ends (3,

3'), are provided with a groove (10, 10' ) .

4. An intrauterine device according to one of the claims 1 to 3, characterised in that the retention means (9) is spherical.

5. An intrauterine device according to claim 4, characterised in that the retention means (9) has a diameter of approximately 3 mm.

6. An intrauterine device according to one of the claims 1 to 5, characterised in that the arms (1, 1') and the retention means (9) are made of plastic.

7. An intrauterine device according to one of the claims 1 to 6, characterised in that the arms (1, 1' ) and the retention means (9) are made of LDPE/BaSθ4.

8. An intrauterine device according to one of the claims 1 to 7, characterised in that the active substance (7) is copper acting as contraceptive.

9. An intrauterine device according to claim 8, characterised in that the copper is provided around the wire (6) in the form of rings.

10. An intrauterine device according to claim 8, characterised in that the copper is provided in the form of a spirally wound copper wire.

11. An intrauterine device according to claim 10, characterised in that the copper wire of the spiral has a diameter of approximately 0.5 mm, and the spiral has a diameter of approximately 3.2 mm.

12. An intrauterine device according to claim 10 or 11, characterised in that the spiral has a length of approximately 16 mm.

13. An intrauterine device according to one of the claims 1 to 12, characterised in that the active substance (8) is contained in a flexible tube provided with openings, made of a uterus-safe plastic.

14. An intrauterine device according to claim 13, characterised in that the active substance (8) is a contraceptive.

15. An intrauterine device according to claim 13, characterised in that the active substance (8) is a drug (8) .

16. Method for inserting an intrauterine device in the uterus wherein the device is provided with at least two flexible arms (1, 1' ) extending symmetrically from a central point (2), and the central point (2) is provided with at least one flexible wire (6) surrounded by an active substance 7, 8), using a tubular applicator, characterised in that the method comprises the following steps:

-mounting the intrauterine device on the applicator such that the flexible arms of the intrauterine device extend in a fixed predetermined direction from one, distal end of the applicator and the flexible wire extends from the other, proximal end of the applicator, -inserting the applicator into the uterus, starting with the distal end of the applicator,

-positioning the flexible arms each in a utero-tubal corner (5, 5'), and -withdrawing the applicator from the uterus.

17. An applicator (11) for inserting an intrauterine device in accordance with one of the claims 1 to 15 into the uterus, characterised in that at one end, the applicator (11) is provided with two recesses (12, 12' ) for receiving and stabilising the flexible arms (1, 1') during insertion into the uterus.

18. An applicator (11) according to claim 17, characterised in that the applicator (11) is made of plastic.