WO2011154602A1

WO2011154602A1 - Uterine cavity exploration tool

Info

Publication number: WO2011154602A1
Application number: PCT/FI2011/050530
Authority: WO
Inventors: Pekka Lähteenmäki; Annamari LÄHTEENMÄKI; Ilkka Kivi; Oskari Heikinheimo
Original assignee: Laehteenmaeki Pekka; Laehteenmaeki Annamari; Ilkka Kivi; Oskari Heikinheimo
Priority date: 2010-06-10
Filing date: 2011-06-07
Publication date: 2011-12-15
Also published as: FI20105659A0

Abstract

The present invention relates an intrauterine device (IUD) insertion system. The system is designed to minimize the risk of uterine perforation during insertion of an IUD, especially in cases where the uterus is antevertedly or retrovertedly steeply flexed. The present invention further relates to a method of inserting an IUD into the uterus with the aid of the present insertion system.

Description

UTERINE CAVITY EXPLORATION TOOL

FIELD OF THE INVENTION

[0001] The present invention relates an intrauterine device (IUD) insertion system. The system is designed to min im ize the risk of uterine perforation during insertion of an IUD, especially in cases where the uterus is antevertedly or retrovertedly steeply flexed.

BACKGROUND OF THE INVENTION

[0002] Intrauterine devices (lUDs) are widely used contraceptive devises having high rate of reliability and long effective life. lUDs are small T- shaped devices with a string attached to the end to ensure correct placement and allow easy removal. There are two main categories of lUDs: copper lUDs and hormonal lUDs releasing progestins.

[0003] lUDs are placed in a uterus by a medical professional during an office visit. Once in place, the IUD stays in the uterus until the medical professional removes it. One problem associated with l U Ds is uterine perforation during insertion thereof, especially in difficult cases where uterus is in steep flexion either anteverted or retroverted, or in situations when the insertion is done after pregnancy, either after abortion or delivery. Uterine walls are then softer than the walls of women that are normally menstruating.

[0004] The challenge is to introduce the IUD safely past the junction of the isthmic part of the uterus and the cervix, all the way into fundal position. Not only can the instrument and/or the insertion tube containing the IUD perforate the uterus, but the insertion tube can also introduce the IUD into the uterine wall, myometrium, or in between endometrium and myometrium. In all these cases, the performance of the IUD is compromised . The patient will suffer from pain and/or excessive bleeding. An IUD introduced all the way into abdominal cavity needs to be removed in operation.

[0005] The challenge of current insertion systems and tubes for lUD^'s is the fact that they are sometimes too straight to accommodate the curved route of IUD insertion. The route can often be explored with current uterine sounds that are curved (plastic sounds), or sounds that can be bent (metallic sounds), but the actual insertion of IUD is compromised. Pulling with a tenaculum attached to the cervix of the uterus often straightens the insertion route, but not always enough. Less experienced person obviously has more often problems than an experienced professional. [0006] Thus, there is an identified need in the art for a safe intrauterine device insertion system.

BRIEF DESCRIPTION OF THE INVENTION

[0007] An object of the present invention is to provide an intrauterine device (IUD) insertion system, especially for use in cases where the uterus is antevertedly or retrovertedly steeply flexed. The insertion system comprises a resil iently flexible elongated sound (21 ) having at least one archedly curved distal part with a spherical tip (22), at least one resiliently flexible elongated tubular distal cannula (23) surrounding the distal part of the sound (22) longitudinally, and a resiliently flexible elongated tubular extension cannula (25) surrounding the sound longitudinally, and situated proximally adjacent to the at least one distal cannula. Either the sound (21 ) or the distal cannula (23), or sometimes both, are provided with a calibrated scale. In some embodiments, markings of the scale are in centimetres zero being in either end.

[0008] In some embodiments, the proximal end of the distal cannula comprises an extended member (24) fitting the distal end of the extension cannula. In further embodiments, the outer diameter of the extended member is from 1 to 2 cm.

[0009] In further embodiments, the sound (21 ) comprises two archedly curved distal parts with different angles, two tubular distal cannulas (23) and an extension cannula (25) in the middle of the distal cannulas (23).

[0010] In still further embodiments, the sound (21 ) comprises two archedly curved distal parts with different d iameters, two tubular distal cannulas (23) and an extension cannula (25) in the middle of the d istal cannulas (23).

[0011] Furthermore, in some embodiments the length of the distal cannula (23) is 5 cm and its position around the sound (21 ) is such that 3 cm of the distal end of the sound is left uncovered by the distal cannula (23).

[0012] Another object of the present invention is to provide use of an I U D insertion system according various embodiments of the present invention for inserting an IUD into a uterus.

[0013] A further object of the present invention is to provide a method of inserting an IUD into a uterus. The method comprises the steps of: (a) pushing an IUD insertion system according to claim 1 through the cervix to the fundus of the uterus, (b) taking a sound measure from the calibrated scale,

(c) removing the sound by pulling through the distal and extension cannulas, while supporting the position of the distal cannula with the extension cannula,

(d) removing the extension cannula while observing the retention of the distal cannula (e) inserting an IUD through the distal cannula into the uterus, guided by the sound measure, and (f) removing the distal cannula over on the IUD insertion tube.

[0014] In some embodiments the step (a) is performed by fixing the cannulas on the sound by joint attachment by fingers of the sound and extension cannula.

[0015] In some other embodiments, the length of the distal cannula (23) is 5 cm and its position around the sound (21 ) is such that 3 cm of the distal end of the sound is left uncovered by the distal cannula (23), and the method comprises the following alternative steps between steps (b) and (c): (i) if the sound measure in step (b) is less than 8 cm, pushing carefully the cannulas over the sound until the extended member (24) touches the cervical os, or (ii) if the sound measure in step (b) is more than 8 cm, letting loose from the cannula when the extended member (24) touches the cervical os, and carefully pushing the sound until touching the fundus.

[0016] Other objects, embodiments, details and advantages of the present invention will become apparent from the following drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached drawings, in which

[0018] Figure 1 A is a schematic side view of a female reproductive anatomy illustrating a antevertedly flexed uterus.

[0019] Figure 1 B is a schematic side view of a female reproductive anatomy illustrating an retrovertedlyflexed uterus.

[0020] Figure 2 is a schematic drawing of an IUD insertion system according to one embodiment of the present invention.

[0021] Figure 3 is a side view of an IUD insertion system having two curved ends according to embodiment of the present invention.

[0022] Figure 4A illustrates placing of an IUD insertion system according to one embodiment of the present invention in a uterus prior to removal of a sound.

[0023] Figure 4B illustrates a situation where a sound has been removed leaving a distal cannula intact in a uterus. An IUD is to be inserted through the distal cannula into a fundal position in the uterus.

DETAILED DESCRIPTION OF THE INVENTION

[0024] In one aspect, the present invention relates to an intrauterine device insertion system for placing an I U D into a uterus. The instrument provides guidance and smooth gliding of an insertion tube of the IUD into a fundal position of the uterus, and protects the uterus from perforation.

[0025] FIG. 1A illustrates uterus 10 in steep anteverted flexion and cervical canal 11.

[0026] FIG. 1 B illustrates uterus 10 in steep retroverted flexion and cervical canal 11.

[0027] FIG. 2 illustrates a non-limiting embodiment of an IUD insertion system 20 which includes a sound 21 , a distal spherical tip 22. Distal part of sound 21 is surrounded longitudinally by a distal open-ended tubular cannula 23 comprising an extension member 24. Proximal part of sound 21 is surrounded longitudinally by a tubular proximal cannula 25, also termed as an extension cannula.

[0028] Sound 21 may be prepared from any desired biologically inert and medically acceptable material including but not limited to commodity plastics such as polyethene (PE) in its different forms (e.g. as HD-PE, LD-PE, LLD-PE, MD-PE), polypropene (PP), polystyrene (PS) and its copolymers styrene acrylon itrile (SAN ), acrylonitrile butadiene styrene (ABS) and acrylonitrile styrene acrylate (ASA), and polyvinyl chloride (PVC). Other suitable polymer materials include, but are not limited to, polycarbonate (PC), poly(ether sulfone) (PES), polyethylene terephthalate (PET), polysulfone (PSU), polybutylene terephthalate (PBT), polyaryletherketones (PEEK), poly(dimethylsiloxane) (PDMS). Furthermore, sound 1 1 may be prepared from polymer mixtures including, but not limited to, mixtures of ABS and PC; ABS and PSU, ABS and PVC, as well as ABS and PS. Medically acceptable plastic materials are preferred due to their low price and ease of sterilization.

[0029] In some embodiments, sound 21 may be prepared from a material modified to enhance ultrasound visibility. Such modifications include coating by or inclusion of air bubbles or hollow glass microspheres within the sound material. Other means and methods for enhancing ultrasound visibility are disclosed e.g. in WO 2006/106180.

[0030] The overall degree of stiffness or flexibility of sound 21 may vary. However, sound 21 should be resiliently flexible to allow bending in conformity with the cervical canal and uterus of a given patient. Flexibility of sound 21 may contribute, at least in part, to diminishing injuries to the uterus including scraping and perforation of the uterus wall.

[0031] Distal end of sound 21 may be shaped as a spherical or round tip 23 to allow easy slide through the cervical canal and to avoid injuries.

[0032] The configuration of sound 21 may vary in length. The sound is designed such that the distal end 22 contacts the fundus of the uterus and the proximal end extends outside the body of the patient. Typically, the sound may be from about 25 cm to about 35 cm in length. In some specific embodiments, the length of the sound is 28 cm.

[0033] It should be understood that in practise all measures given herein are approximate values within a predetermined tolerance and may vary e.g. due to a production tolerance.

[0034] Sound 21 may be provided with a plurality of calibrated markings at predetermined distance from each other. Such a calibrated scale allows an accurate determination of the distance between the cervical os and the fundus of the uterus facilitating and providing safety in the insertion of an IUD. In some typical embodiments the scale is from 1 to 10 cm starting from the distal end 22 of the sound, or vice versa. The distance between individual markings may vary as desired, with a typical distance of 1 cm or 2 cm . In further embodiments, the scale is provided on the concave surface of the sound.

[0035] Furthermore, the configuration of sound 21 may vary in diameter. Typically, the cross section of the sound is round and tapered. In some embodiments, the diameter of sound 21 is about 5 mm (e.g. 5.1 mm) from the proximal end until about 2 cm to about 5 cm from the distal end, then tapering evenly to the diameter of about 2 mm at the distal end 22. The exact diameter of sound 21 may depend, at least partly, on the type of an IUD to be inserted. Typically, the diameter is about 5.1 mm for hormonal lUDs, such as Mirena®, and about 3 mm to about 4 mm for copper lUDs. [0036] Distal part of the sound is archedly curved in order to allow passing the angle of the cervical canal and the flexed uterine cavity without a risk for uterine wall perforation. In some embodiments the arched curve has an angle of 30 degrees but the sound may be provided with varying curvings depending, at least partly, on the anatomy of the patient.

[0037] Longitudinal axis of sound 21 is covered or surrounded by two sequential tubular cannulas, a proximal cannula (i.e. an extension cannula) 25 and a distal cannula 23. The inner diameters of the cannulas depend on the diameter of the sound such that they substantially equal each other. In some embodiments the inner diameter of the distal end of the distal cannula 23 is about 3.5 mm but can be as wide as the sound at its thickest, such as 5.1 mm. The outer diameters of the cannulas are not critical yet a small outer diameter is more comfortable for the patient.

[0038] The length of the distal cannula 23 may vary between about 3 and about 7 cm but is typically about 5 cm. The cannula slides easily over the sound . The original positioning of the distal cannula, when starting the insertion, should be such that about 2 cm to about 4 cm of the distal end of the sound is left uncovered. This is typically 3 cm and the position is maintained by holding the sound with fingertips so that it simultaneously supports the proximal cannula. This position of distal cannula does not leave sharp edges of the cannula open . The proximal end of the distal cannula comprises an extended member 24, such as a conical or funnel-shaped sleeve, fitting the distal end of the proximal cannula 25. The purpose of this extended member is to prevent the distal cannula from sliding into the uterus when inserting an IUD. The additional purpose of the proximal cannula is to keep the position of the distal cannula 23 intact in the uterus upon removal of sound 21. Proximal cannula 25 may vary in length. In one typical embodiment, the length of the proximal cannula is about 10 cm to about 15 cm.

[0039] The material of the cannulas should be elastic allowing bending of the instrument during its placement into the uterus. Furthermore, on one hand, the elasticity of the cannulas provides easy removal of the sound and, on another hand, easy passing of an insertion tube of an IUD through the cannulas. Especially distal cannula 23 should be as thin as possible yet having a sufficient density to retain its integrity under the contractile muscular pressure of the walls of the cervical canal after the sound was been removed. However, in some instances the distal part of the cannula may be so thin and elastic that the anterior and posterior walls collapse when the sound is removed. In this case, the flexed uterus would get safely stretched during the I U D insertion wh ile the collapsed cannu la l ifts the uterine wall for the introduced IUD.

[0040] Suitable materials include biologically inert and medically acceptable polymers, including but not limited to commodity plastics such as polyethene (PE) in its different forms (e.g. as HD-PE, LD-PE, LLD-PE, MD- PE), polypropene (PP), polystyrene (PS) and its copolymers styrene acrylonitrile (SAN), acrylonitrile butadiene styrene (ABS) and acrylonitrile styrene acrylate (ASA), and polyvinyl chloride (PVC). Other suitable polymer materials include, but are not limited to, polycarbonate (PC), poly(ether sulfone) (PES), polyethylene terephthalate (PET), polysulfone (PSU), polybutylene terephthalate (PBT), polyaryletherketones (PEEK), poly(dimethylsiloxane) (PDMS). Furthermore, the cannulas may be prepared from polymer mixtures including, but not limited to, mixtures of ABS and PC; ABS and PSU, ABS and PVC, as well as ABS and PS.

[0041] In some embodiments, distal cannula 23 may be prepared from a material modified to enhance ultrasound visibility. Such modifications include coating by or inclusion of air bubbles or hollow glass microspheres within the sound material. Other means and methods for enhancing ultrasound visibility are disclosed e.g. in WO 2006/106180.

[0042] In some embodiments, distal cannula 23, instead of sound 21 , is provided with a calibrated scale as described in more above.

[0043] FIG. 3 illustrates another embod iment of the present insertion system, wherein sound 21 is provided with two curved ends having different angles. In such cases, the sound is surrounded by three open-ended cannulas, two at the opposing ends and one in the middle. Such an instrument is suitable for a wider spectrum of patients with varying uterine dimensions. It is up to the physician performing the insertion of the IUD to choose the end to be used for a given patient. The end to be used may be referred to as a distal end. Prior to use, the cannula of the proximal end is discarded and the middle cannula may be used as an extension cannula for maintaining the position of the distal cannula intact in the uterus upon removal of the sound.

[0044] Some embodiments provide an insertion system with two curved ends the openings of the distal ends of the distal cannulas being of different width. This IUD insertion system could be used by choice for two different IUD models of different diameter.

[0045] In some embodiments, the instrument is provided in a pre- sterilized package, such as a ruptable envelope. For non-recurring use, the instrument is disposable and provided in a through-away package.

[0046] In a further aspect, the invention provides use of an IUD insertion system according to various embodiments of the present invention for safe insertion of an IUD into a uterus, especially in cases where the operation is no longer considered safe, due to flexed position of the uterus (Fig. 2) and other manouvers such as pulling the cervix by a tenaculum does not straighten the uterus enough so that the IUD inserter could easily and safely be pushed to the bottom of the uterine cavity. The inserter tube of the IUD may be too straight to allow passing the angle of the cervical canal and uterine cavity whereas use of the present curved IUD insertion system curved allows it.

[0047] This aspect of the present invention may be formulated differently, i.e. as a method of inserting an IUD into a fundal position in a uterus. In the following, this aspect of the invention is illustrated with an IUD insertion system according to an embodiment, wherein the length of the distal cannula is 5 cm and its position over the sound is such that 3 cm of the distal end of the sound is left uncovered by the distal cannula. As the configuration of the IUD insertion system may vary, it should be understood that depending on the embodiment being used, the method varies accordingly. Thus, the method is not limited to the following embodiment.

[0048] Prior to IUD insertion, the cervix is cleansed and grasped with a tenaculum . An IUD insertion system according to the embodiment defined above, is then pushed carefully into the cervix and the route through the cervix to the end of the endometrial cavity is explored by fixing the cannulas on the sound by a joint attachment of the sound and proximal cannula by fingers. If the system stops before the extended member has reached the external os while being gently pushed towards the bottom of the uterus, the sound measure is 8 cm minus the distance between the extended member and the os. If, on one hand, the extended member reaches the external os, the medical professional performing the present method loosens his or her grip on proximal cannula and tries to gently push the sound forward. If the system does not move ahead, the sound measure is 8 cm. If the sound moves forward, the additional centimetres are added to said 8 cm to get the final sound measure that is to be recorded. Since the uterus is not tightly attached to pelvis or other organs, the cannula-covered sound may slightly straighten the uterus (Fig . 4A). The gradual widening of the IUD insertion system widens the cervical canal to the width that the IUD to be inserted can be introduced through the distal cannula.

[0049] Next, a firm grip is taken from the insertion system and the sound is then pulled carefully through the distal and proximal cannulas while supporting the proximal cannula. The proximal cannula is then removed while observing the retention of the distal cannula. When the sound has been removed, the flexibility of the distal cannula allows the slightly straightened uterus to revert to its original retroverted or anteverted position (Fig. 4B).

[0050] Next, all necessary procedures required for a particular IUD to be inserted , includ ing pull ing of the IUD into its insertion tube, are performed. While supporting the cervix with a tenaculum, the IUD is inserted through the distal cannula into the uterus. The distal cannula adopted to the flexed uterus protects the uterine wall from perforation by the IUD insertion tube. Note of the reading on the IUD insertion tube is taken. Once the reading reaches 5 cm at the proximal end of the distal cannula, the tip of the insertion tube has reached the distal end of the distal cannula. When the sound measure recorded earlier is 6 cm , an add itional d istance of 5 to 1 cm , respectively, remains to reach the bottom of the uterus cavity.

[0051] In some embodiments, the distal cannula may be removed by pulling over on the IUD insertion tube, and removing the distal cannula and the insertion tube are done simultaneously while securing the free passage of the threads from the insertion tube. After removal of the cannula and the insertion tube, the length of the strings of the IUD are adjusted by cutting to an appropriate length.

[0052] The use of the IUD insertion system does not prevent from using anaesthesia if needed for the IUD insertion.

[0053] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.

Claims

1. An intrauterine device (IUD) insertion system, characterized in that it comprises:

a resiliently flexible elongated sound (21) having at least one archedly curved distal part with a spherical tip (22),

at least one resiliently flexible elongated tubular distal cannula (23) surrounding the distal part of the sound (22) longitudinally,

a resiliently flexible elongated tubular extension cannula (25) surrounding the sound longitudinally, and situated proximally adjacent to the at least one distal cannula

wherein the sound (21) and/or the distal cannula (23) is provided with a calibrated scale.

2. The insertion system according to claim 1, wherein the proximal end of the distal cannula comprises an extended member (24) fitting the distal end of the extension cannula.

3. The insertion system according to claim 2, wherein the outer diameter of the extended member is from 1 to 2 cm.

4. The insertion system according to claim 1, wherein the sound (21) comprises two archedly curved distal parts with different angles, two tubular distal cannulas (23) and an extension cannula (25) in the middle of the distal cannulas (23).

5. The insertion system according to claim 1, wherein the sound (21) comprises two archedly curved distal parts with different diameters, two tubular distal cannulas (23) and an extension cannula (25) in the middle of the distal cannulas (23).

6. The insertion system according to any preceding claim, wherein markings of the scale are in centimetres zero being in either end.

7. The insertion system according to any preceding claim, wherein the length of the distal cannula (23) is 5 cm and its position around the sound (21 ) is such that 3 cm of the distal end of the sound is left uncovered by the distal cannula (23).

8. Use of an IUD insertion system according to claim 1 for inserting an IUD into a uterus.

9. A method of inserting an IUD into a uterus, characterized by comprising the steps of: (a) pushing an IUD insertion system according to claim 1 through the cervix to the fundus of the uterus,

(b) taking a sound measure from the calibrated scale,

(d) removing the extension cannula while observing the retention of the distal cannula,

(e) inserting an IUD through the distal cannula into the uterus, guided by the sound measure, and

(f) removing the distal cannula over on the IUD insertion tube.

10. The method according to claim 8, wherein step (a) is performed by fixing the cannulas on the sound by joint attachment by fingers of the sound and extension cannula.

1 1 . The method according to claim 8 or 9, wherein insertion system is as defined in claim 6, and the method comprises the following alternative steps between steps (b) and (c):

(i) if the sound measure in step (b) is less than 8 cm, pushing carefully the cannulas over the sound until the extended member (24) touches the cervical os, or

(ii) if the sound measure in step (b) is more than 8 cm, letting loose from the cannula when the extended member (24) touches the cervical os, and carefully pushing the sound until touching the fundus.