WO2021138707A1

WO2021138707A1 - A device and method for inducing cervical dilation

Info

Publication number: WO2021138707A1
Application number: PCT/AU2020/000056
Authority: WO
Inventors: Saming Chaisumdet; Rebecca Benischke; Paul Mock
Original assignee: Multigate Medical Devices Pty Ltd
Priority date: 2019-06-26
Filing date: 2020-06-26
Publication date: 2021-07-15
Also published as: AU2019100697A4

Abstract

A device for inducing cervical dilation (10), the device including a shaft (15) having a first end and a second end; a shaft tip formed at the first end; a primary aperture formed at the second end; and, a balloon region (40) formed at or near the first end, proximate the shaft tip; wherein the first end is configured to be inserted into a cervical area such that fluid introduced through the primary aperture inflates a single balloon (45) in the balloon region (40) for inducing cervical dilation.

Description

A Device and Method for Inducing Cervical Dilation

Technical Field

The present invention relates to a device and method for inducing cervical dilation or ripening. In particular, the present invention relates to a device which is configured to mechanically induce cervical ripening during labour.

Background of the Invention

The following references to and descriptions of prior proposals or products are not intended to be and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

For medical reasons, related to both maternal and foetal indications, it is often common practice in obstetrics to induce labour and to commence the childbirth process. Pre-labour artificial cervical ripening, to thereby induce labour is commonly undertaken to increase the likelihood of a vaginal birth outcome. Labour can be induced either medically, through the use of pharmacological compounds, or mechanically through the use of physical means such as acupuncture or cervical sweeping. However, the efficacy and the result of these methods often vary.

Generally, mechanical cervical ripening methods may be considered less invasive, and safer than pharmacological compounds as the pharmacological compounds can cause adverse reactions for both the mother and baby, whereas the mechanical methods do not introduce any new chemicals. However, depending on the situation, an obstetrician may still recommend a pharmacological induction, or if required, a caesarean section, instead of a vaginal birth. The present invention seeks to provide a device and method for inducing cervical dilation which may ameliorate the foregoing shortcomings and disadvantages or which will at least provide a useful alternative.

Summary of the Invention According to one aspect of the invention, there is provided herein a device for inducing cervical dilation, the device including: a shaft having a first end and a second end; a shaft tip formed at the first end; a primary aperture formed at the second end; and, a single balloon region formed at or near the first end, proximate to the shaft tip; wherein the first end is configured to be inserted into a cervical area such that liquid or fluid introduced through the primary aperture inflates the single balloon region to form a single balloon for inducing cervical dilation.

Thus, according to one specific example, it will be appreciated that the device includes a balloon region with a single balloon, which in this specific example includes only one balloon, when the balloon is inflated. Accordingly, for example, the device can be inserted into and through a cervical canal, and when the shaft tip is through an internal orifice of the canal, the single balloon can be inflated, and can rest against and/or slightly through the internal orifice, thereby providing pressure against the cervix/cervical area. Accordingly, the device described herein can assist in cervical dilation.

According to one example, the shaft tip is formed from a single integral material, such that the shaft tip is closed or formed closed.

In yet a further example, the shaft is attached to a patient such that attachment of the shaft causes traction or a force on the cervix. Attachment to the patient can be by tying part of the device to the patient’s leg.

According to another example, the device includes a secondary aperture formed at the second end, the secondary aperture being configured to receive an introducer for guiding the first end through the cervical area.

In yet a further example, the primary aperture includes a valve. According to another form, the primary aperture can include a one-directional or non-return valve. Further, the secondary aperture can include a valve.

According to yet another example, the shaft includes one or more indicators. Thus, in a specific example, in use, when the device is inserted into the cervical area, the one or more indicators provide an indication as to a depth of insertion into the cervical area.

In a further example, the one or more indicators are measurement markings formed on the shaft, indicating length/depth of insertion in centimetres.

According to another example, the marks can be printed on a wall (typically an outside surface of the wall) of the shaft.

In another example, there are one or more indicators provided on at least two sides of the shaft.

In a further example, there are a plurality of indicators disposed along the length of the shaft. It will be appreciated that the indicators can assist medical professionals in determining the depth of insertion of the device into the cervical canal. Thus, in a specific example, the one or more indicators can be visual measurement markings such as showing millimetres or centimetres reflecting the length of the shaft of the device that is being inserted into the cervical canal. According to one specific example, the measurements start at zero from outside the balloon region, and are provided all along the shaft body in incremental markings, towards the primary and secondary legs (or the second end of the shaft)

According to yet another example, to inflate the single balloon, fluid passes through a hole in a shaft wall, into the balloon. Typically, the hole is formed in the balloon region, in the shaft wall. Thus, for example, the balloon surrounds the shaft wall in the balloon region, and moves from a deflated position to an inflated position once the fluid enters the balloon through the hole in the shaft wall. According to yet another example, the shaft includes a body, which is typically elongate, and can further include a primary leg and a secondary leg extending from the elongate body, wherein the primary aperture and the secondary aperture are formed in the primary leg and the secondary leg respectively. According to another example, the elongate body has a central cavity, configured to receive an introducer via the secondary leg.

In a further example, the elongate body has a channel in fluid communication with the primary aperture, whereby fluid for inflating the balloon travels along the channel and exits the hole in the shaft wall. Accordingly, in one specific example, the device for assisting in cervical dilation can include a shaft which has a central channel or central cavity and a balloon inflation channel, where both channels run along substantially the length of the shaft (or shaft body) and are in parallel to each other. The inflation channel is typically used for fluid communication between the primary aperture and the balloon, where fluid passes through the inflation channel and out through the shaft wall to thereby inflate the balloon. The central cavity is typically used to receive an elongate introducer, the diameter for which typically corresponds or fits into the central cavity.

According to another aspect, there is provided herein an introducer for use with a device for inducing cervical dilation as described in the many forms and examples herein. The introducer can assist in guiding the device into the cervical canal.

According to one specific example, the introducer has an elongate body and a hooked-portion extending from the elongate body. Typically, the hooked- portion is a J-loop or the like, which can be crimped or pinched to the device, once the introducer is inserted into the device.

It will be appreciated by persons skilled in the art that any combination of the features described herein is possible and is within scope of the present application. Brief Description of the Drawings

The invention may be better understood from the following non-limiting description of a preferred embodiment, in which:

Figure 1A is a side cross-sectional view of an example of a device for inducing cervical ripening;

Figure 1B is a side cross-sectional view of another example of a device for inducing cervical ripening;

Figure 2 is side cross-sectional view of an example of the device for inducing cervical ripening, showing an inflated balloon; Figures 3A to 3D are perspective views of the device for inducing cervical ripening, showing an inflated balloon;

Figures 4 to 6 are internal plan views of an example insertion of the device of Figure 1 into a cervical area;

Figure 7 is a cross-sectional view of an example shaft wall; Figure 8 is an example of a cross-sectional view of an example of a balloon region;

Figure 9 is a side view of an example introducer;

Figure 10 is a photograph of an example of a balloon; and,

Figures 11 and 12 are photographs of an example shaft showing measurement markings on two sides of the shaft.

Detailed Description of the Drawings

An example of a device 10 for cervical ripening or dilation is shown in Figures 1 to 9.

According to a particular example, as shown in Figure 1 A and 1 B, a device 10 for inducing cervical ripening includes a shaft 15, where the shaft 15 has a first end 20 and a second end 25. The device 10 further includes a shaft tip 30 formed at the first end 20, and a primary aperture, which can include a valve 35 formed at the second end 25.

In the examples shown, a balloon region 40 is formed at or near the first end 20, typically proximate to the shaft tip 30. Accordingly, when the first end 20 is inserted into the cervix or a cervical area 70 (as shown in Figures 4 to 6 and further described below), liquid or fluid introduced through the primary aperture 35 inflates a single balloon 45 in the balloon region 40 (as shown in Figures 2 to 3D) for inducing cervical ripening. In these examples, Figures 1A and 1 B show the single balloon 45 in a deflated state 50, prior to insertion of the device 10 in the cervical canal, and thus prior to inflation of the balloon 45, whereas Figures 2 to 3D show the balloon in an inflated state 45.

It will be appreciated by persons skilled in the art that by having a balloon region 40, which includes or only has a single inflatable balloon 45, can help to minimise the pain caused to a patient when the device 10 is inserted through the cervical area 70.

Notably, Figure 1B also shows a further example of the device 10, where the shaft 15 has one or more indicators 68 disposed on/along the shaft. That is, the indicators 68 can be disposed on a surface of the shaft 15. Thus, it will be appreciated that when in use, when the device 10 can be inserted into the cervical area, where the one or more indicators 68 can provide an indication as to a depth of insertion.

Although the indicators 68 can be in any form, in this particular example, the one or more indicators 68 are marks formed on the shaft 15, indicating length in centimetres. Furthermore, the marks can be printed on a wall of the shaft on either one side or on at least two sides of the shaft, thereby providing double-sided increment markings. Thus, there can be a plurality of indicators disposed along the length of the shaft.

According to one particular example, the one or more indicators can be provided along the length of the shaft on one or multiple sides of the length. Further, the indicators can be printed markings, such as high contrast position markings. According to yet a more specific example, the indicators can start incremental measurements from just outside (proximate) the balloon all along the shaft body to the second end of the shaft.

It will be appreciated that the indicators can assist in providing clinicians or medical practitioners with a guide as to how far the cervical dilating balloon is inserted into the vagina and cervix. That is, the indicators can provide guidance on the “landmarks” as the device 10 is being inserted. In addition to this, once the cervical dilating balloon has been inflated to the maximum volume (say for example, 80ml), and is then required to pull back against the cervical area, the markings again assist with guidance on position. That is, if the cervical dilating balloon is inserted too high, inflated and not pulled down onto the cervix (such that to provide the required traction/pressure on the cervix), it is likely that the device may not assist in cervical dilation.

Accordingly, it can assist medical professionals to confirm the position post inflation when applying traction to the balloon by checking the markings.

According to one particular example, the shaft tip 30 is formed from a single integral material. That is, in this example, the shaft tip 30 is closed or fluid-tight at the tip end 32. Thus, the shaft tip 30 does not include any holes or apertures. It will be appreciated by persons skilled in the art that by forming the shaft tip 30 from a single integral material, and by having the tip end 32 closed, there is a decreased chance of infection or introducing any bacteria to a patient. Further, by having the tip 32 closed, it will be appreciated that the device does not require the use of any closing mechanisms in secondary aperture 55 such as a plug, spigot or the like. Accordingly, it will be appreciated that as no further closing mechanisms are required, the device is a simpler device to use.

In use, and as shown in Figures 4 to 6, the device 10 is inserted into the cervical area 70. It will be appreciated that the cervical area 70 is formed by an external orifice 72, a cervical cavity or canal 74, and an internal orifice 76. The external orifice 72 and the internal orifice 76 are at opposing ends of the cervical canal 74, where the external orifice 72 typically opens into the vagina and the internal orifice 76 typically opens into the uterus (which holds the baby 80, as shown in Figure 6).

The device 10 is thus typically inserted into the cervical area 70 with the shaft tip 30 entering through an external orifice 72. Once the balloon region 40 has entered the cervical canal 74, and past the internal orifice 76, the deflated balloon 50 is inflated by pumping or pushing liquid/fluid through the primary valve 35, via the use of a syringe or the like. Inflation of the balloon 45 applies further pressure on the cervix to move into a ripened state and can therefore assist in inducing labour.

According to one specific example, it will be appreciated that the cervical area is on average around 3cm long. Typically, although the device 10 can be inserted under a light and with a speculum, the measurements/indicators can thus provide a guide to a medical professional as to whether insertion through the cervical canal is too far, or not far enough relative to the desired location/position. Thus, in one example, the shaft 15 can provide 5cm or 10cm marking increments which are clearly visible, and can guide the medical professional on when that they can either pull back or need to keep inserting the device 10.

It will be appreciated however, that every insertion case can be different depending on anatomical differences, in conjunction with clinical practice/technique differences.

Additionally, the process can further include attaching the shaft 15 to the patient, such as the leg of the patient, in order to cause a traction or force on the cervix. That is, additional pressure can be applied to the cervix (and thereby assist with dilation), by placing pressure back through the internal orifice 76, against the cervical canal 72. It is further postulated that attachment of the catheter 15 to the patient’s leg once the device 10 has been inserted and the balloon 45 has been inflated can cause further pressure and subsequent dilation of the cervix. That is, taping the catheter 15 to a patient’s leg can create a “pulling effect” on the balloon 45, which can assist with dilation.

Although different variations may be possible, it will be appreciated by persons skilled in the art that the shaft 15 is typically a catheter, which is made of flexible or pliable material as too rigid a shaft can cause unnecessary damage to or can be uncomfortable/painful for the patient. However, in order to assist in the insertion of the device 10, an introducer (not shown) can be used to stiffen or harden the catheter in order to allow the catheter to be more easily introduced into the cervical canal. In this example, the introducer can be introduced into the shaft 15 via a secondary aperture 55, formed at the second end 25, which can in one example, also include a valve. Thus, the secondary aperture 55 can be configured to receive an introducer into the shaft 15 for guiding and/or holding the shaft 15 (and more specifically, the first end 20) within the cervix/cervical area. The introducer can then be removed once the device 10 is within the cervical canal.

According to one specific example, the primary aperture 35 is a check valve (or a non-return valve), with a colour-coded component 65, which can be used as an identifier to ensure that the syringe used to inflate the balloon 45 is inserted into the correct valve (that is, through the primary aperture). It will be appreciated that a non-return valve is used such that the aperture 35 is in a closed position until the non-return valve is activated by the tip of the syringe which engages the internal mechanism of the valve 35 in order to open the valve 35. This can then allow for fluid such as sterile water to be injected / pushed through a funnel 66 before going through a balloon inflation channel 46 (which extends substantially along a body 12 of the shaft, which is typically an elongate body) and into the balloon 45 for inflation.

In this example, the secondary aperture 55 is a hollow core valve, with its own colour coded area 65, to identify the type of valve. Thus, the secondary aperture 55 is formed such that medical professionals are not able to connect a syringe or the like to the secondary aperture or valve 55, although the aperture 55 can be formed to receive an introducer as discussed herein. Notably, the aperture 55 can also have a cover 67 such as a silicone cover or the like.

Notably, Figures 1 to 3D also show that the second end 25 of the shaft 15 can be split into a primary leg 36 and a secondary leg 56, such that the primary leg 36 and the secondary leg 56 extend from the shaft 15. The primary leg 36 can thus be formed to include the primary valve 35 and the secondary leg 56 can include the secondary valve 55. It will be appreciated that this particular formation can keep the functions of the primary valve 35 and the secondary valve 55 separate, and also allow for both valves/apertures to be used at the same time by medical staff, if need be.

According to one particular example, as shown in Figures 27, and 8, for inflation of the balloon 45, fluid enters the balloon inflation channel 46, which is typically formed at or near the shaft wall 24 via the aperture 35, and exits at a hole or aperture 47, which is typically formed as part of the shaft wall 24. That is, the fluid exits the channel 46, where the balloon 45 is in a deflated state, through an opening 47 that goes through the tubing wall 24 of the shaft 15, to thereby move the balloon into an inflated state. Thus, the primary leg 36 is in fluid communication with the channel 46 located in or near the shaft wall 24 in order to then reach the balloon lumen 45 and inflate the balloon 45. Accordingly, in this particular example, the fluid for inflating the balloon does not pass through the centre of the shaft 15, but passes through the channel 46. In these particular examples, the centre cavity 41 and the channel 46 both run substantially along the length of the shaft body 12, and are parallel to each other, with the channel 46 being formed at our near the shaft wall 24.

Thus, if an introducer 69 is used, the introducer 69 can travel through the secondary leg 56 and through a centre cavity 41 of the shaft 15 without interfering with the fluid through the channel 46 and vice versa. It will be appreciated by persons skilled in the art that the liquid used to inflate the balloon 45 is typically sterile water, although other liquids or fluids may be suitable. It will also be appreciated by persons skilled in the art that in these examples, the length of the catheter tip to balloon is approximately 3.3cm. Further, the balloon width (circumference) when inflated to 80ml is around 6cm, and the balloon height when inflated to 80 ml is around 5cm.

A further example of the balloon region 40, including the balloon 45 is shown in Figure 8. In particular, Figure 8 shows more specifically that the balloon 45 is formed around the shaft 15 at the balloon region 40 and that the balloon 45 and shaft wall 24 are in fluid-communication to inflate the balloon 40. In this particular example, the shaft wall 24 includes a hole 47, which is typically a inflation lumen side hole, which allows fluid moving down the shaft wall 24 to exit at the hole 47 to thereby enter the balloon inflation lumen 46 and inflate the balloon 40.

Notably, Figure 8 also shows a particular example of the balloon 40, whereby the balloon 40 includes balloon ribbing or ridges 42 formed along the length of the balloon 40. The ridges can assist to reinforce the balloon 40 to tolerate the larger balloon volume, when the balloon is inflated (say, for example, to 80ml).

Furthermore, it will be appreciated that although different sizes of balloons/balloon regions are possible, in this particular example, the balloon length L is 45mm +/- 1mm, the length from the shaft tip to the balloon S1 is typically 13mm +/-2mm, and the length from the shaft tip to the lumen side hole S2 is typically 22mm +/- 2mm.

It will be appreciated that as shown in Figures 1A to 2, and 8, the shaft 15 can also include an x-ray line 60, which is configured such that the device 10 would be visible through x-ray imaging for safety reasons, such as in the event that the device is inadvertently left behind in a patient’s body and needs to be identified.

It will be appreciated by persons skilled in the art that the device 10 can be manufactured by a variety of methods. According to one specific example, the channel 46 may be created by extrusion and formed to run substantially the entire length of the shaft body 12.

Furthermore, typically, the device 10 is a silicone tube where the 80ml balloon is bonded to the silicone catheter shaft by a silicone based adhesive. The adhesive is typically applied to the inside of the balloon skirts in a manner which provides a smooth transition between the bonded surface of the shaft and balloon.

Figure 9 shows an example of an introducer 69 that may be used to guide the device 10 into the cervical area/canal. The example introducer in Figure 9 has an elongate introducer body 80, and a hooked portion 85 extending from the introducer body 80.

It will be appreciated that the introducer 69 is typically made from a malleable nylon material that can be manipulated/bent into the desired shape to assist a medical professional with the insertion of the cervical dilating balloon. As an example, in use, the introducer 69 is typically inserted through the middle cavity 41 of the device 10 and the hooked portion 85 can be pressed/crimped against the device 10 once the introducer 69 has been inserted. That is, by pinching the J-loop (formed as a hooked-portion 85) of the introducer 69, this can prevent movement within the device 10 and secure the introducer 69 in place.

In this particular example, although it will be appreciated that different sizes of the introducer 69 may be possible, typically the length A of the introducer 69 is 435mm +/- 10mm and the length B of the hooked portion 85 is typically 30mm +/- 5mm. Further, the distance (or width) C between the hooked portion 85 and the body of the introducer 80 is typically 20mm +/-5mm. Notably, the diameter of the introducer 69 is typically around 1 8mm +/- 0.3mm, to allow the introducer to be inserted into the shaft (typically through the centre of the shaft) via the secondary aperture 55.

As a further example, Figure 10 shows a photograph of an example balloon 45. Furthermore, Figures 11 and 12 show examples of the shaft 15 with measurement markings as indicators 68 on both sides.

Example Methods

According to one particular example, the device 10, can be used with the following method to induce cervical ripening/dilation:

Patient Preparation (using sterile gloves and equipment): 1. Ensure there are no contraindications to the procedure and obtain informed consent

2. Perform an abdominal ultrasound to confirm placental location and foetal presentation 3. Place the patient in the lithotomy position

4. Insert an appropriately sized vaginal spectrum and visualise the cervix Device Placement:

1. Insert the shaft tip 30 of the device 10 into the vagina and advance through the cervix 70 until the balloon has entered the cervical canal 74 and past the internal orifice 76

2. Using a sterile syringe (not shown) inflate the balloon 45 with sterile water via the coloured non-return valve to a volume of 80ml_. The balloon 45 should not be overinflated

3. Perform a digital vaginal examination or ultrasound to ensure the balloon 45 is above the internal orifice 76 of the cervical canal 74.

Ensure the catheter 15 is pulled back snug against the cervix 70

4. If desired, move the patient out of the lithotomy position to a comfortable recline and strap the catheter to the patient’s leg under traction. Notably, this is typically light to moderate traction, however the amount of force typically depends on the level of discomfort felt by the patient and the level that is required to assist in dilation. Once the desired level of traction is achieved depending on clinical usage, the shaft 15 of the device 10 is then taped/secured to the patient’s leg Device Removal:

Notably, the device 10 will typically fall out once the cervix is dilated. Otherwise, the device will typically be changed after 12 hours, in which case, the process below needs to be undertaken: 1. Deflate balloon completely with a syringe via the coloured non-return valve

2. Carefully pull the device out of the vagina and inspect to ensure the device is intact and complete 3. If the device is intended to be single use, dispose of as per facility protocol, ensuring that the device is not reused or resterilised.

It will be appreciated by persons skilled in the art that many advantages may be achieved by having a device with a single balloon region, and thus a single inflatable balloon. For example, the pain felt by the patient in respect of insertion is minimal. It is further postulated that the device 10 as described herein can be generally safer than pharmacological dilation, with a possible result of reducing hyperstimulation, foetal heart rate abnormalities and decreasing the patient having a postpartum haemorrhage greater than 1 litre, which can present a risk to the mother. The term “comprise” and variants of that term such as “comprises” or “comprising” are used herein to denote the inclusion of a stated integer or integers but not to exclude any other integer or integers, unless in the context or usage an exclusive interpretation of the term is required. Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. All such variations and modifications are to be considered within the scope and spirit of the present invention the nature of which is to be determined from the foregoing description.

Claims

1. A device for inducing cervical dilation, the device including: a. a shaft having a first end and a second end; b. a shaft tip formed at the first end; c. a primary aperture formed at the second end; and, d. a balloon region formed at or near the first end, proximate the shaft tip; wherein the first end is configured to be inserted into a cervical area such that fluid introduced through the primary aperture inflates a single balloon in the balloon region for inducing cervical dilation.

2. The device of claim 1 , wherein the shaft tip is closed.

3. The device of claim 2, wherein the shaft tip is formed from a single integral material.

4. The device of any one of claims 1 to 3, wherein the shaft is attached to a patient such that attachment of the shaft causes traction or a force on the cervix.

5. The device of any one of claims 1 to 4, wherein the device includes a secondary aperture formed at the second end, the secondary aperture being configured to receive an introducer for guiding the first end through the cervical area.

6. The device of any one of claims 1 to 5, wherein the primary aperture includes a valve.

7. The device of any one of claims 1 to 6, wherein the shaft includes one or more indicators, wherein in use, when the device is inserted into the cervical area, the one or more indicators provide an indication as to a depth of insertion into the cervical area.

8. The device of claim 7, wherein the one or more indicators are measurement markings formed on the shaft, indicating length/depth of insertion in centimetres.

9. The device of claim 8, wherein the marks are printed on a wall of the shaft.

10. The device of any one of claims 7 to 9, wherein there are one or more indicators provided on at least two sides of the shaft.

11. The device of any one of claims 7 to 10, wherein there are a plurality of indicators disposed along the length of the shaft.

12. The device of any one of claims 1 to 11 , wherein to inflate the single balloon, fluid passes through a hole in a shaft wall, into the balloon, the hole being formed in the balloon region.

13. The device of any one of claims 1 to 12, wherein the shaft includes an elongate body, and a primary leg and a secondary leg extending from the elongate body, wherein the primary aperture and the secondary aperture are formed in the primary leg and the secondary leg respectively.

14. The device of claim 13, wherein the elongate body has a central cavity, configured to receive an introducer via the secondary leg to guide insertion of the device into the cervical canal.

15. The device of claims 13 or 14, wherein the elongate body has a channel in fluid communication with the primary aperture, whereby fluid for inflating the balloon travels along the channel and exits the hole in the shaft wall.