Sheath, stylet, and catheter insertion kit for embryo transfer

Abstract

To provide a sheath and a stylet which enable easy insertion into the uterus.SOLUTION: A sheath 10, which serves to guide insertion of an embryo transfer catheter into the uterus, includes a sheath body 11 formed as a hollow tube and a balloon 20 disposed on a distal side of the sheath body 11, the balloon being configured to expand and contract by having a fluid introduced into and discharged from its interior.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sheath, a stylet, and an embryo transfer catheter insertion kit. [Background technology]

[0002] Embryo transfer instruments used for transferring an embryo (a fertilized egg) fertilized in vitro into the uterus have been known. For example, Patent Document 1 discloses an embryo transfer instrument including a flexible sheath, a flexible stylet removably inserted into the sheath, and a flexible embryo transfer catheter protruding a predetermined length from the tip of the sheath.

[0003] The procedure for embryo transfer using the device disclosed in Patent Document 1 is as follows. (1) Embryos are aspirated from the tip of the embryo transfer catheter. (2) Insert the stylet into the sheath and adjust the shape of the stylet to match the shape of the insertion site. (3) The sheath with the stylet inserted is inserted up to the internal cervical os. (4) The stylet is removed from the sheath, and the embryo transfer catheter is inserted into the sheath. (5) The tip of the embryo transfer catheter is placed a few centimeters from the fundus of the uterus. (6) The embryo is transferred, and the embryo transfer catheter and sheath are removed from the patient. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-129789 Summary of the Invention [Problem to be solved by the invention]

[0005] However, depending on the shape of the patient's cervical canal, it may be difficult to insert the sheath and stylet. Furthermore, forcibly inserting the sheath and stylet is undesirable because it poses a risk of bleeding.

[0006] It is an object of the present invention to provide a sheath and stylet that can be easily inserted into the uterus. [Means for solving the problem]

[0007] One aspect of the sheath of the present invention is a sheath for guiding the insertion of an embryo transfer catheter into the uterus, and is characterized by comprising a hollow cylindrical sheath body and a balloon provided at the tip side of the sheath body that can be expanded and contracted by introducing and guiding a fluid into and from the balloon.

[0008] According to the above configuration, the cervical canal can be dilated by inflating the balloon in a region where it is difficult to insert a sheath, such as the cervical canal. After the cervical canal has been dilated, the balloon can be deflated, allowing the sheath to be easily inserted into the uterus.

[0009] In the sheath according to the present invention, it is preferable that a protective member having a rounded shape is provided at the distal end of the sheath body so as not to block the opening of the sheath body.

[0010] According to the above configuration, even if the tip of the sheath body comes into contact with the vagina, the cervical canal, etc. when the sheath is inserted into the uterus, damage to the vagina, the cervical canal, etc. can be suppressed because the tip of the sheath body is rounded.

[0011] In the sheath according to the present invention, it is preferable that at least a portion of the tip of the balloon is covered with the protective member.

[0012] According to the above configuration, it is possible to prevent the balloon from coming off the sheath body.

[0013] In the sheath according to the present invention, it is preferable that the balloon and the protective member are bonded together via an adhesive.

[0014] According to the above configuration, the balloon can be further prevented from coming off the sheath body.

[0015] One aspect of the present invention is a stylet that is inserted in advance to guide the insertion of an embryo transfer catheter into the uterus, and is characterized by comprising a cylindrical stylet body and a balloon provided at the tip side of the stylet body that can be expanded and contracted by introducing and guiding a fluid into and from the interior.

[0016] According to the above configuration, the cervical canal can be dilated by inflating the balloon in a region where it is difficult to insert a stylet, such as the cervical canal. After the cervical canal has been dilated, the balloon can be deflated, allowing the stylet to be easily inserted into the uterus.

[0017] As described above, the stylet is inserted into the uterus while inside the sheath. Therefore, by providing a balloon on the stylet, the area of ​​the balloon exposed to the outside during insertion of the sheath and stylet can be reduced. This reduces damage to the vagina or cervix, as well as damage to the balloon, caused by the balloon coming into contact with the vagina or cervix.

[0018] In the stylet according to the present invention, the stylet body preferably has a hollow shape.

[0019] According to the above configuration, the balloon provided on the stylet can be inflated and deflated with a simple configuration. [Effects of the Invention]

[0020] The sheath and stylet according to the present invention can be easily inserted into areas where it is difficult to insert a sheath and stylet, such as the cervical canal, making it possible to easily reach the tip of the embryo transfer catheter to the desired location without damaging the uterus. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 10 is a diagram showing a sheath according to an embodiment. [Figure 2] FIG. 2 is an enlarged cross-sectional view showing the vicinity of the tip of a sheath according to an embodiment. [Figure 3] FIG. 10 is an enlarged cross-sectional view showing the vicinity of the tip of a sheath according to another embodiment. [Figure 4] FIG. 1 is a diagram showing an embryo transfer catheter insertion kit according to an embodiment. [Figure 5] FIG. 1 is an enlarged cross-sectional view showing the vicinity of the tip of an embryo transfer catheter insertion kit according to an embodiment. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing the vicinity of the tip of an embryo transfer catheter insertion kit, which is another example of an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an example of an embodiment of a sheath and stylet according to the present invention will be described in detail with reference to the drawings. The embodiment described below is merely an example, and the present invention is not limited to the following embodiment. Furthermore, the present invention includes forms formed by selectively combining multiple embodiments and modified examples described below.

[0023] A sheath 10 as an example of an embodiment will be described with reference to Figures 1 and 2. Figure 1 is a diagram showing the entire sheath 10, and Figure 2 is an enlarged cross-sectional view showing the vicinity of the tip of the sheath 10.

[0024] 1, the sheath 10 includes a hollow cylindrical sheath body 11 and a connector 12 attached to the proximal end of the sheath body 11. The sheath 10 also includes a balloon 20 that is attached to the outer peripheral surface of the distal end of the sheath body 11 and can be inflated and deflated by introducing and discharging a fluid therein, and a protective member 30 that is attached to the distal end of the sheath body 11 and has a rounded shape.

[0025] The sheath 10 is an instrument used to guide the insertion of an embryo transfer catheter into the uterus. The embryo transfer catheter must accurately transfer an embryo to the desired location. Therefore, the position of the tip of the embryo transfer catheter must be precisely controlled. The sheath body 11 is harder and more rigid than the catheter tube of the embryo transfer catheter. Therefore, by passing the embryo transfer catheter through the inside of the sheath 10, the tip of the embryo transfer catheter can be brought to the desired location without the catheter tube being twisted.

[0026] The procedure for embryo transfer using the sheath 10 involves first inserting the sheath 10 up to the internal cervical os with a stylet inserted into it. Then, the stylet is removed from the sheath 10, and an embryo transfer catheter with an embryo aspirated into its tip is inserted into the sheath 10. The embryo is then transferred, and the catheter and sheath 10 are then removed from the patient.

[0027] The sheath body 11 is a flexible, thin tube through which a stylet and a catheter pass. A fluid for inflating and deflating the balloon 20 passes through the sheath body 11. Examples of such a fluid include air, saline, or distilled water.

[0028] The connector 12 has a first port 13 through which a stylet and a catheter are passed, and a second port 14 for introducing and evacuating a fluid into and from the interior of the balloon 20. The second port 14 is connected to, for example, a pump device (not shown), and is configured to allow the fluid to be introduced into or discharged from the interior of the balloon 20.

[0029] The connector 12 is formed from a thermoplastic resin such as polypropylene, polyvinyl chloride, polycarbonate, polyamide, polysulfone, polyacrylate, methacrylate-butylene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, or polyether ether ketone.

[0030] As shown in Figure 2, the sheath body 11 has a double-tube structure consisting of an inner tube 15 and an outer tube 16. The inner tube 15 and the outer tube 16 each have a cylindrical shape with both ends open. A first space 17 is formed inside the inner tube 15, through which a stylet and a catheter pass, and a second space 18 is formed between the inner tube 15 and the outer tube 16, through which a fluid circulating inside the balloon 20 passes. That is, a first port 13 is connected to the first space 17, and a second port 14 is connected to the second space 18.

[0031] The outer diameter of the inner tube 15 is, for example, 1.0 mm or more and 5.0 mm or less, or may be 1.5 mm or more and 4.0 mm or less. The outer diameter of the outer tube 16 may be larger than the outer diameter of the inner tube 15, for example, 1.5 mm or more and 5.5 mm or less, or 2.0 mm or more and 4.5 mm or less. The wall thickness of the inner tube 15 and the outer tube 16 is, for example, 0.05 mm or more and 0.4 mm or less.

[0032] The outer tube 16 is shorter than the inner tube 15, and has a length that is, for example, 75% to 98% of the total length of the sheath body 11. In other words, the tip of the inner tube 15 is the tip of the sheath body 11. The outer surface of the tip side of the outer tube 16 is covered with a balloon 20. This connects the second space 18 to a balloon space 21 inside the balloon 20.

[0033] The material constituting the inner tube 15 and the outer tube 16 is preferably one having a certain degree of shape retention, such as polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, etc. Furthermore, the inner tube 15 and the outer tube 16 may be formed of the same material or may be formed of different materials. For example, the inner tube 15 may be formed of a harder material than the outer tube 16.

[0034] The balloon 20 is an expandable and contractible bag having a balloon space 21 therein for accommodating the fluid flowing in from the second space 18. In this embodiment, the balloon 20 has a substantially spherical shape in an expanded state. The outer diameter and length of the balloon 20 can be appropriately set depending on the intended use. The outer diameter of the balloon 20 in an expanded state is, for example, 10 mm or more and 50 mm or less, or may be 15 mm or more and 40 mm or less. The length of the balloon 20 is, for example, 20 mm or more and 100 mm or less, or may be 30 mm or more and 80 mm or less.

[0035] The distal end of the balloon 20 is joined to the distal end of the inner tube 15, and the proximal end of the balloon 20 is joined to the distal end of the outer tube 16. When fluid flows into the balloon space 21, the balloon 20 expands radially outward from the sheath body 11. The expansion of the balloon 20 enables dilation of a region where it is difficult to insert the sheath 10, such as the cervical canal. Furthermore, when the fluid inside the balloon space 21 is released, the balloon 20 contracts radially inward from the sheath body 11. The contraction of the balloon 20 allows the sheath 10 to pass through the dilated region.

[0036] It is assumed that the sheath body 11 will be inserted while repeatedly inflating and deflating the balloon 20 multiple times during the process of inserting the sheath body 11. In other words, it is assumed that the fluid inside the balloon space 21 will be introduced and evacuated multiple times during the process of inserting the sheath body 11.

[0037] Examples of materials that can be used to form the balloon 20 include polyurethane, silicone, soft polyethylene, soft polyamide, soft polyester, and polyamide elastomer.

[0038] The protective member 30 is provided at the tip of the sheath body 11 and has a substantially spherical shape. That is, the tip side of the protective member 30 has a shape that tapers toward the tip. The protective member 30 has a through-hole 31 therein that extends along the opening direction of the inner tube 15 and is positioned so as not to block the opening of the sheath body 11. By providing the protective member 30 at the tip of the sheath body 11, the tip of the sheath 10 has a rounded shape. This makes it possible to prevent damage to the vagina, cervical canal, etc., even if the tip of the sheath 10 comes into contact with the vagina, cervical canal, etc., when the sheath 10 is inserted into the uterus.

[0039] The outer diameter of the protective member 30 is larger than the outer diameter of the inner tube 15. The difference between the outer diameter of the protective member 30 and the outer diameter of the inner tube 15 is, for example, 0.5 mm or more and 5.0 mm or less, and may be 1.0 mm or more and 3.0 mm or less.

[0040] The protective member 30 is made of, for example, a material harder than the sheath body 11. Similar to the material making up the sheath body 11, examples of materials making up the protective member 30 include polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, polyamide elastomer, polyimide, and polyimide elastomer.

[0041] The base end side of the protective member 30 is disposed so as to cover the distal end side of the balloon 20 and is joined to the distal end side of the balloon 20. By the protective member 30 covering the distal end side of the balloon 20, it is possible to prevent the balloon 20 from coming off the sheath body 11.

[0042] The protective member 30 and the distal end side of the balloon 20 may be bonded together with an adhesive, which strengthens the bond between the protective member 30 and the balloon 20 and further prevents the balloon 20 from coming off the sheath body 11.

[0043] At least a portion of the protective member 30 may be joined to the outer surface of the inner tube 15. The method for joining the protective member 30 to the outer surface of the inner tube 15 is not particularly limited, and they may be joined, for example, via an adhesive or by welding. When joining the protective member 30 to the outer surface of the inner tube 15, it is preferable that the protective member 30 be made of the same material as the inner tube 15. In this case, the protective member 30 can be firmly joined to the outer surface of the inner tube 15, making it difficult for the protective member 30 to come off the sheath body 11.

[0044] The above-described embodiment can be modified as needed without impairing the objectives of the present disclosure. For example, in the above-described embodiment, the protective member 30 is provided at the distal end of the sheath body 11. However, the protective member 30 need not be provided at the distal end of the sheath body 11. Even in this case, the sheath 10 can be easily inserted into a region where insertion of the sheath 10 is difficult, such as the cervical canal, by inflating and deflating the balloon 20.

[0045] Furthermore, in the above embodiment, the balloon 20 has a substantially spherical shape in the inflated state, but the shape of the balloon 20 is not limited to this. For example, as shown in FIG. 3 , the balloon 20 may have a substantially cylindrical shape in the inflated state, with the diameter tapering toward the tip of the balloon 20. When the balloon 20 has such a shape, even if the tip of the sheath body 11 comes into contact with the vagina, cervical canal, or the like when the sheath 10 is inserted into the uterus, damage to the vagina, cervical canal, or the like can be suppressed. In other words, a balloon 20 having such a shape is particularly effective when the sheath 10 is not provided with a protective member 30.

[0046] Next, an embryo transfer catheter insertion kit 1 and a stylet 40 for inserting an embryo transfer catheter, which is one example of an embodiment, will be described with reference to Figures 4 and 5. Figure 4 is a diagram showing the embryo transfer catheter insertion kit 1, and Figure 5 is an enlarged cross-sectional view showing the vicinity of the tip of the embryo transfer catheter insertion kit 1.

[0047] As shown in Figure 4, an embryo transfer catheter insertion kit 1 for inserting an embryo transfer catheter (not shown) into a uterus comprises a stylet 40 and a sheath 60 into which the stylet 40 is inserted and inserted into the uterus. The embryo transfer catheter insertion kit 1 is inserted into the uterus before the embryo transfer catheter and guides the insertion of the embryo transfer catheter into the uterus. During embryo transfer using the embryo transfer catheter, after the embryo transfer catheter insertion kit 1 is inserted into the uterus, the stylet 40 is removed from the sheath 60 and the embryo transfer catheter is inserted into the sheath 60. The sheath 60 comprises a sheath body 61, which is a flexible, thin tube, and a connector 62 attached to the proximal end of the sheath body 61.

[0048] The stylet 40 is harder and more rigid than the sheath 60. Therefore, by using an embryo transfer catheter insertion kit 1 equipped with the stylet 40, it becomes easier to maintain the shape of the sheath 60, allowing the sheath 60 to be smoothly positioned at the desired location. Furthermore, by using the stylet 40, it is possible to prevent bodily secretions and the like from entering the inside of the sheath 60 when the sheath 60 is inserted into the vagina.

[0049] As will be described in more detail below, a balloon 50 is provided at the tip of the stylet 40. The balloon 50 at the tip of the stylet 40 is configured to be able to protrude from the tip of the sheath 60. When the embryo transfer catheter insertion kit 1 is being inserted into the uterus, the balloon 50 may always protrude from the tip of the sheath 60, or may protrude from the tip of the sheath 60 only when the balloon 50 is inflated. In other words, when the balloon 50 is deflated, at least a portion of the balloon 50 may be housed inside the sheath 60.

[0050] As shown in Figure 4, the stylet 40 comprises a cylindrical stylet body 41 and a connector 42 attached to the proximal end of the stylet body 41. In this embodiment, the stylet body 41 has a hollow shape with both ends open. The stylet 40 also comprises a balloon 50 attached to the outer peripheral surface of the distal end of the stylet body 41, which can be inflated and deflated by introducing and evacuating a fluid therein. The stylet 40 is an instrument that is inserted into the sheath 60 in advance to guide the insertion of the embryo transfer catheter into the uterus.

[0051] The connector 42 has a port 43 for introducing and discharging a fluid into the balloon 50. The port 43 is connected to, for example, a pump device (not shown) so that the fluid can be introduced into or discharged from the balloon 50.

[0052] The connector 42 is formed from a thermoplastic resin such as polypropylene, polyvinyl chloride, polycarbonate, polyamide, polysulfone, polyacrylate, methacrylate-butylene-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, or polyether ether ketone.

[0053] 5, stylet body 41 has a hollow shape with both ends open, and has a flow space 44 therein through which a fluid passes for inflating and deflating balloon 50. Flow space 44 is connected to port 43 (see FIG. 5) provided in connector 42 and to balloon space 51 inside balloon 50.

[0054] The outer diameter of the stylet body 41 is smaller than the outer diameter of the sheath 60. The difference between the outer diameter of the stylet body 41 and the outer diameter of the sheath 60 is, for example, 0.1 mm or more and 1.0 mm or less, or may be 0.2 mm or more and 0.8 mm or less. The outer diameter of the stylet body 41 is, for example, 1.0 mm or more and 4.0 mm or less, or may be 1.2 mm or more and 3.0 mm or less.

[0055] The outer diameter of the flow space 44 inside the stylet body 41 is not particularly limited as long as it allows passage of the fluid for inflating and deflating the balloon 50. The outer diameter of the flow space 44 inside the stylet body 41 is, for example, 0.1 mm or more and 3.5 mm or less, or may be 0.2 mm or more and 2.5 mm or less.

[0056] The material constituting the stylet body 41 is preferably harder than the sheath 60, and examples thereof include polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, etc.

[0057] The balloon 50 is an expandable and contractible bag having a balloon space 51 therein for accommodating the fluid flowing in from the flow space 44. In this embodiment, the balloon 50 has a substantially spherical shape in an expanded state. The outer diameter and length of the balloon 50 can be appropriately set depending on the intended use. The outer diameter of the balloon 50 in an expanded state is, for example, 10 mm or more and 50 mm or less, or may be 15 mm or more and 40 mm or less. The length of the balloon 50 is, for example, 20 mm or more and 100 mm or less, or may be 30 mm or more and 80 mm or less.

[0058] The base end of the balloon 50 is joined to the distal end of the stylet body 41. When fluid flows into the balloon space 51, the balloon 50 expands outward from the stylet body 41. The expansion of the balloon 50 allows for dilation of areas that are difficult to insert the embryo transfer catheter insertion kit 1 into, such as the cervical canal. Furthermore, when the fluid inside the balloon space 51 is removed, the balloon 50 contracts inward from the stylet body 41. The contraction of the balloon 50 allows the embryo transfer catheter insertion kit 1 to pass through the expanded area. As described above, the stylet 40 is inserted into the uterus while inserted into the sheath 60. Therefore, for example, by inserting the embryo transfer catheter insertion kit 1 into the uterus with at least a portion of the balloon 50 inserted into the sheath 60 when the balloon 50 is deflated, the area of ​​the balloon 50 exposed to the outside can be reduced. This reduces damage to the vagina or cervical canal, as well as damage to the balloon 50, caused by the balloon 50 coming into contact with the vagina or cervical canal.

[0059] 5, the balloon 50 is bonded to the outer peripheral surface of the distal end of the stylet body 41, but the balloon 50 may also be bonded to the inner peripheral surface of the distal end of the stylet body 41. Bonding the balloon 50 to the inner peripheral surface of the stylet body 41 can reduce damage to the vagina or cervical canal, as well as damage to the balloon 50, which may occur if the balloon 50 comes into contact with the vagina or cervical canal when the stylet 40 is pulled out of the sheath 60.

[0060] In the process of inserting the embryo transfer catheter insertion kit 1, it is assumed that the embryo transfer catheter insertion kit 1 will be inserted while repeatedly inflating and deflating the balloon 50. In other words, in the process of inserting the embryo transfer catheter insertion kit 1, it is assumed that the fluid inside the balloon space 51 will be introduced and evacuated multiple times.

[0061] Examples of materials that can be used to form the balloon 50 include polyurethane, silicone, soft polyethylene, soft polyamide, soft polyester, and polyamide elastomer.

[0062] The above-described embodiments can be modified in design as appropriate without impairing the purpose of the present disclosure. For example, in the above-described embodiments, the stylet body 41 has a hollow shape with both ends open, but the shape of the stylet body 41 is not limited to this. For example, as shown in FIG. 6 , the stylet body 41 may have a solid shape, with an outer tube 45 attached to its outer periphery. A flow space 44 is formed between the stylet body 41 and the outer tube 45, through which a fluid for inflating and deflating the balloon 50 passes. The balloon 50 is joined to the distal end of the outer tube 45.

[0063] Furthermore, in order to grasp the distal end position of the sheaths 10, 60 inside the body using ultrasonic echoes, an echo marker made of a metal part or the like may be provided near the protective member 30 or the balloons 20, 50. [Explanation of symbols]

[0064] 1 Embryo transfer catheter insertion kit, 10 sheath, 11 sheath body, 12 connector, 13 first port, 14 second port, 15 inner tube, 16 outer tube, 17 first space, 18 second space, 20 balloon, 21 balloon space, 30 protective member, 31 through hole, 40 stylet, 41 stylet body, 42 connector, 43 port, 44 flow space, 45 outer tube, 50 balloon, 51 balloon space, 60 sheath, 61 sheath body, 62 connector

Claims

1. A sheath for guiding the insertion of an embryo transfer catheter into a uterus, a hollow cylindrical sheath body; a balloon provided at the distal end of the sheath body and capable of expanding and contracting by introducing and discharging a fluid therein; A sheath.

2. The sheath according to claim 1 , further comprising a protective member having a rounded shape and disposed at the distal end of the sheath body so as not to block the opening of the sheath body.

3. The sheath according to claim 2 , wherein at least a portion of the tip of the balloon is covered by the protective member.

4. The sheath according to claim 3 , wherein the balloon and the protective member are bonded together via an adhesive.

5. A stylet that is inserted in advance to guide the insertion of the embryo transfer catheter into the uterus, a cylindrical stylet body; a balloon provided at the distal end of the stylet body and capable of expanding and contracting by introducing and discharging a fluid therein; A stylet comprising:

6. The stylet of claim 5 , wherein the stylet body has a hollow shape.

7. The stylet according to claim 5 or 6; a sheath inserted into the uterus with the stylet inserted therein; An embryo transfer catheter insertion kit comprising:

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