WO2024024349A1

WO2024024349A1 - Dilator

Info

Publication number: WO2024024349A1
Application number: PCT/JP2023/023165
Authority: WO
Inventors: 大輔島田; 陽助鍋島
Original assignee: テルモ株式会社
Priority date: 2022-07-28
Filing date: 2023-06-22
Publication date: 2024-02-01

Abstract

Provided is a dilator that makes it possible to reduce the length of a guide wire while suppressing undesirable deflection of the guide wire used in combination therewith.　A dilator (10) that can be placed in the inner lumen of a guiding sheath (50) has a dilator shaft (20) formed with a dilator lumen (21) penetrating from the distal end to the proximal end, wherein the dilator shaft (20) has a shaft proximal end portion (22) in which a slit (23) is formed from the proximal end of the dilator shaft (20) toward the distal end, the slit (23) being formed at an angle (θ) of less than 180 degrees around an axial center (X) of the dilator shaft (20) in a cross section perpendicular to the axial center (X), and a tubular shaft distal end portion (24) arranged on the distal end side with respect to distalmost end of the slit (23) and connected to the shaft proximal end portion (22).

Description

dilator

The present invention relates to a dilator that is used by being inserted into a living body.

In recent years, a procedure in which a long catheter is inserted into a living body lumen such as a blood vessel and delivered to a target position for treatment, diagnosis, etc. has become common because it is minimally invasive.

In order to reach a target position with a device such as a long catheter, a guiding sheath, which has a lumen into which the device can be inserted, is sometimes inserted to a predetermined position in a living body lumen. A dilator that functions as a core material of the guiding sheath and expands a narrow region such as a blood vessel to form a passage is sometimes inserted into the guiding sheath (for example, see Patent Document 1).

When using a dilator, a guide wire is inserted further inside the dilator. After the guiding sheath reaches the target position, it is necessary to pull out the dilator, leaving the guiding sheath and guide wire behind. When withdrawing the dilator, it is necessary for the surgeon to be able to continue grasping the guide wire in any position, but in order to do so, the tip of the dilator must be closer to the proximal side than the proximal opening of the guiding sheath. When the guide wire reaches the tip, the tip of the guide wire needs to be located more distally than the tip of the guiding sheath, and the proximal end of the guide wire needs to be located more proximally than the proximal end of the dilator. Therefore, the length of the guide wire is required to be at least twice the length of the guiding sheath, but if the guide wire is long, it becomes complicated to maneuver the guide wire in subsequent procedures.

To this end, Patent Document 1 describes a so-called rapid exchange dilator whose distal end is tubular and whose proximal end is wire-shaped. When using such a dilator, when replacing the guidewire, the guidewire only needs to pass through the tubular tip of the dilator, so the guidewire can be shortened.

US Patent No. 5,496,344

When using a dilator whose distal end is tubular and whose proximal end is wire-like, the guidewire can freely separate from the wire-like proximal end at the proximal end of the tubular distal end. , the guiding sheath may bend inside, increasing sliding resistance.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a dilator that can reduce the length of the guide wire while suppressing undesirable deflection of the guide wire used in combination.

The above object is achieved by the invention described in (1) below.

(1) The dilator according to the present invention is a dilator that can be placed in the inner lumen of a sheath, and has a dilator shaft formed with a dilator lumen that penetrates from the distal end to the proximal end, and the dilator shaft A shaft proximal end portion in which a slit is formed from the proximal end of the shaft toward the distal end, and the slit is formed at an angle of less than 180 degrees around the axial center in a cross section perpendicular to the axial center of the dilator shaft; and a tubular shaft distal end portion disposed on the distal side of the distal end of the slit and connected to the shaft proximal end portion.

The dilator described in (1) above has a slit formed closer to the proximal end than the distal end of the tubular shaft, so it has a so-called rapid exchange type configuration, and the length of the guide wire used in combination can be reduced. Additionally, because the slit at the proximal end of the shaft is formed at an angle of less than 180 degrees around the axis of the dilator shaft, the dilator can better retain the guidewire used in conjunction with the dilator lumen, allowing the dilator to avoid undesirable interference with the guidewire. Deflection can be suppressed.

(2) In the dilator described in (1) above, the shaft base end portion may have a linear reinforcing wire extending along the axis. Thereby, the strength of the dilator that decreases due to the formation of the slits can be compensated for by the reinforcing wire. Therefore, the dilator can suppress undesirable excessive deformation of the dilator shaft and improve operability.

(3) In the dilator according to (1) or (2) above, the slit has two opposing surfaces arranged to face each other, and at least when the dilator shaft is in a natural state, the opposing surfaces A contact portion where the two contact each other may be formed at at least one location along the axis. Thereby, the dilator can compensate for the reduced strength due to the formation of the slits with the contact portion. Therefore, the dilator can suppress undesirable excessive deformation of the dilator shaft and improve operability. Further, the contact portion can prevent the guide wire from moving from the dilator lumen to the outside of the dilator through the slit. Therefore, the dilator can properly hold the guide wire used in conjunction with the dilator in the dilator lumen, and can effectively suppress undesirable deflection of the guide wire. Additionally, when pulling out the dilator leaving behind the guide wire used in conjunction with the dilator, the guide wire can be removed from the dilator lumen by deforming the dilator shaft so as to widen the gap between the slits including the contact portion. . When the dilator shaft has two or more contact portions along the axis, the plurality of contact portions effectively prevent the guide wire from leaving the dilator lumen. This effectively suppresses undesirable deflection of the guide wire, and when the dilator is pulled out leaving behind the guide wire used in combination, the guide wire is removed from the lumen of the dilator, compared to when the entire slit is in contact with the dilator. It is easy to remove the wire to the outside.

(4) In the dilator according to any one of (1) to (3) above, the dilator has a hub attached to the base end of the shaft base end, and the hub has a hub attached to the base end of the shaft base end. A hub slit communicating with the slit from the proximal end to the distal end may be formed. As a result, the dilator is equipped with a hub to improve operability, and the guide wire used in conjunction with the dilator can be held well in the lumen of the hub, and the hub slit allows the dilator to maintain its rapid exchange type. can.

It is a figure showing the dilator concerning this embodiment, (A) is a top view, and (B) is a longitudinal cross-sectional view. 1(A) is a cross-sectional view taken along line AA in FIG. 1(A), and FIG. 1(B) is a cross-sectional view taken along line BB in FIG. 1(A). , (C) is a cross-sectional view taken along line CC in FIG. 1(A). It is a cross-sectional view showing a first modification of the dilator. It is a top view which shows the modification of a dilator, (A) shows a 2nd modification, and (B) shows a 3rd modification. It is a longitudinal cross-sectional view which shows the 4th modification of a dilator. FIG. 2 is a plan view for explaining how the dilator is used, in which (A) shows a guide wire inserted into the inner cavity of the dilator inserted into the guiding sheath, and (B) shows a state where the guide wire is inserted from the slit of the dilator inserted into the guiding sheath. The guide wire is shown being removed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings may be exaggerated and different from the actual ratios for convenience of explanation. In this specification, the side of the device that is inserted into the blood vessel is referred to as the "distal side," and the side that is operated is referred to as the "proximal side."

The dilator 10 according to the present embodiment is a device used together with the guiding sheath 50, and functions as a core material of the guiding sheath 50, and expands a narrowed region such as a constricted part of a living body lumen such as a blood vessel. It has the function of The dilator 10 is of a so-called rapid exchange type in which a tubular portion is disposed only on the distal end side. The configuration of the guiding sheath 50 is not limited as long as it is a tubular device that provides a passage for a long medical device such as a catheter to reach a predetermined position in a living body lumen.

As shown in FIGS. 1 and 2, the dilator 10 includes a dilator shaft 20 in which a dilator lumen 21 penetrating from the distal end to the proximal end is formed, and a hub 30 attached to the proximal end of the dilator shaft 20. .

The dilator shaft 20 includes a shaft proximal end 22 in which a slit 23 is formed, and a tubular shaft distal end 24 disposed on the distal side of the shaft proximal end 22 and in which the slit 23 is not formed. The shaft proximal end portion 22 and the shaft distal end portion 24 are integrally formed from the same material as the same structure, but may be separate structures.

The shaft tip portion 24 is a tubular portion on the tip side of the dilator shaft 20. The shaft tip portion 24 includes a tubular portion 25 having a constant inner diameter and an outer diameter along the axis X of the dilator shaft 20, and a tapered portion having an outer diameter that tapers from the tip of the tubular portion 25 toward the tip. 26. The inner diameter of the tapered portion 26 matches that of the tubular portion 25, or tapers in at least a portion toward the distal end. The tapered portion 26 can be used, for example, to widen a narrowed portion of a blood vessel.

The shaft base end portion 22 is a portion on the base end side of the dilator shaft 20, and is formed from the base end of the dilator shaft 20 to the base end of the shaft tip portion 24. The shaft base end portion 22 has a slit 23 formed along the axis X from the base end to the distal end. The slit 23 has two opposing surfaces 27 arranged opposite to each other. It is preferable that the outer diameter and inner diameter of a portion of the shaft base end portion 22 excluding the slit 23 match the outer diameter and inner diameter of the tubular portion 25 . Therefore, the shaft base end portion 22 is formed into a C-shape in a cross section perpendicular to the axis X. The width of the slit 23 (the distance between the opposing surfaces 27) is formed substantially constant, and is formed at an angle θ of less than 180 degrees around the axis X. Thereby, when the guide wire 60 is placed in the dilator lumen 21 located at the shaft base end 22, the shaft base end 22 can prevent the guide wire 60 from leaving the slit 23 to the outside to some extent.

The smaller the angle θ, the more effectively the dilator 10 can suppress the guide wire 60 from leaving the slit 23 to the outside. Note that if the angle θ is too small, the work for deforming the dilator shaft 20 in order to separate the guide wire 60 from the slit 23 is complicated. As described above, the angle θ is less than 180 degrees around the axis X, but is more preferably 30 degrees or more and 150 degrees or less, and even more preferably 90 degrees or more and 120 degrees or less. Note that the angle θ of the slit 23 around the axis X may vary depending on the radial position of the slit 23 in a cross section perpendicular to the axis X. The radial direction is a radial direction centered on the axis X of the dilator shaft 20. For example, as in the first modification shown in FIG. 3, the angle of the slit 23 around the axis It differs depending on the angle θ2. In such a case, for example, the angle θ around the axis X of the slit 23 is the smallest value of the angles at each position in the radial direction from the inner circumferential surface to the outer circumferential surface of the shaft base end portion 22. may be defined. This is because the smallest value of the angles at each position in the radial direction from the inner circumferential surface to the outer circumferential surface of the shaft base end portion 22 greatly influences whether the guide wire 60 can pass through the slit 23 or not. Therefore, as shown in FIG. 3, when the angle θ1 is smaller than the angle θ2, the angle θ of the slit 23 about the axis X can be set to the angle θ1.

Furthermore, the angle θ of the slit 23 may be 0 degrees as in the second modification shown in FIG. 4(A). That is, the dilator shaft 20 has a contact portion 28 in which the two opposing surfaces 27 are in contact without being separated, at least when the dilator shaft 20 is in a natural state (a state in which no external force is applied). Therefore, when the guide wire 60 is removed from the dilator lumen 21, it is necessary to deform the shaft proximal end 22 so that the two opposing surfaces 27 are separated.

Further, as in a third modification shown in FIG. 4(B), the dilator shaft 20 may have a plurality of contact portions 28 along the axis X at least when the dilator shaft 20 is in its natural state. good. As a result, when the dilator 10 removes the guide wire 60 from the dilator lumen 21, the shaft proximal end portion is moved so that the two opposing surfaces 27 that face each other and are in contact at each contact portion 28 are separated. It is necessary to transform 22.

The inner diameter of the dilator shaft 20 is not particularly limited, but is, for example, 0.38 mm to 1 mm. The maximum outer diameter of the dilator shaft 20 (the outer diameter of the tubular portion 25 and the shaft proximal end portion 22) is not particularly limited, but is, for example, 1 mm to 3 mm. The maximum outer diameter of the dilator shaft 20 is somewhat smaller than the inner diameter of the guiding sheath 50. Thereby, the outer circumferential surface of the guiding sheath 20 can be brought into close contact with the inner circumferential surface of the guiding sheath 50 with almost no gap or with a small gap. The length of the shaft tip 24 in the direction along the axis X is not particularly limited, but is, for example, 100 mm to 300 mm. The length of the shaft base end portion 22 in the direction along the axis X is not particularly limited, but is, for example, 600 mm to 1900 mm.

It is preferable that the dilator shaft 20 is flexible with some degree of flexibility. Therefore, the dilator shaft 20 is made of various thermoplastic elastomers such as styrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, transpolyisoprene, fluororubber, and chlorinated polyethylene. , polyetherketone, polyimide, etc., and one or a combination of two or more of these (polymer alloy, polymer blend, laminate, etc.) can be used. Alternatively, among various elastomers, for example, polyurethane elastomer, polyester elastomer, polyamide elastomer, etc. can be suitably used. Dilator shaft 20 may include an X-opaque material (contrast agent) therein. Examples of radiopaque metals include gold, platinum, silver, bismuth, tungsten, alloys of two or more of these (e.g., platinum-tungsten), barium sulfate, or alloys with other metals (e.g., gold). -iridium, platinum-iridium, platinum-nickel), etc. When the dilator shaft 20 includes an X-ray opaque metal, the operator can grasp the position of the dilator shaft 20 inserted into the body under X-ray contrast.

The hub 30 is a member attached to the base end of the dilator shaft 20, as shown in FIGS. 1 and 2. The hub 30 has a hub slit 31 formed along the axis X from the base end to the distal end. The hub slit 31 has two hub-facing surfaces 32 that are arranged to face each other. Therefore, the hub 30 is formed into a C-shape in a cross section perpendicular to the axis X. The width of the hub slit 31 (the distance between the opposing hub facing surfaces 32) is formed to be substantially constant, and is formed at an angle α of less than 180 degrees around the axis X. Thereby, when the guide wire 60 is placed in the hub inner cavity located in the hub 30, the hub 30 can suppress to some extent the guide wire 60 from leaving the hub slit 31 to the outside. The smaller the angle α, the more effectively the hub 30 can suppress the guide wire 60 from leaving the hub slit 31 to the outside. Note that if the angle α is too small, the work for deforming the hub 30 in order to separate the guide wire 60 from the hub slit 31 is complicated. As described above, the angle α is less than 180 degrees around the axis X, but is more preferably 30 degrees or more and 150 degrees or less, and even more preferably 90 degrees or more and 120 degrees or less. Note that the angle α of the hub slit 31 around the axis X may vary depending on the radial position of the hub slit 31 in the cross section perpendicular to the axis X, similar to the angle θ of the slit 23 described above. .

Furthermore, the angle α of the hub slit 31 may be 0 degrees as in the second modification shown in FIG. 4(A). That is, the dilator shaft 20 has a hub contact portion 33 in which the two opposing hub facing surfaces 32 contact without separating, at least when the dilator shaft 20 is in a natural state (a state in which no external force is applied). There is. Therefore, when the guide wire 60 is removed from the hub lumen, it is necessary to deform the hub 30 so that the two hub facing surfaces 32 are separated.

The hub 30 is preferably flexible with some degree of flexibility. As the constituent material of the hub 30, materials applicable to the dilator shaft 20 described above can be suitably applied. Note that the hub 30 may not be provided.

Further, as in a third modification shown in FIG. 4(B), the hub 30 may have a plurality of hub contact portions 33 along the axis X, at least when the hub 30 is in the natural state. . Accordingly, when the dilator 10 removes the guide wire 60 from the hub lumen, the hub 30 needs to be deformed so that the two opposing hub facing surfaces 32 at each hub contact portion 33 are separated. There is.

Further, as in a fourth modification shown in FIG. 5, the shaft base end portion 22 may have a linear reinforcing wire 40 extending along the axis X. Reinforcement wire 40 is embedded within the material of shaft proximal end 22 . The reinforcing wire 40 is a single straight wire extending along the axis X. In addition, the number of reinforcing wires 40 may be one or more may be provided. The reinforcing wire 40 can compensate for the strength of the dilator shaft 20, which decreases due to the formation of the slit 23. The distal end of the reinforcing wire 40 is disposed near the boundary between the shaft distal end 24 and the shaft proximal end 22, but is preferably disposed on the distal side of the boundary. Thereby, it is possible to suppress bending of the dilator shaft 20 at the boundary between the shaft distal end portion 24 and the shaft proximal end portion 22, where the strength changes. Further, the base end of the reinforcing wire 40 is placed near the base end of the dilator shaft 20, but is preferably placed closer to the base end than the tip of the hub 30. Thereby, bending of the dilator shaft 20 near the tip of the hub 30 where the strength changes can be suppressed.

The constituent material of the reinforcing wire 40 is not particularly limited, but stainless steel, nickel-titanium alloy, etc. can be suitably used, for example. Further, the cross-sectional shape of the reinforcing wire 40 is not particularly limited, and may be, for example, circular, rectangular, square, oval, etc., or may have a different shape depending on the region.

Next, the action of the dilator 10 will be explained.
When using the guiding sheath 50, the operator inserts the distal end of the dilator 10 through the proximal opening of the guiding sheath 50, as shown in FIG. , causing the tapered portion 26 to protrude. Next, the operator passes the guide wire 60 through the dilator lumen 21 and percutaneously inserts the distal end of the guide wire 60 into the blood vessel. Next, the operator pushes the dilator 10 and guiding sheath 50 together along the guide wire 60 while leading the guide wire 60. Since the dilator 10 has a tapered portion 26 at its tip, it supports the outer guiding sheath 50 and allows it to reach a target position while expanding a narrow region such as a narrowed portion of a blood vessel. Since the guide wire 60 is accommodated in the dilator lumen 21, it is not directly accommodated in the lumen of the guiding sheath 50, and is prevented from bending more than necessary in the wide lumen of the guiding sheath 50.

After the guiding sheath 50 reaches the target position, the operator pulls out the dilator 10, leaving the guiding sheath 50 and guide wire 60 behind, as shown in FIG. 6(B). At this time, since the slit 23 is formed in the dilator shaft 20 and the hub slit 31 is formed in the hub 30, the operator can insert the guide wire 60 located on the proximal side of the proximal opening of the guiding sheath 50. , the slit 23 and the hub slit 31 and can be removed to the outside of the dilator 10. Therefore, the guide wire 60 does not need to have a length twice or more that of the guiding sheath 50, and may be short. Therefore, the guide wire 60 can be easily routed in subsequent procedures.

As described above, the dilator 10 according to the present embodiment is a dilator 10 that can be placed in the inner cavity of the guiding sheath 50, and includes the dilator shaft 20 in which the dilator inner cavity 21 penetrating from the distal end to the proximal end is formed. The dilator shaft 20 has a slit 23 formed from the proximal end of the dilator shaft 20 toward the distal end, and the slit 23 extends 180 degrees around the axis X in a cross section perpendicular to the axis X of the dilator shaft 20. a shaft proximal end 22 formed at an angle θ less than or equal to the angle θ; and a tubular shaft distal end 24 disposed on the distal side of the most distal end of the slit 23 and connected to the shaft proximal end 22. As a result, the dilator 10 has the slit 23 formed on the proximal end side of the tubular shaft tip 24, so it has a so-called rapid exchange type configuration, and the length of the guide wire 60 used together can be reduced. Furthermore, since the slit 23 of the shaft proximal end 22 is formed at an angle of less than 180 degrees around the axis X of the dilator shaft 20, the dilator 10 can hold the guide wire 60 used together well in the dilator inner cavity 21. Therefore, undesirable bending of the guide wire 60 can be suppressed.

The shaft base end portion 22 may have a linear reinforcing wire 40 extending along the axis X (see the fourth modification in FIG. 5). Thereby, the dilator 10 can compensate for the strength reduced by the formation of the slit 23 with the reinforcing wire 40. Therefore, the dilator 10 can suppress undesirable excessive deformation of the dilator shaft 20 and improve operability.

The slit 23 has two opposing surfaces 27 that are arranged to face each other, and at least when the dilator shaft 20 is in a natural state, a contact portion 28 where the opposing surfaces 27 contact each other is formed at least once along the axis X. (See the second and third variants in FIG. 4). Thereby, the dilator 10 can compensate for the strength reduced by the formation of the slit 23 with the contact portion 28. Therefore, the dilator 10 can suppress undesirable excessive deformation of the dilator shaft 20 and improve operability. Furthermore, the contact portion 28 can prevent the guide wire 60 from moving from the dilator lumen 21 through the slit 23 to the outside of the dilator 10 . Therefore, the dilator 10 can properly hold the guide wire 60 used together in the dilator inner cavity 21, and can effectively suppress undesirable bending of the guide wire 60. Furthermore, when the dilator 10 is pulled out leaving the guiding sheath 50 and guide wire 60 used together, the dilator shaft 20 is deformed so as to widen the gap between the slits 23 including the contact portions 28. The guide wire 60 can be removed to the outside. When the dilator shaft 20 is formed with two or more contact portions 28 along the axis X, the dilator shaft 20 has a plurality of contact portions 28 that allow the guide wire 60 to separate from the dilator lumen 21 to the outside. In addition, when the dilator 10 is pulled out leaving the guiding sheath 50 and the guide wire 60 used together, the entire slit 23 can be effectively suppressed. It is easier to remove the guide wire 60 from the dilator lumen 21 to the outside compared to the case where the contact portion 28 is provided at the inner lumen 21 of the dilator.

The dilator 10 has a hub 30 attached to the base end of the shaft base end portion 22, and the hub 30 is formed with a hub slit 31 that communicates with the slit 23 from the base end to the distal end of the hub 30. As a result, the dilator 10 is equipped with the hub 30 to improve operability, and the guide wire 60 used together can be held well in the inner cavity of the hub 30. Also, the hub slit 31 allows the dilator 10 to be used as a rapid exchange type. can be maintained.

Note that the present invention is not limited to the embodiments described above, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the biological lumen into which the dilator 10 is inserted is not limited to blood vessels.

Note that this application is based on Japanese Patent Application No. 2022-120522 filed on July 28, 2022, and the disclosures thereof are referenced and incorporated in their entirety.

10 Dilator 20 Dilator shaft 21 Dilator inner cavity 22 Shaft proximal end 23 Slit 24 Shaft tip 25 Tubular portion 26 Tapered portion 27 Opposing surface 28 Contact portion 30 Hub 31 Hub slit 32 Hub opposing surface 33 Hub contact portion 40 Reinforcement wire 50 Guy Ding sheath 60 Guide wire X Axial center α Hub slit angle θ Slit angle

Claims

A dilator positionable in the lumen of the sheath, the dilator comprising:
It has a dilator shaft formed with a dilator lumen that penetrates from the distal end to the proximal end,
The dilator shaft is
A shaft proximal end portion in which a slit is formed from the proximal end of the dilator shaft toward the distal end, and the slit is formed at an angle of less than 180 degrees around the axial center in a cross section perpendicular to the axial center of the dilator shaft. and,
A dilator comprising: a tubular shaft distal end portion disposed on the distal side of the most distal end of the slit and connected to the shaft proximal end portion.
The dilator according to claim 1, wherein the shaft base end portion has a linear reinforcing wire extending along the axis.
The slit has two opposing surfaces arranged to face each other, and at least when the dilator shaft is in a natural state, a contact portion where the opposing surfaces contact each other is located at at least one location along the axis. A dilator according to claim 1 or 2 formed therein.
a hub attached to a proximal end of the shaft proximal end;
The dilator according to claim 1 or 2, wherein the hub has a hub slit that communicates with the slit from the base end to the distal end of the hub.