WO2022249413A1

WO2022249413A1 - Catheter

Info

Publication number: WO2022249413A1
Application number: PCT/JP2021/020290
Authority: WO
Inventors: 雄太中川; 盛貴荻堂
Original assignee: 朝日インテック株式会社
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2022-12-01

Abstract

The present invention is capable of properly guiding a retrograde guide wire to the proximal end side. A catheter 1 comprises: a mesh member 110; a hollow shaft 120 which is connected to a proximal end section of the mesh member 110; a distal end tip 130 which is connected to a distal end section of the mesh member 110; and a core wire 150, the distal end of which is connected to the distal end section of the mesh member 110 and the proximal end of which passes through the mesh member 110 and the hollow shaft 120. The hollow shaft 120 has a center shaft 123 including a core wire lumen 125, the distal end of which is disposed on the proximal end side relative to the distal end of the hollow shaft 120, and into which the core wire 150 is inserted, and a guide wire lumen 124 into which a retrograde guide wire guided from the distal end side is inserted. A surface 123a on the distal end side of the guide wire lumen 124 is tilted with respect to the axial direction of the hollow shaft 120.

Description

catheter

The present invention relates to catheters.

As a medical device for improving blood flow by removing obstructions that block blood vessels such as chronic total occlusion (CTO) A technique is known in which a guide wire is passed through and the guide wire is captured by a mesh-like extension part provided in a catheter (see, for example, Patent Document 1).

In Patent Literature 1, by providing a membrane body made of a flexible material that partially covers the gap of the expansion part, the guide wire inserted into the internal space of the expansion part is prevented from protruding outside the expansion part. A technique for doing so is disclosed.

JP 2019-72301 A

According to the technique described in Patent Document 1, the guide wire (retrograde guide wire) from the opposite side of the obstructing lesion is suppressed by the membrane body from protruding outside the extension portion, and the guide wire is attached to the shaft portion. can lead. However, even if the guide wire can be guided to the shaft portion, there is a possibility that the guide wire cannot be properly guided to the proximal end side if the guide wire comes into contact with the core wire or parts inside the shaft portion.

The present invention has been made based on the circumstances as described above, and its purpose is to provide a technique capable of appropriately guiding a retrograde guidewire to the proximal side.

In order to achieve such an object, a catheter according to one aspect includes a radially expandable and contractible tubular mesh member, a hollow shaft connected to the proximal end of the mesh member, and a distal end of the mesh member. a connected hollow distal tip; and a core wire having a distal end connected to the distal end of the mesh member and/or the distal tip and a proximal end passing through the interior of the mesh member and the hollow shaft; The hollow shaft has a core wire lumen in which the distal end is arranged on the proximal side of the distal end of the hollow shaft and through which the core wire is inserted, and a guide wire lumen through which the retrograde guide wire guided from the distal end is inserted. It has a shaft, and the surface on the distal side of the guide wire lumen is inclined with respect to the axial direction of the hollow shaft.

In the above catheter, the entire distal surface of the inner shaft may be inclined with respect to the axial direction of the hollow shaft.

Further, in the catheter described above, the surface of the inner shaft on the distal side of the core wire lumen may be arranged on the distal side of the surface of the guide wire lumen on the distal side.

Further, in the above catheter, the hollow shaft may be formed so that the diameter of the inner circumference decreases toward the distal end.

According to the present invention, the retrograde guidewire can be appropriately guided to the proximal side.

FIG. 1 is a schematic cross-sectional view of a catheter according to the first embodiment. FIG. 2 is a cross-sectional view of the catheter according to the first embodiment taken along line AA. FIG. 3 is a cross-sectional view enlarging a part of the catheter according to the first embodiment. FIG. 4 is a schematic cross-sectional view of a state in which the mesh member of the catheter according to the first embodiment is expanded. FIG. 5 is a schematic cross-sectional view of a catheter according to a second embodiment. FIG. 6 is a cross-sectional view of the catheter according to the second embodiment taken along line BB. FIG. 7 is a partially enlarged cross-sectional view of the catheter according to the second embodiment.

Although a catheter according to embodiments will be described with reference to the drawings, the present invention is not limited only to the embodiments described in the drawings. In addition, the dimensions of the catheter shown in each drawing are for the purpose of facilitating understanding of the implementation, and do not correspond to the actual dimensions.

In the present specification, the term "guide wire" refers to a medical guide wire that is pushed into a surgical site in a body cavity such as a blood vessel and used for guiding a catheter to the surgical site or for penetrating an obstruction. means

Also, in this specification, the term "distal side" means the direction along the longitudinal direction of the catheter (the direction along the axial direction of the catheter), which is the direction in which the distal tip is located with respect to the mesh member. In addition, the term "proximal side" means a direction along the longitudinal direction of the catheter, which is opposite to the distal side. In addition, the term “distal end” refers to the distal end of any member or site, and the term “basal end” refers to the proximal end of any member or site. In addition, the “maximum expansion diameter” means the outer diameter of a portion where the outer diameter of the mesh member perpendicular to the axial direction is the maximum when the mesh member is expanded (also referred to as “diameter expansion”).

Further, in the present specification, the term "anterograde guidewire" refers to a guidewire that is pushed to an operation site such as an obstruction site in a blood vessel prior to a catheter, and is referred to as a "retrograde guidewire." The term "guide wire" refers to a guide wire that is advanced from the distal end side of a catheter toward the catheter in a blood vessel, for example.

[First embodiment]
FIG. 1 is a schematic cross-sectional view of a catheter according to the first embodiment. FIG. 1 shows a state in which the diameter of the mesh member is reduced in the catheter. FIG. 2 is a cross-sectional view of the catheter according to the first embodiment taken along line AA. FIG. 3 is a cross-sectional view enlarging a part of the catheter according to the first embodiment. FIG. 4 is a schematic cross-sectional view of a state in which the mesh member of the catheter according to the first embodiment is expanded.

The catheter 1 generally comprises a mesh member 110, a hollow shaft 120, a distal tip 130, a core wire 150, a guiding membrane 160 and a connector 170.

The mesh member 110 is a radially expandable tubular member. When the core wire 150 is pulled proximally, the mesh member 110 expands by deforming out of plane and bulging radially outward as shown in FIG. to receive retrograde guidewire W 2 within mesh member 110 .

In this embodiment, the mesh member 110 has a plurality of first strands 111 and a plurality of second strands 112, and the first strands 111 and the second strands 112 are woven in a grid pattern. It is rarely formed to be tubular as a whole. The mesh member 110 is formed with apertures m between adjacent braided strands and receives a retrograde guidewire through the enlarged apertures m when expanded. A distal end portion of each wire constituting mesh member 110 is joined to distal tip 130 , and a proximal end portion of each wire is joined to hollow shaft 120 . Each of the

wires

111 and 112 may be a single wire, or may be a twisted wire obtained by twisting a plurality of single wires.

A metal material or a resin material can be used as a material for forming the

wires

111 and 112 of the mesh member 110 . Examples of such metal materials include stainless steel such as SUS304, nickel-titanium alloys, cobalt-chromium alloys, and the like. Examples of such resin materials include polyamide, polyester, polyacrylate, polyetheretherketone, and the like. Among these materials, metal materials may be used from the viewpoint of improving strength and flexibility. The

wires

111 and 112 may be made of the same material, or may be made of different materials.

In addition, from the viewpoint of improving the visibility of the mesh member 110, a radiopaque material may be included as a material for forming the

strands

111 and 112 of the mesh member 110. Examples of such radiopaque materials include gold, platinum, tungsten, or alloys containing these elements (eg, platinum-nickel alloys, etc.). The surface of each

strand

111, 112 may be coated with a radiopaque material.

The hollow shaft 120 is connected to the proximal end of the mesh member 110. In this embodiment, the hollow shaft 120 includes a hollow distal shaft 121 whose distal end is connected to the proximal end of the mesh member 110, and a hollow central shaft 121 whose distal end is connected to the proximal side of the distal shaft 121. It has a shaft 123 and a hollow proximal shaft 127 whose distal end is connected to the proximal end of central shaft 123 .

The distal shaft 121 has a single lumen 122 through which the retrograde guidewire W2 and the core wire 150 can be passed.

The central shaft 123 is an example of an inner shaft, has an outer diameter corresponding to the inner diameter of the distal shaft 121, and, as shown in FIGS. It is connected to the.

The central shaft 123 has a guidewire lumen 124 through which a retrograde guidewire can be passed, and a corewire lumen 125 through which a corewire 150 can be passed. As shown in FIG. 2, the guide wire lumen 124 has a circular front surface that is partially cut away, and the core wire lumen 125 has a circular front surface. As described above, since the core wire lumen 125 through which the core wire 150 can be inserted is provided, the operability of expanding and contracting the mesh member 110 by the core wire 150 can be improved.

An opening 126 that opens toward the proximal side is formed on the proximal side of the guide wire lumen 124 of the central shaft 123 , and the retrograde guide wire is delivered to the outside of the catheter 1 through the opening 126 . be.

The tip surface 123a on the tip side of the central shaft 123 is arranged at a position closer to the proximal side than the tip side of the tip side shaft 121, as shown in FIGS. A tip surface 123 a of the central shaft 123 is a surface that is inclined with respect to the axis of the hollow shaft 120 . The distal end surface 123 a is positioned so that the surface surrounding the core wire lumen 125 is closer to the distal end than the surface surrounding the guide wire lumen 124 . In addition, in this embodiment, the tip surface 123a is a flat surface. With this configuration, the central shaft 123 can be easily produced by cutting the tip side from a cylindrical state with a plane inclined with respect to the axis. Note that the tip surface 123a is not limited to a flat surface, and may be a curved surface.

In this way, since the distal end surface 123a of the central shaft 123 is a surface that is inclined with respect to the axis of the hollow shaft 120, the guide wire lumen 124 is positioned in a plane perpendicular to the axis of the hollow shaft 120 on the distal side. A portion of the peripheral surface can be absent, and the ratio of the area connected to the guidewire lumen 124 to the lumen 122 in the plane perpendicular to the axis of the hollow shaft 120 can be increased, and the retrograde guide A wire can be effectively guided to the guidewire lumen 124 . A retrograde guidewire can also be effectively guided into the guidewire lumen 124 by an inclination around the guidewire lumen 124 . The slope around corewire lumen 125 can also effectively guide a retrograde guidewire into guidewire lumen 124 .

The proximal side shaft 127 is connected to the proximal side of the central shaft 123 . The proximal shaft 127 internally communicates with the core wire lumen 125 of the central shaft 123 and has a lumen 128 through which the core wire 150 can be inserted.

As the material for the hollow shaft 120, since the hollow shaft 120 is inserted into the blood vessel, it may have antithrombotic properties, flexibility, and biocompatibility, and a resin material and a metal material are adopted. be able to. Since the distal shaft 121 and the central shaft 123 are required to be flexible, resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluorine resin may be used. As the base end side shaft 127, a metal tube such as a hypotube may be adopted because it is required to have pushability.

The distal tip 130 is a member connected to the distal end of the mesh member 110 . Specifically, the tip 130 is sharpened toward the distal side so that the catheter 1 can easily advance through the blood vessel. Each tip is embedded.

The material forming the distal tip 130 may be flexible because the catheter 1 is advanced through the blood vessel. Materials having such flexibility include, for example, resin materials such as polyurethane and polyurethane elastomer.

The core wire 150 is connected at its distal end to the distal end of the mesh member 110 and/or the distal tip 130, and extends through the interior of the mesh member 110 and the hollow shaft 120 such that its proximal end is positioned proximally relative to the proximal end of the hollow shaft 120. extends through. Specifically, the core wire 150 passes through the space inside the mesh member 110, the inside of the hollow shaft 120 (the lumen 122 of the distal shaft 121, the core wire lumen 125 of the central shaft 123, and the lumen 128 of the proximal shaft 127). , and through the through hole 171 of the connector 170 to the outside. By manipulating the core wire 150 outside the connector 170, the core wire 150 advances and retreats in the axial direction, and the mesh member 110 expands and contracts in the radial direction.

The material constituting the core wire 150 may have sufficient tensile strength and rigidity from the viewpoint of preventing the core wire 150 itself from being cut and expanding and contracting the mesh member 110 reliably. Examples of such materials include stainless steel such as SUS304, metal materials such as nickel-titanium alloys, and cobalt-chromium alloys.

The connector 170 is a member for gripping the catheter 1 by the operator. The connector 170 is connected to the proximal end of the hollow shaft 120 and connects the lumen 122 of the distal shaft 121 of the hollow shaft 120, the core wire lumen 125 of the central shaft 123, and the proximal end so that the core wire 150 can be exposed to the outside. It has a through hole 171 communicating with the lumen 128 of the side shaft 127 and an opening 172 formed at the proximal end of the through hole 171 . The shape of the connector 170 is not particularly limited, and may be any shape as long as the operator can easily hold it.

The guide membrane 160 is arranged on the mesh member 110 , and the tip of the guide membrane 160 is positioned between the proximal end of the distal tip 130 and the tip of the hollow shaft 120 . Guiding membrane 160 acts to smoothly guide a retrograde guidewire received through opening m of mesh member 110 toward hollow shaft 120 . The guiding membrane 160 of the present embodiment extends from the substantially central portion in the axial direction of the mesh member 110 where the tip is located (for example, the maximum expanded diameter portion of the mesh member 110) to the tip of the hollow shaft 120 where the proximal end of the guiding membrane 160 is located. It is formed in the mesh member 110 in a region spanning Here, when a retrograde guidewire is to be received in the catheter 1, the mesh member 110 is expanded as shown in FIG. 4, and the guiding membrane 160 is deployed in a funnel shape. Retrograde guidewire W2 is received within mesh member 110 through opening m of mesh member 110 and is directed into hollow shaft 120 against, for example, funneled guide membrane 160 .

The induction film 160 is made of a stretchable material. Examples of materials forming the guide film 160 include resin materials such as polyurethane, polyurethane elastomer, polyamide, polyamide elastomer, and copolymers thereof.

Next, the mode of use of the catheter 1 will be explained. Catheter 1 is used to receive retrograde guidewire W2.

First, after inserting an antegrade guide wire W1 (not shown) into, for example, a blood vessel, it is advanced along the blood vessel to a site where an obstruction exists (hereinafter also referred to as "occlusion site").

Next, after the distal end of the antegrade guidewire W1 reaches the occlusion site, the proximal end of the antegrade guidewire W1 is inserted into the distal end of the distal tip 130 and the lumen of the hollow shaft 120 (lumen 122, guidewire lumen 124). Using the antegrade guidewire W1 as a guide, the distal end of the catheter 1 is advanced in the blood vessel to the occlusion site. At this time, the mesh member 110 is inserted into the blood vessel in a diameter-reduced state, and the diameter-reduced state is maintained until the tip of the catheter 1 reaches the occlusion site.

Next, after the distal end of the catheter 1 reaches the occlusion site, the antegrade guide wire W1 is pulled out from the catheter 1 by pulling the antegrade guide wire W1 toward the proximal end side. Note that the antegrade guidewire W1 may not be pulled out from the catheter 1.

Next, by pulling the core wire 150 exposed to the outside of the connector 170 toward the proximal end side, the distance between the distal end of the mesh member 110 and the distal end of the hollow shaft 120 is narrowed, and as a result, the mesh member 110 faces radially outward. Transform and expand. At this time, as the mesh member 110 is expanded, the opening m is also expanded, so that the retrograde guidewire W2 can be easily received. In this embodiment, since the tip of the induction film 160 is joined to the substantially central portion in the axial direction of the mesh member 110, the induction film 160 is expanded following the expansion of the mesh member 110, and the induction film 160 is expanded as a whole. becomes a funnel shape.

Next, as shown in FIG. 4, the catheter 1 receives the retrograde guidewire W2 coming from the distal end side. As the path through which the retrograde guidewire W2 is directed, for example, a false lumen in the blood vessel wall surrounding the occlusion site, a through hole passing through the occlusion site, etc. are assumed, but any path may be used. After being received in the space inside mesh member 110 through opening m of expanded mesh member 110, retrograde guide wire W2 is guided by guide membrane 160 of mesh member 110 and is guided from opening 120a of hollow shaft 120 to the distal end. It is inserted through the lumen 122 of the side shaft 121 . The retrograde guidewire W2 is effectively guided from the lumen 122 of the distal shaft 121 to the guidewire lumen 124 due to the shape of the distal side of the central shaft 123, and then exits the catheter 1 through the opening 126. sent out. Next, the retrograde guidewire W2 delivered from the opening 126 is delivered outside the body after passing through the blood vessel. As a result, it is possible to create a state in which the retrograde guide wire W2 passes through the obstructed site and both ends of the retrograde guide wire W2 are exposed to the outside of the body.

Thus, the catheter 1 can receive the retrograde guidewire W2 and guide the end portion out of the body, so it can be suitably used as a medical device in combination with the retrograde guidewire W2.

As described above, since the catheter 1 has the configuration described above, the retrograde guidewire W2 guided through the lumen 122 of the distal shaft 121 is effectively guided to the guidewire lumen 124, and the opening 126 is opened. can be sent to the outside via

[Second embodiment]
Next, a catheter 1A according to a second embodiment will be described. FIG. 5 is a schematic cross-sectional view of a catheter according to a second embodiment. FIG. 6 is a cross-sectional view of the catheter according to the second embodiment taken along line BB. FIG. 7 is a partially enlarged cross-sectional view of the catheter according to the second embodiment. In addition, the same code|symbol is attached|subjected about the part similar to the catheter 1 which concerns on 1st Embodiment.

A catheter 1A according to the second embodiment includes a distal shaft 221 instead of the distal shaft 121 of the catheter 1 according to the first embodiment.

As shown in FIGS. 5 and 7, the inner circumference of the tip side shaft 221 is tapered such that the inner diameter gradually decreases from the tip side toward the tip side of the central shaft 123 . With such a configuration, as shown in FIG. 6, the area of the distal end surface 123a of the central shaft 123 that can be seen from the distal end side can be reduced. As a result, the retrograde guidewire W2 is guided along the inner peripheral surface of the distal shaft 221, and can be appropriately prevented from contacting or being caught by the distal surface 123a of the central shaft 123. retrograde guidewire W2 can be easily and effectively guided to the guidewire lumen 124 of the central shaft 123.

In addition, the present invention is not limited to the configuration of the above-described embodiment, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. be done.

For example, in the above-described first embodiment, the distal shaft 121 and the central shaft 123 are configured separately and joined together, but the present invention is not limited to this, and the distal shaft 121 and central shaft 123 may be integrally formed.

In addition, in the above-described first embodiment, the entire front surface of the central shaft 123 is a surface inclined with respect to the axis of the hollow shaft 120, but the present invention is not limited to this. Only the distal surface around the wire lumen 124 may be slanted with respect to the axis of the hollow shaft 120, which also effectively guides the retrograde guidewire into the guidewire lumen 124. can be done.

Reference Signs List

1, 1A catheter 110

mesh member

111, 112 wire 120 hollow shaft 121 distal shaft 123 central shaft 123a distal surface 124 guidewire lumen 125 core wire lumen 127 proximal shaft 130 distal tip 150 core wire 160 guide membrane

Claims

a radially expandable tubular mesh member;
a hollow shaft connected to the proximal end of the mesh member;
a hollow distal tip connected to the distal end of the mesh member;
a core wire having a distal end connected to the distal end of the mesh member and/or the distal tip and a proximal end passing through the interior of the mesh member and the hollow shaft;
The hollow shaft has a core wire lumen, the distal end of which is located closer to the proximal end than the distal end of the hollow shaft, through which the core wire is inserted, and a guide wire lumen through which the retrograde guide wire guided from the distal end is inserted. having an inner shaft,
A catheter in which the tip side surface of the guide wire lumen is inclined with respect to the axial direction of the hollow shaft.
The catheter according to claim 1, wherein the entire distal surface of the inner shaft is inclined with respect to the axial direction of the hollow shaft.
2. The catheter of claim 1, wherein the core wire lumen distal surface of the inner shaft is disposed distally relative to the guide wire lumen distal surface.
2. The catheter according to claim 1, wherein the hollow shaft is formed such that the diameter of the inner circumference decreases toward the distal end side.